Carrying apparatus

A swivel base is provided on a trolley so as to be able to swivel around a vertical axis, and a fork can be slid in a horizontal direction between an advanced position and a retracted position by a sliding mechanism capable of moving up and down along a pillar erected on the swivel base. Thus, it is possible to realize a configuration in which an empty-box skid is loaded in one direction and unloaded in another direction by means of the swiveling swivel base, without employing a configuration in which a plurality of members is supported so as to be able to swivel around different vertical axes. A movable range of the sliding mechanism (a movable range of the fork) in a vertical direction is therefore not significantly limited, and a transfer position of the empty-box skid in the vertical direction can be set to a lower position.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2018-175956 filed on Sep. 20, 2018 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a carrying apparatus. More particularly, the present disclosure relates to an improvement on a carrying apparatus having a swivel base that is mounted on a trolley and is capable of swiveling around a vertical axis.

2. Description of Related Art

A carrying apparatus for carrying a load placed thereon is known that, as disclosed in Japanese Patent Application Publication No. 10-297714 (JP 10-297714 A), has a swivel base that is mounted on a trolley and is capable of swiveling around a vertical axis, and allows a load to be loaded in one direction and unloaded in another direction by means of the swiveling swivel base.

JP 10-297714 A discloses a carrying apparatus including: a trolley (which is called a traveling base in JP 10-297714 A) that travels along a travel path; a swivel base which is supported on the trolley so as to be able to swivel around a first vertical axis (perpendicular axis) and on which a pillar is erected; an elevating stage capable of moving up and down along the pillar; an arm supported by the elevating stage so as to be able to swivel around a second vertical axis offset from the first vertical axis; a hand support body supported by the arm so as to be able to swivel around a third vertical axis offset from the second vertical axis; and a load hand supported by the hand support body.

SUMMARY

The carrying apparatus disclosed in JP 10-297714 A has a configuration in which the swivel base, the arm, and the hand support body are supported so as to be able to swivel around different vertical axes. Therefore, even when the elevating stage that moves up and down along the pillar is moved down to the lowest position, the position of the load hand is still high due to the respective height dimensions of the elevating stage, the arm, and the hand support body. Thus, the movable range of the load hand in the vertical direction is limited, which puts a restriction on setting a lower position as the transfer position in the vertical direction of a load held by the load hand.

For example, there is a constraint that, for the carrying apparatus to receive a load placed on a transportation trolley, the level of an upper surface of the transportation trolley (the surface on which the load is placed) needs to be set to a relatively high level matching the level of the load hand located at the lowest position.

The present disclosure provides a carrying apparatus that allows a load transfer position in a vertical direction to be set to a lower position.

An aspect of the present disclosure relates to a carrying apparatus for carrying a load placed thereon. This carrying apparatus includes: a trolley configured to travel; a swivel base provided on the trolley so as to be able to swivel around a vertical axis; a pillar erected on the swivel base and extending in a vertical direction; a holding member configured to hold the load; and a sliding mechanism capable of moving up and down along a first extension direction of the pillar and configured to slide the holding member in a horizontal direction between an advanced position at which the load is handed over and a retracted position at which the load is located above the swivel base.

In this configuration, a load is held (received) by the holding member as follows: The sliding mechanism moves up or down along the first extension direction of the pillar and thereby moves the holding member to a level at which the load is received. For example, in the case where the load is a skid that is a pallet with a plurality of boxes placed thereon, the holding member is moved to the level of the pallet. Then, the sliding mechanism slides the holding member to the advanced position (the position at which the load is received), and the holding member receives and holds the load. Thereafter, the sliding mechanism slides the holding member to the retracted position (the position at which the load is located above the swivel base), and the load is carried in this state by the traveling trolley.

A load held by the holding member is unloaded (e.g., unloaded onto a chute) as follows: The sliding mechanism moves up or down along the first extension direction of the pillar and thereby moves the holding member to a level at which the load is unloaded (discharged). In this case, if a load receiving direction in which the load is received and a load unloading direction are different from each other, the swivel base is swiveled around the vertical axis such that the load faces the unloading direction. For example, in the case where the load is the skid, the swivel base is swiveled such that the skid faces the unloading direction, and the holding member is moved until the pallet is located at the level of a predetermined placing surface (e.g., an upper surface of the chute). Then, the sliding mechanism slides the holding member to the advanced position (the position at which the load is unloaded), and the load is unloaded from the holding member (e.g., unloaded onto the chute).

A load carrying operation is thus performed. While the swivel base is provided on the trolley so as to be able to swivel around the vertical axis, the holding member is driven by the sliding mechanism to move in the vertical direction (move in the vertical direction as the sliding mechanism moves up and down) and to move in the horizontal direction. This means that the carrying apparatus does not have a configuration in which a plurality of members is supported so as to be able to swivel around different vertical axes (the configuration of the carrying apparatus of JP 10-297714 A). There is therefore no member (member supported so as to be able to swivel around the vertical axis) that constitutes an obstacle to lowering the lowest position to which the sliding mechanism can be moved along the pillar. As a result, the movable range of the sliding mechanism in the vertical direction (the movable range of the holding member in the vertical direction) is not significantly limited, and the load transfer position in the vertical direction can be set to a lower position.

The above carrying apparatus may further include a control unit that controls the sliding mechanism. The erection position of the pillar may be set to a position offset from the center of swiveling of the swivel base. When the holding member is at the retracted position, the load held by the holding member may be located above the center of swiveling. The control unit may be configured to control the sliding mechanism so as to move the holding member to the retracted position before the swivel base swivels.

