JP6206239B2 - Pallet transport device - Google Patents

Description

  The present invention relates to a pallet conveying apparatus that conveys a plurality of pallets on which an object to be conveyed is placed, using a roller conveyor.

  2. Description of the Related Art Conventionally, as a technique related to a conveying apparatus that conveys a plurality of pallets on which objects to be conveyed are placed by a roller conveyor, a conveyed object feeding apparatus disclosed in Patent Document 1 below is known. The transported article feeding device includes a swinging member disposed below the transport path, and a stopper portion is formed at the front end of the swinging member so as to protrude on the transport path and stop the transported object. At the rear end of the moving member, there is provided a brake part that restricts the movement of the subsequent conveyed object by pressing against the free roller from below to prevent the rotation when the rear end is raised. In addition, an operating handle is provided as an operating means for the swinging member to operate the front end of the swinging member to the raised position against the biasing force of the spring member. In addition, a holding member is provided to hold the operating handle in the lifted position so that the operating handle is moved to the front end raised position by the operating handle and the swinging member is held in this state.

  Then, when the restriction of the operation handle by the holding member is released in a state where the movement of the first transported object and the subsequent transported object is stopped continuously by the stopper portion protruding on the transport path, the rear end of the swinging member is lifted. As a result, the stopper portion descends to the lower side of the transport path, and the movement restriction of the first transported object is released. At the same time, the brake part of the swinging member is pressed against the free roller on which the second transported material is placed from below to prevent these rotations, so that the movement of the second transported material remains restricted. . Then, after the first transported object has moved to the front end position of the transport path, the operation handle is pulled up to return the stopper member to the state where the stopper portion protrudes on the transport path with the swinging member as the front end raised position. Moves forward when the restriction by the brake is released. With this configuration, the conveyed objects are conveyed one by one to the front end position of the conveyance path according to the operation of the holding member and the operation handle.

JP 2006-219206 A

  By the way, in order to improve the conveyance efficiency and to ensure the safety of the operator, a conveyance device that automatically and sequentially conveys the pallet to the unloading position is desired. However, in the configuration as described above, it is necessary to operate the holding member and the operation handle every time the pallet transported to the unloading position is unloaded, and therefore, there is a problem that it cannot be applied to a transfer device premised on automation.

  In addition, in a transport device using a roller conveyor, a pallet on which a relatively heavy object to be transported or a pallet on which a relatively light object to be transported is often mixed and transported, depending on the weight difference. The pallet transport speed may change. For example, in a configuration in which the transport restriction of the succeeding pallet by the stopper mechanism is released in accordance with the lifting of the pallet at the unloading position, when a relatively heavy object to be transported is placed on the succeeding pallet when the restriction is released. In this case, the conveyance speed of the subsequent pallet becomes higher than usual. Then, there is a possibility that the succeeding pallet whose transport speed is higher than usual may come into contact with the pallet being lifted. On the other hand, if the inclination angle of the roller conveyor is reduced in order to prevent contact with the pallet during the lifting, if a relatively light object to be transported is placed on the succeeding pallet, the succeeding pallet will be transported even if the restriction is released. There is a possibility of stopping without being.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a pallet transport device that can automatically transport pallets having large weight differences one by one to the unloading position. It is in.

