Warning system of electric forklift

Abstract

The utility model provides a warning system of an electric fork-lift truck, which comprises a fork-lift truck controller connected in series at two ends of a power supply, the fork-lift truck controller is connected with a walking motor and is used for detecting the working state of the walking motor, the output end of the fork-lift truck controller is connected with an alarm relay, the contact of the alarm relay is connected with an alarm, and the alarm is connected with the power supply. A coil of the alarm relay is connected with a DC-DC converter through a proximity switch, and the DC-DC converter is connected to the two ends of a power source. The proximity switch is installed on a forklift portal frame and used for detecting the lifting height of a pallet fork. According to the warning system, in the operation process of the forklift, if it is detected that a pallet fork is lifted to a certain height, the warning system works, that is, the warning system can be triggered only when the system needs to detect whether the forklift is in an operation state or not and whether the lifting height reaches a designated position or not at the same time; therefore, the warning system is more intelligent.

Description

Technical Field

[0001] The utility model belongs to the technical field of forklifts, and in particular relates to a warning system for an electric forklift. Background Art

[0002] With the development trend of intelligence and electrification in the forklift industry, electric forklifts are developing with each passing day. Compared with traditional fuel forklifts, electric forklifts have many advantages. In addition to being environmentally friendly, low-cost, maintenance-free, and low-pollution, electric forklifts also have less noise pollution in terms of ergonomics.

[0003] However, because electric forklifts make less noise during operation, people around the forklift will not pay attention to them, so there are great safety hazards for drivers and pedestrians around the forklift. Especially when the electric forklift is fully loaded, when the fork is raised to a certain height during operation, it is a great safety hazard for pedestrians around. Utility Model Content

[0004] Therefore, in order to solve the problem of timely warning surrounding pedestrians to avoid the forklift when the fork is raised to a certain height during operation, the utility model proposes a warning system for an electric forklift. When the fork is raised to a certain height during operation, the forklift can automatically alarm to remind surrounding pedestrians to pay attention to safety.

[0005] The technical solution of the utility model is as follows:

[0006] A warning system for an electric forklift, comprising a forklift controller connected in series at both ends of a power supply, the forklift controller being connected to a travel motor for detecting the working state of the travel motor, an output end of the forklift controller being connected to an alarm relay, a contact of the alarm relay being connected to an alarm, a coil of the alarm relay being connected to a DC-DC converter via a proximity switch, the DC-DC converter being connected to both ends of the power supply; the proximity switch being installed on a forklift mast for detecting the lifting height of a forklift.

[0007] In a further solution, the driving end A2 of the forklift controller is connected to the common end C1 of the alarm relay, the normally open contact C2 of the alarm relay is suspended, and the normally open contact C3 is connected to the alarm; the two coil ends C4 and C5 of the alarm relay are respectively connected to the normally closed contacts D2 and D3 of the proximity switch, and the coil end C4 of the alarm relay is connected to the negative end of the power supply; the common end D1 of the proximity switch is connected to the low-voltage power supply output end of the DC-DC converter.

[0008] In a further solution, when the proximity switch detects that the fork is lifted to a high position, its normally closed contact D2 is connected to the common terminal D1, and the low-voltage power supply of the DC-DC converter is transmitted to the coil terminal C5 of the alarm relay, and a voltage difference is formed between the two coil terminals C4 and C5; the forklift controller drive terminal A2 outputs a drive voltage to the alarm relay, and the common terminal C1 of the alarm relay is connected to the normally open contact C3 to turn on the alarm circuit, so that the alarm works.

[0009] In a further solution, the positive terminal of the power supply is connected in series with an emergency stop switch and a key switch in sequence, the output end of the key switch is connected to the drive end A1 of the forklift controller and the signal end of the DC-DC converter respectively, and the negative ends of the forklift controller and the DC-DC converter are both connected to the negative end of the power supply.

[0010] In a further solution, the positive terminal of the power supply is connected to the positive terminal of the forklift controller and the positive terminal of the DC-DC converter respectively.

[0011] Preferably, the emergency stop switch and the positive terminal of the DC-DC converter are both connected to a fuse.

[0012] The warning system of the utility model is based on the basic electrical principle. By adding basic electrical components such as alarm relays and alarms, the forklift can be alarmed during operation. Therefore, the system has a wide range of basic applicability and is not targeted at specific vehicle models. The function can be achieved by adding electrical components to the electrical control circuit of existing vehicle models. At the same time, it can also be modified for the aftermarket, and has a wider range of applications.

[0013] This warning system is driven by basic circuit connection, which has better stability and low failure rate. It also has low implementation cost and only requires the principle to be modified, so it has high cost performance.

[0014] The operation of the alarm in the utility model needs to meet the following two conditions at the same time: one is that the forklift is lifted to a high place: when the proximity switch detects that the forklift is lifted to a high place, the low-voltage power supply of the DC-DC converter is transmitted to the alarm relay; the second is that the forklift is in driving state: when the forklift controller detects that the travel motor is working, that is, the forklift is driving, the driving end of the forklift controller outputs a DC voltage to the alarm relay, and the alarm relay turns on the alarm circuit to make the alarm work.

