A grinding vehicle automatic gear-off prevention system

Abstract

The present invention discloses a grinding vehicle anti-automatic gear shifting system, which controls the actual gear shifting action through a dual-way solenoid valve. A zero-speed monitoring relay is installed in the parallel solenoid valve circuit to detect the actual vehicle speed. By collecting the vehicle's own axle speed encoder (1-axis gearbox encoder) and whether the direction handle is in neutral, it is used to determine the conditions for the zero-speed monitoring relay during protection. When all conditions of the zero-speed monitoring relay are met, the gearbox can be protected from automatic gear shifting at the moment of network disconnection. At this time, only when the self-running speed is zero, the gear shifting signal is allowed to occur and the actual gear shifting action is completed.

Description

Technical Field

[0001] The invention belongs to the field of gear disengagement systems, and in particular relates to an automatic gear disengagement prevention system for a grinding vehicle. Background Art

[0002] Through actual vehicle operation, it was found that after a network failure occurs, the vehicle's gear-engaging system will be significantly affected, causing the gear-engaging clutch to automatically disengage and the vehicle to enter a disengaged state. In this case, when the network returns to normal, the gear-engaging clutch will automatically re-engage. However, due to the instantaneous and unstable nature of network failures, the disengagement clutch may frequently disengage and engage in gear during vehicle operation. This not only increases the workload of the gearbox, but may also cause the gears of the disengagement gears to clash when they are frequently switched. The accumulation of this phenomenon will cause irreversible damage to the mechanical structure of the gearbox, directly affecting the reliability and stability of vehicle operation.

[0003] What is more serious is that this unpredictable mechanical action may further amplify its hazards under high-speed operation or complex working conditions, leading to safety hazards in vehicle operation, and may even cause more serious equipment failures or accidents. Therefore, in order to ensure the normal operation and long-term reliability of the vehicle, effective technical means and transformation measures must be taken to avoid the adverse effects of network failures on the gear shifting system, especially to prevent gear shifting or gear shifting under abnormal operating conditions, and fundamentally solve the problem of gear knocking.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a grinding vehicle anti-automatic gear shifting system, thereby solving the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0007] A grinding vehicle automatic gear-off prevention system, comprising a pneumatic unit and an electrical control unit;

[0008] The pneumatic unit is used to realize the gear shifting and disengaging control of the vehicle through the coordinated work of the gear shifting solenoid valve and the gear shifting cylinder. The pneumatic control unit includes: a main air port, a shuttle valve 1 and a shuttle valve 2;

[0009] The original solenoid valve and the newly added solenoid valve, wherein the air source enters the system from the main air inlet and is divided to the original valve and the newly added valve, and the dual-path control of the air source is realized through shuttle valve 1 and shuttle valve 2;

[0010] The gear-engaging cylinder, the gas circuit of which is connected to the output ends of shuttle valve 1 and shuttle valve 2, realizes the extension and retraction of the cylinder by controlling the switching of the gas circuit, thereby completing the gear-engaging or gear-disengaging action;

[0011] The electrical control unit is used to monitor the vehicle's operating status and make logical judgments when a network failure occurs, and to control the action of the pneumatic unit.

[0012] Optionally, the electrical control unit includes

[0013] CAN communication module, used to receive vehicle operation status data;

[0014] Power input unit, used to provide power to the direction signal acquisition module

[0015] A direction signal acquisition module is connected to the power input unit and is used to collect the status signal of the vehicle's direction handle;

[0016] The logic control module is connected to the direction signal acquisition module and is used to activate the subsequent control loop according to the direction signal status.

[0017] Zero speed monitoring module, used to monitor the vehicle running speed and collect vehicle speed signals through the gearbox encoder;

[0018] A relay control circuit is connected to the zero-speed monitoring module and is used to control the gear-engaging solenoid valve according to the zero-speed signal;

[0019] Signal protection circuit, used to ensure the reliability of signal transmission.

[0020] Optionally, the power input unit includes a power input line (6115 line), which is provided with basic power by the output of the CAN module, and a power protection circuit breaker (F1), which is connected to the 6115 line to prevent overload or short circuit and protect subsequent modules;

[0021] The direction signal acquisition module includes a forward signal channel (JYK forward) and a backward signal channel (JYK backward), which are respectively used to detect the forward or backward state of the direction handle. The diode protection circuit includes diodes (V1 and V2), which are respectively connected in series with the forward signal channel and the backward signal channel to ensure unidirectional signal transmission and prevent signal backflow or interference.