In order to achieve the above object, the invention according to claim 1 of the present invention is a roller conveyor (inclined so that a plurality of pallets on which objects (C) are placed are lowered toward the downstream side of the conveyance path. 12, 13) using the pallet transport device (10) for sequentially transporting the pallet (P1) to the unloading position, and restricting the downstream pallet (P2) from being transported when the pallet (P1) is present at the unloading position. And a stopper mechanism (20) for releasing the conveyance restriction when the pallet at the unloading position is unloaded, and a position downstream of the regulated pallet and downstream from the pallet on the conveyance path. By the 1st drive roller (31) which provides conveyance force, the 2nd drive roller (32) arrange | positioned in the position which can provide conveyance force with respect to the pallet of the said conveyance control state, and the said stopper mechanism Detection means (33) for detecting the release of feed restriction, and control means (34) capable of controlling the start and stop of rotation of the first drive roller and the second drive roller, wherein the control means includes the When the detection restriction is detected by the detection means, the rotation of the first drive roller and the second drive roller is stopped, the rotation is started after a set time, and the rotation of the first drive roller is started by the second drive roller. The rotational speed is set high.
In addition, the code | symbol in the parenthesis of a claim and the said means shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  According to the first aspect of the present invention, the first drive roller located downstream of the pallet whose conveyance to the downstream side is regulated by the stopper mechanism and the position where the conveyance force can be applied to the pallet in the conveyance restricted state are arranged. The first driving roller is equipped with the second driving roller, and the first driving roller is set to have a higher rotational speed than the second driving roller, and the start and stop of the rotation of the first driving roller and the second driving roller can be controlled. Control means. Then, when the detection mechanism detects that the subsequent pallet conveyance restriction is released by the stopper mechanism, the control means starts the rotation of the first driving roller and the second driving roller in the rotation stopped state, and the first driving roller is moved to the first driving roller. It is rotated so as to be higher than the rotational speed of the two drive rollers.

  As a result, even if the inclination angle of the roller conveyor is adjusted in accordance with the pallet on which a relatively heavy object is placed, the conveying force of the second driving roller acts on the pallet after the restriction is released by the stopper mechanism. Even if the pallet is loaded with a relatively light object, the pallet does not stop without being transported after the restriction is released.

  When the restriction by the stopper mechanism is released, the pallet that has been regulated for conveyance is transported downstream as the top pallet, and each subsequent pallet connected to the top pallet is also transported downstream. In this transport state, the top pallet is transported by receiving the transport force from the first drive roller, so even if the transport object of the top pallet is relatively light, the transport speed of the top pallet is the following. Since it is higher than the pallet conveyance speed, the interval between the leading pallet and the succeeding pallet increases. Accordingly, it is possible to easily interpose a stopper for restricting the conveyance of the subsequent pallet between the leading pallet and the subsequent pallet. Therefore, pallets with large weight differences can be automatically conveyed one by one to the unloading position.

It is a top view which shows the pallet conveying apparatus which concerns on this embodiment. It is sectional drawing by the cut surface equivalent to the X1-X1 line | wire of FIG. It is the upper side figure which expanded the carrying-out position vicinity. It is sectional drawing which shows the state in which the lever member tilted to the 1st tilt position, and the stopper member tilted to the regulation release tilt position. It is sectional drawing which shows the state which the lever member tilted to the 2nd tilt position, and the stopper member tilted to the conveyance control tilt position. It is sectional drawing which shows the downstream support member vicinity of a stopper mechanism. It is sectional drawing which shows the upstream support member vicinity of a stopper mechanism. It is explanatory drawing for demonstrating the structure which detects the tilting state of the stopper member by the sensor for operation confirmation. It is a block diagram which shows the schematic electrical structure of a conveyance timing adjustment mechanism. It is explanatory drawing explaining the conveyance state by which the unloading waiting pallet is conveyed to the unloading position. It is explanatory drawing explaining the conveyance state immediately after carrying out the carrying-out waiting pallet. It is explanatory drawing explaining the conveyance state in which the subsequent pallet receives the conveyance force by a drive roller.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment in which a pallet carrying device according to the invention is embodied will be described with reference to the drawings.
The pallet conveyance device 10 shown in FIGS. 1 and 2 is configured as a conveyance device that sequentially conveys a plurality of pallets P on which a conveyance object C such as a return box is placed using a roller conveyor. The pallet transport device 10 mainly includes a roller conveyor unit 11, a stopper mechanism 20, and a transport timing adjustment mechanism 30.

  The roller conveyor unit 11 includes two roller conveyors 12 and 13 in which a plurality of rollers are arranged in parallel. Both the roller conveyors 12 and 13 are inclined and arranged in parallel so that the transport path becomes lower toward the downstream side. Has been placed. Each of the roller conveyors 12 and 13 includes a free roller and a driving roller described later, and several free rollers are arranged so that two or more driving rollers are in contact with one pallet. One driving roller is arranged every time. For this reason, when the pallet P on which the object to be conveyed C is placed or the empty pallet P is carried into the upstream side of the roller conveyors 12 and 13 (the right side in FIGS. 1 and 2), the pallet P becomes a roller by its own weight. It will be conveyed to the carry-out position on the conveyors 12 and 13 toward the downstream side (left side in FIGS. 1 and 2).

