Contact unit

Abstract

To provide: a contact unit for power supply which facilitates power supply to a mobile body regardless of indoor use or outdoor use; and a probe for maintenance therefor.SOLUTION: In a power supply system, a slot 6 is provided in a central part of a charger 1, and the slot 6 is closed by a movable wall 29. The charger 1 per se is an insulator, and the movable wall 29 is a metal body but is not electrified. The contact unit is placed on a street and even if a person touches it, no electric shock occurs. Since the slot 6 is closed, no dust or the like enters the contact unit. A rubber packing, brush and the like may be attached as needed to a periphery of the slot 6 or the movable wall 29. Upon receiving an external force, the movable wall 29 is passively or positively pulled in, and a power transmission electrode 5 on a sidewall of the slot is visible. Normally, since the movable wall is closed, it is not possible for a person to insert dust or touch the power transmission electrode 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply contact unit that makes it easy to supply power to a moving object, whether indoors or outdoors. [Background technology]

[0002] Advances in AI technology have made it possible to recognize the contents of image data. With the advent of this technology, mobile devices will be able to operate autonomously. AI itself requires power, and in terms of controllability, batteries and motors are the most suitable driving method. As such, autonomously acting EVs, drones, and robots with various functions (delivery, cleaning, security, etc.) will fill our streets, and society is expected to change dramatically.

[0003] To achieve this, an infrastructure for charging batteries is required. What is required of the infrastructure is rapid charging, making it possible to charge a large amount of energy in a short time. Furthermore, this infrastructure must be able to operate in outdoor environments such as coastal regions where it is exposed to sea breezes. To achieve this, it is necessary to maintain the cleanliness of the electrode surface, prevent oxidation to enable contact with low resistance, and maintain the electrode performance to allow a large current to flow. If a large number of such things are deployed as standardized power supply stations in cities, on roads, etc., the main environmental requirements for mobile devices to be able to operate actively will be met. This power supply infrastructure must also meet the system requirements of recognizing the ID of each mobile unit, charging it, and enabling communication with a center or other mobile units.

[0004] In order to realize such a power supply infrastructure with low cost and high reliability, it is necessary to make polarity selection easier by specifying the shape. A slot is used as the shape. When the slot is placed vertically, the polarity is specified by the left and right of the insertion probe, and when the slot is placed horizontally, the polarity is specified by the top and bottom of the insertion probe. This eliminates the need for extra sensors, switches, and mechanisms for polarity selection, leading to low cost and high reliability. Furthermore, in outdoor environments where people are present, it is necessary to consider safety for people and to devise ways to prevent people from easily inserting trash or other tampering. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2014-143912 [Non-patent literature]

[0006] [Non-Patent Document 1] e-Mobility Power Initiatives (June 4, 2021) Summary of the Invention [Problem to be solved by the invention]

[0007] However, in conventional technologies including Reference 1, the contacts of the connector are simply metal-to-metal contacts, and the contact is via an oxide film and surface irregularities, so the resistance does not decrease. This causes heat generation during fast charging, leading to a decrease in energy efficiency. In particular, with the emergence of all-solid-state batteries capable of fast charging, which are being rapidly developed, there is a demand for performance that allows a large amount of energy to be charged into the battery in a short period of time, but this has not been fully addressed. Furthermore, the present invention aims to provide a simple, highly reliable, safe and automatic power supply port that can easily and quickly charge not only EVs but also other moving objects outdoors.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an outdoor installation terminal technology that revises the conventional contact-type power supply technology and enables rapid charging by passing a large current through a simple, low-contact resistance contact method of inserting a probe into a slot. [Means for solving the problem]

[0009] In order to achieve the above object, the power supply connector according to the present invention comprises: The polarity of the power transmission electrode is determined based on the position of the slot relative to the ground. a probe having a power receiving electrode that is inserted into the slot having the power transmitting electrode and that contacts the power transmitting electrode; The power transmitting electrode and the power receiving electrode are provided with low melting point metal on their surfaces, The contact resistance can be greatly reduced by the pressing mechanism that presses the electrode of the inserted probe against the electrode of the slot. The electrodes are less likely to become dirty from dust and other foreign matter in the atmosphere, and even if they do become dirty, they can be washed, and the oxide film on the electrode surface can be removed. Effect of the Invention

