Non-contact wireless charging equipment and electric forklift

Abstract

The utility model discloses an electric forklift which comprises a wireless energy receiving module arranged on a forklift body of the electric forklift, and the wireless energy receiving module comprises a wireless energy receiving device and a wireless energy receiving controller. The wireless energy receiving controller is configured to convert energy generated by induction of the wireless energy receiving device into direct current to be output when the wireless energy receiving device is aligned with a paired wireless energy transmitting device, so that a power battery of the electric forklift is selectively charged, and the wireless energy receiving controller is characterized in that the wireless energy receiving device comprises a wireless receiving coil; the wireless receiving coil is arranged on a first installation base plate, the first installation base plate is installed on an overhead guard and / or the bottom face of a forklift body, and a warning device is arranged in a driver cabin of the electric forklift. And the warning device is configured to send out a warning signal for allowing wireless charging when the wireless energy receiving device is aligned with the paired wireless energy transmitting device. The utility model further discloses a non-contact wireless charging device for the electric forklift.

Description

Technical Field

[0001] This application generally relates to a contactless wireless charging device for electric forklifts and the electric forklifts themselves. Background Technology

[0002] Electric forklifts are used for material handling and are primarily equipped with power batteries. These power batteries are typically recharged via wired DC charging. The power batteries are typically lithium-ion batteries, and the forklift can be equipped with a charging input interface for charging the lithium-ion batteries and a discharge output interface for supplying power to other electrical appliances in the work area. The current technology uses wired DC charging mainly because electric forklifts have high power requirements, which are easily met by wired DC charging. For example, DC charging allows for equipping the electric forklift with one or two charging units. The charging gun of a single charging unit can be directly inserted into the charging input interface of the electric forklift to charge the power battery; additionally, the charging gun of another charging unit can be inserted into the discharge output interface of the electric forklift (which then functions as a charging port) to simultaneously charge the power battery, increasing charging power and shortening charging time.

[0003] While existing wired DC charging technology offers high charging power, it requires the electric forklift to be parked next to the charging unit before charging. The charging gun, containing the charging cable, must then be removed from the unit and inserted into the corresponding port on the forklift. During this process, the charging cable may be dragged across the surface. Over time, this can cause dust and oil to easily accumulate on the cable's outer sheath, soiling the forklift user. Furthermore, prolonged dragging can damage the cable's insulation, creating a risk of electrical leakage.

[0004] In addition, although some existing warehouse forklifts are equipped with wireless charging devices, the wireless receiver is usually installed only on the side of the mast, resulting in a small installation area. This limits the power of the wireless receiver, resulting in low charging power that cannot meet the needs of long-term operation. Utility Model Content

[0005] To address the aforementioned issues, this application aims to provide an electric forklift and a contactless wireless charging device. This device enables the electric forklift to quickly charge its power battery, and allows users to conveniently park the forklift at a charging location without needing to monitor the charging process, as the power battery can charge itself.

[0006] According to one aspect of this application, an electric forklift is provided, comprising: a wireless energy receiving module disposed on the body of the electric forklift, the wireless energy receiving module including a wireless energy receiving device and a wireless energy receiving controller, the wireless energy receiving controller being configured to convert energy sensed by the wireless energy receiving device when the wireless energy receiving device is aligned with a paired wireless energy transmitting device into DC power output for selectively charging the power battery of the electric forklift, the wireless energy receiving device including a wireless receiving coil disposed on a first mounting plate mounted on the overhead guard and / or bottom surface of the body, and a warning device disposed in the driver's cab of the electric forklift, the warning device being configured to issue a warning signal allowing wireless charging when the wireless energy receiving device is aligned with the paired wireless energy transmitting device.

[0007] Optionally, the first mounting base plate of the wireless power receiving device is mounted on the side of the vehicle body.

[0008] Optionally, the wireless power transmitter includes a wireless transmitting coil arranged on a fixed second mounting plate. A photoelectric sensor is mounted on one of the second mounting plate of the wireless power transmitter and the first mounting plate of the wireless power receiver, and an optical device that reflects or emits light detectable by the photoelectric sensor is mounted on the other of the second mounting plate of the wireless power transmitter and the first mounting plate of the wireless power receiver. When the second mounting plate of the wireless power transmitter and the first mounting plate of the wireless power receiver are aligned with each other, the photoelectric sensor can detect the light reflected or emitted by the optical device to activate the warning device to generate a warning signal. For example, the optical device for reflecting light can be a reflector. As another example, the optical device for emitting light can be an additional light-emitting device.

