PL245376B1 - Rewinding device for an electric vehicle charging cable - Google Patents

Abstract

The subject of the application is a winding device for the charging cable of an electric vehicle, containing a reel with a cross-section H, rotatably mounted on a stationary axis, on which the charging cable terminated with a plug is wound, equipped with a spring cooperating with the reel, in which on one outer side wall (8b) of the reel (1 ) a spiral (13) is grooved, having a number of turns equal to the number of revolutions of the reel (1) needed to unwind the entire charging cable (2), leading during the rotation of the reel (1) to the pin of the slider (14) moved along the rail (15) integrated with the end of the axis ( 3), which, after the charging cable (2) is fully unwound, comes into contact in its extreme position B with the microswitch arm (16) connected to the charging cable (2).

Description

Description of the invention

The subject of the invention is a rewinding device for the charging cable of an electric vehicle.

From the article by Małgorzata Kaliczyńska in Automatyka 5-6/2020, December 22, 2020, https://automatykaonline.pl/Artykuly/Enerqia/Elektromobilnosc-o-problemach-ladowania, it follows that according to the Electromobility Counter launched by the Polish Alternative Fuels Association and the Polish Automotive Industry Association, at the end of April 2020, there were 11,132 electric passenger cars on Polish roads: 6,267 BEH cars (56%), 4,865 PHEV cars, i.e. plug-in hybrids that can be charged from an external source. As the number of vehicles increases, public charging infrastructure is also developing. At the end of April 2020, there were 1,131 electric vehicle charging stations (2,106 points) in Poland. 32% of them were fast DC charging stations, and 68% were slow AC chargers with a power of less than or equal to 22 kW.

Many organizations are working on documents standardizing the physical, electrical and functional properties of EV/PHEV charging systems, including: Institute of Electrical and Electronics Engineers (IEEE), Society of Automotive Engineers (SAE) and International Electrotechnical Commission (IEC). The most popular SAE J1772 standard defines several charging levels, the most common of which are:

• level 1 - allows slow charging in vehicle owners' garages, most often at night; all EV/PHEV cars should be adapted to this charging mode, because it does not require special external equipment;

• level 2 - used for commercial vehicle charging in workplaces and larger groups of cars - called semi-fast mode;

• fast charging - ensures the comfort of a long range of vehicles; used in public places with the largest concentrations of vehicles, such as parking lots and shopping centers.

Achieving the presented charging power levels requires appropriate charging systems. Charging systems are classified into on-board and external chargers, wireless charging systems and battery replacement systems.

Additionally, chargers can be divided into chargers with unidirectional or bidirectional power flow. Chargers with unidirectional energy conversion only allow charging the battery banks, while bidirectional ones also enable the transfer of energy stored in the batteries to the power grid or to another vehicle.

Wired charging systems include on-board and external chargers. The on-board solution is dominated by level 1 chargers with a power of 1.4 kW and level 2 chargers with a power of approximately 3.3 kW. Manufacturers strive to make 6.6-7.0 kW on-board chargers the standard, which enable batteries to be charged in a much shorter time. External chargers are designed for fast charging of vehicles and DC charging dominates with an output power of 40-60 kW.

All batteries, including those used in electric vehicles, use direct current for charging and discharging, while the electrical grid supplies alternating current. Charging systems can be implemented using DC or AC alternating current.

When charging with alternating current, the AC/DC converter is located in the electric vehicle, where alternating current is converted into direct current needed to charge the batteries. When charging with direct current, the AC/DC current conversion takes place in the charger, hence direct current is supplied directly to the electric vehicle. Depending on charging with direct or alternating current, different types of connectors are used to ensure communication between the charger and the vehicle.