[0010] Conventional EV charging terminals have long power supply paths, use low contact pressure contacts, and do not control the metal oxide film, so the resistance stops decreasing and heat is generated. Furthermore, since they are inserted manually, they are not compatible with autonomous EVs. On the other hand, the application of non-contact power supply technology is also being considered, but because it uses magnetic coupling, the leakage magnetic field is large and has an impact on the environment, so the output is limited. Furthermore, the use of inverters and rectifiers makes the system larger and costs more. Copper is used for the coils, but the surplus of copper resources is low, so it is thought that it will not be possible to unify the entire world with non-contact power supply methods. On the other hand, although battery performance has improved and rapid charging capabilities are required, conventional methods generate heat and require the addition of cooling systems, which reduces energy efficiency. Furthermore, there is a growing need for power supply in cities not only for EVs but also for drones, delivery robots, AGVs, etc., and there is a demand for power sources that are suitable for outdoor use, have rapid charging capabilities, are low cost, are safe, are easy to operate, are non-radioactive, and consume low copper resources. The proposed invention satisfies these requirements in the connector section and can be used in conjunction with an existing power unit. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 shows the appearance of a slot-type power supply unit (embodiment). [Diagram 2] 2 shows an embodiment showing a variation of FIG. 1. [Diagram 3] FIG. 1 shows an example of a method for inserting a probe into a moving object. [Figure 4] This shows the most simplified embodiment of FIG. [Diagram 5] FIG. 4 shows an embodiment in which a movable wall is added. [Figure 6] This shows how the movable wall in Figure 5 has been given the ability to brush electrodes. [Figure 7] This shows how the function of reducing electrodes has been added to the movable wall in Figure 5. [Figure 8] FIG. 7 shows the process of refilling the electrolyte. [Figure 9] The operation of the maintenance probe to replace the electrolyte and liquid metal is described for the device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, a charger 1 of a power supply system will be described with reference to Fig. 1. In Fig. 1(a), a slot 6 is opened in the center of the charger 1, and the slot 6 is blocked by a movable wall 29. The charger 1 itself is an insulator, and the movable wall 29 is a metal body, but is not electrified. If placed in the street, people will not receive an electric shock even if they touch it, and because the slot 6 is blocked, no dust or the like can get in. Although not shown in the figure, rubber packing or brushes or the like are assumed to be attached around the slot 6 or the movable wall 29 as necessary. In Fig. 1(b), the moving wall 29 is passively or actively retracted by an external force, and the power transmitting electrode 5 on the side wall of the slot is visible. Normally, the moving wall is closed, so that a person cannot insert garbage or touch the power transmitting electrode 5.

[0013] FIG. 2 shows a variant of the device of the present invention. 2(a1), a power receiving probe 14 can be pushed out and retracted into a moving body 2 by a driving mechanism 24. Power receiving electrodes 13 with opposite polarities are provided on both sides of the tip of the probe. This probe 14 is inserted into the slot 6 of the charger 1 and pushed in until the power receiving electrode 13 overlaps with the power transmitting electrode 5. After being pushed in, the power transmitting electrode and the power receiving electrode are brought into close contact with each other by the pressure mechanism 4A. When FIG. (a1) is viewed as a side view, the charger 1 has the slot 6 standing vertically as shown in FIG. (a2), and the polarity of the transmission electrode 5 in the slot 6 can be predetermined as being on the right or left side with respect to the horizontal plane. When FIG. (a1) is viewed as a plan view, the charger 1 has a horizontal slot as shown in FIG. (a3), and the polarity of the power transmission electrodes in the slot can be predetermined by the top and bottom.

[0014] In Fig. 2(b1), the probe 14 is stored in a rotating manner and can be swung down from top to bottom. As shown in Fig. 2(b2) or (b3), the opposing charger 1 has a slot at a right angle to the corner of the charger 1, and the installation position is different when it is horizontal and when it is vertical.

[0015] In Fig. 2(c1), the probe 14 is stored in a rotating manner and swings up from the bottom. The opposing charger 1, as shown in Fig. 2(c2) or (c3), has a slot on the underside of the charger 1 that can store a vertically rotating one or a horizontally rotating one. The existence of such derived forms will be explained below. In addition, in FIG. 2, the probe 14 is attached to the moving object 2 and the slot 2 is provided in the charger 1, but this may be reversed and the slot may be attached to the moving object and the probe to the charger.

