JP2003112821A - Carrying direction changing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct work sending work by vertically moving a work carrying truck. SOLUTION: This carrying direction changing device is composed of a work carrying truck 10 for carrying work, and a pedestal 30 that is a base for moving the work carrying truck 10. The work carrying truck 10 is composed of traveling sprocket lines 15 and free rollers 24 provided at four corners of a box- shaped chassis 1, a driving shaft 41 driving the traveling sprockets 15 and a follower shaft 42, a chain 5 provided between a driving sprocket 13 provided on the driving shaft 41 and a follower sprocket 14 provided on the follower shaft 42, and one electric motor 4 driving the traveling sprocket line 15 through the chain 5. The pedestal 30 is composed of a tilting rack 35 engaged with the traveling sprocket line 15 and ascending/descending, and a guide rail 34 rolling the free rollers 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveying direction changing device which operates so as to send out an object (workpiece) conveyed on a conveyor line in a predetermined direction. And sending work,
The present invention relates to a conveying direction changing device which is configured to be operated by a self-propelled carriage driven by one electric motor.

[0002]

2. Description of the Related Art In a conventional conveyor device, for example, a roller conveyor as shown in FIG. 7, a conversion device 100 is provided in a part of a main line 50, and a sub line 90 is installed from this part. It is what In this case, an object (work) flowing on the main line 50 as shown by an arrow is sensed at the sensor 80, and the conversion device 100 operates based on the signal sensed at the sensor 80. It is what Specifically, based on the signal of the sensor 80, a power cylinder (not shown) or the like for lifting up the conversion device 100 is operated. At the same time, the sprocket 110 is rotationally driven by driving a separately provided motor (not shown) or the like, and further, the chain 1 driven by the sprocket 110 is driven.
By activating 20, the work or the like conveyed on the conversion device 100 is transferred onto the sub line 90.

[0003]

By the way, the above-mentioned conventional apparatus is provided with a power cylinder device for lifting up as a power unit for operating the converter 100, and further drives the chain 120 and the like. A motor and the like for doing so are separately provided. Therefore, there are problems that a plurality of power sources are required, the entire apparatus becomes large, and the weight (mass) becomes heavy. In order to solve such a problem, an attempt is made to provide a transport direction changing device formed on the basis of a one-motor type self-propelled trolley in which the power source is reduced and the whole is made compact. Is the object (problem) of the present invention.

[0004]

In order to solve the above-mentioned problems, the following measures are taken in the present invention. That is, according to the first aspect of the present invention, with respect to the conveying direction changing device, an electric motor which is mounted on a box-shaped chassis and serves as a power source, and which is provided at four corners of the chassis and is used for lifting. And a traveling sprocket row composed of two descending sprockets, wheels provided in the vicinity of the traveling sprocket row and provided in combination with the traveling sprocket row, and the four traveling sprocket rows described above. The traveling sprocket comprises a work carrier that comprises a chain that transmits the power from an electric motor to rotationally drive the four sets of traveling sprocket rows in a synchronized state, and a base on which the work carrier moves. Two slanted racks meshingly engaged with the row and provided parallel to the slanted racks, wherein the wheels perform rolling motion. That consists guide rails, these was taking a pedestal provided at four positions in a state corresponding to the traveling sprocket arrays provided at the four corners of the chassis, the structure comprising.

By adopting such a configuration, in the present invention, the four sets of traveling sprocket rows provided at the four corners of the chassis make a rotational movement in synchronization with each other by the power from the electric motor. As a result, the self-propelled work carrier truck moves up and down on the inclined rack. As a result, the work mounted on the work transfer carriage is smoothly sent out (dispensed) in a predetermined direction by the operation (movement) of the work transfer carriage. That is, the work transfer direction conversion work can be smoothly advanced.