[0009] Optionally, the photoelectric sensor is at least two photoelectric sensors arranged at intervals, and the optical device is at least two optical devices arranged at intervals.

[0010] Optionally, the warning device includes the same number of indicator lights as the photoelectric sensor, which are activated and illuminate when the photoelectric sensor detects light.

[0011] Optionally, the wireless energy receiver controller is provided with an auxiliary power interface so as to generate power to the battery management system of the power battery before the DC power output of the power battery.

[0012] Optionally, the wireless power receiver controller is configured to periodically wake up the battery management system after the power battery of the electric forklift is fully charged, so that the battery management system automatically detects the current power level of the power battery after being woken up, and selectively sends a charging request command to the wireless power receiver controller based on the detection result of the current power level; or, the battery management system can be woken up using the key switch of the electric forklift.

[0013] According to another aspect of this application, a contactless wireless charging device for an electric forklift is also provided, comprising:

[0014] Compared to a ground-mounted wireless power transmitting module, the wireless power transmitting module includes a wireless power transmitting device; and

[0015] A wireless power receiving module installed on the body of an electric forklift includes a wireless power receiving device and a wireless power receiving controller. The wireless power receiving controller is configured to convert the energy sensed by the wireless power receiving device when it is aligned with the wireless power transmitting device into DC power output to selectively charge the power battery of the electric forklift. The wireless power receiving device includes a wireless receiving coil, which is arranged on a first mounting plate mounted on the overhead guard and / or bottom surface of the forklift body. The contactless wireless charging device also includes a warning device installed in the driver's cab of the electric forklift. The warning device is configured to issue a warning signal allowing wireless charging when the wireless power receiving device is aligned with the paired wireless power transmitting device.

[0016] Optionally, the first mounting base plate of the wireless power receiving device is mounted on the side of the vehicle body.

[0017] Optionally, the wireless power transmitter includes a wireless transmitting coil, which is arranged on a fixed second mounting plate. A photoelectric sensor is mounted on one of the second mounting plate of the wireless power transmitter and the first mounting plate of the wireless power receiver, and an optical device that reflects or emits light that can be detected by the photoelectric sensor is mounted on the other of the second mounting plate of the wireless power transmitter and the first mounting plate of the wireless power receiver. When the second mounting plate of the wireless power transmitter and the first mounting plate of the wireless power receiver are aligned with each other, the photoelectric sensor can detect the light reflected or emitted by the optical device to activate the warning device to generate a warning signal.

[0018] Optionally, the photoelectric sensor is at least two photoelectric sensors arranged at intervals, and the optical device is at least two optical devices arranged at intervals.

[0019] Optionally, the warning device includes the same number of indicator lights as the photoelectric sensor, which are activated and illuminate when the photoelectric sensor detects light.

[0020] Optionally, the wireless energy receiver controller is provided with an auxiliary power interface so as to generate power to the battery management system of the power battery before the DC power output of the power battery.

[0021] Optionally, the wireless power receiver controller is configured to periodically wake up the battery management system after the power battery of the electric forklift is fully charged, so that the battery management system automatically detects the current power level of the power battery after being woken up, and selectively sends a charging request command to the wireless power receiver controller based on the detection result of the current power level; or, the battery management system can be woken up using the key switch of the electric forklift.

[0022] By employing the aforementioned technical means of this application, users of electric forklifts can free their hands when charging them using contactless wireless charging equipment. Furthermore, during breaks, the power battery can be charged simply by parking the electric forklift at a wireless charging location, ensuring convenient and continuous operation. In addition, the contactless wireless charging equipment offers flexible placement and installation, facilitating effective use of the available charging environment. Moreover, aligning the wireless energy receiver of the electric forklift with the ground-based wireless energy transmitter is simple and easy, making it convenient for users to park and charge the forklift. Finally, the electric forklift's power battery can automatically charge, effectively extending its lifespan. Attached Figure Description

[0023] The principles and various aspects of this application will be more fully understood from the detailed description below in conjunction with the accompanying drawings. It should be noted that the scale of the drawings may vary for clarity, but this will not affect the understanding of this application. Furthermore, in the various drawings of this application, features with the same structure or similar function are indicated by the same reference numerals. In the drawings:

[0024] Figure 1 A perspective view of an electric forklift according to one embodiment of this application is schematically shown;

[0025] Figure 2 A perspective view of an electric forklift according to another embodiment of this application is schematically shown;

[0026] Figure 3A perspective view of an electric forklift according to another embodiment of this application is schematically shown;

[0027] Figure 4 A schematic diagram illustrating the basic principle of a contactless wireless charging device according to an embodiment of this application is shown; and

[0028] Figure 5A and Figure 5B The illustration schematically shows the alignment determination process of the wireless power transmitter and wireless power receiver of a contactless wireless charging device according to an embodiment of the present application. Detailed Implementation

[0029] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. However, it should be understood that the drawings are only used to illustrate this application and do not constitute a limitation on this application.

[0030] Figure 1 A perspective view of an electric forklift 100 according to one embodiment of this application is schematically shown. The electric forklift 100 generally includes a body 110 and a fork arm 120 that is vertically mounted relative to the body 110. For example, the fork arm 120 may be vertically mounted relative to the body 110 via a mast (not shown). A wheeled running gear is mounted in the body 110 and is driven by a motor. Alternatively or additionally, the fork arm 120 may also be driven by a separate motor. The motor of the electric forklift 100 is powered by a battery. Therefore, in the context of this application, the electric forklift 100 can be understood as a forklift that is powered entirely by a battery or a forklift in which only the running gear is powered by a battery.

[0031] like Figure 1 As shown, a roof guard 114 is provided on the vehicle body 110, located above the driver's cabin to provide personal protection. According to an embodiment of this application, a wireless power receiver 105 is arranged on the roof guard 114. For example, the wireless power receiver 105 may be a wireless receiving coil. In embodiments of this application, the wireless receiving coil can be constructed in a manner familiar to those skilled in the art, such as being arranged in a meandering, flat manner. For example, the wireless receiving coil can be arranged on a mounting plate 112, and the mounting plate 112 can be fixed to the roof guard 114 such that the wireless receiving coil faces outwards (upwards).

[0032] Further as Figure 1As shown, a suspended bracket 113 is provided. For example, the bracket 113 can be fixed to the ceiling (not shown) of the working charging site of the electric forklift 100, such that the height of the bracket 113 is above the overhead support 114. A wireless power transmitter 104 is arranged on the bracket 113. For example, the wireless power transmitter 104 can be a wireless transmitting coil. In the embodiments of this application, the wireless transmitting coil can be constructed in a manner familiar to those skilled in the art, such as being arranged in a meandering, flat manner. For example, the wireless transmitting coil can be arranged on a mounting plate 111, and the mounting plate 111 can be fixed to the bracket 113 such that the wireless receiving coil faces outward (downward).

[0033] Figure 4A schematic diagram of a contactless wireless charging device according to an embodiment of this application is shown. The contactless wireless charging device generally includes a wireless power transmitting module 001 and a wireless power receiving module 002. For example, the wireless power transmitting module 001 generally includes a wireless power transmitting device 104 and a wireless power transmitting controller 101, which are electrically connected to each other via a line so that electrical energy (e.g., alternating current capable of generating radio electromagnetic waves) can be regulated by the wireless power transmitting controller 101 and transmitted via the line to the wireless power transmitting device 104, and emitted outwards as wireless energy. It should be understood that the wireless power transmitting module 001 can be installed on the ground; for example, one part (containing the wireless power transmitting device 104) can be installed on a bracket 113 as described above, while another part (e.g., containing the wireless transmitting controller 101) can be installed at another location on the ground and connected to the wireless power transmitting device 104 via a line. The wireless power receiving module 002 generally includes a wireless power receiving device 105 and a wireless power receiving controller 102. The wireless power receiver controller 102 is electrically connected via cable 107 to the charging interface of the rechargeable power battery 103 (e.g., a lithium battery) of the electric forklift 100 using its dedicated interface. The wireless power receiver controller 102 is configured to connect via a line to the wireless power receiver 105 and convert the energy induced by the wireless electromagnetic waves emitted by the wireless power transmitter 104 into direct current, which is then transmitted via cable 107 to the power battery 103 for charging. In embodiments of this application, the output power of the wireless power receiver controller 102 can be set to 3 kW or greater. A battery management system (BMS) 106 is typically configured in the power battery 103. An auxiliary power interface 109 is configured in the wireless power receiver controller 102. For example, the auxiliary power interface 109 can supply power to the battery management system 106 via the same cable 107 or via a separate cable. The auxiliary power interface 109 can, for example, output 24V direct current (maximum output current 3A). According to an embodiment of this application, the wireless energy receiver controller 102 is configured to preferentially output a 24V DC voltage via the auxiliary power interface 109 after receiving wireless energy sensed by the wireless energy receiver device 105. This preferentially output 24V DC voltage can serve as a power source for the battery management system 106 of the power battery 103, enabling it to perform a self-test before charging the power battery 103. Furthermore, if the battery management system 106 receives power via the auxiliary power interface 109, it can be considered that the wireless energy receiver module 002 has started operating, allowing preparation for charging the power battery 103.

