Cab vehicle height control circuit and engineering vehicle

Abstract

The utility model discloses a cab vehicle height control circuit and an engineering vehicle, and belongs to the technical field of engineering vehicles. Comprising a cab lifting function switch, a normally-closed relay, a pressure switch, a key panel and a controller. The cab lifting function switch is electrically connected with the first end of the normally-closed relay, the second end of the normally-closed relay is electrically connected with the key panel, the key panel is in communication connection with the controller, and the controller is electrically connected with a first normally-open relay and a second normally-open relay. The first normally open relay is electrically connected with an ascending electromagnetic valve, and the second normally open relay is electrically connected with a descending electromagnetic valve; the pressure switch is arranged on a hydraulic pipeline and electrically connected with the normally-closed relay. A non-professional person can be prevented from mistakenly touching the switch, meanwhile, the operation pressure of the hydraulic system is monitored, and the operation safety is improved; the problem that safety risks exist in cab vehicle height control is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering vehicles, in particular to a cab height control circuit. Background Art

[0002] The statements herein only provide background art related to the utility model and do not necessarily constitute prior art.

[0003] Generally, due to working conditions, in order to have a better view, the cabs of engineering vehicles are set very high. When getting on and off the cab, for welcoming guests to visit, or putting materials in the cab, it is not easy for non-professionals to get on and off the vehicle, and due to the excessive height of the cab, it is dangerous for non-professionals to get on and off the vehicle.

[0004] To solve the above problems, engineering vehicles are designed with liftable cabs. The bottom of the cab is connected to an auxiliary chassis through a hydraulic cylinder, and the height of the cab is adjusted by controlling the telescopic movement of the hydraulic cylinder. Existing engineering vehicles generally adopt an electro-hydraulic system, with a special lift control switch set in the cab. By activating the electro-hydraulic pump through the lift control switch, the pump station provides stable pressure to drive the hydraulic cylinder to act to complete the lifting and lowering of the cab.

[0005] However, there is a risk of accidental touch when solely relying on the lift control switch to control the cab height, which is dangerous for non-professionals; and there is a lack of operation monitoring of the hydraulic system, which is likely to damage the hydraulic system. For example, if the hydraulic pipeline valve block is blocked, resulting in too high pressure in the hydraulic system, and if it is still used continuously at this time, it is likely to cause hydraulic system failures and pose safety risks. Summary of the Utility Model

[0006] Aiming at the deficiencies of the prior art, the purpose of the embodiments of the utility model is to provide a cab height control circuit and an engineering vehicle, which use the cab lift function switch and the key panel to realize the lift control of the cab, and at the same time use the pressure switch to monitor the pressure of the hydraulic system, improve the safety of height control, and avoid damaging the hydraulic system.

[0007] To achieve the above purpose, the embodiments of the utility model provide the following technical solutions:

[0008] A cab height control circuit includes a cab lift function switch, a normally closed relay, a pressure switch, a key panel, and a controller;

[0009] The cab lifting function switch is electrically connected to the first end of the normally closed relay. The second end of the normally closed relay is electrically connected to the key panel. The key panel is communicatively connected to the controller. The controller is electrically connected to a first normally open relay and a second normally open relay respectively. The first normally open relay is electrically connected to a rising electromagnetic valve. The second normally open relay is electrically connected to a falling electromagnetic valve.

[0010] The pressure switch is disposed in the hydraulic pipeline and is electrically connected to the normally closed relay.

[0011] By adopting the above technical solution, when the cab lifting function switch is closed and the rising button or the falling button on the key panel is pressed, the first normally open relay or the second normally open relay can be closed, thereby controlling the corresponding electromagnetic valve oil circuit to realize the lifting of the cab, and avoiding the safety risk brought by the non-professional personnel accidentally touching the switch to cause the cab to lift. At the same time, the pressure of the hydraulic system is detected by the pressure switch. When the pressure is too high, the pressure switch is closed, the normally closed relay is disconnected, and the lifting control of the cab is stopped, avoiding damage to the hydraulic system caused by overuse.