Next, the invention according to claim 2 will be described. This one is also the same as the one described in claim 1 in the basic point. That is, in the present invention, with respect to the conveyance direction changing device, an electric motor that is mounted on a box-shaped chassis and serves as a power source, and one that is provided at four corners of the chassis and is used for raising and lowering. A traveling sprocket row consisting of two sprockets, wheels provided in the vicinity of the traveling sprocket row and provided in combination with the traveling sprocket row;
A drive sprocket provided on a drive shaft that connects between the two sets of traveling sprocket rows provided on one end side of the chassis of the set of traveling sprocket rows and the rest of the chassis. At the driven shaft that connects between two sets of traveling sprocket rows provided on one end side of the driven sprocket and near the respective traveling sprocket rows, and above these driven sprocket and drive sprocket. There are two transfer sprockets provided in a substantially horizontal state at the vertical wall of the chassis, and a chain that connects these two transfer sprockets and four sprockets consisting of a drive sprocket and a driven sprocket in an annular shape.
And a two-row slanted rack that meshes with the traveling sprocket row and that forms a base on which the work transportation carriage moves.
A pedestal consisting of a guide rail that is provided in parallel with the inclined rack and in which the wheels make a rolling motion,
It has been decided to adopt a configuration in which it is provided at four locations in correspondence with the traveling sprocket rows provided at the four corners of the chassis. By adopting such a configuration, also in the case of the present invention, as in the case of the above-described claim 1, the work is moved up and down by the self-propelled work transfer carriage driven by the power from the electric motor. The delivery work (payout work) will proceed smoothly.

Next, the invention according to claim 3 will be described. Also in this case, the basic points are the same as those described in claim 1 or claim 2. That is, in the present invention, in the conveyance direction changing device according to claim 1 or 2, the guide rail is provided continuously with an inclined surface having the same inclination angle as that of the inclined rack, and the inclined surface. In addition, the wheel is formed substantially horizontally at a place where the wheel has climbed up the inclined surface, and the wheel is composed of an idling holding portion formed so as to make an idling motion. Out of the sloping rack
The ascending rack that engages with the ascending traveling sprocket has teeth that engage and engage with the teeth of the sprocket only at the portion corresponding to the inclined surface of the guide rail. The descending rack that meshes with the traveling sprocket has a tooth portion that meshes with the tooth portion of the descending traveling sprocket at the horizontal portion corresponding to the idling holding portion of the guide rail. I decided to adopt the configuration.

By adopting such a configuration, in the present invention, it is possible to smoothly send out (deliver) the work by moving the work transfer carriage up and down at the inclined rack. .
In particular, in the state where the traveling sprocket has finished climbing the inclined rack, it makes an idling motion there, and during this idling motion, the work mounted on the chain is quickly transferred and delivered, that is, It becomes possible to smoothly carry out the payout work. After the delivery work (delivery work) is completed, the work transport carriage can be quickly lowered by reversing the descending traveling sprocket that is always meshed with the descending rack. become. As described above, according to the present invention, the work transfer direction changing work can be smoothly performed by the forward rotation motion or the reverse rotation motion of the traveling sprocket row.

Next, the invention according to claim 4 will be described. Also in this case, the basic points are the same as those in claims 1 to 3 above. That is, in the present invention, in the transport direction changing device according to any one of claims 1 to 3, the electric motor can be arbitrarily controlled in its rotation speed and rotation direction by an inverter control means. Decided to take. By adopting such a configuration, in the present invention, the work feeding work, that is, the paying-out work can be quickly performed by increasing the rotation speed of the electric motor. That is, in the state where the work carrier carrying the work has climbed up the inclined rack and the wheels are settled in the idling holding portion, the drive speed of the electric motor is increased by the inverter control to drive the sprocket, etc. By increasing the moving speed of the chain driven by, the work mounted on the chain can be quickly sent out (dispensed).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. Although it relates to the present embodiment, the configuration thereof relates to a conveyance direction conversion device that sends out a work conveyed on a main line of a conveyor in a predetermined direction such as a sub line, as shown in FIG. It is basically composed of a work transfer carriage 10 for carrying out the work and a pedestal 30 as a base for moving the work transfer carriage 10.

In such a basic structure, the work transfer carriage 10 has a box-shaped chassis 1 and an electric motor 4 mounted on the chassis 1 and forming a power source. And a rotary motion that receives power from the electric motor 4.
A set of running sprocket rows 15 provided at the four corners of
Free rollers 24, which are provided in parallel at the four sets of traveling sprocket rows 15 provided at the four corners and serve as moving wheels of the work transfer carriage 10, and are provided at the four corners. Drive shaft 41 or driven shaft 4 to which each traveling sprocket row 15 is attached
2, a drive sprocket 13 and a driven sprocket 14 which are integrally attached to each other, and a drive sprocket 13 and a driven sprocket 14 which are provided between the drive sprocket 13 and the driven sprocket 14 and in which the power from the electric motor 4 is set to the four sets of traveling sprocket rows 15 And a chain 5 which is provided between the drive sprocket 13 and the driven sprocket 14 in an endless manner.