[0016] The following description will be given taking the probe configuration shown in FIG. 1 as an example. In FIG. 3, the moving body 2 has a sensor 15, and images are recognized by AI or the like in the moving body control device 20, and the moving body 2 moves by controlling the individually controlled Mecanum wheels 18. In particular, when power supply is required, the slot 6 of the charger 1 is recognized and the probe 14 is moved to a position where it can be inserted into the slot 6 . Thereafter, the probe 14 is inserted into the slot 6 using the drive mechanism 24 . When the probe 14 is inserted into the charger 1, the push switch 7 is turned on and the pressure controller 4 activates the pressure mechanism to sandwich the power receiving electrode 13 on the probe side between the power transmitting electrode 5, completing the close contact between the electrodes. Thereafter, the converter 11 and the inverter 10 are operated in response to a command from the charger controller 3, and DC power is transmitted via the rectifier 9. When power is supplied from the inserted probe 14 , the moving object 2 charges the storage battery 21 via the battery charger 23 and the BMS 22 . When charging is completed, a command is sent from the BMS 22 to the mobile unit controller 20, which in turn sends a command to the charger 1 via the probe to stop power transmission, and the pressing mechanism is released so that the probe 14 can be removed. After confirming that power transmission has been stopped, the mobile object 2 retracts the probe 14 and moves on to carry out the next task. These are the series of operations. Signal exchange is not shown in this diagram, but will be explained in the next Figure 4. In this explanation, the power supply system on the charger 1 side is described, but this is just an example and the present invention is not limited to this system. A control system using the Mecanum wheel 18 on the moving body 2 side has also been described, but this is also just one example and the present invention is not limited to this system.

[0017] FIG. 4 mainly describes the case where the probe 14 is inserted into and removed from the slot 6. The mobile object 2 has a mobile object controller 20 and also has a communication function. A communication signal is also sent to the power system. The communication system is connected to the power system via a HPF 26. This makes it possible to separate communication data from power. The probe 14 has power receiving electrodes 13 attached to both sides of the tip of an insulating probe substrate 14A, and is connected to a power line. The power receiving electrodes 13 have low melting point metal 25 attached thereto. The charger 1 also has a slot 6, and a power transmission electrode 5 is attached to the side wall of the slot while being supported by a pressing mechanism 4A. A low melting point metal 25 is also attached to the surface of the power transmission electrode. A switch 7 is attached to the bottom of the slot 6, and when the probe is pressed and the switch is turned On, a pressing mechanism is activated and the power transmitting electrode 5 and the power receiving electrode 13 come into close contact with each other. A low-melting point metal 25 is attached to the surfaces of both electrodes. The low-melting point metal 25 is soft and the oxide film on the surface is easily destroyed, so that by pressing the two electrodes together, contact can be made over a wide area without any oxide film. The low-melting point metal 25 is liquefied at temperatures above its melting point, and so it is considered to include liquid metal. The charger controller 3 drives the inverter 10 and the converter 11 to start power transmission. When charging is completed, a signal is sent from the mobile object controller 20 on the mobile object 1 side and transmitted to the charger controller via the two-stage HPF 26, and the charger controller stops power transmission and releases the pressing mechanism. The mobile object controller 20 recognizes that the power has been turned off, and pulls out the probe 14 from the slot 6. Note that the determination and communication functions may be initiated from the charger side, and are not limited to this method.

[0018] FIG. 5 shows a configuration in which a movable wall 29 is added to the configuration shown in FIG. 5(a) shows a state in which the slot is closed by the movable wall 29. Because the slot 6 is closed by the movable wall 29, people cannot touch the internal power transmitting electrode 5, ensuring safety. This means that even if there is dust floating around, the power transmitting electrode is less likely to become dirty. The movable wall 29 is made of metal, but is not electrically connected to the power transmitting electrode 5. The movable wall 29 is equipped with a lifting mechanism 31, which has the function of contracting in response to an external force and expanding when the external force is removed. However, it can also be driven by a motor or gears (not shown). This lifting function is controlled by a lifting controller 32. Furthermore, felt 30 is attached to both sides of the upper part of the movable wall. When the movable wall 29 is pressed, it presses the switch 7 and notifies the charger controller 3 that it has been pressed. FIG. 5(b) shows the state when the probe 14 is pushed in. When the switch 7 is pressed, the pressing mechanism 4A is activated, and the power transmitting electrode 5 and the power receiving electrode 13 are brought into close contact with each other.