[0034] Furthermore, the battery management system 106 of the power battery 103 can also be electrically connected to the wireless energy receiving controller 102 via the CAN bus 108. This is for communication access between the wireless energy receiving controller 102 and the battery management system 106 after the battery management system 106 is powered through the auxiliary power interface 109. For example, the information for communication access may include, but is not limited to, commands from the battery management system 106 to the wireless energy receiving controller 102 to request to start or stop charging; commands from the battery management system 106 to the wireless energy receiving controller 102 to allow it to output the maximum charging voltage and charging current; information from the battery management system 106 regarding the current state of the power battery 103; information from the battery management system 106 regarding the total output current, maximum cell voltage, minimum cell voltage, maximum cell temperature, etc. of the power battery 103; information from the wireless energy receiving controller 102 regarding its charging voltage, charging current, current state, etc.; and other information that needs to be communicated. Those skilled in the art should understand that the configuration of the CAN bus 108 can be based on methods familiar in the fields of motor vehicles or electric forklifts.

[0035] According to one embodiment of this application, the wireless power receiver controller 102 can be configured with a first dry contact 121 and a second dry contact 122 to be linked with the operation of the electric forklift 100. In the embodiment described in this application, the first dry contact 121 can be a normally closed input dry contact, which allows the contactless wireless charging device to work and charge the power battery 103 when closed, and stops the contactless wireless charging device from working and prevents the power battery 103 from charging when closed; the second dry contact 122 can be a normally open output dry contact, used to control whether the battery management system 106 is powered. For example, when the second dry contact 122 is closed, the battery management system 106 can draw power from the power battery 103 and wake up from the dormant state. It should be clear that in order to achieve the basic purpose of this application, the first dry contact 121 can also be a normally open input dry contact and the second dry contact 122 can also be a normally closed output dry contact, and the working mode of the two can be adjusted accordingly. Therefore, the embodiments described below are merely illustrative and not restrictive.

[0036] Furthermore, in the following description of this application, the opening and closing actions of dry contacts 121 and / or 122 can be implemented manually or by using electromagnetic switching. According to an embodiment of this application, the first dry contact 121 can be implemented, for example, as a normally closed contact of a relay inside the electric forklift 100. The first dry contact 121 is used to switch the power battery 103 between a discharging state and a charging state. For example, when the first dry contact 121 is in the closed state, the power battery 103 is in the charging state; and when the first dry contact 121 is in the open state, the power battery 103 is in the discharging state. According to an embodiment of this application, when the electric forklift 100 moves to a designated wireless charging location, with the wireless power transmitter 104 and the wireless power receiver 105 aligned with each other, the user manually (e.g., rotates) adjusts the electric forklift's key switch 117 to the power-off position, causing the first dry contact 121 to close, thereby allowing the contactless wireless charging device to operate and charge the power battery 103. If the user manually (e.g., rotates) adjusts the electric forklift's key switch 117 to the power-on position, the first dry contact 121 is in the open state, thus stopping the charging of the power battery 103. The second dry contact 122 can be arranged, for example, in the power supply line between the auxiliary power interface 109 and the battery management system 106, so that when the second dry contact 122 is closed, the battery management system 106 can draw power from the power battery 103 and wake up from the dormant state.