Thus, the holding member is moved to the retracted position before the swivel base swivels, and the load is located above the center of swiveling while the load is held by the holding member. This means that the swivel base is swiveled in a state where the center of swiveling of the swivel base and the position of the center of gravity of the load are close to each other, which allows the swivel base to swivel while the load is stably held.

The sliding mechanism may include a guide member extending toward one side and the other side of the pillar in a horizontal direction and configured to be able to move up and down along the first extension direction of the pillar. The holding member may be configured to be able to slide in a horizontal direction along a second extension direction of the guide member.

Thus, when the holding member is moved to the advanced position by the sliding mechanism, the holding member can be located on one side of the pillar in the horizontal direction along the second extension direction of the guide member, and when the holding member is moved to the retracted position by the sliding mechanism, the holding member can be located on the other side of the pillar in the horizontal direction along the second extension direction of the guide member. This means that the holding member has a wide movable range by being able to move toward both one side and the other side of the pillar in the horizontal direction. Since the holding member can be moved to above the center of swiveling of the swivel base, the carrying apparatus can carry a large-sized load.

The trolley may have a bottom plate and a vertical wall extending vertically upward from an outer edge of the bottom plate. The carrying apparatus may include a swivel driving mechanism installed on the bottom plate. The swivel base may be mounted on an upper side of the swivel driving mechanism and configured to be able to swivel by receiving power directed around the vertical axis from the swivel driving mechanism. A lower surface of the swivel base may be located at a level higher than the level of an upper end of the vertical wall of the trolley by a predetermined dimension.

Thus, when the swivel driving mechanism is activated to swivel the swivel base, the swivel base can swivel without interfering with the vertical wall of the trolley by passing above the vertical wall even when the length dimension of the swivel base is relatively large (e.g., even when the length dimension of the swivel base is larger than the width dimension of the trolley). A greater degree of flexibility is thereby allowed for the size and the range of swiveling of the swivel base. Since the swivel driving mechanism on which the swivel base is mounted is installed on the bottom plate located at a lower position than the upper end of the trolley (the upper end of the vertical wall), it is possible to set the installation level of the swivel base to a lower level and thereby contribute to setting the load transfer position in the vertical direction to a lower position.

In the present disclosure, the swivel base is provided on the trolley so as to be able to swivel around the vertical axis, and the holding member (the holding member that holds a load) can be slid in the horizontal direction between the advanced position and the retracted position by the sliding mechanism capable of moving up and down along the pillar erected on the swivel base. Thus, it is possible to realize a configuration in which a load is loaded (received) in one direction and unloaded in another direction by means of the swiveling swivel base, without employing a configuration in which a plurality of members is supported so as to be able to swivel around different vertical axes. There is therefore no member (member supported so as to be able to swivel around the vertical axis) that constitutes an obstacle to lowering the lowest position to which the sliding mechanism can be moved along the pillar. As a result, the movable range of the sliding mechanism in the vertical direction (the movable range of the holding member in the vertical direction) is not significantly limited, and the load transfer position in the vertical direction can be set to a lower position.

DETAILED DESCRIPTION OF EMBODIMENTS

An embodiment of the present disclosure will be described below based on the drawings. In this embodiment, a case will be described where the present disclosure is applied to a carrying apparatus used in an automobile production plant to carry an empty-box skid (a “load” as termed in the present disclosure) that is a pallet having placed thereon a plurality of empty boxes (empty parts boxes) from which parts have been taken out (parts have been fed to a production line), from a transportation trolley to an empty-box skid chute at an empty-box return station. In the following description, an action of picking up an empty-box skid on a transportation trolley by the carrying apparatus will be referred to as an empty-box skid receiving action, and an action of placing an empty-box skid from the carrying apparatus onto an empty-box skid chute will be referred to as an empty-box skid unloading action.

Carrying Apparatus

FIG. 1is a perspective view of a carrying apparatus1according to the embodiment.FIG. 2is a plan view of the carrying apparatus1according to the embodiment. Here, for convenience, the far side inFIG. 1and the left side inFIG. 2will be referred to as a front side of the carrying apparatus1, and the near side inFIG. 1and the right side inFIG. 2will be referred to as a rear side of the carrying apparatus1. Accordingly, the arrows FR, RE, UP, RH, and LH in these drawings indicate a frontward direction, a rearward direction, an upward direction, a rightward direction, and a leftward direction, respectively. Hereinafter, a front-rear direction, a width direction (right-left direction), and an up-down direction of the carrying apparatus1may also be referred to as an X-axis direction, a Y-axis direction, and a Z-axis direction, respectively.

As shown inFIG. 1andFIG. 2, the carrying apparatus1includes a trolley2, a swivel base3, a swivel driving mechanism31, a pillar4, a sliding mechanism5, and a fork (a “holding member” as termed in the present disclosure)6.

Trolley

The trolley2is a member by which the carrying apparatus1travels and which supports the swivel base3, the pillar4, the sliding mechanism5, and the fork6. The trolley2includes a trolley main body21, four wheels22,22,23,23, and a traveling motor (formed by an electric motor)24.

The trolley main body21has a rectangular shape as seen in a plan view, and has a bottom plate21aand vertical walls21b,21b, . . . extending vertically upward from outer edges of the bottom plate21a, and a space to house the swivel driving mechanism31, to be described later, that swivels the swivel base3is provided on an inside of the vertical walls21b,21b, . . . .

