Contact charging method and contact charging system for electric vehicle

During travel of the electric vehicle, the charging arm is extended in the vehicle width direction, a positive electrode overhead line of the power supply device and a positive electrode power reception unit of the charging arm are brought into contact at the same time that a negative electrode overhead line of the power supply device and a negative electrode power reception unit of the charging arm are brought into contact, and a power storage device for driving the electric vehicle is charged. A charging head that is the tip section of the charging arm is held within a V-shaped groove to which the positive electrode overhead line and the negative electrode overhead line are attached, thereby minimizing the loss of contact even if the charging arm shakes in the vertical direction as a result of the condition of the road surface, brake operation, or the like.

TECHNICAL FIELD

The present invention relates to a contact charging method and a contact charging system for an electric vehicle, which during traveling of the electric vehicle, charges an electrical storage device provided in the electric vehicle and which is used for driving by way of contact charging from an external power supply device.

BACKGROUND ART

Heretofore, a resonance-type non-contact charging (power supplying) system for a vehicle has been proposed in International Publication No, WO 2011/142421 pamphlet (hereinafter referred, to as WO 2011/142421A).

SUMMARY OF INVENTION

With the resonance-type non-contact, charging (power supplying) system proposed in WO 2011/132421A, as a result of carrying out transmission and reception of high frequency large scale power between a primary side resonator coil on an infrastructure side and a secondary side resonator coil on the side of an electric vehicle, problems occur in that it is likely for generation of external noise to be large, or for control of the power supply to become complex.

For resolving these problems, a contact charging system, may be considered, which is constituted so as to bring a charging arm, which is provided on an electric vehicle, into contact, with a power supplying device, which is disposed on an external member, during traveling of the electric vehicle, whereby an electrical storage device of the electric vehicle is charged from the power supplying device through the charging arm.

However, with such a contact charging system, when the electric vehicle, which is traveling while undergoing charging through the charging arm, swings or rocks in a upper and lower directions (pitching directions) due to road conditions or acceleration and braking operations or the like, contact between the charging arm and the power supplying device becomes unstable, which can lead to a situation in which contact cannot be assured.

The present invention has been devised taking into consideration the aforementioned problems, and has the object of providing a contact, charging method and a contact charging system for an electric vehicle in which, during traveling while carrying out contact charging between a power supplying device and the electric vehicle through a charging arm of the electric vehicle, even if the electric vehicle undergoes swinging motion in upper and lower directions, loss of assurance of the contact state is suppressed, together with enabling a reduction in size of the electric vehicle charging system.

A contact charging method for an electric vehicle according to the present invention comprises the steps of providing a power supplying device, which includes a power line retaining part in which a V-shaped groove is provided that faces toward a side portion of the electric vehicle and is formed to open in upper and lower directions of the electric vehicle and to extend in a running direction of the electric vehicle, and in which a positive electrode power line on one inner surface and a negative electrode power line on another inner surface of the V-shaped groove of the power line retaining part are fixed to the power line retaining part respectively along the running direction and at positions to maintain an insulation distance mutually therebetween, and causing a charging arm, which is accommodated in the side portion of the electric vehicle and includes a positive electrode power reception unit and a negative electrode power reception unit, which are provided on a distal end thereof and are disposed so as to face the corresponding positive electrode power line and the corresponding negative electrode power line of the power supplying device, to extend out in a vehicle widthwise direction, and to bring into contact simultaneously the positive electrode power line of the power supplying device and the positive electrode power reception unit of the charging arm, and the negative electrode power line of the power supplying device and the negative electrode power reception unit of the charging arm, and charging an electrical storage device for driving of the electric vehicle.

A contact charging system for an electric vehicle according to the present invention is constituted from a power supplying device, and the electric vehicle equipped with an electrical storage device for driving to which power from the power supplying device is supplied, wherein the power supplying device is of a structure that includes a power line retaining part in which a V-shaped groove is provided that faces toward a side portion of the electric vehicle and is formed to open in upper and lower directions of the electric vehicle and to extend in a running direction of the electric vehicle, and in which a positive electrode power line on one inner surface and a negative electrode power line on another inner surface of the V-shaped groove of the power line retaining part are fixed to the power line retaining part respectively along the running direction and at positions to maintain an insulation distance mutually therebetween, and the electric vehicle is of a structure comprising a charging arm configured to extend out in a vehicle widthwise direction, which is accommodated in the side portion of the electric vehicle and includes a positive electrode power reception unit and a negative electrode power reception unit, which are provided on a distal end thereof and are disposed so as to face the corresponding positive electrode power line and the corresponding negative electrode power line of the power supplying device, wherein during charging, the charging arm is extended out in the vehicle widthwise direction, and the positive electrode power line of the power supplying device and the positive electrode power reception unit of the charging arm, and the negative electrode power line of the power supplying device and the negative electrode power reception unit of the charging arm are placed in contact simultaneously, and the electrical storage device is charged.