[0037] According to an embodiment of this application, the battery management system 106 is configured to automatically enter a sleep state and stop sending and receiving communication messages via the CAN bus 108 after the power battery 103 has been fully charged for a period of time or after it has been idle for a long time without being discharged. While the battery management system 106 is in a sleep state, it can be woken up in two ways to charge the power battery 103. Firstly, when the key switch 117 of the electric forklift 100 is operated (e.g., changed from the power-off position to the power-on position and then back to the power-off position), the first dry contact 121 is closed again to allow charging of the power battery 103. In this case, the auxiliary power interface 109 of the wireless energy controller 102 resumes outputting 24V DC power, waking the battery management system 106 from its sleep state. Simultaneously, the wireless energy controller 102 detects whether the CAN bus 108 has received a command from the battery management system 106 requesting charging of the power battery 103. Secondly, the wireless power receiver controller 102 can be configured to periodically (e.g., according to a certain number of days or weeks) wake up the battery management system 106. For example, when the periodic timer expires, the second dry contact 122 is closed for 3 to 5 seconds to allow the battery management system 106 to draw power from the power battery 103 and be woken up, entering the startup self-test program. If the battery management system 106 detects that the auxiliary power interface 109 of the wireless power controller 102 outputs 24V DC power, and subsequently detects the information (message) sent by the wireless power controller 102 indicating that charging preparation is complete via the CAN bus 108, then the battery management system 106 controls the power battery 103 to enter the charging mode.

[0038] To ensure sufficient wireless energy is transferred from the wireless energy transmitter 104 to the wireless energy receiver 105 to charge the power battery 103, the projected area of ​​the coil of the wireless energy transmitter 104 is typically larger than that of the coil of the wireless energy receiver 105. For example, "projection" here refers to a vertical projection. Therefore, the projections of the wireless transmitting coil and the wireless receiving coil can be considered as vertical projections onto planes parallel to each other. To maximize wireless energy transfer, the wireless energy transmitter 104 and the wireless energy receiver 105 must be aligned before charging using a contactless wireless charging device. In the context of this application, alignment means that, when viewed in the projection plane, the entire projection plane of the coil of the wireless energy receiver 105 lies within the projection plane of the wireless energy transmitter 104, specifically, the geometric center of the former coincides with the geometric center of the latter. This ensures that most of the wireless energy emitted by the coil of the wireless energy transmitter 104 can be received by the coil of the wireless energy receiver 105, improving energy conversion efficiency.

[0039] According to an embodiment of this application, a wireless receiving coil, serving as a wireless power receiving device 105, is disposed on a mounting substrate 112, and a wireless transmitting coil, serving as a wireless power transmitting device 104, is disposed on a mounting substrate 111. Figure 1 Correspondingly, in the embodiments shown, Figure 5A and Figure 5B The diagram schematically illustrates the alignment determination process between the wireless power receiver 105 and the wireless power transmitter 104. It should be noted that... Figure 5A and Figure 5B In this context, XY can represent a plane in a planar coordinate system parallel to the ground, and the wireless power receiver 105 or its mounting base 112, as part of the electric forklift 100, can move as needed in the XY plane. Therefore, Figure 5A and Figure 5B It can also be considered as being with Figure 1 The top view corresponding to the illustrated embodiment. Figure 5A and Figure 5B This paper only schematically shows the wireless power receiver 105 and its mounting base 112, and the wireless power transmitter 104 and its mounting base 111, omitting other components of the contactless wireless charging device and the electric forklift 100. In the embodiments of this application, the mounting base 111 and mounting base 112 are substantially flat and have essentially the same shape to facilitate alignment. Furthermore, the geometric center of the wireless coil of the wireless power receiver 105 coincides with the geometric center of the corresponding mounting base 112, and the geometric center of the wireless coil of the wireless power transmitter 104 also coincides with the geometric center of the corresponding mounting base 111. Thus, if the mounting bases 111 and 112 overlap, it can be considered that the wireless coil of the wireless power transmitter 104 and the wireless coil of the wireless power receiver 105 are aligned. In the illustrated embodiment, the mounting bases 111 and 112 are substantially rectangular, particularly elongated. For example, on the side of mounting substrate 112 facing mounting substrate 111 during wireless charging, photoelectric sensors 118 and 119, capable of emitting and receiving light, are respectively mounted at both ends along at least one diagonal of its rectangle or rectangle; simultaneously, on the side of mounting substrate 111 facing mounting substrate 112 during wireless charging, reflectors 123 and 124 are respectively mounted at both ends along at least one diagonal of its rectangle or rectangle (which coincides or substantially coincides with the corresponding diagonal of mounting substrate 112 during wireless charging), such that when mounting substrates 111 and 112 overlap vertically, reflector 123 faces photoelectric sensor 118 and reflector 124 faces photoelectric sensor 119, thereby the light emitted by the photoelectric sensor is reflected by the reflector and then received by the photoelectric sensor. For example, in Figure 5AIn this process, when the electric forklift 100 has traveled to the designated wireless charging location, and as the wireless energy receiver 105 moves along direction A, gradually moving to be below and overlapping with the wireless energy transmitter 104, photoelectric sensors 118 and 119 emit light respectively. For example, photoelectric sensor 118 can be linked with indicator light 115 arranged inside the electric forklift 100, and photoelectric sensor 119 can be linked with indicator light 116 arranged inside the electric forklift 100. When photoelectric sensors 118 or 119 receive light reflected by the corresponding reflectors 123 or 124, they generate signals to excite indicator lights 115 or 116 to light up. Only when the driver of the electric forklift 100 sees indicator lights 115 and 116 lighting up simultaneously is the corresponding key switch 117 allowed to be operated to start the wireless charging process. If only one indicator light is lit, the driver can determine how to further move and adjust the position of the electric forklift 100 based on the position of the wireless power receiver 105 on the mounting base plate 112 represented by the lit indicator light and the posture of the electric forklift 100, so that the mounting base plate 111 and the mounting base plate 112 overlap and align with each other.