A travel power source support bracket25extending in a horizontal direction toward the front side is mounted on a front end surface of the trolley main body21. The traveling motor24serving as a travel power source is supported on a lower surface of the travel power source support bracket25. The traveling motor24includes a driving shaft (output shaft) extending along the front-rear direction of the carrying apparatus1(X-axis direction). The wheels22,22serving as driving wheels are provided respectively on right and left sides of the travel power source support bracket25(on both sides in the Y-axis direction). The wheels22,22rotate by receiving power from the traveling motor24. Specifically, a power transmission mechanism (not shown) that transmits power from the traveling motor24to the wheels22,22is mounted on the travel power source support bracket25. The power transmission mechanism includes a gear mechanism that changes a rotation direction of rotating power output from the traveling motor24(converts rotation around the X-axis into rotation around the Y-axis), a speed reducer that reduces the rotation speed, etc.

The wheels23,23serving as driven wheels are supported so as to be rotatable around a horizontal axis (Y-axis) by brackets21c,21cmounted on a rear end surface of the trolley main body21.

Swivel Base

The swivel base3is formed by a substantially rectangular plate member that is smaller than the bottom plate21aof the trolley main body21, and is mounted so as to be able to rotate (swivel) around a vertical axis (Z-axis) on an upper side of the swivel driving mechanism31that is provided at a center part of the bottom plate21aof the trolley main body21. The dimension of the swivel base3in a longitudinal direction (the dimension in the X-axis direction in the state shown inFIG. 1andFIG. 2; the state of the swivel base3shown inFIG. 1andFIG. 2will be referred to as an initial swiveling position of the swivel base3) is smaller than the dimension of the trolley main body21in a longitudinal direction (the dimension in the X-axis direction). The dimension of the swivel base3in the longitudinal direction is larger than the dimension of the trolley main body21in the width direction (the dimension in the Y-axis direction). However, the swivel base3at the initial swiveling position is disposed such that the longitudinal direction thereof coincides with the longitudinal direction of the trolley main body21, and not with the width direction of the trolley main body21, which makes the configuration of the carrying apparatus1compact.

A fork pocket detection sensor7is mounted on the swivel base3through a bracket71. The fork pocket detection sensor7is a sensor, such as a laser sensor, that detects a fork pocket FP of a pallet P of an empty-box skid S (seeFIG. 4) to be described later. Specifically, the fork pocket detection sensor7detects the position of the fork pocket FP, for example, by emitting a laser beam along the width direction of the carrying apparatus1(Y-axis direction) (emitting a laser beam toward the pallet P so as to pass through the upper side of the trolley main body21) in a state where the swivel base3is at the initial swiveling position, and then detecting light reflecting off a side surface of the pallet P of the empty-box skid S. The mounting position of the fork pocket detection sensor7is not limited to the swivel base3but may also be on the trolley main body21.

The swivel driving mechanism31includes a sprocket33supported on the bottom plate21aso as to be rotatable around the vertical axis (Z-axis), and the swivel base3is mounted on an upper surface of the sprocket33by means of bolt fastening etc. so as to be able to rotate integrally. The swivel driving mechanism31includes a swiveling motor32. The swiveling motor32is provided at a rearward position on the bottom plate21aof the trolley main body21, and serves as a swivel power source for the swivel base3. The swiveling motor32includes a driving shaft (output shaft) extending along the front-rear direction of the carrying apparatus1(X-axis direction). The sprocket33rotates by receiving power from the swiveling motor32. As the sprocket33rotates, the swivel base3rotates around the vertical axis (Z-axis). Specifically, a power transmission mechanism (not shown) that transmits power from the swiveling motor32to the sprocket33is provided between the swiveling motor32and the sprocket33. This power transmission mechanism includes a gear mechanism that changes a rotation direction of rotating power output from the swiveling motor32(converts rotation around the X-axis into rotation around the Z-axis), a speed reducer that reduces the rotation speed, etc. A chain is suspended between a sprocket (driving-side sprocket; not shown) coupled to this speed reducer and the sprocket (driven-side sprocket)33, and rotating power output from the swiveling motor32is transmitted to the driven-side sprocket33through the power transmission mechanism, allowing the swivel base3to rotate around the vertical axis (Z-axis).

The level of the swivel base3is set such that the level of a lower surface of the swivel base3is slightly higher than the level of an upper end of the vertical wall21bof the trolley main body21. In other words, the swivel driving mechanism31is provided on the bottom plate21asuch that the level of the upper surface of the sprocket33on which the swivel base3is mounted is slightly higher than the level of the upper end of the vertical wall21bof the trolley main body21. Thus, when the swivel base3rotates around the vertical axis, the swivel base3does not interfere with the trolley main body21(the vertical wall21bof the trolley main body21). To set the installation level of the swivel base3to as low a level as possible, it is preferable that the interval between the level of the lower surface of the swivel base3and the level of the upper end of the vertical wall21bof the trolley main body21be small.

Pillar

The pillar4is erected at a rearward position on the swivel base3(a rearward position with the swivel base3at the initial swiveling position shown inFIG. 1), and extends in the vertical direction. Specifically, the pillar4is erected at a rearward position (a position offset toward the rear side) from a center of swiveling O around which the swivel base3is swiveled by the swivel driving mechanism31(the center of rotation of the driven-side sprocket33). The pillar4includes a pair of right and left pillar members41,41extending in the vertical direction, and a plurality of coupling members42,42, . . . provided at positions at predetermined intervals in the vertical direction so as to couple together the pillar members41,41.