  Here, the carry-out position is a position where the pallet P is in contact with the cushion portion of the cushion-type stopper 14 provided at the ends of the roller conveyors 12 and 13 (see the two-dot chain line P1 in FIG. 3). is there. The pallet located at this unloading position (hereinafter also referred to as unloading pallet P1) is lifted (picked) by a forklift or the like and unloaded to the next step.

  Next, the configuration of the stopper mechanism 20 will be described with reference to the drawings. FIG. 3 is an enlarged top view of the vicinity of the carry-out position. FIG. 4 is a cross-sectional view showing a state in which the lever member 21 is tilted to the first tilt position and the stopper member 23 is tilted to the deregulation tilt position, and FIG. 5 is a plan view in which the lever member 21 is tilted to the second tilt position. It is sectional drawing which shows the state which the member 23 tilted to the conveyance control tilt position, and is equivalent to sectional drawing by the cut surface equivalent to the X2-X2 line | wire of FIG. 3, respectively. FIG. 6 is a cross-sectional view showing the vicinity of the downstream side support member 22 of the stopper mechanism 20, and is based on a cut surface corresponding to the line X 3 -X 3 in FIG. 4. FIG. 7 is a cross-sectional view showing the vicinity of the upstream support member 24 of the stopper mechanism 20, and is based on a cut surface corresponding to the line X 4 -X 4 in FIG. 5. In addition, in FIG. 5, illustration of each to-be-conveyed object C is abbreviate | omitted for convenience.

  When the unloading waiting pallet P1 is transported to the unloading position, the stopper mechanism 20 regulates the downstream transport of the subsequent pallet (hereinafter also referred to as the succeeding pallet P2), and the unloading waiting pallet P1 is unloaded. This is a mechanism for canceling the conveyance restriction of the pallet P2. As shown in FIGS. 3 to 5, the stopper mechanism 20 includes a lever member 21, a downstream support member 22 that supports the lever member 21 so that the lever member 21 can tilt, a stopper member 23, and the stopper member 23 that can tilt. An upstream support member 24 and a link mechanism 25 are provided.

  As shown in FIGS. 3 to 6, the downstream side support member 22 is assembled to the roller conveyor unit 11 so as to be positioned below the carry-out waiting pallet P <b> 1, and the downstream side support member 22 includes a lever member 21. A shaft 22a to which one end 21a is fixed is pivotally supported. The lever member 21 is urged clockwise in FIGS. 4 and 5 by a spring member (not shown) so as to contact the unloading pallet P1 from below at the other end 21b.

  For this reason, as shown in FIG. 4, the lever member 21 is tilted at a position where the other end 21 b protrudes between the roller conveyor 12 and the roller conveyor 13 on the conveyance path when the pallet P is not in the carry-out position (hereinafter referred to as “the pallet P”). , Also referred to as a first tilt position). Then, when the pallet P is transported to the unloading position, the lever member 21 is shown in FIG. 5 so that the other end 21b is pushed down against the urging force of the spring member or the like by the pallet P existing at the unloading position. It tilts about the shaft 22a to the tilt position shown (hereinafter also referred to as the second tilt position).

  As shown in FIG. 3 to FIG. 5 and FIG. 7, the upstream side support member 24 has a stopper member 23 that is tilted to the transport regulation tilt position between the roller conveyor 12 and the roller conveyor 13, and a carry-out waiting pallet P <b> 1. Is attached to the roller conveyor unit 11 so as to come into contact with the subsequent pallet P2 that is separated by a predetermined distance to the upstream side and restrict its conveyance. Further, the upstream support member 24 has free rollers 24 a and 24 b for assisting conveyance of the pallets conveyed on the roller conveyors 12 and 13, one on the downstream side and one on the upstream side with respect to the stopper member 23. Has been placed.