[0019] 6 shows a state in which, when the probe 14 is not inserted into the slot 6, the power transmitting electrode 5 is pressed against the felt 30, and the lifting mechanism 31 rubs the surface of the power transmitting electrode 5 with the felt 30, thereby removing dirt from the surface of the power transmitting electrode. This keeps the surface of the power transmitting electrode 5 clean.

[0020] 7 shows an electrolyte-impregnated felt 30A. In the electrode surface rubbing mode of FIG. 6, a voltage is applied between the movable wall 29 and each power transmitting electrode 5 so that the power transmitting electrode 5 is (-) and the movable wall 29 is (+). In this way, the oxide film on the surface of the low melting point metal (including liquid metal) is electrochemically removed (reduced). This reduction switch 34 is controlled by the charger controller 3. The power transmitting electrode 5 may be rubbed with the electrolyte-impregnated felt 30A.

[0021] 8 shows a cross-sectional side view of the charger 1. A lifting mechanism 31 moves the movable wall 29, and electrolyte-impregnated felt 30A is attached to the side of the movable wall 29. At the top, there is a tank 36 for the electrolyte, and the electrolyte can be supplied 38 to the electrolyte-impregnated felt 30A from a nozzle 39. The nozzle 39 is electromagnetically controlled, and starts supplying the electrolyte when the electrolyte in the electrolyte-impregnated felt 30A runs low, and is normally closed. On the bottom, there is a reservoir 37 for collecting dripping electrolyte. In this way, even if the electrolyte evaporates, it can be gradually replenished. The electrolyte used is 1N (1 base) sodium hydroxide. Even if it evaporates, the Na component remains, so low-concentration sodium hydroxide or water is supplied 39.

[0022] In FIG. 9, a maintenance probe is inserted from an external dedicated device to replenish the electrolyte, suck out the electrolyte from the electrolyte reservoir 37, and replace the liquid metal on the surface of the power transmission electrodes 5 on both sides. The power transmitting electrode 5 is composed of a power transmitting base electrode 5A and a sintered metal 5B impregnated with liquid metal attached to it. Copper is used for the sintered metal impregnated with the liquid metal, and the porosity is approximately 80%. The voids are impregnated with a eutectic alloy (liquid metal) of Ga, In, and Sn, and since the liquid metal has wettability with the copper sintered metal, the liquid metal can flow freely within the sintered metal. For this reason, the liquid metal can be exchanged as a fluid by attaching a supply pipe and a suction pipe from the outside and applying pressure and suction. The maintenance probe 41 is replaceable with respect to the liquid metal-impregnated sintered metal on both sides. The maintenance probe 41 is provided with a function for bending the supply pipe 40 and moving the pipe end (not shown in the drawing). Incidentally, since the melting point of the eutectic alloy (liquid metal) of Ga, In, and Sn is -19°C, heaters are attached to the movable wall 29 and the maintenance probe 41 for use in cold regions. Furthermore, since the electrolyte itself is an aqueous solution, it freezes at temperatures below -10°C, so heaters are also required in the electrolyte tank 36 and the supply pipe 40 (not shown in the figure). The power receiving electrode 13 is also composed of a power receiving side substrate electrode 13A and a sintered metal 13B impregnated with liquid metal (not shown in the figure). A maintenance probe is used for replacing the electrolyte, but this is not limiting and a supply and drainage system may be provided on the charging equipment side. [Industrial Applicability]

[0023] It is expected that a world will come in which robots, drones, EVs, etc. will be controlled by AI and operated automatically in various facilities such as towns, factories, offices, and schools. At that time, it is expected that all-solid-state batteries capable of rapid charging will also be put to practical use, so a rapid charging system that can be used outdoors will be essential. The present invention is a contact unit for use in such applications that has outdoor compatibility, rapid charging capabilities, low cost, safety, ease of operation, non-radioactive properties, low copper resource consumption, etc. [Explanation of symbols]