The height dimension of the pillar4is set such that the position of an upper end of the pillar4is equivalent to a transfer level in the vertical direction of an empty-box skid S that is located farthest on the upper side when empty-box skids S are piled up by the carrying apparatus1(e.g., when empty-box skids S, S, . . . are piled up in tiers on an empty-box skid conveyor SC of an empty-box skid chute SS to be described later).

Sliding Mechanism and Fork

The sliding mechanism5is capable of moving up and down along the extension direction of the pillar4, and slides the fork6in a horizontal direction between an advanced position (the position indicated by solid lines inFIG. 2) at which the empty-box skid S is handed over (received and unloaded) and a retracted position (the position indicated by imaginary lines inFIG. 2) at which the empty-box skid S is located above the swivel base3in a state where the fork6holds the empty-box skid S.

Specifically, the sliding mechanism5includes guide members51,52that guide the sliding of the fork6. These guide members are an upper guide member51and a lower guide member52that are provided parallel to each other (parallel along the Y-axis direction) with a predetermined interval left in the vertical direction. The upper guide member51and the lower guide member52are coupled together at both ends in a longitudinal direction by coupling members53,53. Thus, there is a predetermined interval in the vertical direction between the upper guide member51and the lower guide member52that corresponds to the height dimension of the coupling member53. The guide members51,52extend toward one side and the other side of the pillar4in the horizontal direction (Y-axis direction). Specifically, on one side in the longitudinal direction (Y-axis direction), the guide members51,52extend over a predetermined dimension in the leftward direction (the leftward direction inFIG. 1), and have leading ends located on the left side of a left-side edge of the trolley2as seen in a plan view. Similarly, on the other side in the longitudinal direction (Y-axis direction), the guide members51,52extend over a predetermined dimension in the rightward direction (the rightward direction inFIG. 1), and have leading ends located on the right side of a right-side edge of the trolley2as seen in a plan view.

The fork6includes a pair of prongs61,62extending along the Y-axis direction, and a coupling part63extending in the front-rear direction (X-axis direction) so as to couple together base ends of the prongs61,62. With a rear end portion of the coupling part63engaged with the upper guide member51and the lower guide member52, the fork6is slidable in the horizontal direction.

An elevating motor54is provided on the swivel base3, near a lower end of the pillar4. The elevating motor54includes a driving shaft (output shaft) extending along the up-down direction (Z-axis direction). The driving shaft of the elevating motor54is connected to a power transmission mechanism54ainstalled on the swivel base3. The power transmission mechanism54aincludes a gear mechanism that changes a rotation direction of rotating power output from the elevating motor54(converts rotation around the Z-axis into rotation around the Y-axis), a speed reducer that reduces the rotation speed, etc. An output shaft (not shown) of the power transmission mechanism54aextends toward both sides in the Y-axis direction, and pulleys54b,54bare mounted on both sides of this output shaft. On the other hand, pulleys54c,54c,43,43rotatable around axes in the width direction of the carrying apparatus1(Y-axis direction) are provided respectively on lower ends and upper ends of the pillar members41,41of the pillar4. A belt54dis wound around the pulleys54b,54c,43. Thus, when the elevating motor54is activated to rotate the pulleys54b,54bmounted on the output shaft of the power transmission mechanism54a, the resulting rotating power causes the belt54dto travel across the pulleys54b,54c,43. The guide members51,52of the sliding mechanism5are coupled to the belts54d,54din a span between the pulleys54c,43, and the sliding mechanism5moves up and down along the extension direction of the pillar4as the belts54d,54dtravel. Therefore, the elevation position of the sliding mechanism5can be controlled by adjusting the amount of rotation of the elevating motor54. Since the fork6is engaged with the upper guide member51and the lower guide member52as described above, the fork6also moves up and down as the sliding mechanism5moves up and down, and therefore the elevation position of the fork6can be controlled by controlling the elevation position of the sliding mechanism5.

A sliding motor55is supported through a bracket55aon a right-side end of an upper surface of the upper guide member51. The sliding motor55includes a driving shaft (output shaft) extending along the front-rear direction (X-axis direction) of the swivel base3at the initial swiveling position. A speed reducer55dis connected to the driving shaft of the sliding motor55. A pulley55bis mounted on an output shaft of the speed reducer55d. On the other hand, a pulley56rotatable around an axis in the front-rear direction (X-axis direction) of the swivel base3at the initial swiveling position is supported through a bracket56aon a left-side end of the upper surface of the upper guide member51. A belt55cis wound around the pulley (driving-side pulley)55bcoupled to the sliding motor55and the pulley (driven-side pulley)56provided at the left-side end of the upper surface of the upper guide member51. Thus, when the sliding motor55is activated to rotate the driving-side pulley55b, the resulting rotating power causes the belt55cto travel across the driving-side pulley55band the driven-side pulley56. The coupling part63of the fork6is coupled to the belt55c, and the fork6slides along the extension direction of the guide members51,52(horizontal direction) as the belt55ctravels. Therefore, the sliding position of the fork6can be controlled by adjusting the amount of rotation of the sliding motor55. The fork6can be thereby slid in the horizontal direction between the advanced position (the position indicated by solid lines inFIG. 2) at which the empty-box skid S is handed over (received and unloaded) and the retracted position (the position indicated by imaginary lines inFIG. 2) at which the empty-box skid S is located above the swivel base3in a state where the fork6holds the empty-box skid S. When the fork6is at the retracted position, the prongs61,62of the fork6are located one on each side of the center of swiveling O of the swivel base3(on each side in a direction along the X-axis direction) as seen in a plan view. Thus, at the retracted position, the empty-box skid S held by the fork6is located above the center of swiveling O of the swivel base3. In other words, the empty-box skid S is held by the fork6in a state where the position of the center of gravity of the empty-box skid S and the center of swiveling O of the swivel base3are close to each other.

