Automatic speed limiting system and method for mechanical gearbox of automobile crane

Abstract

The invention discloses an automatic speed limiting system and method for a mechanical gearbox of an automobile crane, and the method comprises the steps: a steering mode switching handle transmits a steering mode signal to a controller, an accelerator pedal controls the opening degree of the accelerator pedal, a vehicle speed sensor transmits the collected vehicle speed to the controller, and an engine speed sensor transmits the collected engine speed to the controller; and the controller obtains the highest steering speed of the engine and the target rotating speed of the engine, performs comparative analysis, confirms the output rotating speed of the engine, and finally sends the output rotating speed of the engine to the ECU. The current speed ratio of the gearbox is reversely deduced through the current vehicle speed and the current rotating speed of the engine, so that the highest steering rotating speed of the engine under the current speed ratio of the gearbox is determined and compared with the target rotating speed of the engine under the current opening degree of the accelerator pedal, and the target rotating speed of the engine is prevented from being larger than the highest steering rotating speed of the engine. The vehicle speed exceeds the maximum vehicle speed in the current steering mode, and safety accidents are caused.

Description

Technical Field

[0001] This invention relates to the field of truck crane technology, specifically to an automatic speed limiting system and method for a truck crane's mechanical transmission. Background Technology

[0002] Currently, when the all-wheel steering system of a truck crane is operating, it is necessary to limit the maximum speed under different steering modes to prevent damage to the axle due to speeding, which could lead to rollovers and other dangers. Because the crane's gearbox is a mechanical gearbox, the gear position cannot be directly detected, and the engine cannot limit its maximum speed based on the maximum speed under different steering modes. This can easily lead to speeding and cause safety accidents. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an automatic speed limiting system and method for a truck crane mechanical transmission. By inferring the current speed ratio of the transmission from the current vehicle speed, the maximum steering speed of the engine under the current speed ratio of the transmission is determined, thereby limiting the vehicle speed and avoiding the problem of vehicle speeding.

[0004] The technical solution of this invention is as follows:

[0005] An automatic speed limiting system for a truck crane's mechanical transmission includes a controller, a steering mode switching handle, an accelerator pedal, a vehicle speed sensor, an engine speed sensor, and an electronic control unit (ECU) connected to the controller. The steering mode switching handle sends steering mode signals, the accelerator pedal releases accelerator pedal opening signals, the vehicle speed sensor sends collected vehicle speed signals, and the engine speed sensor sends collected engine speed signals to the controller. The controller then sends the engine output speed signals to the ECU.

[0006] An automatic speed limiting method for a truck crane's mechanical transmission specifically includes the following steps:

[0007] (1) The vehicle speed sensor collects the current vehicle speed and the engine speed sensor collects the current engine speed and sends them to the controller respectively. The controller calculates the current gear ratio of the transmission.

[0008] (2) The steering mode switching handle sends the current steering mode signal to the controller, and the controller confirms the engine's maximum steering speed under the current gear ratio of the transmission;

[0009] (3) The accelerator pedal sends its current opening to the controller, and the controller determines the engine target speed under the current opening of the accelerator pedal based on the current opening of the accelerator pedal;

[0010] (4) When the target engine speed is not greater than the maximum steering speed of the engine, the controller sends the target engine speed as the engine output speed to the ECU, and the ECU controls the engine speed.

[0011] (5) When the target engine speed is greater than the maximum engine steering speed, the controller sends the maximum engine steering speed as the engine output speed to the ECU, and the ECU controls the engine speed.

[0012] The controller calculates the current gear ratio of the transmission according to the following formula (1);

[0013] ia=0.377×n×r / (V×ib) (1);

[0014] In equation (1), ia represents the current gear ratio of the transmission, n represents the current engine speed, r represents the rolling radius, V represents the current vehicle speed, ib represents the axle speed ratio, and is a constant.

[0015] The steering mode switching handle sends the current steering mode signal to the controller. The controller confirms the maximum vehicle speed corresponding to the current steering mode and, in conjunction with the current gear ratio of the transmission, calculates the maximum engine steering speed under the current gear ratio of the transmission.

[0016] The controller sends the current accelerator pedal opening to the ECU, the ECU confirms the target engine speed at the current accelerator pedal opening, and then resends the calculated target engine speed to the controller.

[0017] Advantages of this invention:

[0018] This invention uses the current vehicle speed and current engine speed to deduce the current gear ratio of the transmission, thereby confirming the maximum engine steering speed under the current gear ratio of the transmission. It then compares this speed with the target engine speed under the current accelerator pedal opening, thus avoiding the problem of the target engine speed exceeding the maximum engine steering speed, which could cause the vehicle speed to exceed the maximum speed under the current steering mode and lead to a safety accident. Attached Figure Description

[0019] Figure 1 This is a structural block diagram of the automatic speed limiting system for the mechanical transmission of a truck crane according to the present invention.

[0020] Figure 2 This is a flowchart of the automatic speed limiting method for the mechanical transmission of a truck crane according to the present invention.

