JPH0853214A - Pallet conveying apparatus - Google Patents

Abstract

PURPOSE:To provide a pallet conveying apparatus of a fixed flow type, by which a pallet can be positioned correctly. CONSTITUTION:A pallet 8 is installed on a feed belt 7. A positioning device 5 is disposed in a stop position set along the transport path for a pallet 8. The pallet 8 comprises a base 10 fixed to the feed belt, a placing plate 11 slidably installed on the base plate, and a lock mechanism 12 for connecting the base and the placing plate to each other. The positioning device advances a positioning guide body 30 to the pallet 8 stopped in an area of a working unit, the lock condition of the placing plate 11 and the base plate 10 is released, and the placing plate 11 is positioned in the preset stop position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pallet conveying device in an assembly line or the like that uses pallets conveyed along a predetermined path.

[0002]

2. Description of the Related Art There is known a pallet transfer device for mounting a pallet on a feed belt in an assembly line or the like, placing a work on the pallet, and transferring the work along a transfer path. The pallet transport device has a pallet placed on the feed belt but is not connected to the belt. The pallet is stopped and positioned by a separate positioning device that is placed along the feed belt. There is a fixed flow type in which a pallet is attached to the feed belt and the pallet is stopped and positioned by stopping the belt itself.

In the free flow type, since the pallet is stopped and positioned by the positioning device provided at each work unit, there is an advantage that it is easy to accurately position each work unit, but on the other hand, the pallet is placed on the feed belt. The positional relationship of the work parts during assembly may shift due to shocks when they collide with each other or shocks when the pallets are disengaged at the points of each work unit to start moving and when they are engaged and stopped. However, even if the pallet is stopped at the stop position, the feed belt is moving, so there is a problem that the pallet may vibrate and affect delicate work on the work. In addition, a device is required to collect the pallet carried at the end of the feed belt and send it back to the start end of the feed belt.

On the other hand, in the fixed flow type, there is no collision between the pallets, and the shocks at the start and stop of the feed belt (that is, when the pallet starts to move and when the pallet starts to move) are slowly started by the drive mechanism of the feed belt. This can be dealt with by using an index device that performs feed and slow stop. Further, when the pallet is stopped, the feed belt is also stopped, so that there is an advantage that the pallet does not vibrate during the work and it is easy to perform precision work on the work. On the other hand, since the stop position of the pallet depends on the stop of the feed belt, it is difficult to maintain a high positioning accuracy for each work unit due to the influence of the belt stretch and the backlash in the drive mechanism. There is a drawback that the accuracy becomes poor.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixed flow type pallet transfer device capable of accurately positioning pallets.

[0006]

[Means for Solving the Problems]

(1) The present invention relates to a pallet transport device for mounting a pallet on a feed belt, placing a work on the pallet, and transporting the work. The positioning device is arranged at the stop position set along the transport path. The pallet includes a base body fixed to the feed belt, a mounting plate slidably mounted on the base body in the moving direction of the feed belt, and a lock mechanism for connecting the mounting plate to the base body in a normal state. The positioning device includes a positioning guide body that projects toward the pallet in a direction transverse to the moving direction of the feed belt. At the protruding position, the positioning guide body releases the locked state of the mounting plate and the base body by the lock mechanism and positions the mounting plate at the set stop position.

(2) The following configuration is added to the configuration of (1) above. Guide pins are formed on the lower surface of the mounting plate so as to project downward. The locking guide body is disposed on the base body so as to be slidable in a direction transverse to the moving direction of the feed belt and always biased in the guide pin direction. A lock mechanism is configured by the guide pin and the lock guide body engaged with the guide pin. The positioning guide body of the positioning device pushes the locking guide body back in the protruding state to release the engagement with the guide pin, and at the same time, guides and positions the guide pin to the set stop position.

(3) The following configuration is added to the configuration of (2) above. The locking guide body is composed of a fixed portion and a movable portion connected to the fixed portion by a spring, and has a flat rectangular shape as a whole. The locking guide body is provided in a slide groove formed across the base body in a direction crossing the moving direction of the feed belt,
The movable portion is fixed to the base body with the movable portion being the guide pin side, and the movable portion is slidably inserted. The lock guide body has substantially the same thickness dimension (depth dimension) and width dimension as those of the slide groove.

