Double-key speed control system of reach forklift

Abstract

The utility model discloses a double-key speed control system of a reach truck, which comprises an energy storage power supply, a power converter, a motor controller, a driving thumb switch and a motor, and a first key switch is arranged on a line where the energy storage power supply is connected with a control port C of the power converter. The output end of the power converter is connected with one end of a coil of a relay through a second key switch. Through the control of the first key switch and the second key switch, when the first key is turned on, the maximum running speed of the whole vehicle is in a low mode, when the first key switch and the second key switch are simultaneously turned on, the maximum running speed of the whole vehicle is in a high mode, and when the second key switch is independently turned on, the whole vehicle cannot be powered on to run. The maximum running speed of the whole vehicle is effectively controlled, the change operation of a driver on the speed of the whole vehicle in the running process is reduced, the running safety of the whole vehicle is guaranteed, and customer use is met.

Description

Technical Field

[0001] The utility model relates to the technical field of reach forklifts, in particular to a dual-key speed control system for reach forklifts. Background Technique

[0002] As a type-II electric forklift, the reach electric forklift has the advantages of a high-lift mast, in-situ steering, and a small turning radius, and is an ideal tool for loading, unloading, and stacking in warehouses, supermarkets, and workshops. With the increasing number of places where reach electric forklifts are used, higher requirements are put forward for improving the safety of forklift use. The whole vehicle does not have a PES gear position mode switch of type-I electric forklifts, and the driving speed of the whole vehicle is controlled by the magnitude of the analog quantity input by the driving thumb switch. For some places with small spaces, it is difficult to control the driving speed of the whole vehicle, and the braking distance of the forklift cannot be effectively guaranteed. At the same time, if the driving speed is too fast, the shaking phenomenon of the high cargo position of the mast will be aggravated, and the safety of the driver cannot be guaranteed. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems in the related technologies to some extent. For this purpose, an object of the utility model is to provide a dual-key speed control system for reach forklifts. By closing and disconnecting two key switches, the whole vehicle is controlled to realize the switching of two maximum driving speed modes, meeting the different requirements of customers for controlling the driving speed, ensuring the driving safety of the whole vehicle, and meeting the requirements of customers.

[0004] A double-key speed control system for a reach forklift according to the present utility model includes an energy storage power supply, a power converter, a motor controller, a travel thumb switch, and a motor. The positive pole of the energy storage power supply is respectively connected to the positive input terminal of the power converter, the control port C of the power converter, and the positive wiring port B+ of the motor controller. A main contactor switch is provided on the line connecting the positive pole of the energy storage power supply and the positive wiring port B+ of the motor controller. The NMC port and the PMC port of the motor controller are connected to a main contactor coil. A first key switch is provided on the line connecting the energy storage power supply and the control port C of the power converter. The first key switch is also connected to the KSI port of the motor controller. The output terminal of the power converter is connected to one end of the coil of a relay through a second key switch. The other end of the coil of the relay, the negative pole of the power converter, and the negative wiring port B- of the motor controller are respectively connected to the negative pole of the energy storage power supply. The switch of the relay is respectively connected to the slow speed gear port and the 12V- port of the motor controller. The speed signal port, the 12V+ port, the reverse gear port, the forward gear port, and the 12V- port of the travel thumb switch are respectively connected to the speed signal port, the 12V+ port, the reverse gear port, the forward gear port, and the 12V- port of the motor controller. The U port, the V port, and the W port of the motor controller are respectively connected to the U port, the V port, and the W port of the motor.

[0005] Preferably, it includes a foot safety switch. The safety switch port of the motor controller is connected to the negative pole of the energy storage power supply through the foot safety switch.

[0006] Preferably, an emergency power-off switch is provided on the line connecting the energy storage power supply and the first key switch.

[0007] Preferably, it includes a fuse F1, a fuse F2, a fuse F3, and a fuse F4. The fuse F1 is provided on the line connecting the positive pole of the energy storage power supply and the positive input terminal of the power converter. The fuse F2 is provided on the line connecting the energy storage power supply and the control port C of the power converter. The fuse F3 is provided on the line connecting the output terminal of the power converter and the coil of the relay. The fuse F4 is provided on the line connecting the positive pole of the energy storage power supply and the positive wiring port B+ of the motor controller.

[0008] Preferably, it includes a fuse integration box. The fuses F1, F2, and F3 are all installed in the fuse integration box.

[0009] Preferably, a freewheeling diode D1 is connected in parallel at both ends of the coil of the relay.

[0010] Preferably, the relay is a normally closed relay.

[0011] The beneficial effects of the present utility model are as follows: By controlling the operation of the whole vehicle through the first key switch and the second key switch, when the first key is turned on, the maximum driving speed of the whole vehicle is in the low mode. When the first and second key switches are closed simultaneously, the maximum driving speed of the whole vehicle is in the high mode. When the second key switch is closed alone, the whole vehicle cannot be powered on and run, effectively controlling the maximum driving speed of the whole vehicle, reducing the driver's operation of changing the vehicle speed during driving, ensuring the driving safety of the whole vehicle, and meeting the customer's use. Description of the Drawings

[0012] In the drawings:

[0013] Figure 1 is the circuit schematic diagram of the dual-key speed control system for the reach truck proposed by the present utility model.

