JP6083343B2 - Non-contact charging system for electric forklift - Google Patents

Description

  The present invention relates to a contactless charging system for an electric forklift that charges a battery mounted on the electric forklift without contact.

  An example of a prior art of a non-contact charging system that charges a battery mounted on an electric forklift in a non-contact manner is disclosed in Patent Document 1. In the non-contact charging system in Patent Document 1, a coiled electric wire is provided below the floor surface, while a cored winding is protruded below the lower part of the vehicle body, and the lower portion of the floor surface is provided. When the driver drives the forklift so that the magnetic core generated when the AC voltage is applied to the electric wire from the AC power source, Voltage) is induced, the induced voltage is converted into a DC voltage by a rectifier, and the battery is charged with the DC voltage.

JP-A-6-86470

  However, in the conventional non-contact charging system disclosed in the above-mentioned Patent Document 1, since the core-attached winding projects below the lower portion of the vehicle body, such a non-contact charging system is used. If it was going to be applied to an electric forklift (not equipped with a contact charging system), it was necessary to secure a working space by lifting the body of the forklift, etc., and it was not easy to attach the cored winding. Furthermore, laying the electric wire below the floor surface means that a large-scale construction for burying the electric wire by removing the floor plate of the equipment to be applied (or digging up the ground) is required. For these reasons, it has been difficult to apply the non-contact charging system disclosed in Patent Document 1 to an existing electric forklift.

  Accordingly, an object of the present invention is to provide a non-contact charging system for an electric forklift that makes it easy to construct a system for charging a battery mounted on an existing electric forklift without contact.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is a non-contact charging system for charging a battery mounted on an electric forklift in a non-contact manner, and an AC power source outside the electric forklift. A power transmission line connected to the power supply unit, a power receiving unit provided on the upper wall surface of the mast side of the body portion of the electric forklift, and an AC voltage sent from the power receiving unit disposed on the electric forklift. A rectifier that converts the voltage to the battery, and the power reception unit includes a magnetic core having a protrusion and a power reception winding that is wound around the magnetic core, and the power transmission line is The battery is charged through the rectifier by generating an induced voltage in the power receiving unit due to an alternating current flowing through the power transmission line by being hung on the protrusion of the magnetic core. It is possible der is, the power transmission lines are air-core coil is a by power windings which can be hung on the protrusion of the magnetic core and the air-core portion is formed, the magnetism of the power receiving portion A body core that is disposed on a body body side of the electric forklift, a center protrusion that protrudes from the center of the base and extends away from the body body, and a center protrusion that protrudes from both ends of the base. Two end projections extending in the same direction, the power receiving winding is wound around the central projection, and by hanging the air core portion of the power transmission winding on the central projection, to generate an induced voltage in the power receiving unit and said can der Rukoto.

  According to the above configuration, since only the power transmission line connected to the AC power source needs to be prepared as the configuration on the power transmission side, it is not necessary to perform a construction for burying the electric wire under the floor. In addition, the power receiving unit is provided in the upper part of the mast-side wall surface (front wall surface of the chassis), usually in the vicinity of the driver's seat and easily accessible by the operator. The power receiving unit can be easily mounted on the electric forklift.

Moreover, according to the said structure, since the air core part of a power transmission winding should just be hung on the center protrusion extended in the direction away from a vehicle body main body part (chassis), what part of a power transmission line should be hung on which part of a power receiving part It is easy to determine whether or not the power is applied, and the work of applying the power transmission winding can be easily performed from the outside of the electric forklift.

The invention according to claim 2 is the non-contact charging system for the electric forklift according to claim 1 , wherein the size of the air core part of the power transmission winding is wound around the central protrusion. It is characterized by being larger than the outer diameter of the power receiving winding.

  According to the above configuration, since the power receiving winding and the central protrusion are accommodated in the air core portion, the work of hanging the power transmission winding on the central protrusion can be smoothly performed, and the induced voltage caused by the alternating current flowing through the transmission line can be easily obtained. Can be generated.

  According to the present invention, the configuration on the power transmission side does not have to be embedded under the floor or in the ground, and the configuration on the power reception side is provided at a position where the operator can easily work. It has an effect that it is easy to construct a charging system for charging by contact.

