JPH0450224B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a trolley-type transport device used in automobile assembly lines, etc., and more specifically, for placing objects to be transported, such as car bodies, along a transport path. The present invention relates to a transport device in which a transport vehicle is self-propelled.

(Prior Art) Conventionally, as a device of this kind, according to Japanese Patent Application Laid-Open No. 48-59511, a pit is constructed by embedding a wide groove-shaped track frame over the entire width of the conveyance path, and A pair of traveling rails and a guide rail are fixed to the wall at the center of the bottom surface, and a steering frame is attached to the lower surface of the carriage body via a vertical steering shaft. Wheels rolling on running rails at both left and right ends of the truck are pivotally supported, and a pair of front and rear guide rollers that contact one side of the guide rail are pivotally supported on the steering frame. A movable swinging frame is provided, and a drive roller and a drive motor are attached to the swinging frame, which abuts on the other side of the guide rail.
It is known that the swing frame is biased by a spring so that the drive roller comes into pressure contact with the guide rail.

In this device, the conveyance cart moves by itself along the conveyance path by the rotation of the drive roller, and at the curved part of the conveyance path, the pressure reaction force of the drive roller against the guide rail causes the
The steering frame is rotated so that both the pair of guide rollers come into contact with the guide rail, the direction of the wheels changes, and the carriage is steered at the curved portion.

(Problems to be Solved by the Invention) In the above-mentioned device, pits are formed over the entire width of the conveyor path, so the work space of the conveyor path cannot be utilized, and the load is transferred by the wheels attached to the steering frame. As a result, the rotational resistance of the steering frame increases, making it difficult to perform steering smoothly.Furthermore, in addition to the steering frame, it is necessary to provide a swinging frame with a drive roller attached to the bogie body. , there is a problem that the structure is complicated.

In view of the above points, the present invention aims to provide a transport device with a simple structure in which the transport path is formed flat so that it can be used as a work space, and the maneuverability of the transport vehicle is improved. purpose.

(Means for solving the problem) In order to achieve the above object, in the invention of claim 1,
In a trolley-type conveyance device in which a conveyance cart is self-propelled along a conveyance path, a pit is formed at the center in the width direction of the conveyance path, a guide rail is laid in the pit, and a pit is installed on the top surface of the pit. A track that is flush with the road surface of the conveyance path covering the pit is formed, a slit communicating with the pit is formed at the center in the width direction of the track, and the main body of the conveyance cart is grounded on the road surface of the conveyance path. At least one of the front wheels of a plurality of wheels attached to the truck is configured as a caster wheel, and a steering frame rotatable around a vertical steering axis is pivotally supported on the main body of the truck, and the steering frame is attached to the track. A drive wheel that touches the ground substantially directly below the steering axis and a travel motor that rotates the drive wheel are installed, and a guide member that engages and is guided by the guide rail is provided, and the guide member is inserted into the slit. It was connected to the steering frame through. In this case, in order to facilitate the construction work of the conveyance path and improve the maintenance workability in the pit, as in the invention of claim 2, the pit is buried in the center of the width direction of the conveyance path.
It consists of a letter-shaped track frame, and a pair of cover plates facing each other with a gap forming the slit are removably locked to the upper ends of the side plates on both sides of the track frame. Preferably, the track is formed by a plate.

Further, in order to apply an appropriate ground load to the driving wheels, the steering frame is pivoted to a movable frame that is biased downwardly by a biasing means on the bogie body. Further, as in the invention of claim 4, the movable frame is pivotally supported on the truck main body at its front and rear ends so as to be swingable in the vertical direction, and the width of the movable frame with respect to the truck main body is fixed to the pivot portion. It is preferable to provide an elastic member that allows tilting in the direction.

Further, as in claim 5, the guide member is freely separable from the steering frame, and an operating member for pulling up the movable frame against the biasing means is provided, and further as in claim 6, , all of the wheels attached to the trolley body are composed of caster wheels, and
A second guide member that is guided by engaging with the slit or the guide rail is provided on the truck body, and the second guide member is spaced apart from the drive wheel in the front and rear direction.
It is desirable to provide an engaging member that can be freely engaged and detached from the guide member.