[0021] Attached reference numerals: 1-Controller, 2-Steering mode switch handle, 3-Accelerator pedal, 4-Vehicle speed sensor, 5-Engine speed sensor, 6-Electronic control unit (ECU). Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] See Figure 1 An automatic speed limiting system for a truck crane's mechanical transmission includes a controller 1, a steering mode switching handle 2, an accelerator pedal 3, a vehicle speed sensor 4, an engine speed sensor 5, and an electronic control unit (ECU) 6, all connected to the controller 1. The steering mode switching handle 2 sends a steering mode signal, the accelerator pedal 3 sends an accelerator pedal opening signal, the vehicle speed sensor 4 sends a sampled vehicle speed signal, and the engine speed sensor 5 sends a sampled engine speed signal to the controller 1. The controller 1 sends the current accelerator pedal opening signal to the ECU 6. The ECU 6 confirms the target engine speed at the current accelerator pedal opening signal and then resends the calculated target engine speed signal to the controller 1. Finally, the controller 1 sends the engine output speed signal to the ECU 6.

[0024] See Figure 2 An automatic speed limiting method for a mechanical transmission of a truck crane, specifically including the following steps:

[0025] (1) The vehicle speed sensor 4 collects the current vehicle speed and the engine speed sensor 5 collects the current engine speed and sends them to the controller 1 respectively. The controller 1 calculates the current gear ratio of the transmission according to the following formula (1).

[0026] ia=0.377×n×r / (V×ib) (1);

[0027] In formula (1), ia represents the current gear ratio of the transmission, n represents the current engine speed, r represents the rolling radius, V represents the current vehicle speed, ib represents the axle speed ratio, and is a constant.

[0028] (2) The steering mode switching handle 2 sends the current steering mode signal to the controller 1. The controller 1 confirms the maximum vehicle speed corresponding to the current steering mode and calculates the maximum engine steering speed under the current gear ratio of the transmission by combining the current gear ratio of the transmission.

[0029] (3) The accelerator pedal 3 sends its current opening to the controller 1. The controller 1 sends the current opening of the accelerator pedal to the ECU 6. The ECU 6 confirms the target engine speed under the current opening of the accelerator pedal and then sends the calculated target engine speed back to the controller 1.

[0030] (4) When the target engine speed is not greater than the maximum steering speed of the engine, the controller 1 sends the target engine speed as the engine output speed to the ECU 6, and the ECU 6 controls the engine speed.

[0031] (5) When the target engine speed is greater than the maximum engine steering speed, the controller 1 sends the maximum engine steering speed as the engine output speed to the ECU 6, and the ECU 6 controls the engine speed.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic speed limiting system for a truck crane's mechanical transmission, characterized in that: It includes a controller, a steering mode switching handle, an accelerator pedal, a vehicle speed sensor, an engine speed sensor, and an electronic control unit (ECU) connected to the controller. The steering mode switching handle sends steering mode signals, the accelerator pedal sends accelerator pedal opening signals, the vehicle speed sensor sends the collected vehicle speed signals, and the engine speed sensor sends the collected engine speed signals to the controller. The controller then sends the engine output speed signals to the electronic control unit (ECU).

2. The automatic speed limiting method of the automatic speed limiting system for the mechanical gearbox of a truck crane according to claim 1, characterized in that: Specifically, it includes the following steps: (1) The vehicle speed sensor collects the current vehicle speed and the engine speed sensor collects the current engine speed and sends them to the controller respectively. The controller calculates the current gear ratio of the transmission. (2) The steering mode switching handle sends the current steering mode signal to the controller, and the controller confirms the engine's maximum steering speed under the current gear ratio of the transmission; (3) The accelerator pedal sends its current opening to the controller, and the controller determines the engine target speed under the current opening of the accelerator pedal based on the current opening of the accelerator pedal; (4) When the target engine speed is not greater than the maximum steering speed of the engine, the controller sends the target engine speed as the engine output speed to the ECU, and the ECU controls the engine speed. (5) When the target engine speed is greater than the maximum engine steering speed, the controller sends the maximum engine steering speed as the engine output speed to the ECU, and the ECU controls the engine speed.

3. The automatic speed limiting method according to claim 2, characterized in that: The controller calculates the current gear ratio of the transmission according to the following formula (1); ia=0.377×n×r / (V×ib) (1); In equation (1), ia represents the current gear ratio of the transmission, n represents the current engine speed, r represents the rolling radius, V represents the current vehicle speed, ib represents the axle speed ratio, and is a constant.

4. The automatic speed limiting method according to claim 2, characterized in that: The steering mode switching handle sends the current steering mode signal to the controller. The controller confirms the maximum vehicle speed corresponding to the current steering mode and, in conjunction with the current gear ratio of the transmission, calculates the maximum engine steering speed under the current gear ratio of the transmission.

5. The automatic speed limiting method according to claim 2, characterized in that: The controller sends the current accelerator pedal opening to the ECU, the ECU confirms the target engine speed at the current accelerator pedal opening, and then resends the calculated target engine speed to the controller.

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