According to the present invention, a configuration is provided such that, when the electrical storage device for driving, which is mounted in the electric vehicle, is charged during traveling, by causing the charging arm, which is provided on the vehicle body and on which the positive, electrode power reception unit and the negative electrode power reception unit, are disposed above and below on the distal end thereof, to extend out in a lateral direction of the vehicle body, and to be placed in contact with the power line that is disposed along the running direction of a travel path, the positive electrode power line of the power supplying device and the positive electrode power reception unit, of the charging arm along with the negative electrode power line of the power supplying device and the negative electrode power reception unit of the charging arm, wherein the positive electrode power line is fixed to one inner surface and the negative electrode power line is fixed to another inner surface of the V-shaped groove that faces toward the side portion of the electric vehicle and is formed to open in upper and lower directions of the electric vehicle and to extend along the running direction of the electric vehicle, are brought into contact simultaneously, and the electrical storage device for driving of the electric vehicle is charged. Therefore, even if the charging arm swings or rocks in upper and lower directions due to road conditions or braking operations or the like, the distal end part of the charging arm is retained inside the V-shaped groove, and contact is prevented from not being secured.

Further, because the positive electrode power line and the negative electrode power line are fixed above and below on inner surfaces of the V-shaped groove, both the power supplying device and the charging arm can be made smaller in scale, and as a result, it is possible for the contact charging system, as a whole to foe made smaller in scale.

Since the power supplying device carries out charging by way of contact charging, in comparison with a resonance-type non-contact charging system, generation of external noise is greatly reduced, and the power supplying control is simplified.

The present invention also includes the power supplying device and the charging arm of the above-described contact charging system for an electric vehicle.

According to the present invention, the positive electrode power reception unit and the negative electrode power reception unit of the charging arm on the side of the vehicle are brought into contact and charging is carried out with respect to the positive electrode power line and the negative electrode power line, which are fixed above and below on inner surfaces of the V-shaped groove extending along the running direction. Therefore, even if the charging arm swings or rocks in upper and lower directions due to road conditions or braking operations or the like, the distal end part of the charging arm is retained inside the V-shaped groove. Then, during traveling of the electric vehicle while contact charging takes place through the charging arm with respect to the power supplying device, contact is prevented from not being secured. Also, a reduction in size of the contact charging system for an electric vehicle can foe achieved.

DESCRIPTION OF EMBODIMENTS

Below, descriptions will be given concerning embodiments of the present invention with reference to the accompanying drawings.

InFIGS. 1A, 1B, 1C, there are shown schematic overall structural views of a contact charging system12(first embodiment) for an electric vehicle10to which a method of the invention according to an embodiment thereof is applied.

The electric vehicle10is a vehicle in which there are mounted an electric motor110for vehicle propulsion (shown only inFIG. 1A), and an electrical storage device100(shown only inFIG. 1A) for driving the electric motor110. For example, the electric vehicle10corresponds to an electrically driven automobile, a hybrid vehicle equipped with an internal combustion engine, and a fuel cell vehicle equipped with a fuel cell, or the like.

The contact charging system12basically is constituted from a power supplying device26equipped with a power line retaining part14made of an insulating material, and the electric vehicle10, which is equipped with a charging arm18on a side portion10sof a vehicle body11. The charging arm18may be disposed on both side portions of the electric vehicle10.

The power supplying device26is disposed at a length of a predetermined region on the shoulder of a road (including a high speed expressway) that forms a travel path70, or on the shoulder of a travel path70of an automobile race track, etc. The length of the predetermined region is set to a length within which it is possible for the electric vehicle10having a predetermined electrical consumption to be charged with an amount of charge that enables traveling from the position of one power supplying device26to the position of a next power supplying device26.