[0022] The logic control module comprises a zero-speed monitoring relay (K2) and a relay control output circuit (6115.5 and 6115.6). The zero-speed monitoring relay (K2) is triggered by a forward signal or a reverse signal output by a direction signal acquisition module, and after the relay contacts (13, 14) are closed, a signal is transmitted to the relay control output circuit; the relay control output circuit (6115.5 and 6115.6) is connected to the contacts of the relay (K2) for transmitting the signal to the zero-speed monitoring module or the gear-engaging solenoid valve control module.

[0023] Optionally, the power protection circuit breaker (F1) is an automatic recovery type circuit breaker that can automatically disconnect and restore the power supply after an overload or short circuit fault. The diodes (V1, V2) of the direction signal acquisition module are unidirectional conductive diodes, which are respectively connected in series with the forward signal channel (JYK forward) and the reverse signal channel (JYK reverse).

[0024] Optionally, the zero-speed monitoring relay (K2) includes: an input end, connected to the output of the direction signal acquisition module, for receiving a forward signal or a reverse signal; output contacts (13, 14), connected to the relay control output circuit (6115.5 and 6115.6), for transmitting signals to the zero-speed monitoring module and the gear shifting solenoid valve control module, the relay control output circuit (6115.5 and 6115.6) are respectively connected to the zero-speed monitoring module and the gear shifting cylinder, the zero-speed monitoring module is used to determine the vehicle speed status; the gear shifting cylinder is used to trigger the gear shifting or disengaging action.

[0025] Optionally, the zero-speed monitoring relay (K2) has a self-locking function. When the direction signal is non-zero, the relay contacts remain closed until the direction signal returns to zero or the system power is restarted. The power protection circuit breaker (F1) and the diode protection circuit (V1, V2) together constitute a signal protection unit, which is used to protect the direction signal acquisition module and the logic control module in the event of electrical interference or overload.

[0026] Optionally, the zero-speed monitoring module includes a speed monitoring unit (DD2503 module) and a power supply line. It performs speed monitoring by receiving pulse signals (SIG A and SIG B) from the vehicle gearbox encoder. When the vehicle speed is zero, the speed monitoring unit provides a zero-speed signal through its output ports (Out1 and Out2). The power supply range of the power supply line is 110V to 240V AC / DC.

[0027] Optionally, the relay control circuit includes a zero-speed monitoring relay (K1), which is triggered by the zero-speed signal of the DD2503 module; the relay contacts (13 and 14, 19 and 20) are respectively connected to the control circuit of the gear-engaging solenoid valve; when the zero-speed signal is triggered, the relay contacts close, allowing the gear-engaging solenoid valve to operate.

[0028] Optionally, the signal protection circuit includes multiple diodes (V3, V4 and V6) for unidirectional conduction of the signal to prevent signal backflow; the external power supply circuit provides a stable working power supply for the module and the relay.

[0029] Optionally, the speed monitoring unit (DD2503 module) performs dual-channel signal judgment through the pulse signal (SIG A and SIG B) of the encoder, and the zero-speed monitoring relay (K1) in the relay control circuit has a self-locking function. When the speed signal is zero, the contacts (13 and 14, 19 and 20) are closed and remain closed until the speed signal returns to non-zero. The diodes (V3, V4 and V6) in the signal protection circuit adopt a unidirectional conduction design, which are respectively used to protect the external power supply line, the gear solenoid valve and the signal transmission of the speed monitoring unit. The output port (6115.5 and 6115.6) of the relay control circuit is connected to the gear solenoid valve through the relay contact, which is used to control the gear shifting or disengaging action.

[0030] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all the advantages described below at the same time:

[0031] The present invention controls the actual disengagement and shifting action through a dual-circuit solenoid valve. A zero-speed monitoring relay is installed in the parallel solenoid valve circuit to detect the actual vehicle speed. By collecting the vehicle's own axle speed encoder (1-axis gearbox encoder) and whether the direction handle is in neutral, it is used to determine the conditions for the zero-speed monitoring relay during protection. When all conditions of the zero-speed monitoring relay are met, the gearbox can be automatically disengaged at the moment of network disconnection. At this time, only when the self-running speed is zero, the disengagement signal is allowed to occur and the actual disengagement action is completed.