It is a perspective view which shows the electric forklift provided with the non-contact charge system in an example of embodiment of this invention. It is the top view and sectional drawing which show the principal part structure of the power transmission circuit of the embodiment. It is a figure which shows the principal part structure of the receiving circuit of the embodiment, (a) is a top view, (b) is sectional drawing, (c) is sectional drawing which shows a mode that the power transmission winding was hung on the center protrusion. is there.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, duplicate description is omitted by assigning the same reference numerals to the same components. In addition, the drawings schematically show each component for easy understanding. In addition, the shape of each component shown in the following embodiment, the numerical value of the physical quantity, and the like are merely examples and are not particularly limited, and various modifications are possible without departing from the effects of the present invention. It is. The configurations shown in the following embodiments are examples and are not particularly limited, and can be appropriately changed without departing from the effects of the present invention.

  FIG. 1 is a perspective view for explaining an electric forklift provided with a non-contact charging system in an example of an embodiment of the present invention. A non-contact charging system for an electric forklift described below is for charging a battery (for example, a lead storage battery) mounted on an existing electric forklift (battery vehicle).

  An electric forklift 11 shown in FIG. 1 is provided with a power receiving unit 51 (details are provided) on the front wall 18 in front of the driver's seat 19 (the fork 16 side is the front), that is, on the mast 20 side of the vehicle body 12. (Described later).

  Although not shown in FIG. 1, a power transmission circuit 30 shown in FIG. 2 is prepared in a standby place of the electric forklift 11 as a part of the non-contact charging system of the present embodiment. The power transmission circuit 30 is prepared separately from the electric forklift 11, that is, outside the electric forklift 11.

  As shown in the plan view on the upper side of FIG. 2, the power transmission circuit 30 includes a high frequency power supply device 43 connected to an AC power supply 44 (for example, AC 200 V commercial power supply) and a power transmission line 32 to which a high frequency voltage is applied from the high frequency power supply device 43. And a power transmission coil 34 (an example of a power transmission winding) formed on the power transmission line 32.

  As shown in the lower cross-sectional view of FIG. 2, the power transmission coil 34 is spirally wound, and the inside of the spiral is a gap. That is, the power transmission coil 34 is an air core coil (air core winding) having an air core portion 36. When a high-frequency voltage is applied to the power transmission line 32, an alternating magnetic field is generated by the power transmission coil 34, and the magnetic flux of the alternating magnetic field penetrates the air core part 36 while changing its direction and magnitude.

  On the other hand, the power reception unit 51 provided in the upper part of the front wall surface 18 in FIG. 1 is a part of the power reception circuit 50 (FIG. 3) disposed in the electric forklift 11. As shown in FIG. 3A, the power receiving unit 51 includes a magnetic core 52 made of a magnetic material (for example, ferrite) and a power receiving coil 58 wound around the magnetic core 52 (an example of a power receiving winding). )have.

  As shown in the cross-sectional view of FIG. 3B, the magnetic core 52 includes a base 53 that spreads in the right and left in the drawing, a central protrusion 54 that protrudes from the center of the base 53, and a center from both ends of the base 53. Two end projections 55A and 55B projecting in the same direction as the projection 54 are provided. With such a structure, the magnetic core 52 has an E-shaped cross section.

  The base 53 of the magnetic core 52 is disposed on the front wall surface 18 side of the vehicle body 12 (see FIG. 1). For this reason, the central projection 54 and the end projections 55A and 55B extend in a direction away from the front wall surface 18, that is, in a direction away from the vehicle body main body 12.

  As shown in FIG. 3A, the power receiving coil 58 is wound around the central protrusion 54 of the magnetic core 52. The power receiving coil 58 is connected to a charger 45 provided in the power receiving circuit 50 in the electric forklift 11 via a power receiving wire 56. When an induced voltage is generated in the power receiving coil 58, the charger 45 charges the battery 41 mounted on the electric forklift using the induced voltage.

When a magnetic flux fluctuation occurs in the magnetic core 52 as the core of the power receiving coil 58, an induced voltage is generated in the power receiving coil 58.
Here, as shown in FIG. 3C, the power core 34 of the power transmission coil 34 of the power transmission line 32 is hung on the central protrusion 54 of the magnetic core 52, and the power transmission coil 34 is disposed outside the power reception coil 58. In addition, when a high frequency voltage is applied to the power transmission line 32, the magnetic flux penetrating the air core portion 36 passes through the magnetic core 52 (the power transmission line 32 and the power reception unit 51 are electromagnetically coupled). )

  Since the magnetic flux penetrating through the air core portion 36 is due to an alternating magnetic field caused by alternating current (high frequency voltage) applied to the power transmission line 32, magnetic flux fluctuations are generated in the magnetic core 52. Therefore, an induced voltage is generated in the power receiving coil 58 wound around the magnetic core 52 by electromagnetic induction. With this induced voltage, the battery 41 is charged via the charger 45 shown in FIG.