The electric vehicle10travels along the power supplying device26on the travel path70on which the power supplying device26is arranged, and while traveling, charges the electrical storage device100from the power supplying device26through the charging arm18.

The power line retaining part14extends along the length of the predetermined region, and the rear side thereof is fixed at a predetermined interval on a guard post20(seeFIG. 1C).

Power lines24, which are made up from a positive electrode power line24pof a conductive material to which a DC high voltage is applied front an external power supply apparatus (not shown) and a negative electrode power line24nof a conductive material, are fixed to the front side of the power line retaining part14like a rail. The voltage may be an AC voltage instead of a DC voltage.

On a charging head34that forms the distal end part of the charging arm18, a power reception unit36is attached, which is made up from a positive electrode power reception unit36pthat contacts the positive electrode power line24p, and a negative electrode power reception unit36nthat contacts the negative electrode power line24n. Both the positive electrode power reception unit36pand the negative electrode power reception unit36nare rolling wheels.

For the sake of convenience, the respective constituent elements of the electric vehicle10shown inFIGS. 1A, 1B, and 1Care depicted as structural components according to a first example, although the electrical circuitry functions thereof also are the same in the later-described examples.

InFIG. 2, there is shown a front cross-sectional configuration with partial omission of the power line retaining part14according to the first example.

InFIG. 3, there is shown a front configuration with partial omission of the charging head34according to the first example.

InFIG. 4, there is shown a plan configuration with partial omission of the charging arm18according to the first example.

InFIG. 5, there is shown in perspective a configuration showing a contact condition of the charging arm18with the power lines24that are retained in the power line retaining part14in the contact charging system12according to the first embodiment.

InFIG. 6, there is shown a front configuration showing a contact condition of the charging arm18with the power lines24that are retained in the power line retaining part14in the contact charging system12according to the first embodiment.

Below, with reference toFIGS. 1A, 1B, 1C, and 2 through 6, the power line retaining part14according to the first example, the charging arm18according to the first, example, and the contact charging system12according to the first embodiment, which is equipped with the power line retaining part14and the charging arm18, will be described in detail.

As shown inFIGS. 1A and 4, the charging arm18is constituted from the charging head34, a substantially L-shaped bracket53to which the charging head34is attached, and a slider crank mechanism30that, moves (rotates) the charging head34along the directions (q1, q2) of the arrow q through the bracket53.

The slider crank mechanism30is constituted from, an arm member19that extends between the bracket53and a pin32(shaft) that is disposed on the vehicle body of the electric vehicle10, a spring damper39a, one end of which is attached rotatably to the middle of the arm member IS and the other end of which is attached rotatably to an actuator38that slides on a slide rail37in the directions of the arrow p, and a spring damper39b, one end of which is fixed to the vehicle body and the other end of which is fixed to the actuator38.

The actuator38is biased so as to move on the slide rail37in the direction of the arrow p1, whereby the arm member19is moved in the direction of the arrow q1about the center of rotation of the pin32through the spring damper39a, which functions as a lever that swings within a limited range, and the power reception unit36of the charging head34is urged by the spring dampers39a,39binto a state of contact with the power lines24.

In this manner, the charging arm18is extended out (deployed or tilted) toward the side of the power supplying device26from the side portion10sof the electric vehicle10. More specifically, the charging arm18is extended in a lateral outward direction of the vehicle body11.

On the other hand, by urging the actuator38on the slide rail37in the direction of the arrow p2, the arm member19is moved in the direction of the arrow q2, and the charging head34is returned to the home position of the vehicle body11.

The charging head34is attached on one end of the bracket53to a head main body41through an attachment member (seeFIG. 3). The head main body41is generally covered by a casing52made of an insulating material, with the exception of the electrical connecting portions of the power reception unit36.

As discussed above, the power supplying device26includes the power line retaining part14, and a bottom portion of the power line retaining part14is fixed to a bottom portion60dof a channel-shaped induction recess60(seeFIG. 6) made of a non-conducting material, and is fixed to the guard post20through the bottom portion60dof the induction recess60(seeFIG. 1C).