  The link mechanism 25 is a mechanism that tilts the stopper member 23 according to the tilting state of the lever member 21, and a support piece 25 a that supports the stopper member 23 from below and changes the tilt angle of the stopper member 23, and this support And a plurality of link members that switch the support state of the stopper member 23 by the piece 25a in accordance with the rotation state of the shaft 22a.

  As shown in FIG. 5, when the lever member 21 is tilted to the second tilt position, the link mechanism 25 tilts the stopper member 23 with the support piece 25a that is switched to the pushed-up state by each link member. Functions to push up to the position. As shown in FIG. 4, when the lever member 21 is tilted to the first tilt position, the link mechanism 25 tilts the stopper member 23 by tilting the support piece 25a in the push-up release direction by each link member. It functions to tilt to a position where it does not contact the pallet on the conveyance path (hereinafter also referred to as a regulation release tilt position).

  As a result, the lever member 21 is tilted to the second tilting position by the unloading waiting pallet P1 that has been transported to the unloading position, so that the stopper member 23 pushed up to the transport regulation tilting position causes the downstream pallet P2 to move downstream. Conveyance is regulated. Then, when the lever member 21 is tilted to the first tilting position by unloading the unloading pallet P1 by a forklift or the like, the stopper member 23 tilts to the deregulation tilting position so that the stopper member 23 sinks. P2 transport restriction is released.

  Next, the configuration of the transport timing adjustment mechanism 30 will be described with reference to the drawings. FIG. 8 is an explanatory diagram for explaining a configuration for detecting the tilting state of the stopper member 23 by the operation confirmation sensor 33. FIG. 9 is a block diagram illustrating a schematic electrical configuration of the transport timing adjustment mechanism 30.

  The conveyance timing adjustment mechanism 30 is a mechanism for increasing the gap between the unloading pallet P1 and the subsequent pallet P2 and adjusting the conveyance resumption timing of the subsequent pallet P2 to be delayed from the unloading timing of the unloading pallet P1. The transport timing adjustment mechanism 30 includes a plurality of drive rollers, an operation confirmation sensor 33, and a drive control circuit 34.

  Each drive roller has a built-in motor roller with an accumulator function that has the same function as a clutch because the starting torque and tangential force are weak without damaging the motor even if continuously locked with a high impedance and low current design in the roller body. And as above-mentioned, it arrange | positions between the free rollers of both roller conveyors 12 and 13. Of the drive rollers, a drive roller (hereinafter also referred to as drive roller 31) located on the downstream side of the stopper member 23 is a drive roller (hereinafter also referred to as drive roller 32) located on the upstream side of the stopper member 23. Is also set to increase its rotational speed. The driving roller 31 may correspond to an example of a “first driving roller” described in the claims, and the driving roller 32 may correspond to an example of a “second driving roller” described in the claims. .

  The operation confirmation sensor 33 functions as a detection unit that detects the release of conveyance restriction by the stopper mechanism 20, and a detection signal indicating whether or not the stopper member 23 is tilted to the conveyance restriction tilt position is sent to the drive control circuit 34. It is configured to output. As shown in FIG. 8, the operation confirmation sensor 33 is assembled to the upstream support member 24 and detects the inclination of the tilting piece 36 that changes in accordance with the inclination of the pressing piece 35 fixed to the stopper member 23. By doing so, the tilting state of the stopper member 23 is detected.

  As the detection signal output to the drive control circuit 34, the operation confirmation sensor 33 outputs a restriction maintaining signal when the stopper member 23 is tilted to the conveyance restriction tilt position (see the solid line 23 in FIG. 8). When the stopper member 23 is tilted so as to sink from the conveyance regulation tilt position (see the two-dot chain line of reference numeral 23 in FIG. 8), a regulation release signal is output.

  As shown in FIG. 9, the drive control circuit 34 is a circuit that functions as a control unit that controls the drive rollers 31 and 32 according to the detection result of the operation confirmation sensor 33, and is housed in an unillustrated case or the like. The upstream support member 24 and the like are assembled. When a restriction release signal is input from the operation confirmation sensor 33, the drive control circuit 34 immediately stops the rotation of the drive rollers 31 and 32, and after a predetermined time elapses from this input timing, the drive roller 31 , 32 is controlled to start rotation.

