Wheel excavator and gear shifting protection device thereof

Abstract

The utility model relates to a wheel excavator, in particular to a gear shifting protection device of the wheel excavator. The gear shifting protection device comprises a gear shifting relay, a gear shifting switch, a brake pressure switch and a gear shifting logic device, the gear shifting relay is used for being connected with a gear shifting reversing valve of a gear shifting system of the wheel excavator, and the brake pressure switch is used for being connected with a brake system of the wheel excavator and is closed when the brake pressure of the brake system reaches a preset value; the gear shifting logic device is connected with the gear shifting switch, the brake pressure switch and the gear shifting relay, and therefore after the gear shifting switch is closed, the gear shifting reversing valve can be controlled through the gear shifting relay according to the closing condition of the brake pressure switch. On the basis of the gear-shifting protection device provided by the utility model, only the gear-shifting logic device needs to be configured as required, so that the situation that gears of the gearbox are damaged due to the fact that gear-shifting operation is executed when the gearbox is in a rotating state can be avoided.

Description

Technical Field

[0001] The utility model relates to a wheeled excavator, in particular to a gear shift protection device for the wheeled excavator. Background Art

[0002] Currently, some wheeled excavators can only shift gears when stopped, which means that the driver needs to brake the vehicle completely to a stop and then operate the shift mechanism to switch gears. If the driver tries to shift gears while the vehicle is moving, the gearbox gears of the vehicle will wear and damage.

[0003] At present, most excavators only have some signs on the vehicle to remind the driver that he must stop before changing gears. However, it is still common for the driver to change gears while the vehicle is driving due to distraction or lack of operating habits. Therefore, it is necessary to design a gear shift protection device to prevent the driver from changing gears while the vehicle is driving and causing damage to the vehicle. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a gear shift protection device, and those skilled in the art can implement gear shift protection for a wheeled excavator based on the device.

[0005] In order to solve the above technical problems, the utility model provides a gear shift protection device for a wheeled excavator, which includes a gear shift relay, a gear shift switch, a brake pressure switch and a gear shift logic device. The gear shift relay is used to connect to the gear shift reversing valve of the gear shift system of the wheeled excavator. The brake pressure switch is used to connect to the brake system of the wheeled excavator and close when the brake pressure of the brake system reaches a preset value. The gear shift logic device is respectively connected to the gear shift switch, the brake pressure switch and the gear shift relay, so that after the gear shift switch is closed, the gear shift reversing valve can be controlled by the gear shift relay according to the closing status of the brake pressure switch.

[0006] Based on the gear shift protection device provided by the utility model, technical personnel in this field only need to configure the gear shift logic according to needs to achieve gear shift protection for the vehicle, and judge whether the gear shift operation is a gear shift operation in the parking state according to the length of time the brake system reaches the parking pressure, thereby increasing the safety of the gear shift operation and avoiding damage to the gearbox gears caused by performing the gear shift operation when the gearbox is in a rotating state.

[0007] The utility model also provides a wheeled excavator, which includes a brake system and a shift system. The shift system includes a shift reversing valve, a power supply and a shift protection device provided by the utility model. The shift relay is connected to the shift reversing valve, the brake pressure switch is connected to the brake system, and the shift logic is also connected to the power supply.

[0008] The wheeled excavator performs gear shifting operations only after braking. Even if the driver tries to shift gears during driving, the gear shift protection device will not trigger the gear shift reversing valve to perform gear shifting, thus avoiding gear shifting operations when the gearbox is rotating, which may cause damage to the gearbox gears. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The schematic diagram of the existing gear shifting system of a wheeled excavator is shown;

[0010] Figure 2 This is a schematic diagram of a gear shifting system for a wheeled excavator according to an embodiment of the utility model;

[0011] Figure 3 This is a control flow chart of a shift logic device according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0012] Figure 1 The schematic diagram of the existing gear shifting system of a wheeled excavator includes a hydraulic oil tank 1, a hydraulic pump 2, a gear shift reversing valve 3, a gearbox 4, a gear shifting cylinder 5, a gear shifting switch 6 and a power supply 7. After the gear shifting switch 6 is replaced with a gear shifting protection device 8, the following is obtained: Figure 2 The gear shift system with gear shift protection function is shown.