  As a specific example of the circuit around the charger 45, as shown in FIG. 3A, a resonance capacitor 42 that resonates at the frequency of the high frequency voltage together with the power receiving coil 58 is connected to both ends of the power receiving coil 58. There is a method in which a charger 45 is connected to both ends of the resonance capacitor 42 to configure a circuit for charging the battery 41. The charger 45 includes at least a rectifier that converts an induced voltage (high-frequency voltage AC) sent from the power receiving coil 58 into a DC voltage (for example, DC 300 V), and the battery 41 is connected to the DC voltage converted by the rectifier. Charge. Note that the charger 45 may include a filter, a converter, and the like in addition to the rectifier.

  According to such a configuration, when the air core portion 36 of the power transmission coil 34 is hung on the central protrusion 54 of the magnetic core 52, that is, the air core portion 36 of the power transmission coil 34 formed on the power transmission line 32 through which alternating current flows. When the magnetic core 52 is disposed therein, an induced voltage (high frequency voltage) is induced in the power receiving coil 58 wound around the magnetic core 52, and the induced voltage (induced voltage) is charged to the charger 45. Is converted into a DC voltage (for example, DC 300V). Then, the DC voltage is supplied to the power supply system of the electric forklift 11 via the interface circuit, and the battery 41 of the electric forklift 11 is charged.

  According to the present embodiment described above, the power receiving unit 51 shown in FIG. 1 is provided on the upper portion of the wall surface (front wall surface 18) on the mast 20 side of the vehicle body main body 12. When mounting on the electric forklift 11 (without a contact charging system), the power receiving unit 51 is provided on the front wall surface 18 at a position close to the driver's seat 19 where the operator can easily approach. Therefore, mounting can be performed without lifting the electric forklift 11, and the construction of a non-contact charging system is easy.

  Further, it is not necessary to embed the power transmission circuit 30 shown in FIG. 2 under the floor (or underground), and the AC power supply 44 (and the high-frequency power supply device 43) is connected to a place (such as a standby place) where the electric forklift 11 is charged. What is necessary is just to prepare the transmission line 32 to be prepared. From this point, it is easy to construct a non-contact charging system.

  Moreover, as shown in FIG.3 (c), since charging is performed by hooking the power transmission coil 34 of the power transmission line 32 on the center protrusion 54 of the magnetic body core 52, what should be hung (power transmission coil 34) It is easy to visually recognize the object to be applied (the central protrusion 54). That is, it is easy to determine “where and what should be multiplied”. It is also easy to visually determine that “currently charging”.

  In addition, since the power transmission coil 34 of the power transmission line 32 provided outside is hung on the central protrusion 54 of the magnetic core 52 extending in the direction away from the front wall surface 18 (the direction toward the outside of the electric forklift 11), the power transmission coil It is easy to perform the operation of hanging 34 on the central projection 54 from the outside of the electric forklift 11, and the workability is high.

  In addition, if the size of the air core portion 36 of the power transmission coil 34 is larger than the outer diameter of the power receiving coil 58 as shown in FIG. The work can be smoothly performed without being caught by the coil 58.

  In addition, about the provision method of the power receiving part 51 in the front wall part 18, although FIG. 1 shows a mode that the base 53 of the magnetic body core 52 is directly attached to the front wall part 18, it does not restrict to this. Alternatively, a pedestal of a member (such as a metal plate) that is easily fixed by bolting or welding to the front wall portion 18 may be attached to the front wall portion 18 first, and the magnetic core 52 may be attached to the pedestal. . In this case, a part of the receiving wire 56 shown in FIG. Moreover, you may provide the coating body which protects the power receiving part 51 from an impact or dust.

  Further, the position of the pedestal of the power receiving unit 51 can be changed on the front wall portion 18 (for example, in the case of bolting, a plurality of bolt holes are provided in the front wall portion 18). The power receiving unit 51 can be arranged at a position where a person can easily perform a charging operation (work for placing the power transmission line 32 on the power receiving unit 51), and workability is further improved.