(4) The following configuration is added to the configuration of (2) or (3). A restriction groove is formed on the upper surface of the movable portion of the locking guide body so as to traverse the moving direction of the feed belt. A holding plate having a width narrower than that of the regulation groove is fixed to the base body across the upper portion of the slide groove. The pressing plate is flush with the upper surface of the base and is fitted into the restriction groove, and is fixed to the base so that the lower surface of the pressing plate contacts the bottom surface of the restriction groove.

(5) The present invention relates to a fixed flow type pallet conveyor. The positioning device is arranged at the stop position set along the transport path. The pallet includes a base body fixed to the feed belt and a mounting plate mounted on the base body slidably in the moving direction of the feed belt. The mounting plate is provided with a pressure receiving portion projecting downward on the lower surface, and is locked by a locking spring that opposes the pressure receiving portion between the base body and the pressure receiving portion in both directions in the moving direction of the feed belt. The positioning device includes a positioning guide body that projects toward the pallet in a direction transverse to the moving direction of the feed belt. The positioning guide body positions the mounting plate at the set stop position against the force of the locking spring at the protruding position.

(6) The following configuration is added to the configuration described in any one of (1) to (5) above. Groove rails are formed on the side surface of the pallet along the moving direction of the feed belt. A hanging wall is formed on both sides of the mounting plate. The base body is fitted between the hanging walls of the mounting plate, and the mounting plate is mounted on the base body so as to be slidable in the moving direction of the feed belt. The tip of the retaining pin attached from the outer side surface of the hanging wall toward the base body side is slidably inserted into the groove rail of the base body without backlash.

[0012]

[Operation] The feed belt conveys the pallet. The pallet is used to place and convey the work. The positioning device releases the locked state of the mounting plate and the base body by the lock mechanism at the projecting position of the positioning guide body, and positions the mounting plate of the pallet at the set stop position. The configuration in which the pallet is composed of a base body fixed to the feed belt and a mounting plate mounted so as to be slidable in the moving direction of the feed belt with respect to the pallet can correct the position of the mounting plate with respect to the stop position of the base body. To do. The lock mechanism prevents the mounting plate from moving with respect to the base body while the pallet is moving.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a pallet transfer device 1 according to the present invention.
In the figure, a conveyor device 3, a work unit 4 (a to c), and a positioning device 5 (a to c) are arranged on the machine frame 2. Actually, other various accessory mechanisms are arranged and the number of working units 4 and the like is large, but only parts particularly relevant to the present invention are shown in order to avoid complexity.

The conveyor device 3 includes a wide timing belt 7 (hereinafter, referred to as a "timing belt 7") endlessly stretched between timing pulleys (not shown) pivotally supported at both ends of a frame 6.
The feeding belt 7) is provided with a plurality of pallets 8 (a to d) arranged at regular intervals. The frames 6 are arranged on both sides of the feed belt 7 in the left-right direction (moving direction f of the feed belt 7) so that the feed belt 7 and the pallet 8 swing back and forth (direction orthogonal to the moving direction f of the feed belt). It is a guide to prevent. An index device 9 is attached to the drive device of the feed belt 7, and the feed belt 7 is slowly started, rapidly fed,
It is designed to stop slowly.

The work unit 4 is a gate motion or swing motion loader to which an opening / closing chuck and other work attachments are attached. The work unit 4 sequentially performs work on the work on the pallet 8 in synchronization with the movement of the pallet 8. It is a commercial product. The positioning device 5 moves the moved pallet 8 to the work unit 4
To stop at the position set for
It will be described later.

The pallets 8 (a-d) are made of metal in this embodiment and have the same structure. The pallet 8 (FIG. 2) is a flat plate having a rectangular appearance, and includes a base body 10 (FIG. 2) fixed to the feed belt 7 and a mounting plate mounted on the base body 10 slidably in the left-right direction. 11 and a lock mechanism 12 for connecting the mounting plate 11 to the base body 10 in a normal state.