From the article entitled Compendium of knowledge - Safe charging of electric cars of November 26, 2021, in: Knowledge base, available at https://electromobilitv.one/baza-Wiedzv/kompendium-wiedzy-bezpieczne-ladowanie-szkolow-elektricznych/ shows that home stations charging electric and hybrid PHEV vehicles must have a number of anti-shock and anti-overvoltage protections to be safe for the user and the electrical installation. Like any electrical device, a charging station must meet a number of standards to be approved for use. An improperly constructed and secured station may prove dangerous both for the user and for the electrical installation to which it is connected. In case of direct danger to the user, we are talking primarily about electric shock and fire. It is extremely important that both the station and the electrical installation are equipped with the necessary switches that will disconnect the voltage quickly enough in the event of a failure. It is worth paying attention to high-quality materials used in the production of charging stations, which eliminate the possibility of overheating the cables or burning the contacts, which may consequently cause a fire. When we talk about the impact on the electrical installation, we have two main threats:

1) network overload - this means that the current consumed by the connected device, e.g. a charging station, exceeds the capacity of the electrical installation and will cause the overcurrent fuse to turn off;

2) DC leakage - if an electric car is connected, the system must be protected against DC leakage. When faults occur in an electric car, such as damage to the insulation of the DC installation wires or damage to the built-in power electronics, direct current may appear in the network. It will damage the residual current circuit breaker in the electrical installation, which in the event of electric shock may result in serious health consequences or even death of the user. The RCD switch will protect us against this threat, as it will disconnect us from the dangerous voltage.

Charging stations must be equipped with a number of functionalities to ensure operational safety:

- real-time continuity test of the protective conductor,

- verification of correct connection of the vehicle to the charging station,

- possibility of applying voltage to the station output only after the vehicle is properly connected,

- switching off the voltage at the station output after a control circuit failure or providing information about the maximum allowable charging current to the charged vehicle.

Additionally, the system must be equipped with a residual current device that disconnects the power supply when a DC leakage is detected. The regulations and standards do not specify whether such a switch must be on the side of the charging station or the electrical installation.

Charging stations offer additional functionalities, including:

- real-time network load control (allows you to avoid network overload by automatically reducing the charging power)

- network check before charging (after automatically checking the network, the station starts charging with a power adjusted to the capabilities of the electrical installation)

- temperature control of station components and disconnection in case of overheating.

When charging electric cars, a signal is sent to the vehicle informing about the double-sided connection of the charging cable. This allows you to start the charging process. Winding the charging cable onto a special spool generates the risk of heating the charging cable if current starts to flow through it when it is mostly wound on the spool.

Application description P.406472 indicates that numerous devices and methods for winding threads, strings and electric cables are known. In the case of electrical cables that must remain connected during rewinding, the problem is ensuring electrical contact while the drum rotates. Often the end of the cable inside the drum must remain in electrical connection with the connector, which is stationary, as the drum rotates. Typically, this problem is solved in three ways. The first is the use of rotary connectors, the second is the simultaneous winding of two cables, and the third solution involves the use of at least two drums, with one drum rotating around the other while rotating around its own axis.

From the patent description PL192599 there is known a winding device, especially for hoses and/or cables, comprising a rotary member rotating during unwinding or winding of the hose and/or cable, equipped with a spring device cooperating with the rotary member, the spring device being stretched when the member rotates. rotary in the unwinding direction when pulling the hose and/or cable from the reeling device, and when winding the hose and/or cable on the reeling device, after pulling the hose and/or cable from the reeling device, the spring device imparts rotational movement of the rotary member in the winding direction, characterized in that it further comprises a braking device for reducing the rotational speed of the rotating member in the winding direction, comprising at least one electric power generating machine connected in a motion transmission system to a rotating member driving said electric machine upon rotation of the rotating member under the action of the spring device in the winding direction winding, and at least one electric loading device connected to the electric machine, receiving and absorbing the electrical energy generated by the electric machine. Preferably, the rotating member is in the form of a drum on which a hose and/or cable is preferably wound. The rotating member in the form of a drum may have a gear ring placed adjacent to the peripheral part of the drum, and the electric machine may have a gear wheel on the output shaft, this gear wheel being connected to the gear ring in the motion transmission system.

The purpose of the invention described in application description CN112659951A is, among others, eliminating the influence of humidity on the elements of electric vehicle charging stations. This problem was solved by temperature and humidity sensors, a fan installed on an inclined support plate and a thermal insulating coating on the protective cover.

From application description CN111376726, a disconnecting device for the charging inlet of an electric vehicle battery is known, including: a housing, a handle installed in the cover and an emergency disconnection cable, one side of which is connected to the handle and the other side is connected to the emergency disconnection lever. As the handle is rotated, the emergency disconnect cable is pulled and the emergency disconnect lever is rotated to release the stop at the outlet. When the emergency disconnect lever is rotated, the stopper lug is released. The handle is inserted into the mounting part of the handle and rotated in the mounting part of the handle, and the handle returns to its starting position after being activated by the spring in the handle. The user can easily disconnect the charging in an emergency situation by pressing the handle.