In addition to the bottom portion60dthereof, the induction recess60is constituted from, guide members60a,60b, and60c. The upper and lower guide members60cextend in a horizontal direction toward the side of the travel path70(road) from upper and lower ends of the bottom portion60d. The vertical interval between the upper and lower guide members60cis formed by an interval having a redundancy with respect to the outer diameter of a casing35(seeFIG. 6) of the charging head34. The upper and lower guide members60care connected contiguously with the upper and lower guide members60bthat extend further in the horizontal direction. The vertical interval between the upper and lower guide members60bis narrowed so as to be smaller than the outer shape of the casing35of the charging head34. The upper and lower guide members60bare connected contiguously with the upper and lower guide members60a, which widen in upper and lower directions UL. The interval of the open ends of the guide members60ais set to an interval whereby the charging head34can be guided into the interior of the induction recess60, even if the charging head34swings upwardly and downwardly in the directions UL when the charging arm18is extended.

On the front side of the power line retaining part14, there is provided a V-shaped groove23that opens in upper and lower directions UL of the side portion10sof the electric vehicle10, and is formed to extend in the running directions RD of the electric vehicle10.

A rear surface of the positive electrode power line24pfrom among the power lines24is fixed to one inner surface of the V-shaped groove23, and a rear surface of the negative electrode power line24nfrom among the power lines24is fixed to another inner surface of the V-shaped groove23. The positive electrode power line24pand the negative electrode power line24nare fixed by portions thereof being embedded in the power line retaining part14at positions to maintain an insulation distance mutually therebetween. Sides of the positive electrode power line24pand the negative electrode power line24nthat come into contact with the charging head34are in the form of a V-shape.

On the other hand, the charging head34is equipped with the power reception unit36having at upper and lower locations thereof the positive electrode power reception unit (positive electrode roller)36pand the negative electrode power reception unit (negative electrode roller)36n, both of which are rolling wheels (rotating rollers), respectively. The positive electrode power reception unit36pand the negative electrode power reception unit36nare formed in the shape of truncated cones, respective bottom surfaces of which vertically face one another, and which are symmetrical with respect to the axis of the charging head34(arm member19). More specifically, the contact portions thereof are formed in the shape of wedges that make line contact with the V-shaped groove23.

The power reception unit36is engaged with bearings40,42(seeFIG. 3) of the head main body41. On a rear end of the head main body41, there are provided, respectively, a vehicle widthwise direction WD suspension48constituted by a spring44, and an upper and lower direction UL suspension50constituted by springs46a,46b.

The charging head34is fixed by the bracket53that is formed on the other end of the arm member19through an attachment member54that constitutes part of the suspension50(seeFIG. 4).

In the contact charging system12according to the first embodiment, which is equipped with the charging arm18according to the first example and the power supplying device26according to the first example that are constructed basically as described above, when the electric vehicle10during traveling thereof reaches a position in the vicinity of the power supplying device26, the charging arm18is urged outwardly in the vehicle widthwise direction WD, and the charging head34is guided through the induction recess60to the power lines24, whereupon as shown inFIGS. 1C, 5, and 6, the charging arm18and the power supplying device26are connected together electrically in a state of contact.

In this manner, the charging arm18, on which the positive electrode power reception unit36pand the negative electrode power reception unit36nare provided above and below on the distal end thereof, is extended out in a lateral or sideways direction of the vehicle body11, and by being placed in contact with the power lines24that are disposed along the running directions RD of the travel path70, the electrical storage device100for driving, which is mounted in the electric vehicle10, can be charged during traveling.

More specifically, a configuration is provided in which the positive electrode power reception unit36pof the charging arm18and the positive electrode power line24pof the power supplying device26, and the negative electrode power reception unit36nof the charging arm18and the negative electrode power line24nof the power supplying device26, wherein the positive electrode power line24pis fixed to one inner surface and the negative electrode power line24nis fixed to another inner surface of the V-shaped groove23that faces toward the side portion10sof the electric vehicle10and is formed to open in upper and lower directions DL of the electric vehicle10and to extend along the running directions RD of the electric vehicle10, are brought into contact simultaneously, and the electrical storage device100for driving of the electric vehicle10is charged. Therefore, even if the charging arm18swings or rocks in upper and lower directions DL due to road conditions of the travel path70or braking operations or the like, the charging head34that defines the distal end part of the charging arm18is retained inside the V-shaped groove23under the action of the suspension50, etc., and contact is prevented from not being secured.

Further, because the positive electrode power line24pand the negative electrode power line24nare fixed above and below on inner surfaces of the V-shaped groove23, both the power supplying device26and the charging arm18can be made smaller in scale, and as a result, it is possible for the contact charging system12as a whole to be made smaller in scale.