[0015] That is, the warning system of the utility model realizes that during the operation of the forklift, the warning system will only work if it detects that the forks are lifted to a certain height. That is, the system needs to detect both whether the forklift is in operation and whether the lifting height reaches the specified position to trigger the alarm system. Therefore, the warning system is more intelligent. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1This is a circuit principle block diagram of the utility model. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] See also Figure 1 , a warning system for an electric forklift, comprising a forklift controller 9 connected in series at both ends of a power supply 1, the forklift controller 9 is connected to a travel motor 10 for detecting the working state of the travel motor, an output end of the forklift controller 9 is connected to an alarm relay 6, a contact of the alarm relay 6 is connected to an alarm 8, a coil of the alarm relay 6 is connected to a DC-DC converter 5 through a proximity switch 7, and the DC-DC converter 5 is connected to both ends of the power supply 1; the proximity switch 7 is installed on a forklift mast for detecting the lifting height of the forks.

[0019] The specific circuit connection is: the driving end A2 of the forklift controller 9 is connected to the common end C1 of the alarm relay 6, the normally open contact C2 of the alarm relay 6 is suspended, and the normally open contact C3 is connected to the alarm 8; the two coil ends C4 and C5 of the alarm relay 6 are respectively connected to the normally closed contacts D2 and D3 of the proximity switch 7, and the coil end C4 of the alarm relay 6 is connected to the negative end of the power supply 1; the common end D1 of the proximity switch 7 is connected to the low-voltage power supply output end of the DC-DC converter 5.

[0020] The operation of the alarm 8 in the utility model needs to meet two conditions:

[0021] One is that the fork is lifted to a high position: when the proximity switch 7 detects that the fork is lifted to a high position, its normally closed contact D2 is connected to the common terminal D1, and the low-voltage power supply of the DC-DC converter 5 is transmitted to the coil terminal C5 of the alarm relay 6, and a voltage difference is formed between the two coil terminals C4 and C5;

[0022] The second is that the forklift is in driving state: when the forklift controller 9 detects that the travel motor 10 is working, that is, the forklift is driving, the driving terminal A2 of the forklift controller 9 outputs a DC voltage to the alarm relay 6, and the common terminal C1 of the alarm relay 6 is connected to the normally open contact C3 to turn on the alarm 8 circuit, so that the alarm 8 works.

[0023] like Figure 1As shown, the warning circuit in this embodiment also includes: the positive end of the power supply 1 is divided into three paths, one of which is connected in series with a fuse F2, an emergency stop switch 3, and a key switch 4 in sequence, and the output end of the key switch 4 is respectively connected to the drive end A1 of the forklift controller 9 and the signal end of the DC-DC converter 5, and the negative ends of the forklift controller 9 and the DC-DC converter 5 are both connected to the negative end of the power supply 1. At the same time, the other two paths of the power supply 1 are respectively connected to the positive ends of the forklift controller 9 and the DC-DC converter 5, and the positive ends of the DC-DC converter 5 are both connected to the fuse F1 to protect the startup circuit of the DC-DC converter 5.

[0024] In this embodiment:

[0025] Power supply 1 provides power for the normal operation of the electric forklift;

[0026] Fuse 2 is a protective device on the key start circuit of the electric forklift to protect the start circuit and prevent the start circuit from being burned due to short circuit and other reasons;

[0027] Emergency stop switch 3 is normally closed under normal conditions. When an abnormal situation occurs in the forklift, it needs to be disconnected urgently to prevent the forklift from losing control;

[0028] Key switch 4 controls the power-on and power-off process of the electric forklift, and then directly controls the start and stop of the forklift;

[0029] The DC-DC converter 5 is a DC converter of the electric forklift, which converts the DC high voltage of the power supply 1 of the electric forklift into a DC low voltage, and then supplies power to the low-voltage electrical components (such as proximity switches) of the electric forklift;

[0030] The alarm relay 6 is a normally open element, whose common terminal C1 is connected to the drive terminal A2 of the forklift controller, the normally open contact C2 is suspended, and C3 is connected to the alarm 8; when there is a voltage difference between the two coil terminals C4 and C5 of the alarm relay, when the coil is powered on, the common terminal C1 and the normally open contact C3 are attracted and connected, thereby turning on the alarm 8 circuit, and the alarm 8 works.

[0031] The proximity switch 7 is an NPN normally closed proximity switch, which is used to detect the lifting height of the fork, wherein the normally closed contacts D3 and D2 are connected to the coil terminals C4 and C5 of the alarm relay respectively, and the common terminal D1 is connected to the low-voltage power supply output terminal (12V) of the DC-DC converter. When the proximity switch 7 does not detect the fork, the normally closed contacts D3 and D2 are connected to the ground, and the coil terminals C4 and C5 of the alarm relay cannot be powered on;

[0032] The alarm 8 can be selected as a buzzer warning light in this embodiment; the buzzer warning light can beep when powered on to alert the driver and pedestrians around the forklift;

[0033] The forklift controller 9 is an existing device on the forklift, which is responsible for controlling the normal operation of the forklift and providing the drive terminal A2 with a DC voltage output to drive the alarm relay 6 and the alarm 8 to realize an alarm;

[0034] The travel motor 10 is an existing device on the forklift, which is used to drive the electric forklift to travel and retreat normally. The forklift controller 9 detects the speed of the travel motor through the three ports of the speed encoder end A3\A4\A5, and then can obtain the speed and movement state of the electric forklift.