The base body 10 is a member having a groove shape on the lower surface side having side wall portions 14 and 14 extending downward on both sides of the flat plate portion 13. The side wall portions 14 and 14 are arranged along both sides of the feed belt 7. It is attached to the feed belt 7, and the feed belt 7 is attached to both side walls 14
It is made to fit in between. The substrate 10 is then
A mounting member 15 arranged in a direction traversing the belt 7 with the belt 7 sandwiched therebetween from the back side of the feed belt 7.
Is fixed to the feed belt 7 by attaching it to the base 10 with the screws 17, 17 screwed from the upper surface side of the base 10 via the spacer 16. The mounting member 15 is
The groove on the upper surface is fitted and fixed to one tooth of the feed belt 7 (FIG. 5), the spacers 16 are arranged between both sides of the mounting member 15 and the base body 10, and the base body 10 is fixed. It is intended to be mounted parallel to the upper surface of 7.

A slide groove 18, a mounting groove 19 and a guide pin moving space 2 are formed on the upper surface (flat plate portion 13) of the base body 10.
0 is formed. The slide groove 18 is formed in the front-rear direction at substantially the center of the base body 10, and the mounting groove 19 is formed in the left-right direction across the slide groove 18 and shallower than the slide groove 18. In addition, the guide pin moving space 2
0 is formed at the front end of the slide groove 18 in the left-right direction. Groove rails 21 and 21 are formed on the front side surface and the rear side surface (side wall portion 14) of the base body 10 in parallel with the upper surface of the base body 10.

The mounting plate 11 is a groove-shaped member having hanging walls 23 on the front and rear sides of the mounting portion 22, and is fitted and inserted into the base 10 with the hanging walls 23, 23 along both sides of the base 10. Polymerized so that it can slide left and right. Mounting holes 24 are formed in both left and right ends of the front and rear hanging walls 23, and retaining pins 25 are fitted and fixed in these holes. The four retaining pins 25 are formed flat on the tip end side so that they can be fitted into the groove rails 21 of the base body 10. A guide pin set screw 26 is inserted through a mounting hole 27 near the center of the upper surface of the mounting portion 22, and a guide pin 29 is mounted on the lower surface side of the mounting plate 11 by the guide pin set screw 26. . Further, a rectangular cutout 28 is formed in the mounting plate 11 at a position corresponding to the guide pin moving space 20 of the base body 10 at the center of the front hanging wall 23.

The lock mechanism 12 includes a lock guide body 30.
And the guide pin 26 described above. The lock guide body 30 includes a fixed portion 31 and a movable portion 33 connected to the fixed portion 31 by a spring 32, and has a flat rectangular shape as a whole. The front-rear dimension of this flat plate body is substantially equal to the front-rear dimension of the base body 10 when the spring 32 is compressed by about half.
The thickness dimension and the width dimension are substantially equal to the depth (thickness) dimension and the width dimension of the slide groove 18 formed on the upper surface of the base body 10. Therefore, the locking guide body 30 is mounted in the slide groove 18 without play, and the upper surface thereof is flush with the upper surface of the base body 10. Further, a restriction groove 34 is formed on the upper surface of the movable portion 33 of the locking guide body 30 so as to traverse in the left-right direction. The dimension (width) of the groove 34 in the front-rear direction is larger than the dimension (width) of the mounting groove 19 formed in the upper surface of the base 10 in the left-right direction. The front end of the movable portion 33 is cut out in a V shape.

The pallet 8 is attached to and assembled with the feed belt 7 as follows. The locking guide body 30 is mounted in the slide groove 18 of the base body 10 with the movable portion 33 as the front side, and the mounting member 1 is attached to the lower surface side of the feed belt 7.
5 and the spacer 16 are arranged, the rear screw 17 is a washer, the fixing portion 31 of the locking guide body 30, the base body 10,
The spacer 16 penetrates through the spacer 16 and is screwed into the rear portion of the attachment member 15, and the screw 17 in the front portion is attached to the base 10 and the spacer 16.
The base body 10 is fixed to the feed belt 7 by being screwed into the front portion of the mounting member 15 by penetrating therethrough, and the locking guide body 30 is attached to the base body 10 (FIG. 6). In the locking guide body 30, the fixed portion 31 is fixed to the base body 10, and the movable portion 33 is slidably inserted in the front-rear direction.
The spring 32 constantly biases the guide pin 29 toward the guide pin 29.