[0040] It should be understood that the above description is merely one feasible implementation for determining whether mounting substrates 111 and 112 are aligned with each other. Those skilled in the art can make any suitable modifications upon understanding the inventive spirit of this application. For example, in an alternative embodiment, reflectors 123 and / or 124 can be replaced by light-emitting elements, while photoelectric sensors 118 and / or 119 only have the function of detecting light. Thus, when light-emitting elements 123 and 124 are aligned with photoelectric sensors 118 and 119 respectively, photoelectric sensors 118 and 119 can cause indicator lights 115 and 116 in the driver's cockpit to illuminate based on the light detection of light from light-emitting elements 123 and 124. Additionally, in additional or alternative embodiments, indicator lights 115 and / or 116 can be connected to a buzzer for simultaneous operation or can be replaced by a buzzer to enhance the warning effect on the driver. Furthermore, the arrangement of the reflectors or light-emitting elements and photoelectric sensors is not limited to the embodiments shown and described, as long as the photoelectric sensors can generate signals instructing the indicator lights and / or buzzers to operate accordingly when mounting substrates 111 and 112 are aligned with each other. The aforementioned indicator lights and / or buzzers are merely non-limiting examples of warning devices; other components capable of alerting the driver may also be used as supplementary or alternative warning devices. Furthermore, when mounting bases 111 and / or 112 are non-rectangular, the aforementioned reflectors or light-emitting elements and photoelectric sensors may be mounted at other locations on the corresponding mounting bases, provided that the chosen mounting location facilitates alignment of the mounting base.

[0041] According to another additional or alternative embodiment of this application, such as Figure 2As shown, the wireless power receiver 105 and its mounting base 112 can be arranged on the bottom surface of the vehicle body 110 of the electric forklift 100, and the wireless power transmitter 104 and its mounting base 111 can be mounted on the ground, for example, partially buried in the ground so that the top surface of the wireless coil of the wireless power transmitter 104 is flush with the ground. In this way, when the contactless wireless charging device needs to start working for wireless charging, the mounting bases 111 and 112 should be approximately aligned with each other.

[0042] According to another additional or alternative embodiment of this application, such as Figure 3 As shown, the wireless power receiver 105 and its mounting base 112 can be arranged on the side of the vehicle body 110 of the electric forklift 100, and the wireless power transmitter 104 and its mounting base 111 can be fixed on the bracket 113 mounted on the ground, so that the wireless power transmitter 104 and its mounting base 111 are substantially perpendicular to the ground. Within the scope of this application, the side of the vehicle body 110 can be understood as the left and / or right side of the vehicle body 110. Thus, when the contactless wireless charging device needs to start working for wireless charging, the mounting bases 111 and 112 should be substantially aligned with each other.