Moreover, as shown inFIG. 1B, springs also are interposed in upper and lower directions UL on the pin32(shaft), whereby the charging arm18functions as a suspension in the upper and lower directions UL.

Below, descriptions will be given concerning second through fourth embodiments. In the drawings to be referred to below, the same features or corresponding features to those shown inFIGS. 1 through 6are denoted by the same reference numerals, or by the reference numerals in which hundredth place digits have been added to the same reference numerals, and detailed descriptions of such features are omitted. Further, since the slider crank mechanism30, by which the charging arm18extends out laterally or is accommodated on the side of the vehicle body, utilizes the same structure as that shown inFIG. 1A, detailed description thereof is omitted.

Second Embodiment

InFIGS. 7 and 8, there is shown a state of engagement (contact condition) of a charging head134according to a second example that constitutes a charging arm118according to the second example with power lines124that are retained in a power line retaining part114according to the second example. The power line retaining part114and the charging arm118are included in a contact charging system112according to the second embodiment.

The charging head134is equipped with a power reception unit136made up from a positive electrode power reception unit136pand a negative electrode power reception unit136nhaving halves of truncated conical shapes, which are embedded with the exception of front surfaces thereof by way of resin molding in a resin material head main body141. The positive electrode power reception unit136pand the negative electrode power reception unit136ndo not undergo rolling, unlike the positive electrode power reception unit36pand the negative electrode power reception unit36nof the charging head34shown inFIG. 6. Thus, they can also be considered as the configuration in the form of sliding plate-like shapes.

A rolling wheel74is attached to a bearing72on the distal end of the charging head134. The rolling wheel74is adapted to roll in the running directions RD along a surface of the power line retaining part114, in which a groove-shaped bottom portion of a V-shaped groove123is in the form of a U-shaped groove.

In the power line retaining part114, on one inner-surface of the V-shaped groove123, there is fitted a rear surface side projection of a positive electrode power line124phaving a gourd shape in cross section (a shape generally in the form of an oval with a constricted or narrowed center portion), and on the other inner surface thereof, there is fitted a rear surface side projection of a negative electrode power line124n. The front sides of the positive electrode power line124pand the negative electrode power line124nare formed with semicircular shapes in cross section (i.e., with a rounded bar shape with respect to the running directions RD).

While the rolling wheel74of the charging arm118rolls along the U-shaped groove of the groove-shaped bottom portion of the V-shaped groove123, the positive electrode power line124pof the power line retaining part114and the positive electrode power reception unit136pof the charging head134undergo sliding contact by way of point contact, and together therewith, the negative electrode power line124nof the power line retaining part114and the negative electrode power reception unit136nof the charging head134undergo sliding contact by way of point contact, whereby the electrical storage device100for driving of the electric vehicle10is charged from a power supplying device126through the power lines124and the charging arm118.

Third Embodiment

InFIGS. 9 and 10, there is shown a state of engagement (contact condition) of a charging head234according to a third example that constitutes a charging arm218according to the third example with the power lines24that are retained in the power line retaining part14according to the first example. The power line retaining part14and the charging arm218are included in a contact charging system212according to the third embodiment. The distal end of the charging head234opens expansively in a reverse V-shape, and power reception units236made up from a positive electrode power reception unit236pand a negative electrode power reception unit236n, which are cylindrically shaped rolling wheels, are attached to retaining members238a,238bof the reverse V-shape. By the positive electrode power reception unit236pand the negative electrode power reception unit236nsliding in line contact while rolling respectively on the positive electrode power line24pand the negative electrode power line24n, the electrical storage device100for driving of the electric vehicle10is charged from the power supplying device26through the charging head234.

FIGS. 11 and 12show a contact condition of a charging head234′ according to a modification of the third example with the power lines24that are retained in the power line retaining part14according to the first example. The power line retaining part14and the charging head234′ are included in the contact charging system212′ according to a modification of the third embodiment. The charging head234′ is in the form of a reverse V-shape, and upper and lower retaining members238a′,238b′ thereof are offset with respect to the running directions RD.