A pressing plate 35 is fitted into the mounting groove 19 from the upper part of the base 10 and the locking guide body 30 mounted as described above, and is fixed by countersunk screw nuts 36, 36 (FIG. 4).
The upper surface is flush with the substrate 10. At the portion where the pressing plate 35 crosses the slide groove 18, the pressing plate 35 is fitted into the restriction groove 34 of the movable portion 33 of the locking guide body 30, and the lower surface thereof contacts the bottom surface of the restriction groove 34. As a result, the movable portion 33 is prevented from slipping out upward, and the forward / backward movement of the movable portion 33, particularly the forward movement thereof, is restricted (FIG. 3).

The set screw 26 for the guide pin is inserted into the mounting hole 27 of the mounting plate 11, and the guide pin 29 is provided below the set screw 26.
Install. Then, the mounting plate 11 is placed from above the base body 10.
The guide pin 29 so that the guide pin 29 faces the front, and the retaining pin 25 is attached to the attachment hole 24 formed in the hanging wall 23.
Insert the flat part of the tip into the groove rail 2 of the base 10.
It fits in 1,21 and fixes (FIG. 8). At this time, the movable portion 33 of the locking guide body 30 is slightly pushed back by the guide pin 29 against the spring force. The mounting plate 11 is the base 1
It is mounted so as to be slidable in the left-right direction with respect to 0, and is prevented from slipping out in the vertical direction. At the same time, the guide pin 29 is located in the front guide pin moving space 20,
The movable portion 33 of the lock guide body 30 is pushed by and engaged with the spring 32, whereby the lock guide body 30 and the guide pin 29 form the lock mechanism 12 that defines the position of the mounting plate 11 with respect to the base body 10. I am configuring.

The positioning device 5 (FIG. 9) has a cam mechanism 37.
It is provided with a positioning guide body 38 which is reciprocally moved in the front-rear direction by, and is arranged close to the front frame 6 in the drawing. The positioning guide body 38 projects into and out of the pallet 8 side through a window hole 39 provided in the front frame 6, has a V-shaped notch at its tip, and is a movable member in the locking guide body 30. It comes into contact with the front end portion of 33 and further advances to engage with the guide pin 29. The positioning guide body 38 is driven in synchronization with the start / stop of the feed belt 7 by the index device 9,
The center line passing through the apex of the shape cutout is the stop position set for the work unit 4.

The pallet transfer device 1 operates as follows. In the pallet 8, the feed belt 7 is the index device 9
By being step-fed by, the work units 4 (a to c) are moved to the positions and stopped. While the feed belt 7 is moved, the positioning guide body 39 of the positioning device 5 is at the retracted position moved outward from the conveyance path of the pallet 8. The pallet 8 is started, conveyed, and stopped. Since 11 is locked to the base 10 by the lock mechanism 12 (FIG. 7), a difference between the base 10 and the mounting plate 11 is caused by acceleration when the feed belt 7 is started and stopped and vibration during conveyance. Absent.

When the pallet 8 is stopped, the cam mechanism 37
By this, the positioning guide body 38 of the positioning device 5 projects from the window hole 39 toward the pallet 8, passes through the rectangular notch 28 formed in the front side wall of the mounting plate 11, and projects.
First, the tip contacts the front end of the movable portion 33 of the locking guide body 30 and pushes it in to move the movable portion 33 and the guide pin 2.
Release the engagement with 9. At this time, the mounting plate 11 becomes slidable with respect to the base body 10 in the belt feeding direction. Then, as the positioning guide body 38 further advances,
The guide pin 29 is formed by the inclined wall surface of the V-shaped notch.
Is guided to the center line position of the V-shaped notch, that is, the set stop position, and positioned at that position (broken line in FIG. 7). In this case, the base 10 is fixed to the feed belt 7 and cannot move, but the mounting plate 11 provided with the guide pins 29 slides with respect to the base 10 and is positioned at the set stop position. As a result, the mounting plate 11
The upper work is arranged at the stop position set for the work unit 4, and a predetermined work is performed.

When the work is completed, the positioning guide plate 38 is pulled in by the end signal or after a predetermined time accompanying the rotation of the cam mechanism 37, and the pallet 8 is moved.
Is evacuated from the transport path. Then, in accordance with this, the movable portion 33 of the locking guide body 30 is pushed by the spring 32 and returns to the front, guides the guide pin 29 disengaged from the set position, and locks it at a predetermined position. Then, the feed belt 7 is started and the pallet 8 is moved to the next working unit 4
Is transported to the position.