  Here, the predetermined time is set to such a time that the subsequent pallet P2 that has resumed conveyance after the release of the conveyance restriction does not come into contact with the unloading waiting pallet P1, and is set to, for example, 5 seconds in this embodiment. .

  Next, the conveyance state of each pallet P using the pallet conveyance apparatus 10 configured as described above will be described with reference to the drawings. In addition, FIG. 10 is explanatory drawing explaining the conveyance state in which the unloading waiting pallet P1 is conveyed to the unloading position. FIG. 11 is an explanatory diagram for explaining a transport state immediately after the unloading waiting pallet P1 is unloaded. FIG. 12 is an explanatory diagram for explaining a conveyance state in which the subsequent pallet P <b> 2 receives a conveyance force by the driving roller 31. In addition, in FIG. 10-FIG. 12, illustration of each to-be-conveyed object C is abbreviate | omitted for convenience.

  In a state where the pallet P is not conveyed, as shown in FIG. 4, the lever member 21 is tilted to the first tilt position, and the stopper member 23 is tilted to the restriction release tilt position so as to sink from the transport path. Yes.

  And when the pallet P is sequentially carried in from the carrying-in side (upstream side) of the roller conveyor part 11 in the state which rotated the drive rollers 31 and 32, each pallet P is sequentially conveyed on the roller conveyors 12 and 13. The At the initial stage of carry-in, the pallets P are sequentially transported at appropriate intervals. As shown in FIG. 10, when the leading pallet P is conveyed to the carry-out position, the lever member 21 at the first tilt position is pushed down by this pallet P and tilted to the second tilt position. The leading pallet P that pushes down the lever member 21 at the second tilt position becomes the unloading pallet P1.

  Then, the lever member 21 that has been pushed down tilts to the second tilt position, so that the stopper member 23 pushed up to the transport regulation tilt position restricts the transport of the next pallet (subsequent pallet P2) to the downstream side. (Refer to FIG. 5), the other pallets further following this succeeding pallet P2 are also brought into contact with each other and their conveyance is restricted. For this reason, each pallet P on the upstream side of the subsequent pallet P <b> 2 enters the transport restricted state in a state where it is in contact with no gap. In addition, when the specified time has elapsed after the restriction release signal is input to the drive control circuit 34, the drive rollers 31 and 32 are in a rotation stopped state as controlled by the drive control circuit 34.

  Then, as shown in FIG. 11, when the unloading pallet P1 is unloaded by the forklift F, the lever member 21 tilts to the first tilt position and tilts to the restriction release tilt position so that the stopper member 23 sinks. Thus, the conveyance restriction of the subsequent pallet P2 by the stopper member 23 is released.

  At this time, a restriction release signal is input from the operation confirmation sensor 33 to the drive control circuit 34, but the drive rollers 31 and 32 are maintained in a rotation stopped state until the predetermined time elapses. Then, since the driving roller 32 in a rotation stopped state that is in contact with the subsequent pallet P2 functions as a conveyance suppression unit, the conveyance of the subsequent pallet P2 is suppressed even if the stopper member 23 is tilted to the deregulation tilt position. The subsequent pallet P2 is prevented from coming into contact with the unloading waiting pallet P1 in the middle of unloading.

  When the predetermined time elapses, the drive rollers 31 and 32 start to rotate by the drive control circuit 34, so that the conveyance of the subsequent pallet P2 and the subsequent pallet P is resumed. After the subsequent pallet P2 is conveyed as the conveyance speed V2 by the conveyance force by the driving roller 32, when the conveyance power by the driving roller 31 is started, the subsequent pallet P2 is conveyed by the driving roller 31 so as to be accelerated as the conveyance speed V1. On the other hand, the next pallet following the subsequent pallet P2 (see P3 in FIG. 12) is conveyed at a lower conveyance speed than the subsequent pallet P2 up to the position where the conveyance force by the driving roller 31 is received. As shown, the distance from the subsequent pallet P2 gradually increases.