A power reception unit236′ made up from a positive electrode power reception unit236p′ and a negative electrode power reception unit236n′, which are cylindrically shaped rolling wheels, are attached to the offset upper and lower retaining members238a′,238b′. By the positive electrode power reception unit236p′ and the negative electrode power reception unit236n′ sliding in line contact while rolling respectively on the positive electrode power line24pand the negative electrode power line24n, the electrical storage device100for driving of the electric vehicle10is charged from the power supplying device26through the charging head234′.

Because the positive electrode power reception unit236p′ and the negative electrode power reception unit236n′ are attached in an offset manner in forward and rearward directions of the running directions RD, compared with the charging head234of the example ofFIGS. 9 and 10, the pitching behavior of the charging head234′ in the direction of movement (the running directions RD of the electric vehicle10) of the charging head234′ is stabilized.

Fourth Embodiment

InFIGS. 13, 14, and 15, there is shown a contact condition of a charging head334according to a fourth example that constitutes a charging arm318according to a fourth example with the power lines124that are retained in the power line retaining part114according to the second example. The power line retaining part114and the charging arm318are included in a contact charging system312according to a fourth embodiment.

The charging head334includes a base section348shaped in the form of a triangular prism. An attachment member354is mounted on one side surface of the base section348, and rolling wheels352are attached through attachment members350to ends on upper and lower surfaces (in directions perpendicular to the sheet inFIG. 14) of the base section348.

Further, attachment plates358to which a power reception unit336is attached are disposed in parallel on both remaining side surfaces of the base section348. The power reception unit336includes a positive electrode power reception unit336pand a negative electrode power reception unit336n, which are biased respectively through springs356toward a side of the positive electrode power line124pand toward a side of the negative electrode power line124n.

The attachment plates358are biased by the springs356toward the sides of the power lines124about respective supporting shafts disposed between facing surfaces of the attachment members350on the sides of the rolling wheels352.

More specifically, the attachment plates358are urged in the directions of the arrows r, together with movement thereof being regulated by spring mechanisms95made up from the springs356, pins94, regulating members93, and pins92.

In the charging head334according to the fourth example, while the rolling wheels352roll along a U-shaped groove of the V-shaped groove123in which the groove-shaped bottom portion thereof is in the form of a U-shaped groove, the positive electrode power reception unit336pis kept in contact by a compression force of the spring356with respect to the positive electrode power line124p, and together therewith, the negative electrode power reception unit336nis kept in contact by a compression force of the spring356with respect to the negative electrode power line124n, whereby the electrical storage device100for driving of the electric vehicle10is charged from the power supplying device126through the charging head234.

SUMMARY OF EMBODIMENTS

As described above, according to the aforementioned embodiments, for example as shown inFIGS. 1A, 1B, 1C, and 6, a configuration is provided comprising the power supplying device26, which includes the power line retaining part14in which the V-shaped groove23is provided that faces toward the side portion10sof the electric vehicle10and is formed to open in upper and lower directions DL of the electric vehicle10and to extend in the running directions ED of the electric vehicle10, and the positive electrode power line24pon one inner surface and the negative electrode power line24non another inner surface of the V-shaped groove23that makes up the power line retaining part14are fixed to the power line retaining part14respectively along the running directions RD and at positions to maintain an insulation distance mutually therebetween. In addition, the charging arm18, which is accommodated in the side portion10sof the electric vehicle10and includes the positive electrode power reception unit36pand the negative electrode power reception unit36n, which are provided on a distal end thereof and are disposed so as to face the corresponding positive electrode power line24pand the negative electrode power line24nof the power supplying device26, is made to extend out in a vehicle widthwise direction WD, and to bring into contact simultaneously the positive electrode power line24pof the power supplying device26and the positive electrode power reception unit36pof the charging arm18, and the negative electrode power line24nof the power supplying device26and the negative electrode power reception unit36nof the charging arm18, so as to charge the electrical storage device100for driving of the electric vehicle10. Therefore, even if the charging arm18swings or rocks in upper and lower directions UL due to road conditions or braking operations or the like, the charging head34that defines the distal end part of the charging arm18is retained inside the V-shaped groove23, and contact is prevented from not being secured.

Further, because the positive electrode power line24pand the negative electrode power line24nare fixed above and below on inner surfaces of the V-shaped groove23, both the power supplying device26and the charging arm18can be made smaller in scale, and as a result, it is possible for the contact charging system12as a whole to be made smaller in scale.

The present invention is not limited to the above-described embodiments, and it goes without saying that various configurations could be adopted therein, based on the content disclosed in the present specification.