[0014] In the figure: 1 - energy storage power supply, 2 - fuse integration box, 3 - emergency power-off switch, 4 - first key switch, 5 - power converter, 6 - motor controller, 7 - main contactor coil, 8 - foot safety switch, 9 - travel thumb switch, 10 - second key switch, 11 - relay, 12 - motor. Detailed Embodiments

[0015] Referring to Figure 1 , a dual-key speed control system for a reach truck includes an energy storage power supply 1, a power converter 5, a motor controller 6, a travel thumb switch 9, and a motor 12. The positive pole of the energy storage power supply 1 is respectively connected to the positive input terminal of the power converter 5, the control port C of the power converter 5, and the positive wiring port B+ of the motor controller 6. A main contactor switch is provided on the line connecting the positive pole of the energy storage power supply 1 to the positive wiring port B+ of the motor controller 6. The NMC port and the PMC port of the motor controller 6 are connected with a main contactor coil 7. A first key switch 4 is provided on the line connecting the energy storage power supply 1 to the control port C of the power converter 5. The first key switch 4 is also connected to the KSI port of the motor controller 6. The output terminal of the power converter 5 is connected to one end of the coil of a relay 11 through a second key switch 10. The other end of the coil of the relay 11, the negative pole of the power converter 5, and the negative wiring port B- of the motor controller 6 are respectively connected to the negative pole of the energy storage power supply 1. The switch of the relay 11 is respectively connected to the slow gear port and the 12V- port of the motor controller 6. The speed signal port, 12V+ port, reverse gear port, forward gear port, and 12V- port of the travel thumb switch 9 are respectively connected to the speed signal port, 12V+ port, reverse gear port, forward gear port, and 12V- port of the motor controller 6. The U port, V port, and W port of the motor controller 6 are respectively connected to the U port, V port, and W port of the motor 12.

[0016] Obviously, based on the above, in this embodiment, the operation of the whole vehicle is controlled by the first key switch 4 and the second key switch 6 to realize the switching between two maximum driving speed modes.

[0017] In this embodiment, the dual-key speed control system of the reach truck may include a foot safety switch 8. The safety switch port of the motor controller 6 is connected to the negative pole of the energy storage power supply 1 through the foot safety switch 8.

[0018] Obviously, based on the above, when the foot safety switch 8 is turned off in this embodiment, the whole vehicle cannot move, ensuring that when the driver is not in the driver's seat, the whole vehicle will not malfunction.

[0019] In this embodiment, an emergency power-off switch 3 may be provided on the line where the energy storage power supply 1 is connected to the control port C of the power converter 5.

[0020] Obviously, based on the above, the whole vehicle can be quickly powered off by setting the emergency power-off switch 3.

[0021] In this embodiment, the dual-key speed control system of the reach truck may include a fuse F1, a fuse F2, a fuse F3, and a fuse F4. The fuse F1 is provided on the line where the positive pole of the energy storage power supply 1 is connected to the positive input terminal of the power converter 5. The fuse F2 is provided on the line where the energy storage power supply 1 is connected to the control port C of the power converter 5. The fuse F3 is provided on the line where the output terminal of the power converter 5 is connected to the coil of the relay 11. The fuse F4 is provided on the line where the positive pole of the energy storage power supply 1 is connected to the positive wiring port B+ of the motor controller 6.

[0022] Obviously, based on the above, by setting the fuse F1, the fuse F2, the fuse F3, and the fuse F4, damage to electronic components caused by excessive current in the circuit can be prevented.

[0023] In this embodiment, the dual-key speed control system of the reach truck may include a fuse integration box 2, and the fuse F1, the fuse F2, the fuse F3, and the fuse F4 are all installed in the fuse integration box 2.

[0024] Obviously, based on the above, integrating the fuse F1, the fuse F2, and the fuse F3 in a fuse integration box 2 facilitates the repair and replacement of the fuses.

[0025] In this embodiment, a freewheeling diode D1 may be connected in parallel across the coil of the relay 11.

[0026] Obviously, based on the above, the coil of the relay 11 is protected by setting the freewheeling diode D1.

[0027] In this embodiment, the relay 11 can be a normally-closed relay.

[0028] Obviously, based on the above, when there is no trigger current in the coil of the relay 11, the switch of the relay 11 is closed. At this time, the low-speed gear on the motor controller 6 is in the triggered state. When there is trigger current in the coil of the relay 11, the switch of the relay 11 is opened. At this time, the low-speed gear on the motor controller 6 is in the un-triggered state.