[0013] See also Figure 2 The shift protection device 8 includes a shift relay 81, a shift switch 82, a brake pressure switch 83 and a shift logic 84. The shift logic 84 is connected to the shift switch 82, the brake pressure switch 83 and the shift relay 81 respectively. Figure 1 The existing shifting system shown in the figure can trigger the shifting reversing valve 3 to shift gears by simply turning on the shifting switch 6. Figure 2 After the shift switch 82 of the shift system shown in the figure is turned on, the shift reversing valve 3 will not be triggered directly, but the shift logic 84 will first make a judgment based on the situation of the brake pressure switch 83 (the vehicle brake system pressure value reaches 90%, the brake pressure switch 83 is closed and transmits a signal to the shift logic 84). If the brake pressure switch 83 is turned on, preferably has been turned on for a period of time, it means that the driver does not want to change gears while the vehicle is driving. At this time, the shift logic 84 will control the shift reversing valve 3 to shift gears through the shift relay 81.

[0014] The gear shift logic 84 is a single-chip microcomputer. Those skilled in the art only need to write a program according to specific needs (for example, how long the brake pressure switch 83 needs to be connected before controlling the gear shift reversing valve 3 to shift gears) and then burn the program into the single-chip microcomputer. They can then use the gear shift protection device 8 to implement the gear shift protection function, that is, the gear is not shifted immediately after the gear shift switch 82 is turned on. Instead, it is first determined whether the brake pressure switch 83 has been connected for a predetermined period of time, and only then is the gear shift reversing valve 3 controlled to shift gears. This can effectively prevent the gear shifting valve 3 from shifting gears during vehicle driving, causing damage to the gears of the gearbox 4.

[0015] Those skilled in the art may refer to Figure 3 You can write the program by following the flowchart shown in the figure, or you can write the program yourself according to your specific needs. Figure 3 The shift logic 84 first determines the state of the shift switch 82 to obtain the control demand for shifting; when there is a shift demand, it determines whether the brake pressure switch 83 is closed; if the brake pressure switch 83 is closed, it determines whether the closing time reaches x seconds (those skilled in the art determine x as needed, for example, x is set to 5), and if so, controls the shift relay 81 to make the shift reversing valve 3 control the shift cylinder 5 to perform the shift action.

[0016] Based on the shift protection device provided by the utility model, those skilled in the art only need to configure the shift logic according to the needs to realize the shift protection of the vehicle, and judge whether the shift operation is a shift operation in the parking state according to the length of time the brake system reaches the parking pressure, thereby increasing the safety of the shift operation and avoiding the damage of the gearbox gear caused by performing the shift operation when the gearbox is in the rotating state. During the test of the running sports car, the on-site debugging personnel do not have to worry about the misoperation of the shift switch. When the brake is not pressed and the shift switch is operated, the shift gearbox will not perform the shift action, protecting the gearbox.

Claims

1. A gear shift protection device (8) for a wheeled excavator, characterized in that: The gear shift protection device (8) comprises a gear shift relay (81), a gear shift switch (82), a brake pressure switch (83) and a gear shift logic unit (84); the gear shift relay (81) is used to connect to a gear shift reversing valve (3) of a gear shift system of a wheeled excavator; the brake pressure switch (83) is used to connect to a brake system of the wheeled excavator and close when the brake pressure of the brake system reaches a preset value; the gear shift logic unit (84) is respectively connected to the gear shift switch (82), the brake pressure switch (83) and the gear shift relay (81), so that after the gear shift switch (82) is closed, the gear shift reversing valve (3) can be controlled through the gear shift relay (81) according to the closing condition of the brake pressure switch (83).

2. The gear shift protection device according to claim 1, characterized in that: The gear shift logic (84) is a single chip microcomputer.

3. A wheeled excavator, comprising a brake system and a gear shifting system, wherein the gear shifting system comprises a gear shift reversing valve (3) and a power supply (7), characterized in that: The gear shift system also includes a gear shift protection device (8) as claimed in claim 1 or 2, the gear shift relay (81) is connected to the gear shift reversing valve (3), the brake pressure switch (83) is connected to the brake system, and the gear shift logic (84) is also connected to the power supply (7).

4. The wheeled excavator according to claim 3, characterized in that: The gear shifting system further comprises a gear shifting oil cylinder (5) and a gearbox (4); the gear shifting reversing valve (3) is connected to the gear shifting oil cylinder (5); the gear shifting oil cylinder (5) is connected to the gearbox (4); and the gear shifting reversing valve (3) controls the speed change and gear shifting of the gearbox (4) by controlling the movement of the gear shifting oil cylinder (5).

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