[0032] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described below are only some embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0034] In the figure:

[0035] Figure 1 This is the flow chart of the pneumatic unit;

[0036] Figure 2 This is one of the schematic diagrams of the electrical control unit;

[0037] Figure 3 This is the second schematic diagram of the electrical control unit.

[0038] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0039] The present invention will now be described in further detail with reference to the accompanying drawings.

[0040] See also Figure 1-3 As shown, in this embodiment, a grinding vehicle automatic gear-shift prevention system is provided, including a pneumatic unit and an electrical control unit;

[0041] The pneumatic unit is used to realize the gear shifting and disengaging control of the vehicle through the coordinated work of the gear shifting solenoid valve and the gear shifting cylinder. The pneumatic control unit includes: a main air port, a shuttle valve 1 and a shuttle valve 2;

[0042] The original solenoid valve and the newly added solenoid valve, wherein the air source enters the system from the main air inlet and is divided to the original valve and the newly added valve, and the dual-path control of the air source is realized through shuttle valve 1 and shuttle valve 2;

[0043] The gear-engaging cylinder, the gas circuit of which is connected to the output ends of shuttle valve 1 and shuttle valve 2, realizes the extension and retraction of the cylinder by controlling the switching of the gas circuit, thereby completing the gear-engaging or gear-disengaging action;

[0044] The electrical control unit is used to monitor the vehicle's operating status and make logical judgments when a network failure occurs, and to control the action of the pneumatic unit.

[0045] In this embodiment, the electrical control unit includes

[0046] CAN communication module, used to receive vehicle operation status data;

[0047] Power input unit, used to provide power to the direction signal acquisition module

[0048] A direction signal acquisition module is connected to the power input unit and is used to collect the status signal of the vehicle's direction handle;

[0049] The logic control module is connected to the direction signal acquisition module and is used to activate the subsequent control loop according to the direction signal status.

[0050] Zero speed monitoring module, used to monitor the vehicle running speed and collect vehicle speed signals through the gearbox encoder;

[0051] A relay control circuit is connected to the zero-speed monitoring module and is used to control the gear-engaging solenoid valve according to the zero-speed signal;

[0052] Signal protection circuit, used to ensure the reliability of signal transmission.

[0053] In this embodiment, the power input unit includes a power input line (6115 line), which is provided with basic power by the output of the CAN module, and a power protection circuit breaker (F1), which is connected to the 6115 line to prevent overload or short circuit and protect subsequent modules;

[0054] The direction signal acquisition module includes a forward signal channel (JYK forward) and a backward signal channel (JYK backward), which are respectively used to detect the forward or backward state of the direction handle. The diode protection circuit includes diodes (V1 and V2), which are respectively connected in series with the forward signal channel and the backward signal channel to ensure unidirectional signal transmission and prevent signal backflow or interference.

[0055] The logic control module comprises a zero-speed monitoring relay (K2) and a relay control output circuit (6115.5 and 6115.6). The zero-speed monitoring relay (K2) is triggered by a forward signal or a reverse signal output by a direction signal acquisition module, and after the relay contacts (13, 14) are closed, a signal is transmitted to the relay control output circuit; the relay control output circuit (6115.5 and 6115.6) is connected to the contacts of the relay (K2) for transmitting the signal to the zero-speed monitoring module or the gear-engaging solenoid valve control module.

[0056] In this embodiment, the power protection circuit breaker (F1) is an automatic recovery type circuit breaker, which can automatically disconnect and restore the power supply after an overload or short circuit fault. The diodes (V1, V2) of the direction signal acquisition module are unidirectional conductive diodes, which are respectively connected in series with the forward signal channel (JYK forward) and the reverse signal channel (JYK reverse).