As described above, the pallet 8 is the same as the conventional fixed flow type pallet carrier while there is no differential between the base 10 and the mounting plate 11 while being conveyed by the feed belt 7, while the pallet 8 is When stopped, the substrate 10
Even if the position is slightly deviated from the stop position set with respect to the work unit 4, the mounting plate 11 can be slid to the base body 10 and positioned at the set stop position. It will be in the same state.

In addition, since the pallets 8 do not collide with each other, unlike the free-flow type, there is less chance that the work placed during assembly will be displaced due to a shock at the time of collision. Further, since the base body 10 and the mounting plate 11 are locked when the pallet 8 is conveyed, the position of the workpiece being mounted on the mounting plate 11 during the assembly is displaced due to the difference between these. There is no. Furthermore, the feed belt also stops when it is stopped, so that the pallet does not vibrate during work.

FIG. 10 shows a pallet 8 in the second embodiment.
With respect to the above, the lock mechanism 12 is characterized. The other structure is not different from the first embodiment. The same parts as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted. The pallet 8 includes a base 10 fixed to the feed belt 7 and a mounting plate 11 mounted on the base 10 so as to be slidable in the left-right direction. The mounting plate 11 is provided with a pressure receiving portion 40, which is a projection having a rectangular cross section, which projects downward on the lower surface, and the ends of the locking springs 41, 41 arranged between the mounting plate 11 and the base body 10 are in contact with each other. The lock springs 41, 41 are mounted in a compressed state of about half in this embodiment. That is, the pressure receiving portion 40 is brought into a locked state by the locking springs that are opposed to each other in the right and left directions. The same applies to the case where the pressure receiving portion 40 is provided on the base body 10 side and two springs arranged on both sides thereof are mounted in a semi-compressed state with the mounting plate 11.

The positioning device 5 is provided with a positioning guide body 38 projecting in the front-rear direction toward the pallet 8 similarly to the first embodiment, and the positioning guide body 38 is fixed to the mounting plate 11 at the projecting position. The inclined surface of the V-shaped notch is brought into contact with the guide pin 29, and the mounting plate 11 is slid to the set stop position against the force of the locking springs 41, 41 to be positioned.

Also in this configuration, it is possible to prevent the differential between the substrate 10 and the mounting plate 11 due to acceleration and vibration due to start / stop during conveyance, and to accurately mount the mounting plate 11 at the set stop position. Can be positioned. Further, this embodiment does not require a slide member such as the locking guide body 30 in the first embodiment, so that the structure can be simplified. The biasing strength of the lock spring 41 is determined by the speed at which the pallet 8 is conveyed and the mass of the pallet 8.

The above is an embodiment, and the present invention is not limited to the illustrated specific configuration. For example, the base 10 may be attached to the feed belt 7 by screwing directly onto the belt. Further, the holding plate 35 is the movable plate 33.
It is also possible to replace with a stopper of another form that regulates the amount of forward movement of the.

[0034]

EFFECTS OF THE INVENTION A plurality of pallets can be conveyed all at once to a work unit at high speed and reliably. On the other hand, since the work can be accurately positioned at the set stop position with respect to the work unit, highly accurate work can be performed at high speed by using this pallet device. In addition, since the feed belt is stopped during work, the work does not vibrate and precise work can be performed. Even though it is a fixed flow type, it is possible to accurately correct variability in positional deviation such as extension of the feed belt and backlash of the mechanical section.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a part of a pallet transport device.

FIG. 2 is an exploded perspective view of a pallet (first embodiment).

FIG. 3 is a perspective view of the assembled base body.

FIG. 4 is a sectional view taken along the line AA of FIG. 6 (a belt is omitted).

FIG. 5 is a front view of a pallet (a spacer is omitted).

6 is a cross-sectional view in which the cross-sections BB, CC, and DD in FIGS. 4 and 5 are combined.

FIG. 7 is a plan view of a base body.

FIG. 8 is a plan view of a mounting plate.

FIG. 9 is a plan view of a positioning device.

FIG. 10 is a schematic plan view for explaining a second embodiment.