In the above-mentioned structure, the electric motor 4 is configured so that the rotation speed, the forward rotation and the reverse rotation, etc. are appropriately controlled by an inverter control system. A drive shaft 41 is connected to the electric motor 4 and one end thereof forms a vertical wall of the box-shaped chassis 1, and a bearing 43 is provided at a chain cover 19 for protecting the chain 5. It is designed to be supported through. And
In the vicinity of such a chain cover 19 and the drive shaft 4
A drive sprocket 13 is attached to the position 1 (see FIG. 2). Further, the chain cover 1 is formed so as to form a pair with the drive shaft 41.
At the rear end, which is one end of 9, the driven shaft 42
One end of is supported via a bearing 43 (see FIG. 2). The drive shaft 41 is provided around the bearing 43 and at the driven shaft 42.
The driven sprocket 14 is provided in the same manner as in the above case. As a result, the power from the electric motor 4 is also transmitted to the driven shaft 41 and the driven sprocket 14 via the chain 5.

In the vicinity of the upper end of the chain cover 19, the two transfer sprockets 11 and 1 are arranged parallel to the drive sprocket 13 and the driven sprocket 14.
2 is provided, and the chain 5 is annularly mounted between the transport sprockets 11 and 12 and between the drive sprocket 13 and the driven sprocket 14. by this,
With the one electric motor 4, the drive sprocket 13,
The driven sprockets 14 and the transfer sprockets 11, 1
2 will be driven simultaneously. Further, as shown in FIG. 3, a chain guide 51 is provided below the chain 5 between the two transport sprockets 11 and 12 having such a configuration, and the chain guide 51 is It is designed to be attached to the upper end of the chain cover 19. This prevents the chain 5 from hanging downward when the work is mounted on the chain 5. It should be noted that the chain cover 19 is provided in the form of a set of two plates, and a part of the chain 5 and the sprockets 11, 12, 13 and 14 are housed therein. ing. The chain cover 19 not only functions as a cover, but also receives the mass of the work and the electric motor 4.

At the respective tip portions of the drive shaft 41 and the driven shaft 42 having such a structure, that is, at the four corners of the box-shaped chassis 1, a set of traveling as shown in FIG. Sprocket row 15 and free roller 24
And are provided. The traveling sprocket row 15 is composed of two sprockets. One of them is the drive shaft 41 and the driven shaft 4 described above.
It is designed to be directly connected to 2 and a pedestal 3 to be described later.
The sprocket 151 for raising, which is activated when the work carrier 10 ascends, is formed on the inclined portions of 0 and 30 '. The other one is the drive shaft 41.
Alternatively, it is attached to the driven shaft 42 via a freewheel mechanism 63 composed of a one-way clutch mechanism, and when it makes an idling motion during the ascending motion, and when descending the inclined part of the pedestals 30, 30 '. The traveling sprocket 152 for lowering is formed. Then, in the vicinity of such four sets of traveling sprocket rows 15 and above the drive shaft 4
1 and the driven shaft 42 are provided with free rollers 24 that form wheels, and are adapted to roll on guide rails 34 provided at pedestals 30 and 30 'described later. is there. In addition, this free roller 2
A flange 25 is provided on the outer peripheral portion of the guide roller 4, so that when the free roller 24 rolls on the guide rail 34, the free roller 24 moves the guide roller 34.
It is designed to prevent it from falling off.

Next, the pedestals 30 and 3 which serve as a base for supporting the movement of the work transfer carriage 10 such as raising and lowering.
0'will be described. This is based on the fact that the box-shaped chassis 1 is provided at four locations corresponding to the traveling sprocket rows 15 and the free rollers 24 provided at the four corners of the box-shaped chassis 1. Further, such pedestals 30 and 30 'are arranged to be symmetrical with respect to the pedestal frame 31 on the lower side of the frame 7 forming the conveyor line (see FIG. 2). . And such pedestals 30, 3
As shown in FIG. 1, 0'includes one on the front side (30) and one on the opposite side (left side) (30 '), which are installed so as to form a symmetrical shape. . In addition, the pedestals 30 and 30 ′ are respectively an ascending rack 351 and a descending rack 352 with which the traveling sprocket row 15 engages with each other, and a guide rail 34 with which the free roller 24 rolls. ,. The ascending traveling sprocket 151 meshes with the ascending rack 351 and the descending traveling sprocket 1 is provided at the descending rack 352.
52 is adapted to engage with each other.