Control Block

FIG. 3is a block diagram showing the configuration of a control system of the carrying apparatus1according to the embodiment. As shown inFIG. 3, the control system of the carrying apparatus1includes a control panel8. Although this is not shown, the control panel8includes a commonly known central processing unit (CPU), a read-only memory (ROM), a random-access memory (RAM), and others.

The ROM stores a control program etc. used to control the carrying apparatus1to carry the empty-box skid S. The CPU executes a computation process based on the control program stored in the ROM. The RAM is a memory that temporarily stores a computation result of the CPU etc. Alternatively, the carrying apparatus1may be controlled by a command from a control unit provided outside the carrying apparatus1. The control unit in the present disclosure may be the control panel8or a control unit provided outside the carrying apparatus1.

The control panel8is connected to the fork pocket detection sensor7, a transportation trolley control panel81, a supplier determination unit82, and an empty-box skid conveyor control unit83, and information from these are input into the control panel8.

As described above, the fork pocket detection sensor7detects the position of the fork pocket FP, for example, by emitting a laser beam toward the pallet P of the empty-box skid S and detecting light reflecting off a side surface of the pallet P. A detection signal output from the fork pocket detection sensor7is input into the control panel8, and the control panel8thereby recognizes the position of the fork pocket FP of the pallet P.

The transportation trolley control panel81controls traveling and stopping of the transportation trolley CC (seeFIG. 5that shows the empty-box return station ST inside the automobile production plant) when the transportation trolley CC with the empty-box skid S placed thereon travels toward the empty-box return station ST. Specifically, the transportation trolley CC is moved to the empty-box return station ST by being towed by a tow vehicle (not shown). As control of traveling and stopping of the transportation trolley CC towed by a tow vehicle is publicly known, the description thereof will be omitted here. An output signal from the transportation trolley control panel81is input into the control panel8, and the control panel8thereby recognizes the stopping position of the transportation trolley CC. More specifically, in this embodiment, a plurality of transportation trollies CC, CC, . . . is coupled to one another and moved to the empty-box return station ST as shown inFIG. 5. Accordingly, the output signal from the transportation trolley control panel81includes information on stopping positions of the respective transportation trollies CC, CC, . . . .

The supplier determination unit82acquires information on a return destination of the empty-box skid S placed on the transportation trolley CC, i.e., the supplier of parts having been contained in parts boxes B, B, . . . of the empty-box skid S (parts having been fed to a production line). For example, the supplier determination unit82determines the supplier by recognizing a label etc. displayed on or attached to a side surface of the pallet P or side surfaces of the parts boxes B, B, . . . of the empty-box skid S (by taking images and performing image recognition). The supplier determination unit82is connected to a database DB1that stores information in which information on suppliers is associated with the empty-box skid chutes SS installed at the empty-box return station ST. By referring to the information stored in the database DB1, the supplier determination unit82specifies the empty-box skid chute SS from the information on the supplier, and sends the acquired information to the control panel8. An output signal from the supplier determination unit82is input into the control panel8, and the control panel8thereby ascertains the separate return destinations (the empty-box skid chutes SS as return destinations) of the empty-box skids S, S, . . . placed on the respective transportation trollies CC, CC, . . . . The supplier determination unit82may be installed at the empty-box return station ST, or may be configured to acquire information on the return destinations of the empty-box skids S, S, . . . at a stage before the transportation trollies CC, CC, . . . are moved to the empty-box return station ST.

The empty-box skid conveyor control unit83controls the empty-box skid conveyor SC of the empty-box skid chute SS installed at the empty-box return station ST. Specifically, the empty-box skid conveyor SC is controlled as follows: When the upper limit of the number of tiers of the empty-box skids S placed on the empty-box skid conveyor SC is four, the empty-box skid conveyor SC is activated when four tiers of empty-box skids S are placed on the empty-box skid conveyor SC, to convey these four tiers of empty-box skids S, S, . . . toward an unloading side (e.g., a side where a freight truck is on standby). The empty-box skid conveyor control unit83is connected to a database DB2that stores setting information on the upper limit of the number of tiers of the empty-box skids S placed on the empty-box skid conveyor SC. By referring to the information stored in the database DB2, the empty-box skid conveyor control unit83sends to the control panel8the setting information on the upper limit of the number of tiers of the empty-box skids S placed on the empty-box skid conveyor SC. The control panel8receives an output signal from the empty-box skid conveyor control unit83, and thereby ascertains the current number of tiers of the empty-box skids S placed on the empty-box skid conveyor SC and the upper limit of the number of tiers of the empty-box skids S placed on the empty-box skid conveyor SC. The control panel8controls the loading height at which the empty-box skid S is placed on the empty-box skid conveyor SC (the loading height of the empty-box skid S that is determined by moving up and down the sliding mechanism5) accordingly.

The control panel8is connected to each of the traveling motor24, the swiveling motor32, the elevating motor54, and the sliding motor55, and controls the traveling action of the carrying apparatus1, the swiveling action of the swivel base3, the up-and-down moving action of the sliding mechanism5, and the sliding action of the fork6by outputting control signals to these motors24,32,54,55.