[Explanation of symbols]

1 Pallet Conveying Device 26 Guide Pin Set Screw 2 Machine Frame 27 Mounting Hole 3 Conveyor Device 28 Notch 4 Working Unit 29 Guide Pin 5 Positioning Device 30 Locking Guide Body 7 Feed Belt 31 Fixing Part 8 Pallet 32 Spring 9 Indexing Device 33 Movable part 10 Base body 34 Restriction groove 11 Placement plate 35 Holding plate 12 Lock mechanism 36 Countersunk head screw nut 13 Flat plate portion 37 Cam mechanism 14 Side wall portion 38 Positioning guide body 15 Mounting member 39 Window hole 16 Spacer 40 Pressure receiving portion 17 Screw 41 Locking Spring 18 Slide Groove 19 Mounting Groove 20 Guide Pin Moving Space 21 Groove Rail 22 Placement Part 23 Hanging Wall 24 Mounting Hole 25 Locking Pin

Claims (6)

[Claims] 1. A pallet transporting device for mounting a pallet on a feed belt, placing a work on the pallet and transporting the work, wherein a positioning device is arranged at a stop position set along a transport path. The pallet is composed of a base fixed to the feed belt, a mounting plate slidably attached to the base in the moving direction of the feed belt, and a lock mechanism for connecting the mounting plate to the base in a normal state. The apparatus includes a positioning guide body that projects toward the pallet in a direction transverse to the moving direction of the feed belt, and the positioning guide body releases the locked state of the mounting plate and the base body by the locking mechanism at the protruding position and mounts the positioning plate. A pallet transfer device characterized in that a placing plate is positioned at a set stop position. 2. The pallet transfer device according to claim 1, wherein guide pins are formed on the lower surface of the mounting plate so as to project downward, and a locking guide body is provided on the base body to traverse the moving direction of the feed belt. The guide pin and the locking guide body engaged with the guide pin constitute a locking mechanism, while the positioning guide body of the positioning device is A pallet conveying device characterized in that the locking guide body is pushed back in a projecting state to release the engagement with the guide pin, and at the same time, the guide pin is guided to and positioned at a set stop position. 3. The locking guide body is composed of a fixed portion and a movable portion coupled to the fixed portion by a spring, and has a flat plate-like rectangular shape as a whole, and traverses the base body in a direction transverse to the moving direction of the feed belt. Thickness and width dimensions are almost the same as the formed slide groove, the movable part is arranged in the slide groove with the guide pin side, the fixed part is fixed to the base body, and the movable part is slidably inserted. The pallet conveyor according to claim 2, wherein 4. A regulation groove is formed on the upper surface of the movable portion of the locking guide body so as to traverse the moving direction of the feed belt, and a holding plate having a width narrower than the regulation groove traverses the upper portion of the slide groove on the base body. The upper surface of the base is flush with the upper surface of the base and is fixed to the base by being fitted into the restriction groove, and the lower surface of the holding plate is in contact with the bottom surface of the restriction groove. The pallet transfer device described in. 5. A pallet transporting device for mounting a pallet on a feed belt, placing a work on the pallet and transporting the work, wherein a positioning device is arranged at a stop position set along a transport path. The pallet is composed of a base body fixed to the feed belt, and a mounting plate mounted on the base body so as to be slidable in the moving direction of the feed belt. The mounting plate includes a pressure receiving portion protruding downward on the lower surface, The positioning device is locked by a locking spring that opposes a force that urges the pressure receiving portion in both directions in the moving direction of the feed belt with the base body, and the positioning device traverses the moving direction of the feed belt toward the pallet. Is provided with a positioning guide body that projects in the direction of rotation, and the positioning guide body positions the mounting plate at a set stop position against the force of the locking spring at the protruding position. A pallet transport device that is a characteristic. 6. A base is formed by forming groove rails along the moving direction of the feed belt on the side surface of the base, forming hanging walls on both sides of the placing plate, and inserting the base between the hanging walls of the placing plate. The mounting plate is slidably mounted in the direction of movement of the feed belt, and the tip of the retaining pin mounted from the outer surface of the hanging wall toward the base side is slidably inserted into the groove rail of the base. The pallet conveyor according to any one of claims 1 to 5, wherein