[0035] The working process of this warning system is as follows:

[0036] When the key switch 4 is closed, the power supply 1 of the electric forklift is powered on through the key switch startup circuit. At this time, the electric forklift system is powered on and everything is normal;

[0037] 1. When the electric forklift is not moving and the forks are raised to a certain height in situ:

[0038] At this time, after the fork reaches a certain lifting height, when the proximity switch 7 detects the fork, the common terminal D1 and the normally closed contact D2 of the proximity switch 7 are turned on. At this time, the 12V positive voltage at the output end of the DC-DC converter 5 is connected to the coil end C5 of the alarm relay 6 through the proximity switch D1 and D2, and C4 is connected to the negative pole of the power supply 1. A voltage difference is formed at both ends of the coil, so the coil is electrically sucked and connected to the common terminal C1 and the normally open contact C3. However, at this time, when the forklift controller 9 detects that the travel motor 10 has no speed through the encoder, it means that the electric forklift is in a stationary state and is not moving, then the drive end A2 of the forklift controller 9 cannot output the drive voltage, so the alarm relay 6 does not work, and the alarm 8 cannot work either.

[0039] 2. When the fork of the electric forklift is not raised to a certain height:

[0040] When the fork is not lifted to a certain height, that is, the proximity switch 7 does not detect the fork, the coil terminals C4 and C5 of the alarm relay 6 are not powered, and the common terminal C1 of the alarm relay 6 is always connected to the normally open contact C2 and is in a suspended state; the alarm 8 cannot work.

[0041] 3. When the electric forklift is lifted to a certain height and driving normally:

[0042] When the fork is lifted to a certain height and the proximity switch 7 detects the fork, the coil terminals C4 and C5 of the alarm relay 6 are normally powered on, and the common terminal C1 and the normally open contact C3 are turned on; at this time, the travel motor 10 is working, and the forklift controller 9 detects the vehicle speed, then the drive terminal A2 of the forklift controller 9 will output a DC voltage to the common terminal C1 of the alarm relay 6, and the alarm relay 6 will work to connect the working circuit of the alarm 8, and the alarm 8 will sound a buzzer alarm to achieve a warning reminder.

[0043] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0044] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A warning system for an electric forklift, comprising a forklift controller (9) connected in series to both ends of a power supply (1), wherein the forklift controller (9) is connected to a travel motor (10) for detecting the working state of the travel motor, and wherein: The output end of the forklift controller (9) is connected to an alarm relay (6), the contacts of the alarm relay (6) are connected to an alarm (8), the coil of the alarm relay (6) is connected to a DC-DC converter (5) via a proximity switch (7), and the DC-DC converter (5) is connected to both ends of a power source (1); the proximity switch (7) is mounted on a forklift mast and is used to detect the lifting height of a forklift.

2. The warning system for an electric forklift according to claim 1, characterized in that: The driving end A2 of the forklift controller (9) is connected to the common end C1 of the alarm relay (6); the normally open contact C2 of the alarm relay (6) is suspended, and the normally open contact C3 is connected to the alarm (8); the two coil ends C4 and C5 of the alarm relay (6) are respectively connected to the normally closed contacts D2 and D3 of the proximity switch (7); the coil end C4 of the alarm relay (6) is connected to the negative end of the power supply (1); the common end D1 of the proximity switch (7) is connected to the low-voltage power supply output end of the DC-DC converter (5).

3. The warning system for an electric forklift according to claim 2, characterized in that: When the proximity switch (7) detects that the forklift is lifted to a high position, its normally closed contact D2 is connected to the common terminal D1, and the low-voltage power supply of the DC-DC converter (5) is transmitted to the coil terminal C5 of the alarm relay (6), thereby forming a voltage difference between the two coil terminals C4 and C5; the driving terminal A2 of the forklift controller (9) outputs a driving voltage to the alarm relay (6), and the common terminal C1 of the alarm relay (6) is connected to the normally open contact C3 to turn on the circuit of the alarm (8), so that the alarm (8) works.

4. The warning system for an electric forklift according to claim 1, characterized in that: The positive terminal of the power supply (1) is connected in series with an emergency stop switch (3) and a key switch (4), the output end of the key switch (4) is connected to a drive end A1 of a forklift controller (9) and a signal end of a DC-DC converter (5), respectively, and the negative ends of the forklift controller (9) and the DC-DC converter (5) are both connected to the negative end of the power supply (1).

5. The warning system for an electric forklift according to claim 1, characterized in that: The positive terminal of the power supply (1) is respectively connected to the positive terminals of the forklift controller (9) and the DC-DC converter (5).

6. The warning system for an electric forklift according to claim 4, characterized in that: The positive terminals of the emergency stop switch (3) and the DC-DC converter (5) are both connected to a fuse (2).

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