From the application description WO2011054752A2, a device for electrically connecting an electric vehicle to a power point is known, comprising a cable winding unit having a drum mounted rotatably on a supporting structure, a rotary drive for the drum and a power transmission device integrated in the drum. The rotary drive is created by an electric motor, properly controlled in the direction of rotation, which is coupled to the drum via a gear transmission. In a simpler embodiment, the rotary drive is a tension spring. The charging cable moved by the rotation of the drum is connected via a power transfer device to a connecting cable which is held rotatably and connected to the battery. Cables have at least two current-carrying charging lines. The cable winding assembly may have an oscillator that can be moved toward the drum axis on the guide to wind the charging cable in an orderly manner. The oscillator is equipped with a hole for the charging cable and is forcibly guided by the control element on a rotating guide.

To control the winding process, the rotational movement of the cable winding assembly may be blocked or released by a latch or other mechanical release means. It is also possible to control it by pulling a cord or possibly by remotely controlled electric release means. The cable rewind assembly may have a safety device that monitors the charging current or temperature on the charging cable and interrupts charging if necessary.

Application CN112172557A discloses a charging cable connection device comprising an H-shaped spool having a socket on one side surface and an outer rotating ring connected to the outside of the side wall on the same side of the spool, with a plug mounted inside the socket. One end of the charging cable is wound and fixed on the outer wall of the reel, and the other end of the charging cable is permanently connected to the manual plug connector. The device is equipped with a return spring. The drive motor is mounted inside the spool cavity on the shaft.

From the description of utility model CN205076568, a portable device for charging an electric vehicle with a winding locking pawl is known, which includes a drum for winding the vehicle's power cable, mounted in a housing. The drum is electrically driven and is also equipped with a pawl and a spring. During charging, the vehicle's power cable is stretched and the drum is forced to transfer force to the pawl through the pawl teeth. The engagement between the pawl and the drum causes the drum to rotate clockwise under force, the spring is compressed, and the vehicle power cable is wound around the drum in the pull-out direction. Once charged, when the vehicle's power cable needs to be coiled, it is stretched to rotate the drum and the pawl disengages from engagement with the drum. Under the action of the torsional force of the spring, the drum rotates counterclockwise.

Currently, there are no solutions that allow for a safe and automatic way to eliminate the risk of heating the charging cable while winding it, if electricity starts flowing through it when it is mostly wound on the spool.

The purpose of the invention is to solve the technical problem of eliminating the risk of heating the charging cable while winding it, if current starts to flow through it when it is mostly wound on the spool.

The above purpose is achieved by a winding device for the charging cable of an electric vehicle, containing a reel with a cross-section H, rotatably mounted on a stationary axis, on which the charging cable terminated with a plug is wound, equipped with a spring cooperating with the reel, characterized according to the invention in that on one external side wall of the reel there is a grooved spiral with a number of turns equal to the number of revolutions of the reel needed to unwind the entire charging cable, leading during the reel's rotation to the pin of the slider moved along the rail integrated with the end of the axis, which, after the charging cable has been fully unwound, in its extreme position B, comes into contact with the microswitch arm connected to the charging cable .

Preferably, a spring is attached to the slider on the axis side.

Preferably, on the second outer side wall of the reel, a spring is connected to the other end of the axis, which is tensioned during unwinding of the charging cable.

Preferably, a ratchet mechanism is located on the second external side wall of the spool, consisting of a protrusion made in the spool wall and a tooth mounted on the housing.

Thanks to the use of a mechanism in the device according to the invention that allows the flow of a signal that starts charging the electric vehicle only after the entire charging cable has been unwound, the risk of the charging cable heating up during its rewinding is eliminated if current starts to flow through it when it is mostly wound on the spool.