[0029] To more clearly illustrate the solutions and effects of this embodiment, an example is given in combination with the accompanying drawings:

[0030] Please refer to Figure 1 , when the customer is about to use the forklift, the driver first closes the first key switch 4. The positive pole of the energy storage power supply 1 is sequentially connected to the power input port KS1 of the motor controller 6 through the fuse F2 in the fuse integration box 2, the emergency power-off switch 3, and the first key switch 4. After the motor controller 6 is powered on and self-checked, a voltage difference is generated in the main contactor coil 7 connected in series between the control ports NMC and PMC of the motor controller 6, causing the main contactor switch K1 connected to the positive terminal B+ of the motor controller 6 through the fuse F4 to be attracted and conducted; when the driver stands in the driving position and steps on the foot safety switch 8, the safety switch pin of the motor controller 6 is pulled low and triggered. At this time, when the driving thumb switch 9 is pushed forward or pulled backward, the analog signal of the driving thumb switch 9 is input to the speed signal pin of the motor controller 6. The speed signal and the forward or reverse gear signal of the motor controller 6 are triggered, and the whole vehicle controls the vehicle speed according to the slow gear function of the maximum driving speed in the low mode and the magnitude of the analog quantity input to the speed signal input port; at this time, the positive power output port 12V+ of the power converter 5 is connected to the second key switch 10 through the fuse F3 in the fuse integration box 2; when the first key switch 4 is closed and the second key switch 10 is also closed, the output terminal of the second key switch 10 is connected to the coil L2 of the relay 11. The coil L2 of the relay 11 is powered on and works to trigger the normally-closed switch K2 to open, and the low-speed gear port signal of the motor controller 6 disappears. The whole vehicle changes to the high-mode maximum driving speed state and runs and maintains. At this time, the vehicle driving speed is linearly adjusted according to the magnitude of the analog quantity input to the speed signal port of the driving thumb switch 9; when the driver stops using the forklift, only the first key switch 4 needs to be disconnected and the driver leaves the driving position. The first key switch 4 and the foot safety switch 8 are disconnected, and the whole vehicle can cut off the power supply and stop working; when the first key switch 4 is closed and the driver is not in the driving position, that is, the first key switch 4 is closed and the foot safety switch 8 is disconnected, the whole vehicle cannot drive, ensuring that when the driver is not in the driving position, the whole vehicle will not malfunction; when only the second key switch 10 is closed and the first key switch 4 is not closed, the power converter 5 of the whole vehicle is not powered on and works, and the signal terminal of the power converter 5 has no output.

Claims

1. A dual-key speed control system for a reach forklift, characterized in that: The invention comprises an energy storage power supply (1), a power converter (5), a motor controller (6), a driving thumb switch (9) and a motor (12), wherein the positive electrode of the energy storage power supply (1) is respectively connected to the positive input terminal of the power converter (5), the control port C of the power converter (5) and the positive wiring port B+ of the motor controller (6), a main contactor switch is arranged on the line connecting the positive electrode of the energy storage power supply (1) and the positive wiring port B+ of the motor controller (6), the NMC port and the PMC port of the motor controller (6) are connected to the main contactor coil (7), the line connecting the energy storage power supply (1) and the control port C of the power converter (5) is provided with a first key switch (4), the first key switch (4) is also connected to the KSI port of the motor controller (6), the power converter (5) The output end is connected to one end of the coil of the relay (11) through the second key switch (10); the other end of the coil of the relay (11), the negative electrode of the power converter (5) and the negative electrode connection port B- of the motor controller (6) are respectively connected to the negative electrode of the energy storage power supply (1); the switch of the relay (11) is respectively connected to the slow gear port and the 12V- port of the motor controller (6); the speed signal port, 12V+ port, reverse gear position forward gear port and 12V- port of the driving thumb switch (9) are respectively connected to the speed signal port, 12V+ port, reverse gear position forward gear port and 12V- port of the motor controller (6); the U port, V port and W port of the motor controller (6) are respectively connected to the U port, V port and W port of the motor (12).

2. A dual-key speed control system for a reach forklift according to claim 1, characterized in that: It comprises a foot safety switch (8), and the safety switch port of the motor controller (6) is connected to the negative electrode of the energy storage power supply (1) through the foot safety switch (8).

3. A dual-key speed control system for a reach forklift according to claim 1, characterized in that: An emergency power-off switch (3) is provided on the line connecting the energy storage power source (1) and the first key switch (4).

4. A dual-key speed control system for a reach forklift according to claim 1, characterized in that: The invention comprises a fuse F1, a fuse F2, a fuse F3 and a fuse F4, wherein the fuse F1 is arranged on a line connecting the positive electrode of the energy storage power source (1) and the positive input terminal of the power converter (5), the fuse F2 is arranged on a line connecting the energy storage power source (1) and the control port C of the power converter (5), the fuse F3 is arranged on a line connecting the output terminal of the power converter (5) and the coil of the relay (11), and the fuse F4 is arranged on a line connecting the positive electrode of the energy storage power source (1) and the positive wiring port B+ of the motor controller (6).

5. A dual-key speed control system for a reach forklift according to claim 4, characterized in that: It comprises a fuse integrated box (2), wherein the fuse F1, the fuse F2, the fuse F3 and the fuse F4 are all installed in the fuse integrated box (2).

6. A dual-key speed control system for a reach forklift according to claim 1, characterized in that: A freewheeling diode D1 is connected in parallel at both ends of the coil of the relay (11).

7. A dual-key speed control system for a reach forklift according to claim 1, characterized in that: The relay (11) is a normally closed relay.

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