FIG. 4is a view showing an example of the empty-box skid S to be carried by the carrying apparatus1. As shown inFIG. 4, the empty-box skid S has the form of the pallet P with a plurality of empty boxes (empty parts boxes) B, B, . . . placed thereon. In this embodiment, the fork pockets FP, FP are provided in side surfaces of the pallet P, and the empty-box skid S can be lifted (held) and carried with the prongs61,62of the fork6respectively inserted into the fork pockets FP, FP.

Although this is not shown, information on a parts manufacturer that is the supplier of the part having been contained in the empty box B is displayed on a side surface of the pallet P. For example, the name of the parts manufacturer, or a two-dimensional code etc. for identifying the parts manufacturer is displayed. The supplier determination unit82determines the supplier by reading the displayed information.

Empty-Box Return Station

Next, the empty-box return station ST at which the carrying apparatus1configured as has been described above is used will be described. As described above, the carrying apparatus1is used to carry the empty-box skid S from the transportation trolley CC to the empty-box skid chute SS at the empty-box return station ST.

As shown inFIG. 5, a plurality of empty-box skid chutes SS, SS, . . . installed for the respective parts manufacturers are provided at the empty-box return station ST. (InFIG. 5, one of the empty-box skid chutes SS is indicated by imaginary lines.) Each empty-box skid chute SS includes the empty-box skid conveyor SC that conveys the empty-box skids S, S, . . . . At the empty-box return station ST, a carrying apparatus path P1is provided on a side closer to the empty-box skid chute SS along the direction in which the empty-box skid chutes SS, SS, . . . are provided, and a transportation trolley path P2is provided on a side farther away from the empty-box skid chute SS, adjacent to the carrying apparatus path P1. Thus, while traveling along the carrying apparatus path P1, the carrying apparatus1receives the empty-box skid S from a predetermined transportation trolley CC among the transportation trollies CC, CC, . . . having traveled along the transportation trolley path P2, and carries this empty-box skid S onto the empty-box skid conveyor SC of a predetermined empty-box skid chute SS.

In this embodiment, the transportation trollies CC, CC, . . . coupled to one another are moved to the empty-box return station ST by being towed by the tow vehicle (not shown) as described above. The transportation trolley CC is provided with a handle CC1that allows a worker to move the transportation trolley CC.

Empty-Box Skid Carrying Operation

Next, an operation of carrying the empty-box skid S at the empty-box return station ST, i.e., an operation in which the carrying apparatus1receives the empty-box skid S from the transportation trolley CC and places the empty-box skid S on a predetermined empty-box skid chute SS, will be described.

In this carrying operation of the empty-box skid S, an empty-box skid receiving action of picking up the empty-box skid S on the transportation trolley CC by the carrying apparatus1, a traveling action of the carrying apparatus1, and an empty-box skid unloading action of placing the empty-box skid S from the carrying apparatus1onto the empty-box skid chute SS, are sequentially performed. These actions will be sequentially described below.

Empty-Box Skid Receiving Action

In the empty-box skid receiving action, first, the return destinations of the empty-box skids S, S, . . . placed on the respective transportation trollies CC, CC, . . . to be moved to the empty-box return station ST by being towed by the tow vehicle, i.e., the empty-box skid chutes SS, SS, . . . onto which the empty-box skids S, S, . . . should be respectively unloaded, are determined (the suppliers of the parts are determined) by the supplier determination unit82. Specifically, the supplier determination unit82determines the supplier by recognizing a label etc. displayed on or attached to a side surface of the pallet P or side surfaces of the parts boxes B, B, . . . of the empty-box skid S, and by referring to the information stored in the database DB1, acquires information in which the information on the determined supplier is associated with the empty-box skid chute SS, and sends the acquired information to the control panel8of the carrying apparatus1. The control panel8thereby ascertains the separate return destinations (the empty-box skid chutes SS as return destinations) of the empty-box skids S, S, . . . placed on the respective transportation trollies CC, CC, . . . .

Then, the traveling motor24is activated to rotate the wheels22,22,23,23, and the carrying apparatus1travels to a position at which the carrying apparatus1faces the transportation trolley CC on which the empty-box skid S to be carried is placed. For example, the carrying apparatus1travels to the position at which the carrying apparatus1faces the second transportation trolley CC from the near side inFIG. 5.FIG. 5shows a state where the empty-box skid S is being carried by the carrying apparatus1.FIG. 6AandFIG. 6Bare schematic views showing a state where the carrying apparatus1has traveled to the position at which the carrying apparatus1faces the empty-box skid S during the empty-box skid receiving action of the carrying apparatus1.FIG. 6Ais a plan view andFIG. 6Bis a perspective view. (InFIG. 6AandFIG. 6B, the transportation trolley CC is not shown.)

After the carrying apparatus1thus travels to the position at which the carrying apparatus1faces the transportation trolley CC on which the empty-box skid S is placed, the elevating motor54is activated to move the sliding mechanism5up or down along the extension direction of the pillar4and thereby move the fork6to a position at which the fork6faces the pallet P (a position at which the prongs61,62of the fork6can be inserted into the fork pockets FP, FP).

The control to cause the carrying apparatus1to travel to the position at which the carrying apparatus1faces the transportation trolley CC and the control to move the fork6to the position at which the fork6faces the pallet P are performed by controlling each of the traveling motor24and the elevating motor54based on detection signals (detection signals of the position of the fork pocket FP) output from the fork pocket detection sensor7. That is, the prongs61,62of the fork6are controlled in each of the horizontal direction (X-axis direction) and the vertical direction (Z-axis direction) so as to face the fork pockets FP, FP, respectively.