[0024] 1 charger 2. Mobile 3. Charging Controller 4. Press Controller 5. Power transmission electrode 5A Power transmission side base electrode 5B Liquid metal impregnated sintered metal 6 Slots 7 Push Switch 8 Step-up transformer 9 rectifier 10 Inv.(DC / AC) 11 Conv. (AC / DC) 12 AC power supply 13 Receiving electrode 13A Receiving side board electrode 13B Liquid metal impregnated sintered metal 14 Probe 14A Probe board (insulator) 15 Sensors 16 Motor 17 Inv. (for motor drive) 18 Mecanum Wheel 19 Insertion Controller 20 Mobile controller 21 Storage battery 22 BMS (Battery Management System) 23 battery charger 24 Drive mechanism 25 Low melting point metals 26 HPF (High Pass Filter) 27 Load 28 Charger body 29 Movable wall 30 Felt 30A Electrolyte-impregnated felt 31 Lifting mechanism 32 Lift controller 33 Reduction Cycle 34 Reduction switch 35 Reduction Battery 36 Electrolyte Tank 37 Liquid reservoir 38 Injection 39 Nozzle 40 Supply Pipe 41 Maintenance Probe 42 Injection pipe

Claims

1. A contact unit in which a mobile object approaches a charger with a slot and receives charging by inserting a probe into the slot, The mobile object side probe substrate has a power receiving electrode with a low melting point metal arranged on both sides of the approximate tip, and is connected to a load including a mobile object side battery charger, and the mobile object controller is connected to the probe via an HPF to send and receive communication signals. When the probe is pushed to the bottom of the slot, the power-receiving electrode of the probe faces the power-transmitting electrode provided with a low-melting-point metal attached to both sides of the inner wall of the slot. The power transmitting electrodes are connected to a power transmitting circuit on the charger side, and are connected to the charging controller via an HPF for transmitting and receiving communication signals. When the probe is pushed into the bottom of the slot, the push switch is turned on and the pressing mechanism is activated, pressing the transmitting electrode and the receiving electrode together, causing the oxide film of the low-melting point metal to break and come into contact, resulting in a low contact resistance connection that enables high power transmission. When the mobile device is fully charged, it communicates with the charger. The charger stops transmitting power and releases the pressure. The moving object will be able to remove the probe. Contact unit.

2. A movable wall supported by a lift mechanism is added to the contact unit of claim 1, and normally closes the slot. Felt is provided on both sides of the movable wall facing the current transmitting electrode, The charging control device can press the power transmission electrode to contact the felt and operate the lifting mechanism to clean the surface of the power transmission electrode with the felt. Contact Unit

3. 3. The contact unit according to claim 2, wherein when the felt is in contact with the power transmitting electrode, the felt is impregnated with an electrolyte, the movable wall is a conductor and a voltage is applied to the movable wall such that the movable wall is at a positive potential and the power transmitting electrode is at a negative potential; The oxide film on the surface of low melting point metals can be removed electrochemically. Contact Unit

4. The contact unit according to claims 2 to 3, An electrolyte tank is disposed on the upper portion of the slot in the charger body, and a nozzle that is electromagnetically controllable by the charge controller is disposed on the bottom surface of the electrolyte tank; A liquid damper is provided at the bottom of the slot. The charge controller controls the lifting mechanism to move the felt to the nozzle position, Refill the felt with electrolyte as needed. The remaining electrolyte can be stored in a liquid waste Contact Unit

5. The contact unit according to any one of claims 1 to 4, The low melting point metal in the power transmitting electrode and the power receiving electrode is formed by depositing sintered metal on each electrode substrate and impregnating the sintered metal with liquid metal. Contact Unit

6. A maintenance probe for the contact unit according to claim 4 and claim 5, It has the functions of injecting electrolyte, recovering waste liquid, and driving the supply pipes and the ends of the supply pipes for liquid metal exchange. Insert the maintenance probe into the slot. Replenishing the electrolyte by connecting a supply pipe for replenishing the electrolyte to an injection pipe for replenishing the electrolyte in the contact unit; The supply pipe for suctioning the electrolyte is lowered into the reservoir to suck up the accumulated waste liquid. A supply pipe for exchanging liquid metal is brought into contact with two or more different points of the liquid metal-impregnated sintered metal; Liquid metal is supplied from some of the supply pipes for liquid metal exchange, and liquid metal is sucked from other supply pipes for liquid metal exchange to exchange the liquid metal. Maintenance Probes

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