Next, specific structures of the guide rail 34, the ascending rack 351 and the descending rack 352 will be described with reference to FIGS. 4 to 6. In addition,
Basically, these are roughly divided into two parts, an inclined part and an upper end side in a substantially horizontal state. In such a basic structure, the guide rail 34 receives the load of the work transfer carriage 10 from the free rollers 24 as shown in FIG.
Inclined surface 3 that lifts 0 upward (lifts up)
4a and an idling holding portion (horizontal portion) 34b which is continuously formed on the upper end portion of the inclined surface 34a and is formed in a substantially horizontal shape. In addition,
A vertical wall-shaped lower end stopper 39 is provided at the lower end of the inclined surface 34a having such a configuration, and an upper end stopper 38 made of a vertical wall is provided at the distal end of the idling holding portion 34b. Is provided. In addition, each of the stoppers 38, 39
In some cases, an electric switch or the like corresponding to this may be installed as another device. In addition, the idling holding portion 34 formed on the upper end of the guide rail 34.
As shown in FIG. 4, a reverse taper portion having an inclination angle θ is provided in b. As a result, the free roller 24 is prevented from being unexpectedly backed and lowered due to the inertial force of the work transfer carriage 10 or the like.

Next, in the lifting rack 351 forming the pedestals 30, 30 ', the lifting traveling sprocket 151 receives the rotational force from the electric motor 4 and meshes with the teeth of the inclined rack to convey the work. It serves to raise the carriage 10 along the inclined portion.
More specifically, as shown in FIG. 5, the upper rack 351 has an upper end in which a tooth portion 355 is formed substantially horizontally over the entire inclined portion 351a and continuously on the upper end side of the inclined portion 351a. It is designed to be provided up to the position in front of the portion 351b. By providing such a tooth portion 355, when the free roller 24 is present in the idling holding portion 34b, the traveling traveling sprocket 1 is raised.
The tooth portion 155 of the 51 is the tooth portion 355 of the rack 351 for lifting.
Will not mesh with each other, and the traveling sprocket 151 for main climbing will start idle motion.

Next, in the descending rack 352 forming the pedestals 30, 30 ', the descending traveling sprocket 152 receives the rotational force from the electric motor 4 and engages with the tooth portion 355 of the descending rack 352. The function is to lower the work transport carriage 10 along the inclined portion 352a. Specifically, the main lowering rack 352 has teeth 355 as shown in FIG.
Are provided on the entire inclined portion 352a and on a horizontal portion 352b formed substantially horizontally and continuously from the upper end portion of the inclined portion 352a. Therefore, the tooth portion 355 meshes with the tooth portion 155 of the descending traveling sprocket 152 even when the free roller 24 contacts the upper end stopper 38.

Next, the operation mode of the device having such a structure will be described. First, when a work is conveyed on the conveyor line, the electric motor 4 starts a rotational movement by a predetermined signal to rotationally drive the drive sprocket 13. As a result, the chain 5 is driven and each of the traveling traveling sprockets 1 provided at the four corners.
51 starts a rotational movement. As a result, the ascending traveling sprockets 151 have the same structure as the ascending racks 351 shown in FIG.
The slanted portion 351a is raised while meshing with the tooth portion 355 of the raising rack 351. As a result, the work transfer carriage 10 rises and lifts the moving surface of the chain 5 further above the upper surface of the transfer roller 8 forming the conveyor line. As a result, the work carried on the conveyor line is sent to the sub-line or the like while being rotated on the carrying sprockets 11 and 12 while being mounted on the chain 5. In addition,
When the work carrier 10 is lifted up and the work is sent out (discharging work) when the chain 5 is operated, the traveling sprocket 151 for lifting the work carrier 10 moves the inclined portion 351 a of the lifting rack 351. After climbing up and over the upper end 351b,
That is, the free roller 24 is set to the idle holding portion 34.
In the state where the free roller 24 reaches the position b, the free roller 24 has a substantially horizontal idling holding portion 3
It comes into contact with the upper end stopper 38 in the shape of a vertical wall provided at the back of 4b and is retained there. Then, the idling operation will be performed here. In such a state, a command (signal) is sent from the separately provided control means to the electric motor 4. Based on this signal, the rotation speed of the electric motor 4 is increased. As a result, the drive sprocket 1
3, the transport sprockets 11 and 12 to which the rotational driving force from the drive sprocket 13 is transmitted, and the chain 5 provided between the sprockets 11, 12 and 13 are driven at high speed. The work mounted on the drive chain 5 is transferred (sent out) at a high speed. In this way, the work transfer direction changing work (sending work) can be performed quickly.