Thereafter, the sliding motor55is activated to slide the fork6to the advanced position (the position at which the empty-box skid S is received; the position at which the prongs61,62of the fork6are inserted into the fork pockets FP, FP) and thereby hold the empty-box skid S by the fork6. (In reality, the elevating motor54is activated to slightly move up the fork6so as to lift and hold the empty-box skid S.)FIG. 7AandFIG. 7Bare schematic views showing a state where the fork6has slid to the advanced position during the empty-box skid receiving action of the carrying apparatus1.FIG. 7Ais a plan view andFIG. 7Bis a perspective view. (InFIG. 7AandFIG. 7B, the transportation trolley CC is not shown.)

In the state where the fork6is thus holding the empty-box skid S, the sliding motor55is activated to slide the fork6to the retracted position (the position at which the empty-box skid S is located above the swivel base3). Moreover, the elevating motor54is activated to move up the sliding mechanism5along the extension direction of the pillar4and also move up the empty-box skid S accordingly.FIG. 8AandFIG. 8Bare schematic views showing a state where the fork6has slid to the retracted position and the sliding mechanism5has moved up during the empty-box skid receiving action of the carrying apparatus1.FIG. 8Ais a plan view andFIG. 8Bis a perspective view. The elevating motor54is controlled here such that the empty-box skid S and the sliding mechanism5move up to such a level as not to interfere with the handle CC1of the transportation trolley CC etc. Since the level of the handle CC1is specified in advance, the position to which the sliding mechanism5is moved up is also specified in advance.

Traveling Action of Carrying Apparatus

In the traveling action of the carrying apparatus1, the traveling motor24is activated to rotate the wheels22,22,23,23, and the carrying apparatus1travels to a position at which the carrying apparatus1faces the empty-box skid chute SS onto which the empty-box skid S held by the carrying apparatus1is to be unloaded. For example, the carrying apparatus1travels to the position at which the carrying apparatus1faces the empty-box skid chute SS located on the near side inFIG. 5.

Empty-Box Skid Unloading Action

In the empty-box skid unloading action, a swiveling action of the swivel base3, an up-and-down moving action of the sliding mechanism5, and a sliding action of the fork6are performed.

In the swiveling action of the swivel base3, the swivel base3is swiveled 180° such that the empty-box skid S faces the empty-box skid chute SS. Specifically, the swiveling motor32is activated and rotating power output from the swiveling motor32is transmitted through the power transmission mechanism to the driven-side sprocket33, and thereby the swivel base3is rotated around the vertical axis (Z-axis).FIG. 9AtoFIG. 9Care plan views of the carrying apparatus illustrating the swiveling action of the swivel base3.FIG. 9AtoFIG. 9Cshow states of having swiveled 45°, 90°, and 135°, respectively.FIG. 10AandFIG. 10Bare schematic views showing a state of the swivel base3upon completion of swiveling.FIG. 10Ais a plan view andFIG. 10Bis a perspective view.

In the up-and-down moving action of the sliding mechanism5, it is ascertained how many tiers of the empty-box skids S are placed on the empty-box skid conveyor SC of the empty-box skid chute SS onto which the empty-box skid S is to be placed, and the elevation position of the sliding mechanism5is determined accordingly. Specifically, the control panel8receives an output signal from the empty-box skid conveyor control unit83, and ascertains the current number of tiers of the empty-box skids S placed on the empty-box skid conveyor SC (e.g., the current number of tiers of the empty-box skids S placed on the empty-box skid chute SS located on the near side inFIG. 5). The elevating motor54is controlled to move up or down the sliding mechanism5such that the level of the lower surface of the empty-box skid S that is currently held matches the level of the upper surface of the empty-box skid conveyor SC, according to each of cases where there is no empty-box skid S on the empty-box skid conveyor SC, where there is one empty-box skid S placed on the empty-box skid conveyor SC, where the empty-box skids S, S are placed in two tiers on the empty-box skid conveyor SC, and where the empty-box skids S, S, . . . are placed in three tires on the empty-box skid conveyor SC (such that the level of the lower surface of the empty-box skid S that is currently held matches the level of the upper surface of the empty-box skid conveyor SC in the case where there is no empty-box skid S on the empty-box skid conveyor SC and matches the level of the upper surface of the empty-box skid S located in the top tier in the case where there are one or more empty-box skids S on the empty-box skid conveyor SC).

In the sliding action of the fork6, the sliding motor55is activated to slide the fork6to the advanced position (the position at which the empty-box skid S is unloaded; the position at which the fork6is advanced to above the empty-box skid conveyor SC), and thereby the empty-box skid S is unloaded onto the empty-box skid conveyor SC. (In reality, the elevating motor54is activated to slightly move down the fork6so as to place the empty-box skid S onto the empty-box skid conveyor SC.)FIG. 11AandFIG. 11Bare schematic views showing a state where the sliding mechanism5has moved down to a predetermined position and the fork6has slid to the advanced position during the empty-box skid unloading action of the carrying apparatus1.FIG. 11Ais a plan view andFIG. 11Bis a perspective view. (InFIG. 11AandFIG. 11B, the empty-box skid chute SS is not shown.)

In a state where the empty-box skid S is thus placed on the empty-box skid conveyor SC, the sliding motor55is activated to slide the fork6to the retracted position. Specifically, the prongs61,62of the fork6are extracted from the fork pockets FP, FP.FIG. 12AandFIG. 12Bare schematic views showing a state where the fork6has slid to the retracted position during the empty-box skid unloading action of the carrying apparatus1.FIG. 12Ais a plan view andFIG. 12Bis a perspective view. (InFIG. 12AandFIG. 12B, the empty-box skid chute SS is not shown.)