  For this reason, when the accelerated subsequent pallet P2 pushes down the lever member 21, the subsequent pallet P3 is positioned upstream from the stopper member 23, so that the subsequent pallet P2 and the subsequent pallet P3 The stopper member 23 pushed up with respect to the gap can be reliably interposed. Further, even if the transporting speed of the pallet P3 is likely to be high because the transported object C of the subsequent pallet P3 is relatively heavy, each of the drive rollers 31 and 32 includes a motor unit for rotation having an accumulating function. Therefore, a change in the conveyance speed due to the weight difference of the pallet is suppressed, and a stable conveyance speed is maintained. Thereby, the said space | interval can be ensured reliably by position adjustment of the pallet by the rotational speed difference of the drive roller 31 and the drive roller 32. FIG.

  As described above, in the pallet conveyance device 10 according to the present embodiment, the driving roller 31 positioned downstream of the subsequent pallet P2 whose conveyance to the downstream side is regulated by the stopper mechanism 20 and the subsequent in the conveyance regulation state. A drive roller 32 disposed at a position where a conveying force can be applied to the pallet P2, and a drive control circuit 34 capable of controlling the start and stop of rotation of the drive roller 31 and the drive roller 32 are provided. When the release restriction of the subsequent pallet P2 by the stopper mechanism 20 is detected by the operation confirmation sensor 33, the drive control circuit 34 drives the drive roller 31 and the drive roller 32 in the rotation stopped state more than the drive roller 32. The rotation is started in a state where the rotation speed of the roller 31 is high.

  Thereby, even if the inclination angles of the roller conveyors 12 and 13 are adjusted in accordance with the pallet on which a relatively heavy object is placed, the conveying force by the driving roller 32 is applied to the pallet after the restriction is released by the stopper mechanism 20. Therefore, even if the pallet has a relatively light object to be transported, the pallet does not stop without being transported after the restriction is released.

  When the restriction by the stopper mechanism 20 is released, the succeeding pallet P2 is conveyed downstream as the leading pallet, and each succeeding pallet connected to the leading pallet is also conveyed downstream. In this transport state, the leading succeeding pallet P2 is transported by receiving a transport force by the driving roller 31, and therefore, even if the transport object C of the leading pallet is relatively light, the leading succeeding pallet P2 is transported. Since the speed V1 is higher than the conveyance speed V2 of the succeeding pallet P3, the interval between the leading succeeding pallet P2 and the succeeding pallet P3 is increased. Thereby, the stopper member 23 for restricting the conveyance of the succeeding pallet P3 can be easily interposed between the leading succeeding pallet P2 and the succeeding pallet P3. Accordingly, the pallets P having a large weight difference can be automatically conveyed one by one to the unloading position.

  Furthermore, the drive rollers 31, 32 are motors with an accumulating function that have the same function as a clutch because the starting torque and tangential force are weak without damaging the motor even if the roller body is locked continuously with a high impedance and low current design. Built-in roller. For this reason, the conveyance speed change resulting from the weight difference of a pallet is suppressed, the stable conveyance speed is maintained, and the said space | interval is ensured reliably by the position adjustment of the pallet by the rotational speed difference of the driving roller 31 and the driving roller 32. can do.

  In particular, even when an overload occurs when the drive rollers 31 and 32 in the driven state come into contact with the pallet in the conveyance stopped state, transmission of the overload to the motor unit is blocked by the clutch unit. Then, even if a rotation instruction is issued to the drive roller that is in contact with the pallet in the conveyance stopped state, it will not be damaged by overload. For this reason, since a plurality of driving rollers 31 and 32 are disposed on the roller conveyors 12 and 13, the driving roller to be rotated for pallet conveyance (for example, the driving roller 32 disposed in the vicinity of the loading position). Since the contact is made with the pallet in the conveyance stop state, it is possible to instruct rotation to the drive roller (for example, the drive roller 32 disposed near the upstream of the stopper member 23) to be stopped. That is, by adopting the motor roller with the accumulating function as the driving roller, each driving roller of the roller conveyors 12 and 13 can be controlled on and off by one driving control circuit. Thus, not only can the cost be reduced, but also the control configuration can be simplified.