[0012] In some embodiments, the key panel is provided with a rising button and a falling button. A control chip is disposed in the key panel. The second end of the normally closed relay is electrically connected to the rising button and the falling button respectively. The rising button and the falling button are electrically connected to the control chip respectively. The control chip is connected to the controller through a CAN bus.

[0013] By adopting the above technical solution, when the cab needs to rise or fall, the rising button or the falling button is pressed, and a CAN bus message is output to the controller through the control chip. The controller outputs an electrical signal to the first normally open relay or the second normally open relay, and then controls the rising electromagnetic valve or the falling electromagnetic valve to make the corresponding hydraulic pipeline conduct, realizing the lifting of the cab.

[0014] In some embodiments, the normally closed relay includes a normally closed switch and a first coil. A first diode is connected in parallel with the first coil.

[0015] The first end of the normally closed switch is electrically connected to the cab lifting function switch. The second end of the normally closed switch is electrically connected to the key panel. The first end of the first coil is grounded. The second end of the first coil is electrically connected to the pressure switch.

[0016] By adopting the above technical solution, when the pressure of the hydraulic system exceeds the preset threshold, the pressure switch is closed, the first coil is powered on, the normally closed switch is disconnected, and the cab height control circuit stops running, avoiding overuse of the hydraulic system. At the same time, a diode is provided in the normally closed relay to prevent reverse current and improve the safety of the circuit.

[0017] In some embodiments, the first normally open relay includes a first normally open switch and a second coil, and a second diode is connected in parallel with the second coil;

[0018] A first output terminal of the controller is electrically connected to a first end of the second coil, a second end of the second coil is grounded, and the first normally open switch is electrically connected to the rising electromagnetic valve.

[0019] By adopting the above technical solution, when an electrical signal is output from the first output terminal of the controller, the second coil is energized, the first normally open switch is closed, and the rising electromagnetic valve is activated, thereby controlling the rise of the cab; at the same time, a diode is provided in the first normally open relay to prevent reverse current and improve the safety of the circuit.

[0020] In some embodiments, the second normally open relay includes a second normally open switch and a third coil, and a third diode is connected in parallel with the third coil;

[0021] A second output terminal of the controller is electrically connected to a first end of the third coil, a second end of the third coil is grounded, and the second normally open switch is electrically connected to the descending electromagnetic valve.

[0022] By adopting the above technical solution, when an electrical signal is output from the second output terminal of the controller, the third coil is energized, the second normally open switch is closed, and the descending electromagnetic valve is activated, thereby controlling the descent of the cab; at the same time, a diode is provided in the second normally open relay to prevent reverse current and improve the safety of the circuit.

[0023] In some embodiments, the rising electromagnetic valve is disposed on a rising hydraulic pipeline, and the descending electromagnetic valve is disposed on a descending hydraulic pipeline.

[0024] By adopting the above technical solution, the lifting control of the cab is realized by controlling the on / off of the hydraulic pipeline by the electromagnetic valve.

[0025] In some embodiments, an alarm is further included. A first end of the pressure switch is electrically connected to a power supply, the power supply is electrically connected to a first end of the alarm, and a second end of the alarm is electrically connected to a second end of the pressure switch.

[0026] In some embodiments, the alarm is a buzzer.

[0027] By adopting the above technical solution, when the pressure of the hydraulic system is too high, an alarm signal is emitted by the buzzer to prompt the operator to perform safety maintenance on the hydraulic system in time.

[0028] In some embodiments, the pressure switch is a normally open pressure switch, and the controller is a PLC controller.

[0029] The present utility model also provides an engineering vehicle, including the cab height control circuit described above.

[0030] One or more technical solutions provided by the present utility model have at least the following technical effects or advantages:

[0031] 1. For the technical solution provided by the present utility model, the start control of the cab height control circuit is carried out through the cab lifting function switch and the key panel. The cab height control circuit is started only when both the cab lifting function switch and the up or down button are pressed, reducing the safety risk caused by accidental touch by non-operating personnel in the cab.

[0032] 2. For the technical solution provided by the present utility model, the pressure of the hydraulic system is monitored through a pressure switch and is cooperated with a normally closed relay to control the cab height control circuit. When the hydraulic pipeline valve block is blocked, the normally closed relay disconnects, and the cab height control circuit stops running, ensuring the safe operation of the hydraulic system and avoiding damage to the equipment caused by overuse.