Next, the lowering operation of the work carrier 10 will be described with reference to FIG. When the work delivery work (payout work) is completed, the electric motor 4 makes a reverse motion by a signal from a separately provided control means. As a result, the chain 5 and each traveling sprocket 15
1, 152 starts a reversing movement. As a result, the teeth portion 155 of the descending traveling sprocket 152 is moved to the descending rack 35.
The second horizontal portion 352b meshes with the tooth portion 355 to start the backward movement. When the traveling sprockets 151, 152 come to the inclined portions 352a, 351a, the traveling traveling sprocket 151 also comes into meshing engagement with the tooth portion 355 of the rack provided on the inclined portion 351a. In this way, the two traveling sprockets 151 and 152 are attached to the inclined portion 351 of the inclined rack 35.
a, descend at 352a. At the same time, the free roller 24 moves on the guide rail 34 and descends to a position where it hits the lower end stopper 39. By such a series of operations, the work transfer carriage 10 is moved to the base 30,
Descent over 30 'and return to original position.

[0021]

According to the present invention, the transfer direction changing device for sending out the work transferred on the conveyor line in a predetermined direction is mounted on the box-shaped chassis and serves as a power source. An electric motor, a traveling sprocket row which is provided at the four corners of the chassis and is composed of two ascending and descending sprockets, and which is provided in the vicinity of the traveling sprocket row and is paired with the traveling sprocket row. A wheel provided in a state, and a work transfer carriage including a chain for transmitting the power from the electric motor to the four sets of traveling sprocket trains and rotationally driving the four sets of traveling sprocket trains in a synchronized state, and the work. Two slant racks, which form a base on which a transport carriage moves, and engage with the traveling sprocket row, and the slant racks. And a pedestal that is provided in parallel and that is composed of guide rails in which the wheels make rolling motions and that are provided at four locations in a state corresponding to the traveling sprocket rows provided at the four corners of the chassis. Therefore, the four sets of traveling sprocket rows provided at the four corners of the chassis are rotated by the power from the electric motor in a synchronized state, which allows the self-propelled work carrier truck to move. The work is moved up and down on the inclined rack, and the work mounted on the work transfer carriage is operated (moved) by the work transfer carriage.
This makes it possible to smoothly send out (pay out) in a predetermined direction.

Further, in the present invention, the guide rail is provided continuously with an inclined surface having the same inclination angle as that of the rack, and the wheel is climbed up the inclined surface. Of the two tilted racks are meshed with a traveling sprocket of the two tilted racks. The ascending rack has a tooth portion that engages with the tooth portion of the sprocket only at a portion corresponding to the inclined surface of the guide rail, and engages with the descending traveling sprocket. The descending rack should also have teeth at the horizontal portion corresponding to the idling holding portion of the guide rail, which engages with the teeth of the descending traveling sprocket. Since it was decided to employ a configuration was, the workpiece transfer carriage can now be performed smoothly feeding (payout) work by lifting the place of the inclined rack. In particular, in the present invention, when the traveling sprocket has finished climbing the inclined rack, it makes an idling motion there, and during this idling motion, the work mounted on the chain is quickly transferred. The delivery work (delivery work) can now be carried out smoothly. After the delivery work (delivery work) is completed, the work transport carriage can be quickly lowered by reversing the descending traveling sprocket that is always meshed with the descending rack. It became so. That is, in the present invention, it is possible to smoothly perform the work transfer direction changing work by the forward rotation motion or the reverse rotation motion of the traveling sprocket row.

Further, in the present invention, the electric motor has a structure in which the rotation speed and the rotation direction can be arbitrarily controlled by the inverter control means. That is, the paying-out work can be quickly performed by increasing the rotation speed of the electric motor. That is, in the state where the work carrier carrying the work has climbed up the inclined rack and the wheels are settled in the idling holding portion, the drive speed of the electric motor is increased by the inverter control to drive the sprocket, etc. By increasing the moving speed of the chain driven by, the work mounted on the chain can be quickly delivered (dispensed).

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of the present invention.

FIG. 2 is a cross-sectional view showing a meshing engagement state of a traveling sprocket row forming a main part of the present invention with an inclined rack.

FIG. 3 is a sectional view showing a structure of a chain and a chain guide according to the present invention.