[0043] According to a preferred embodiment of this application, when mounting substrates 111 and 112 are aligned with each other in preparation for wireless charging, the vertical distance between the wireless coil of the wireless power transmitter 104 and the wireless coil of the wireless power receiver 105 is maintained approximately between 20 mm and 45 mm to ensure efficient electromagnetic wave transmission. Furthermore, in the context of this application, alignment between mounting substrates 111 and 112, or alignment between their geometric centers, can also mean that their geometric centers fall within a predetermined range. For example, if their geometric centers fall within a radius of 25 mm to 40 mm, it can also be considered that mounting substrates 111 and 112 are aligned with each other.

[0044] According to one embodiment of this application, the contactless wireless charging device can be configured to periodically charge the power battery 103. For example, when the electric forklift 100 is parked in the wireless charging location and the mounting bases 111 and 112 are aligned (i.e., the wireless coil of the wireless energy transmitter 104 and the wireless coil of the wireless energy receiver 105 are aligned with each other), as described above, the key switch 117 is adjusted to the power-off position so that the wireless energy receiver controller 102 charges the power battery 103. If the power battery 103 is 100% charged and maintains a low charging current for a predetermined period of time, the battery management system 106 can automatically enter a sleep state, in which case the communication connection with the CAN bus 108 is disconnected.

[0045] If the electric forklift 100 has been parked in a wireless charging location for an extended period of time without use, the contactless wireless charging device, such as its wireless energy receiver controller 102, can be configured to periodically (e.g., on a number of days or weeks) wake up the battery management system 106, for example, by closing the second dry contact 122 for 3 to 5 seconds. The battery management system 106 can be configured to automatically detect the current charge level of the power battery 103 after being woken up. If the current charge level is lower than a predetermined value, the battery management system 106 can send a charging request command to the wireless energy receiver controller 102 via the CAN bus 108. Subsequently, the wireless energy receiver controller 102 charges the power battery 103 until it is 100% fully charged again. This cycle is repeated to prevent severe power degradation of the power battery 103 after the electric forklift 100 has been idle for a long time, which would affect the user's ability to use the vehicle again, and to effectively extend the lifespan of the power battery.

[0046] Although specific embodiments of this application are described in detail herein, they are provided for illustrative purposes only and should not be construed as limiting the scope of this application. Furthermore, those skilled in the art will understand that the various embodiments described herein can be used in combination with each other. Various substitutions, modifications, and alterations can be conceived without departing from the spirit and scope of this application.

Claims

1. An electric forklift (100), comprising: A wireless energy receiving module (002) is installed on the body (110) of an electric forklift (100). The wireless energy receiving module (002) includes a wireless energy receiving device (105) and a wireless energy receiving controller (102). The wireless energy receiving controller (102) is configured to convert the energy sensed by the wireless energy receiving device (105) when it is aligned with a paired wireless energy transmitter (104) into direct current output, selectively supplying power to the electric forklift (100). Charging of the power battery (103), characterized in that the wireless energy receiving device (105) includes a wireless receiving coil, and the wireless receiving coil is arranged on a first mounting plate, the first mounting plate being mounted on the overhead guard (114) and / or the bottom surface of the vehicle body (110), and a warning device is provided in the driver's cab of the electric forklift (100), the warning device being configured to issue a warning signal allowing wireless charging when the wireless energy receiving device (105) is aligned with the paired wireless energy transmitting device (104).

2. The electric forklift (100) according to claim 1, characterized in that, The first mounting plate of the wireless power receiving device (105) is mounted on the side of the vehicle body (110).

3. The electric forklift (100) according to claim 1 or 2, characterized in that, The wireless power transmitter (104) includes a wireless transmitting coil, which is arranged on a fixed second mounting plate. A photoelectric sensor is mounted on one of the second mounting plate of the wireless power transmitter (104) and the first mounting plate of the wireless power receiver (105), and an optical device that reflects or emits light that can be detected by the photoelectric sensor is mounted on the other of the second mounting plate of the wireless power transmitter (104) and the first mounting plate of the wireless power receiver (105). When the second mounting plate of the wireless power transmitter (104) and the first mounting plate of the wireless power receiver (105) are aligned with each other, the photoelectric sensor can detect the light reflected or emitted by the optical device to activate the warning device to generate a warning signal.