Thus, the operation of carrying one empty-box skid S from the transportation trolley CC to a predetermined empty-box skid chute SS is completed. Thereafter, another empty-box skid S is carried from the transportation trolley CC to a predetermined empty-box skid chute SS in the same manner, and the same operation is repeatedly performed.

Effects of Embodiment

In this embodiment, the swivel base3is provided on the trolley2so as to be able to swivel around the vertical axis, and the fork6can be slid in the horizontal direction between the advanced position and the retracted position by the sliding mechanism5capable of moving up and down along the pillar4erected on the swivel base3. Thus, it is possible to realize a configuration in which the empty-box skid S is loaded (received from the transportation trolley CC by the carrying apparatus1) in one direction and unloaded (unloaded from the carrying apparatus1onto the empty-box skid chute SS) in another direction by means of the swiveling swivel base3, without employing a configuration in which a plurality of members is supported so as to be able to swivel around different vertical axes (the configuration of the carrying apparatus of JP 10-297714 A). There is therefore no member (member supported so as to be able to swivel around the vertical axis) that constitutes an obstacle to lowering the lowest position to which the sliding mechanism5can be moved along the pillar4. As a result, the movable range of the sliding mechanism5in the vertical direction (the movable range of the fork6in the vertical direction) is not significantly limited, and the transfer position of the empty-box skid S in the vertical direction can be set to a lower position.

The following are effects of the embodiment in comparison with the carrying apparatus of JP 10-297714 A: To move a load in the horizontal direction, the carrying apparatus of JP 10-297714 A requires activating a plurality of motors corresponding to the first to third vertical axes at the same time, which involves complicated control. By contrast, the embodiment requires activating only the sliding motor55to move a load (empty-box skid S) in the horizontal direction, and thus can achieve simplification of the control. Since the carrying apparatus of JP 10-297714 A bears the weight of a load by a leading end portion of a plurality of links, it is difficult to increase the allowable weight of a load to be carried. In the embodiment, by contrast, the empty-box skid S is held from below by the fork6having the two prongs61,62, which makes it possible to stably hold even a heavy empty-box skid S, and to increase the allowable weight of the empty-box skid S to be carried.

In the embodiment, when the fork6is at the retracted position, the empty-box skid S held by the fork6is located above the center of swiveling O of the swivel base3. Thus, the swivel base3is swiveled in a state where the center of swiveling O of the swivel base3and the position of the center of gravity of the empty-box skid S are close to each other, which allows the swivel base3to swivel while the empty-box skid S is stably held.

In the embodiment, the sliding mechanism5includes the guide members51,52extending toward one side and the other side of the pillar4in the horizontal direction and capable of moving up and down along the extension direction of the pillar4, and the fork6is slidable in the horizontal direction along the extension direction of the guide members51,52. Thus, when the fork6is moved to the advanced position by the sliding mechanism5, the fork6can be located on one side of the pillar4in the horizontal direction along the extension direction of the guide members51,52. When the fork6is moved to the retracted position by the sliding mechanism5, the fork6can be located on the other side of the pillar4in the horizontal direction along the extension direction of the guide members51,52. This means that the fork6has a wide movable range by being able to move toward both one side and the other side of the pillar4in the horizontal direction. Accordingly, the carrying apparatus can carry a large-sized empty-box skid S.

In the embodiment, the level of the lower surface of the swivel base3is set to a level by a predetermined dimension (slightly) higher than the level of the upper end of the vertical wall21bof the trolley2. Thus, when the swivel driving mechanism31is activated to swivel the swivel base3, the swivel base3can swivel without interfering with the vertical wall21bof the trolley2by passing above the vertical wall21beven when the length dimension of the swivel base3is relatively large. A greater degree of flexibility is thereby allowed for the size and the range of swiveling of the swivel base3. Since the swivel driving mechanism31on which the swivel base3is mounted is installed on the bottom plate21alocated at a lower position than the upper end of the vertical wall21bof the trolley2, it is possible to set the installation level of the swivel base3to a lower level and thereby contribute to setting the transfer position of the empty-box skid S in the vertical direction to a lower position.

Other Embodiments

The present disclosure is not limited to the above embodiment, and any modifications and applications included in the scope of the claims and an equivalent scope are possible.

For example, in the above embodiment, the case has been described where the present disclosure is applied to the carrying apparatus1used to carry the empty-box skid S from the transportation trolley CC to the empty-box skid chute SS at the empty-box return station ST inside an automobile production plant. The carrying apparatus1according to the present disclosure is not limited to this example but can also be used in production plants other than an automobile production plant. The present disclosure can also be used as a carrying apparatus that carries a skid that is a pallet with parts boxes containing parts placed thereon (a skid with delivered parts boxes placed thereon).

In the above embodiment, the fork6is adopted as the holding member, and the prongs61,62of the fork6are inserted into the fork pockets FP, FP of the pallet P to hold and carry the empty-box skid S. The holding member in the present disclosure is not limited to this example but may instead sandwich (hold) a load from right and left sides.

In the above embodiment, the fork pocket detection sensor7is a laser sensor. The present disclosure is not limited to this example, and the fork pocket detection sensor7may also be an infrared sensor.

The present disclosure is applicable to a carrying apparatus used to carry an empty-box skid from a transportation trolley to an empty-box skid chute.