FIG. 4 is a side view showing a state of rolling motion on a guide rail of a free roller according to the present invention.

FIG. 5 is a side view showing the shape of the lifting rack with which the lifting sprocket according to the present invention meshes and engages.

FIG. 6 is a side view showing the shape of a descending rack with which the descending traveling sprocket according to the present invention meshes and engages.

FIG. 7 is a perspective view showing an overall configuration of a conventional example.

[Explanation of symbols]

1 chassis 11 Transport sprockets 12 Transport sprockets 13 Drive sprocket 14 Driven sprockets 15 Running sprocket row 151 climbing sprocket 152 Traveling sprocket for lowering 155 Sprocket tooth 19 chain cover 24 free rollers 25 flange 30 pedestal (right side) 30 'pedestal (left side) 31 pedestal frame 34 Guide rail 34a inclined surface 34b Idling holder (horizontal part) 35 inclined rack 351 Lifting rack 351a inclined part 351b upper end 352 Lowering rack 352a inclined portion 352b horizontal part 355 teeth 38 Upper end stopper 39 Lower end stopper 4 electric motor 41 drive shaft 42 Driven shaft 43 bearing 5 chains 51 Chain guide 63 freewheel 7 frames 8 Conveyor rollers 10 Work transfer cart

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeru Tsukamoto             Aya Prefecture, Chikusa-ku, Chaya 1-4 Saka             No. 16 Toho Machine Industry Co., Ltd. F-term (reference) 3F016 AA01 CC05 CE01 CG01

Claims (4)

[Claims] 1. An electric motor, which is mounted on a box-shaped chassis and serves as a power source, and a traveling sprocket, which is provided at four corners of the chassis and includes two sprockets for raising and lowering. Row, wheels provided in the vicinity of the traveling sprocket row and provided in combination with the traveling sprocket row, and the four sets of traveling sprocket rows by transmitting power from the electric motor to the four groups. Two inclined racks, which form a work carrier including a chain that rotationally drives the traveling sprocket trains in synchronization with each other, and a base on which the work carrier travels, and which engage with the traveling sprocket trains. And guide rails that are provided in parallel with the inclined rack and in which the wheels make rolling motions, and these are installed at the four corners of the chassis. A conveyance direction changing device comprising: a pedestal provided at four locations in a state corresponding to the running sprocket row. 2. A traveling sprocket, which is mounted on a box-shaped chassis and serves as a power source, and two sprocket for raising and lowering, which are provided at four corners of the chassis. Row, wheels provided in the vicinity of the traveling sprocket row and provided in combination with the traveling sprocket row, and one end side of one of the chassis of the four traveling sprocket rows A drive sprocket provided on a drive shaft that connects between two sets of traveling sprocket rows provided on the drive shaft and the electric motor, and two sets of traveling sprocket rows provided on the other end side of the remaining chassis. The driven sprocket provided at the driven shaft and the upper part of the driven sprocket and the drive sprocket at the vertical wall of the chassis. 4 consisting of two transfer sprockets provided in a substantially horizontal state, and these two transfer sprockets and a drive sprocket and a driven sprocket
A two-row slanted rack is provided which is provided with a work transfer carriage composed of a chain for connecting two sprockets in an annular shape and which forms a base on which the work transfer carriage moves, and which meshes with and engages with the traveling sprocket row. And pedestals, which are provided in parallel with the inclined rack and in which the wheels make rolling motions, are provided at four locations corresponding to the traveling sprocket rows provided at the four corners of the chassis. A transport direction changing device characterized in that. 3. The transport direction changing device according to claim 1, wherein the guide rail is provided continuously with an inclined surface having the same inclination angle as the inclined rack and the inclined surface. And the wheel is composed of an idling holding portion which is formed substantially horizontally when the wheel has climbed up the inclined surface and which is formed so as to make an idling motion, while the two inclined racks are provided. Of the above, the raising rack that engages with the raising traveling sprocket has a tooth portion that engages with the tooth portion of the sprocket only in the portion corresponding to the inclined surface of the guide rail. The descending rack that engages with the descending traveling sprocket and the teeth of the descending traveling sprocket at the horizontal portion corresponding to the idling holding portion of the guide rail. A conveying direction changing device having a tooth portion which engages with each other. 4. The conveyance direction changing device according to claim 1, wherein the rotation speed and the rotation direction of the electric motor can be arbitrarily controlled by an inverter control means. Transport direction changing device.