In the present embodiment, when the conveyance restriction release of the subsequent pallet P2 by the stopper mechanism 20 is detected by the operation confirmation sensor 33, the drive control circuit 34 maintains the rotation stop state of the drive roller 31 and the drive roller 32. The rotation of the drive roller 32 and the drive roller 31 whose rotational speed is higher than that of the drive roller 32 is started after a lapse of a predetermined time from the detection of the conveyance restriction cancellation.
The drive roller 32 is rotated so as to be lower than the rotation speed of the roller 31.

  Thereby, immediately after the carry-out waiting pallet P1 is carried out and the conveyance restriction of the succeeding pallet P2 by the stopper mechanism 20 is released, the rotation of the driving roller 32 contacting the succeeding pallet P2 is stopped. For this reason, the drive roller 32 in the rotation stop state functions as a conveyance suppressing unit that suppresses the conveyance of the subsequent pallet P2, and the conveyance of the subsequent pallet P2 is suppressed until the predetermined time elapses. As a result, it is possible to reliably prevent the subsequent pallet P2 from coming into contact with the pallet in the middle of unloading (unloading pallet P1).

In addition, this invention is not limited to the said embodiment, For example, you may actualize as follows.
(1) The tilting state of the stopper member 23 is not limited to being detected using a detecting means configured by the operation confirmation sensor 33, the pressing piece 35, and the tilting piece 36, but may be a stopper such as a contact sensor or an optical sensor. You may detect using the other detection means which can detect the tilting state of the member 23. FIG.

(2) The stopper mechanism 20 is not limited to the above-described lever member 21, the stopper member 23, and the like. By using other constituent members, the unloading pallet P1 is conveyed to the unloading position. Then, the conveyance of the subsequent pallet P2 may be restricted and the conveyance restriction of the subsequent pallet P2 may be canceled by carrying out the unloading pallet P1.

(3) The predetermined time is not limited to a predetermined value, and can be appropriately changed according to the transport environment.

DESCRIPTION OF SYMBOLS 10 ... Pallet conveying apparatus 12, 13 ... Roller conveyor 20 ... Stopper mechanism 23 ... Stopper member 30 ... Conveyance timing adjustment mechanism 31 ... Drive roller (1st drive roller)
32 ... Driving roller (second driving roller)
33 ... Operation confirmation sensor (detection means)
34 ... Drive control circuit (control means)
P1 ... Pallet waiting to be unloaded (pallet at unloading position)
P2: Subsequent pallet (subsequent pallet)

Claims (3)

A pallet transport device (10) for sequentially transporting a plurality of pallets on which objects (C) to be transported are placed to a carry-out position using roller conveyors (12, 13) inclined so that the transport path is lowered toward the downstream side. And
A stopper mechanism (20) that restricts conveyance of the subsequent pallet (P2) to the downstream side when the pallet (P1) is present at the unloading position and releases the conveyance restriction by unloading the pallet at the unloading position. )When,
A first drive roller (31) that is positioned downstream of the restricted pallet and that imparts downstream conveyance force to the pallet on the conveyance path;
A second drive roller (32) disposed at a position where a conveyance force can be applied to the conveyance-regulated pallet;
Detection means (33) for detecting the release of conveyance restriction by the stopper mechanism;
Control means (34) capable of controlling the start and stop of rotation of the first drive roller and the second drive roller,
When the detection restriction is detected by the detection means, the control means stops rotation of the first drive roller and the second drive roller, starts rotation after a set time, and from the second drive roller A pallet transport device characterized in that the rotation speed of the first drive roller is set high.   The first driving roller and the second driving roller are configured as a motor roller in which a motor unit and a clutch unit capable of interrupting transmission of an overload to the motor unit are built in a roller body. The pallet conveying apparatus according to claim 1. The control means stops the rotation of the first drive roller and the second drive roller when the detection restriction is detected by the detection means, and the first drive is performed after a predetermined time has elapsed since the detection of the transfer restriction release. The pallet transport device according to claim 1 or 2, wherein the roller rotates the first drive roller and the second drive roller in a state where the rotation speed of the roller is higher than that of the second drive roller.

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