[0033] 3. For the technical solution provided by the present utility model, a diode is provided in the relay, improving the safety of the overall circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings forming a part of this utility model are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model.

[0035] Figure 1 is a schematic circuit connection diagram provided by an embodiment of the present utility model;

[0036] In the figure: 1. Cab lifting function switch; 2. Normally closed relay; 3. Pressure switch; 4. Key panel; 5. Controller; 6. First normally open relay; 7. Second normally open relay; 8. Up solenoid valve; 9. Down solenoid valve.

[0037] The distances or dimensions between each part are exaggerated for showing the positions of each part, and the schematic diagram is only for illustration. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present utility model. Unless otherwise specified, all technical and scientific terms used in the present utility model have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs.

[0039] Embodiment 1

[0040] As introduced in the background art, the lifting of the cab in the prior art is mostly controlled by a single switch, which has the risk of accidental touch; and the operating state of the hydraulic system is not considered, which has safety risks. To solve the above technical problems, the present utility model proposes a cab height control circuit.

[0041] Combined with Figure 1 , the cab height control circuit includes a cab lifting function switch 1, a normally closed relay 2, a pressure switch 3, a key panel 4, a controller 5, a rising solenoid valve 8 and a falling solenoid valve 9; a rising button and a falling button are installed on the key panel 4, the normally closed relay 2 includes a normally closed switch and a first coil, and a first diode is connected in parallel with the first coil; a first normally open relay 6 includes a first normally open switch and a second coil, and a second diode is connected in parallel with the second coil; a second normally open relay 7 includes a second normally open switch and a third coil, and a third diode is connected in parallel with the third coil. The setting of the diode prevents the reverse flow of current and improves the safety of the circuit; the pressure switch 3 is installed on the hydraulic pipeline for collecting the pressure information of the hydraulic system, the rising solenoid valve 8 is installed on the rising hydraulic pipeline, and the falling solenoid valve 9 is installed on the falling hydraulic pipeline. A rising button and a falling button are installed on the key panel 4, and a control chip is installed inside the key panel 4.

[0042] The power supply is electrically connected to the first end of the cab lifting function switch 1, the second end of the cab lifting function switch 1 is electrically connected to the first end of the normally closed switch, the second end of the normally closed switch is electrically connected to the rising button and the falling button respectively, the rising button and the falling button are electrically connected to the control chip respectively, and the control chip communicates with the controller 5 through the CAN bus. The first output end of the controller 5 is electrically connected to the first end of the second coil, and the second end of the second coil is grounded; the power supply is electrically connected to the first end of the second normally open switch, and the second end of the second normally open switch is electrically connected to the rising solenoid valve 8; the second output end of the controller 5 is electrically connected to the first end of the third coil, the second end of the third coil is grounded, the power supply is electrically connected to the first end of the third normally open switch, and the second end of the third normally open switch is electrically connected to the falling solenoid valve 9.

[0043] The working mode of this embodiment is as follows:

[0044] When the cab lifting function needs to be used, close the cab lifting function switch 1, and the key panel 4 is powered on; when the cab needs to rise, press the rising button, transmit a rising signal to the control chip, output a rising signal to the controller 5 through the control chip, the controller 5 outputs an electrical signal to the second coil, the second coil is powered on, the first normally open switch closes, the rising solenoid valve 8 is powered on and starts, and the rising hydraulic pipeline drives the hydraulic cylinder to extend, realizing the rise of the cab.

[0045] When the cab needs to be lowered, press the down button to transmit an up signal to the control chip. The control chip outputs a down signal to the controller 5, and the controller 5 outputs an electrical signal to the third coil. The third coil is energized, the second normally open switch closes, and the down solenoid valve 9 is energized and starts. The down hydraulic pipeline drives the hydraulic cylinder to contract, realizing the lowering of the cab.

[0046] When the pressure of the hydraulic system is too high, the pressure switch 3 closes, the first coil is energized, and the normally closed switch opens. The cab height control circuit stops operating, enabling it to stop operating in a timely manner when there are faults such as blockage of the hydraulic pipeline valve block in the hydraulic system.