  Further, if the power transmission line 32 can be easily approached from the side of the vehicle body main body 12, the base 53 is not disposed on the front wall 18 side as shown in FIG. The power receiving unit 51 may be provided so that the portion (the central protrusion 54 in FIG. 3) faces the vehicle body side.

  2 shows a configuration of the power transmission line 32 in which a power transmission coil 34 (power transmission winding) is formed. However, the configuration is not limited to this, and the power transmission line 32 has no winding portion. However, if it is a flexible material, it is possible to form an arcuate portion that becomes a folded portion of the power transmission path by bending it smoothly, so that the formed arcuate portion is used as a protrusion of the power receiver 51 (the central protrusion 54 in FIG. 3). If the high frequency voltage is applied in a state where the power transmission line 32 is passed through both sides of the protrusion, the magnetic flux can be changed in the magnetic core 52, and the battery 41 is charged. It can be performed.

  2 shows a circuit configuration in which the power transmission coil 34 (power transmission line 32) is directly connected to the high frequency power supply device 43. However, the power transmission coil 34 is interposed between the power transmission coil 34 and the high frequency power supply device 43. In addition, a resonance capacitor that resonates at the frequency of the high-frequency voltage may be connected. In this case, a resonance capacitor may be connected in parallel to the power transmission coil 34 to form a parallel resonance circuit, or a series resonance circuit may be formed by connecting in series.

  3 shows an E-shaped magnetic core 52 having a central protrusion 54 and end protrusions 55A and 55B. However, an induced voltage is applied to the receiving coil 58 due to the alternating current flowing through the power transmission line 32. For example, a configuration in which a protrusion is further provided between the center protrusion 54 and the end protrusions 55A and 55B may be used.

  Further, in the power receiving circuit 50 shown in FIG. 3A, parts other than the power receiving unit 51 are disposed in the electric forklift 11, and the power receiving wire 56 is preferably provided so as to pass through the vehicle body of the electric forklift 11. If not disturbing the operator, the receiving wire 56 may be provided so that the surface of the vehicle body is turned up.

  In FIG. 3C, the power receiving coil 58 is wound over the entire height of the central protrusion 54 so that the power receiving coil 58 is accommodated in the air core portion 36 of the power transmitting coil 34. It may be wound only at the base of the central protrusion 54 (base 53 side), and the power transmission coil 34 may be hung on the distal end side of the central protrusion 54. Thus, the power transmission coil 34 and the power reception coil 58 face each other during charging. In this case, the size of the air core portion 36 of the power transmission coil 34 may be approximately the same as the width of the central protrusion 54.

DESCRIPTION OF SYMBOLS 11 Electric forklift 12 Car body part 18 Front wall surface 20 Mast 30 Power transmission circuit 32 Power transmission line 34 Power transmission coil 36 Air core part 41 Battery 45 Charger 50 Power receiving circuit 51 Power receiving part 52 Magnetic body core 54 Central protrusion 58 Power receiving coil

Claims (2)

A contactless charging system for charging a battery mounted on an electric forklift contactlessly,
A power transmission line connected to an AC power source outside the electric forklift,
A power receiving portion provided on the upper wall surface of the mast side of the body portion of the electric forklift;
A rectifier disposed on the electric forklift, for converting an AC voltage sent from the power receiving unit into a DC voltage and sending it to the battery;
With
The power receiving unit includes a magnetic core having a protrusion and a power receiving winding wound around the magnetic core,
It is possible to charge the battery via the rectifier by causing the power receiving unit to generate an induced voltage caused by an alternating current flowing through the power transmission line by hooking the power transmission line on the protrusion of the magnetic core. der is,
The power transmission line is formed with a power transmission winding that is an air core winding and that can hang the air core portion on the protrusion of the magnetic core,
A magnetic core of the power receiving unit includes a base disposed on the body main body side of the electric forklift, a central protrusion that protrudes from the center of the base and extends away from the vehicle body, and both ends of the base. Two end projections protruding and extending in the same direction as the central projection,
The power receiving winding is wound around the central protrusion,
Wherein the air-core portion of the power transmission coil by multiplying the central projection, the non-contact charging system of an electric forklift, wherein can der Rukoto to generate an induced voltage in the power receiving unit. The size of the air-core portion of the transmission winding, being greater than the outer diameter of the wound to the central projection the power receiving coil, a contactless charging system for an electric forklift according to claim 1.

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