[0057] In this embodiment, the zero-speed monitoring relay (K2) includes: an input end connected to the output of the direction signal acquisition module, for receiving a forward signal or a reverse signal; output contacts (13, 14), connected to the relay control output circuit (6115.5 and 6115.6), for transmitting signals to the zero-speed monitoring module and the gear-engaging solenoid valve control module, the relay control output circuit (6115.5 and 6115.6) are respectively connected to the zero-speed monitoring module and the gear-engaging cylinder, the zero-speed monitoring module is used to determine the vehicle speed state; the gear-engaging cylinder is used to trigger the gear-engaging or gear-disengaging action.

[0058] In this embodiment, the zero-speed monitoring relay (K2) has a self-locking function. When the direction signal is non-zero, the relay contacts remain closed until the direction signal returns to zero or the system power is restarted. The power protection circuit breaker (F1) and the diode protection circuit (V1, V2) together constitute a signal protection unit for protecting the direction signal acquisition module and the logic control module in the event of electrical interference or overload.

[0059] In this embodiment, the zero-speed monitoring module includes a speed monitoring unit (DD2503 module) and a power supply line. The speed is monitored by receiving pulse signals (SIG A and SIG B) from the vehicle gearbox encoder. When the vehicle speed is zero, the speed monitoring unit provides a zero-speed signal through its output ports (Out1 and Out2). The power supply range of the power supply line is 110V to 240V AC / DC.

[0060] In this embodiment, the relay control circuit includes a zero-speed monitoring relay (K1), which is triggered by the zero-speed signal of the DD2503 module; the relay contacts (13 and 14, 19 and 20) are respectively connected to the control circuit of the gear-engaging solenoid valve; when the zero-speed signal is triggered, the relay contacts are closed, allowing the gear-engaging solenoid valve to operate.

[0061] In this embodiment, the signal protection circuit includes a plurality of diodes (V3, V4 and V6) for unidirectionally conducting the signal to prevent the signal from flowing back; the external power supply circuit provides a stable working power supply for the module and the relay.

[0062] In this embodiment, the speed monitoring unit (DD2503 module) performs dual-channel signal judgment through the pulse signal (SIG A and SIG B) of the encoder, and the zero-speed monitoring relay (K1) in the relay control circuit has a self-locking function. When the speed signal is zero, the contacts (13 and 14, 19 and 20) are closed and remain closed until the speed signal returns to non-zero. The diodes (V3, V4 and V6) in the signal protection circuit adopt a unidirectional conduction design, which are respectively used to protect the external power supply line, the gear-engaging solenoid valve and the signal transmission of the speed monitoring unit. The output port (6115.5 and 6115.6) of the relay control circuit is connected to the gear-engaging solenoid valve through the relay contact, which is used to control the gear-engaging or gear-disengaging action.

[0063] Take car No. 1 as an example:

[0064] 1) Speed ​​monitoring system power supply, the 6615 line number cable provides the basic power supply for the entire zero-speed monitoring system, which is synchronized with the computer control to a certain extent; after passing through the normally open contact of the K2 relay, it supplies power to the zero-speed monitoring relay K1 (line number is 6115.5), and the contact No. 13 of the zero-speed monitoring relay K1 supplies power, and at the same time supplies power to the zero-speed monitoring relay K5 of the non-control vehicle No. 2.

[0065] 2) Direction acquisition signal, which is the forward and backward signal when the handle is in a non-zero position. When the direction handle is in a non-zero position and no matter it is in the forward or backward direction, the zero-speed monitoring relay K2 is powered by diodes V1 and V2 through the F1 circuit breaker. At the same time, the normally open contact of the K2 relay is closed and the zero-speed monitoring relay is started.

[0066] 3) Speed ​​monitoring: When the zero-speed monitoring relay meets the preconditions and the vehicle is in operation, the speed signal of the axle gearbox encoder of axis 1 is fed back to point C8 of the CAN31 module, and the A\B phase signal is separated and then fed back to the speed monitoring port of the speed monitor through the normally open contact of relay K3.

[0067] 4) Vehicle speed>0, handle zero position control, when the speed monitor K1 is started, its contacts 19 and 20 are closed, and the self-locking control supplies power to other vehicles through the unidirectional diode V4, and supplies power to the speed monitor through the diode V5. Therefore, when the handle decelerates back to zero, the speed monitor can complete the speed monitoring through the self-locking of the speed monitor. In order to improve the safety of the system, an isolation relay K3 is installed in the speed feedback circuit at the same time.