[0047] In this embodiment, the pressure switch 3 is a normally open pressure switch 3, the controller 5 is a plc controller 5, the key panel 4 is a CAN communication interface control panel, and the model of the control chip is SGL8022K.

[0048] As an implementation method, in order to timely remind the operator when the pressure of the hydraulic system is too high, an alarm is set. The first end of the pressure switch 3 is electrically connected to the power supply, the power supply is electrically connected to the first end of the alarm, and the second end of the alarm is electrically connected to the second end of the pressure switch 3.

[0049] In this embodiment, the alarm is a buzzer. When the pressure of the hydraulic system is too high, the pressure switch 3 closes, and the pressure switch 3, the power supply, and the buzzer form a closed loop, and the buzzer emits a sound to remind the operator.

[0050] Embodiment 2

[0051] Based on the above cab height control circuit, the embodiment of the present utility model further provides an engineering vehicle. The cab of the engineering vehicle is provided with the cab height control circuit described in the above embodiment. Since the above cab height control circuit has the above technical effects, the technical effects of the engineering vehicle using the cab height control circuit can refer to the above embodiment.

[0052] Although the specific implementation manners of the present utility model are described above in conjunction with the drawings, it is not a limitation to the protection scope of the present utility model. Those skilled in the art should understand that various modifications or deformations that can be made without creative labor on the basis of the technical solution of the present utility model are still within the protection scope of the present utility model.

Claims

1. A cab height control circuit, characterized in that: Including cab lifting function switch, normally closed relay, pressure switch, key panel and controller; The cab lifting function switch is electrically connected to the first end of the normally closed relay, the second end of the normally closed relay is electrically connected to the key panel, the key panel is communicatively connected to the controller, and the controller is electrically connected to the first normally open relay and the second normally open relay respectively; the first normally open relay is electrically connected to the lifting solenoid valve, and the second normally open relay is electrically connected to the lowering solenoid valve; The pressure switch is arranged in the hydraulic pipeline, and the pressure switch is electrically connected to the normally closed relay; The key panel is provided with an up button and a down button, a control chip is provided in the key panel, the second end of the normally closed relay is electrically connected to the up button and the down button respectively, the up button and the down button are electrically connected to the control chip respectively, and the control chip is connected to the controller via a CAN bus; The pressure switch is a normally open pressure switch, and the controller is a plc controller.

2. The cab height control circuit according to claim 1, characterized in that: The normally closed relay comprises a normally closed switch and a first coil, wherein the first coil is connected in parallel with a first diode; The first end of the normally closed switch is electrically connected to the cab lifting function switch, and the second end of the normally closed switch is electrically connected to the button panel; the first end of the first coil is grounded, and the second end of the first coil is electrically connected to the pressure switch.

3. The cab height control circuit according to claim 1, characterized in that: The first normally open relay comprises a first normally open switch and a second coil, and the second coil is connected in parallel with a second diode; The first output end of the controller is electrically connected to the first end of the second coil, the second end of the second coil is grounded, and the first normally open switch is electrically connected to the rising solenoid valve.

4. The cab height control circuit according to claim 1, characterized in that: The second normally open relay comprises a second normally open switch and a third coil, and the third coil is connected in parallel with a third diode; The second output end of the controller is electrically connected to the first end of the third coil, the second end of the third coil is grounded, and the second normally open switch is electrically connected to the descending solenoid valve.

5. The cab height control circuit according to claim 1, characterized in that: The ascending solenoid valve is arranged on the ascending hydraulic pipeline, and the descending solenoid valve is arranged on the descending hydraulic pipeline.

6. The cab height control circuit according to claim 1, characterized in that: It also includes an alarm, wherein the first end of the pressure switch is electrically connected to a power source, the power source is electrically connected to the first end of the alarm, and the second end of the alarm is electrically connected to the second end of the pressure switch.

7. The cab height control circuit according to claim 6, characterized in that: The alarm is a buzzer.

8. An engineering vehicle, characterized in that: It comprises the cab height control circuit as described in any one of claims 1-7.

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