4. The electric forklift (100) according to claim 3, characterized in that, The photoelectric sensor is at least two photoelectric sensors arranged at intervals, and the optical device is at least two optical devices arranged at intervals.

5. The electric forklift (100) according to claim 4, characterized in that, The warning device includes the same number of indicator lights as the photoelectric sensor, which are activated and illuminate when the photoelectric sensor detects light.

6. The electric forklift (100) according to claim 5, characterized in that, The wireless power receiver controller (102) is provided with an auxiliary power interface (109) so as to generate power to the battery management system (106) of the power battery (103) before the DC power output of the power battery (103).

7. The electric forklift (100) according to claim 6, characterized in that, The wireless power receiver controller (102) is configured to periodically wake up the battery management system (106) after the power battery (103) of the electric forklift (100) is fully charged, so that the battery management system (106) automatically detects the current power level of the power battery (103) after being woken up, and selectively sends a charging request instruction to the wireless power receiver controller (102) based on the detection result of the current power level; or, the battery management system (106) can be woken up by the key switch (117) of the electric forklift (100).

8. A contactless wireless charging device for an electric forklift (100), comprising: Relative to a ground-mounted wireless power transmission module (001), the wireless power transmission module (001) includes a wireless power transmission device (104); and A wireless energy receiving module (002) is installed on the body (110) of an electric forklift (100). The wireless energy receiving module (002) includes a wireless energy receiving device (105) and a wireless energy receiving controller (102). The wireless energy receiving controller (102) is configured to convert the energy sensed by the wireless energy receiving device (105) when the wireless energy receiving device (105) is aligned with the wireless energy transmitting device (104) into DC power output, so as to selectively supply power to the power battery (103) of the electric forklift (100). The charging device is characterized in that the wireless energy receiving device (105) includes a wireless receiving coil, and the wireless receiving coil is arranged on a first mounting plate, the first mounting plate being mounted on the overhead guard (114) and / or the bottom surface of the vehicle body (110), and the contactless wireless charging device further includes a warning device disposed in the driver's cab of the electric forklift (100), the warning device being configured to issue a warning signal allowing wireless charging when the wireless energy receiving device (105) is aligned with a paired wireless energy transmitting device (104).

9. The contactless wireless charging device according to claim 8, characterized in that, The first mounting plate of the wireless power receiving device (105) is mounted on the side of the vehicle body (110).

10. The contactless wireless charging device according to claim 8 or 9, characterized in that, The wireless power transmitter (104) includes a wireless transmitting coil, which is arranged on a fixed second mounting plate. A photoelectric sensor is mounted on one of the second mounting plate of the wireless power transmitter (104) and the first mounting plate of the wireless power receiver (105), and an optical device that reflects or emits light that can be detected by the photoelectric sensor is mounted on the other of the second mounting plate of the wireless power transmitter (104) and the first mounting plate of the wireless power receiver (105). When the second mounting plate of the wireless power transmitter (104) and the first mounting plate of the wireless power receiver (105) are aligned with each other, the photoelectric sensor can detect the light reflected or emitted by the optical device to activate the warning device to generate a warning signal.

11. The contactless wireless charging device according to claim 10, characterized in that, The photoelectric sensor is at least two photoelectric sensors arranged at intervals, and the optical device is at least two optical devices arranged at intervals.

12. The contactless wireless charging device according to claim 11, characterized in that, The warning device includes the same number of indicator lights as the photoelectric sensor, which are activated and illuminate when the photoelectric sensor detects light.

13. The contactless wireless charging device according to claim 12, characterized in that, The wireless power receiver controller (102) is provided with an auxiliary power interface (109) so as to generate power to the battery management system (106) of the power battery (103) before the DC power output of the power battery (103).

14. The contactless wireless charging device according to claim 13, characterized in that, The wireless power receiver controller (102) is configured to periodically wake up the battery management system (106) after the power battery (103) of the electric forklift (100) is fully charged, so that the battery management system (106) automatically detects the current power level of the power battery (103) after being woken up, and selectively sends a charging request instruction to the wireless power receiver controller (102) based on the detection result of the current power level; or, the battery management system (106) can be woken up by the key switch (117) of the electric forklift (100).

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