[0068] 5) Solenoid valve control, when the K1 speed monitoring relay is working, the newly added gear shifting solenoid valve will work after the normally open contacts 13 and 14 are closed. When the control handle decelerates back to zero, the gear shifting solenoid valve is powered at the same time through the self-locking circuit of the speed monitor K1. The speed monitor will stop monitoring until the speed reaches zero or is less than 0.5km / H (gear shifting creep speed) and wait for new monitoring after the next vehicle start.

[0069] Overview of Pneumatic Principles

[0070] 1) The solenoid valve is normally in exhaust mode (no power) and is connected to the rodless chamber of the towing gear cylinder. When the computer system controls the gear shifting, the vehicle has speed and the newly added solenoid valve is connected to the gear shifting air path through the shuttle valve to provide air source power to the gear shifting cylinder and connect to the rodless chamber of the gear shifting cylinder. At this time, when the original vehicle solenoid valve suddenly loses power, the newly added solenoid valve still provides air source power, thus ensuring that the vehicle will not shift out of gear during operation.

[0071] 2) When the computer control system sends out a shift-out signal, even if the newly added valve wants to shift gears, it cannot be shifted due to the restriction of the shuttle valve.

[0072] Post-transformation test demonstration

[0073] After the transformation, the neutral signal input is demonstrated first. The neutral signal inputs the power supply of the zero-speed protection relay. At this time, the zero-speed protection relay has no input or output. The neutral signal output is always maintained, the solenoid valve is powered off, the gear cylinder is retracted, and the gear box has no teeth.

[0074] The gear engagement signal is maintained after a network failure during operation after the gear is engaged. The encoder is disassembled, the gear is engaged, the neutral signal has no output, the relay K2 is powered off, the normally closed contact is closed and the vehicle speed signal is transmitted to the zero-speed protection relay, and a network failure is simulated to verify that the CAN module output is powered off and the zero-speed relay continues to output. At this time, the speed is gradually reduced to zero. The zero-speed relay is activated to complete the gear disengagement. After the network fault is eliminated, the CAN module 33 output is re-engaged, the vehicle is running, and the zero-speed relay is protected. When the network is interrupted again or fails, the vehicle speed is guaranteed to drop to zero before the gear disengagement action is completed. This protects the internal gear from being knocked when the gear is disengaged at a non-zero speed.

[0075] The present invention is not limited to the above-mentioned embodiments. Anyone should be aware that any structural changes made under the enlightenment of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the protection scope of the present invention. The technology, shape, and structural parts not described in detail in the present invention are all well-known technologies.

Claims

1. A grinding vehicle anti-automatic gear shifting system, characterized in that: include: Pneumatic unit and electrical control unit; The pneumatic unit is used to realize the gear shifting and disengaging control of the vehicle through the coordinated work of the gear shifting solenoid valve and the gear shifting cylinder. The pneumatic control unit includes: a main air outlet, a shuttle valve 1 and a shuttle valve 2; The original solenoid valve and the newly added solenoid valve, wherein the air source enters the system from the main air inlet and is divided to the original valve and the newly added valve, and the dual-path control of the air source is realized through shuttle valve 1 and shuttle valve 2; The gear-engaging cylinder, the gas circuit of which is connected to the output ends of shuttle valve 1 and shuttle valve 2, realizes the extension and retraction of the cylinder by controlling the switching of the gas circuit, thereby completing the gear-engaging or gear-disengaging action; The electrical control unit is used to monitor the vehicle's operating status and make logical judgments when a network failure occurs, and to control the action of the pneumatic unit.

2. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The electrical control unit includes CAN communication module, used to receive vehicle operation status data; Power input unit, used to provide power to the direction signal acquisition module A direction signal acquisition module is connected to the power input unit and is used to collect the status signal of the vehicle's direction handle; The logic control module is connected to the direction signal acquisition module and is used to activate the subsequent control loop according to the direction signal status. Zero speed monitoring module, used to monitor the vehicle running speed and collect vehicle speed signals through the gearbox encoder; A relay control circuit is connected to the zero-speed monitoring module and is used to control the gear-engaging solenoid valve according to the zero-speed signal; Signal protection circuit, used to ensure the reliability of signal transmission.

3. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The power input unit includes a power input line (6115 line), which is provided with basic power by the output of the CAN module, and a power protection circuit breaker (F1), which is connected to the 6115 line to prevent overload or short circuit and protect subsequent modules; The direction signal acquisition module includes a forward signal channel (JYK forward) and a backward signal channel (JYK backward), which are respectively used to detect the forward or backward state of the direction handle. The diode protection circuit includes diodes (V1 and V2), which are respectively connected in series with the forward signal channel and the backward signal channel to ensure unidirectional signal transmission and prevent signal backflow or interference. The logic control module comprises a zero-speed monitoring relay (K2) and a relay control output circuit (6115.5 and 6115.6). The zero-speed monitoring relay (K2) is triggered by a forward signal or a reverse signal output by a direction signal acquisition module, and after the relay contacts (13, 14) are closed, a signal is transmitted to the relay control output circuit; the relay control output circuit (6115.5 and 6115.6) is connected to the contacts of the relay (K2) for transmitting the signal to the zero-speed monitoring module or the gear-engaging solenoid valve control module.

4. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The power protection circuit breaker (F1) is an automatic recovery type circuit breaker, which can automatically disconnect and restore the power supply after an overload or short circuit fault. The diodes (V1, V2) of the direction signal acquisition module are unidirectional conductive diodes, which are connected in series with the forward signal channel (JYK forward) and the reverse signal channel (JYK reverse) respectively.

5. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The zero-speed monitoring relay (K2) comprises: an input end connected to the output of the direction signal acquisition module and used to receive a forward signal or a reverse signal; output contacts (13, 14) connected to the relay control output circuit (6115.5 and 6115.6) and used to transmit signals to the zero-speed monitoring module and the gear-engaging solenoid valve control module, the relay control output circuit (6115.5 and 6115.6) being connected to the zero-speed monitoring module and the gear-engaging cylinder respectively, the zero-speed monitoring module being used to judge the vehicle speed state; the gear-engaging cylinder being used to trigger the gear-engaging or gear-disengaging action.

6. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The zero-speed monitoring relay (K2) has a self-locking function. When the direction signal is non-zero, the relay contacts remain in a closed state until the direction signal returns to zero or the system power is restarted. The power protection circuit breaker (F1) and the diode protection circuit (V1, V2) together constitute a signal protection unit, which is used to protect the direction signal acquisition module and the logic control module in the event of electrical interference or overload.

7. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The zero-speed monitoring module includes a speed monitoring unit (DD2503 module) and a power supply line. It monitors the speed by receiving pulse signals (SIGA and SIG B) from the vehicle gearbox encoder. When the vehicle speed is zero, the speed monitoring unit provides a zero-speed signal through its output ports (Out1 and Out2). The power supply range of the power supply line is 110V to 240V AC / DC.

8. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The relay control circuit includes a zero-speed monitoring relay (K1), which is triggered by the zero-speed signal of the DD2503 module; the relay contacts (13 and 14, 19 and 20) are respectively connected to the control circuit of the gear-engaging solenoid valve; when the zero-speed signal is triggered, the relay contacts are closed, allowing the gear-engaging solenoid valve to operate.

9. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The signal protection circuit includes multiple diodes (V3, V4 and V6) for unidirectional signal conduction to prevent signal backflow; the external power supply circuit provides a stable working power supply for the module and relay.

10. The grinding vehicle anti-automatic gear shifting system according to claim 1, characterized in that: The speed monitoring unit (DD2503 module) performs dual-channel signal judgment through the pulse signal (SIG A and SIG B) of the encoder. The zero-speed monitoring relay (K1) in the relay control circuit has a self-locking function. When the speed signal is zero, the contacts (13 and 14, 19 and 20) are closed and remain closed until the speed signal returns to non-zero. The diodes (V3, V4 and V6) in the signal protection circuit adopt a unidirectional conduction design, which are respectively used to protect the external power supply line, the gear-engaging solenoid valve and the signal transmission of the speed monitoring unit. The output ports (6115.5 and 6115.6) of the relay control circuit are connected to the gear-engaging solenoid valve through relay contacts to control the gear-engaging or gear-disengaging action.

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