The invention is illustrated in the drawing, in which Fig. 1 shows a side view of the winding device in the housing; Fig. 2a shows a side view of the spool with a ratchet mechanism; Fig. 2b shows a side view of the spool with a ratchet mechanism closed by a cover; Fig. 3a shows a front view of the spool with the disconnect mechanism; Fig. 3b shows the spool with the disconnection mechanism in longitudinal section; Fig. 3c shows a section of the longitudinal section of the spool with the disconnection mechanism; Fig. 4a shows a side view of the disconnect mechanism with a slider; Fig. 4b shows a front view of the disconnect mechanism with a slider; Fig. 5a shows the microswitch in the on position; Fig. 5b shows the microswitch in the disconnected position; Fig. 6 shows a winding device connected to a vehicle charging station; Fig. 7 shows the connection of the charging cable to the microswitch.

The winding device has a reel 1 with a cross-section H with a charging cable 2 wound on it. The reel 1 is mounted on bearings and rotatably mounted on a stationary axis 3. The charging cable 2 is wound onto the reel 1, terminated on one side with a plug 4 connected to the vehicle's socket, and on the other passing through a hole in axis 3 - ending with a plug 5 integrated with the housing 6, connected to the charging station.

The housing 6 has a recess 7 for a plug 4 connected to the vehicle's socket.

On the outer side wall 8a of the spool 1, a spring 9 is connected to the axis 3, which is tensioned while unwinding the charging cable 2. After releasing the charging cable 2, the spring 9 causes rotation of the spool 1 in the opposite direction, allowing it to be wound again. The connection of the spring 9 with the axis 3 is protected by a cover 10.

On the same side wall 8a, there is a ratchet mechanism consisting of a protrusion 11 made in the wall 8 of the spool 1 and a tooth 12 mounted on the casing 6. During the rotation of the spool 1, every one full revolution, the tooth 12 may get stuck in the protrusion 11 of the wall 8a of the spool 1 causing a blockage to prevent the charging cable from winding up 2.

On the outer side wall 8b of spool 1, a spiral 13 is grooved, leading to the pin of the slider 14. The number of turns of the spiral 13 is equal to the number of revolutions of the reel 1 needed to unwind the entire charging cable 2. The slider 14 is placed on a rail 15 integrated with the other end of the axis 3, along which moves, pushed by the spiral 13, during the rotation of the spool 1. In its extreme position B, the slider 14 contacts the arm of the microswitch 16, attached to the frame 17 of the rail 15, closing the circuit and thus allowing the flow of the signal that starts the charging process. Similarly, when winding the charging cable 2, the slider 14 moves in the opposite direction, releasing the microswitch arm 16. The slider 14 has two extreme positions: A and B. In position A of the slider 14, the entire charging cable 2 is wound on the spool 1. In position B charging cable 2 is fully extended and microswitch 16 is turned on.

A spring 18 is attached to the slider 14 on the side of axis 3, which prevents the slider pin 14 from losing contact with the spiral 13 when the slider 14 is in the extreme position A. The device allows the integration of the cable reel with a charger for electric cars. To use the device, connect it to the charging station with the plug 5 integrated in the housing 6. Then, remove the plug 4 from the recess 7 in the housing 6, unwind the charging cable 2 and connect it to the car socket. The charging start signal is provided by the CP cable connected to the microswitch 16, which is one of the cores of the main charging cable 2.

Claims (4)

Patent claims 1. A winding device for the charging cable of an electric vehicle, comprising a reel with a cross-section H, rotatably mounted on a stationary axis, on which the charging cable terminated with a plug is wound, equipped with a spring cooperating with the reel, characterized in that on one outer side wall (8b) of the reel ( 1) a spiral (13) is grooved, having a number of turns equal to the number of revolutions of the reel (1) needed to unwind the entire charging cable (2), leading during the rotation of the reel (1) to the pin of the slider (14) moved along the rail (15) integrated with the end of the axis (3), which comes into contact after the charging cable (2) is fully unwound in its extreme position B with the microswitch arm (16) connected to the charging cable (2). 2. The device according to claim 1. 1, characterized in that a spring (18) is attached to the slider (14) from the side of the axis (3). 3. The device according to claim 1 or 2, characterized in that on the second outer side wall (8a) of the spool (1) a spring (9) is connected to the other end of the axis (3) and is tensioned during unwinding of the charging cable. 4. The device according to claim 1 or 2 or 3, characterized in that on the second outer side wall (8a) of the spool (1) there is a ratchet mechanism consisting of a protrusion (11) made in the wall (8a) of the spool (1) and a tooth (12) mounted on the housing (6).