(Function) The transport vehicle travels along the transport path on the road surface by the rotation of the drive wheels, and at the curved portion of the transport path, the steering frame is rotated via a guide member guided by the guide rail in the pit, and the drive wheel rotates. The wheels are steered so as to face in the tangential direction of the track at the center of the transport path, and the direction of the front wheels, which are made up of caster wheels, changes in response to the tangential propulsive force from the drive wheels, and the Steering is performed.

Here, since the weight of the truck, including the transported object, is supported by the wheels attached to the truck body, the weight of the truck does not directly act on the drive wheels, and the drive wheels are positioned approximately directly below the steering axis on the track. Because it is in contact with the ground, the steering reaction force of the drive wheels that causes turning resistance of the steering frame is reduced, the steering frame can be turned smoothly following the guide rail, and the steering performance of the transport vehicle is improved. , the conveyance truck runs smoothly along the curved portion of the conveyance path.

Note that the conveyance path is formed flat over its entire width including the track, allowing the operator to work while standing on the conveyance path.

Further, according to the invention of claim 3, the urging force of the urging means acts on the drive wheel via the movable frame and the steering frame,
An appropriate ground load necessary to prevent the drive wheels from slipping is applied to the drive wheels, and furthermore, according to the fourth aspect of the invention, even if the wheels pick up undulations on the road surface and the truck body tilts, this tilting is prevented by elasticity. The drive wheels are absorbed by the members and ground stably on the track, and one side of the drive wheels does not float up and cause slips.

Further, according to the invention of claim 5, the guide frame can be separated from the steering frame, and the movable frame can be pulled up by the operating member to lift the drive wheels from the track. When a transport vehicle malfunctions, it can be easily removed from the transport path.

According to the invention of claim 6, by using all wheels as caster wheels, the turning performance of the transport vehicle is improved, and the transport vehicle is guided by two guide members at two points spaced apart in the front and rear direction. Even if the conveyance path is complicatedly curved, the conveyance cart can be accurately driven along the conveyance path.

Incidentally, when removing the transport vehicle from the transport path, the engaging member is disengaged from the second guide member.

By the way, in the conventional technology in which a pit is formed by burying a wide track frame that spans the entire width of the conveyance path, the track frame becomes large and the weight of the bogie is transferred to the track frame through the running rail fixed to the track frame. As a result, the track frame needs to be reinforced, and the track frame burying work becomes large-scale.

However, in the present invention, the pit is only formed at the center in the width direction of the conveyance path, and the track frame constituting the pit can be narrow and small, and the wheels of the truck body that receive the weight of the truck are placed in the width direction of the conveyance path. Since the track frame is in contact with the road surface, no large load is applied to the track frame, and a pit can be easily formed by simply burying the track frame in the center of the conveyance path without any special reinforcement. According to the invention described in item 2, the track in the center of the conveyance path that covers the pit is constructed with a cover plate that is removably attached to the upper ends of both side plates of the track frame, so maintenance inside the pit can be easily performed by removing the cover plate. able to perform work.

(Embodiment) In the illustrated embodiment, the present invention is applied to an automobile assembly line for assembling various parts to an automobile body W. Referring to FIGS. 1 and 2, 1 is an assembly line. The conveyance path provided along the conveyance path, 2 indicates a conveyance truck, and the conveyance truck 2 includes a support table 5 on which a vehicle body W is placed on a truck body 3 via an X-link mechanism 4.
A total of four front and rear wheels 6 are provided on the lower surface of the trolley body 3 and are in contact with the road surface on both the left and right sides of the conveyance path 1, and a drive wheel 7, which will be described later, is installed in the center of the front part of the trolley body 5. Attach the transport trolley 2 to the transport path 1.
The vehicle body W was transported to the assembly line by moving along the road.

As shown in FIG. 3, the conveyance path 1 has a substantially U-shaped track frame 8 embedded in the widthwise center thereof.
A guide rail 9 is laid in a pit constituted by the track frame 8, and side plates 8a, 8 on both sides of the track frame 8 are installed.
A pair of left and right cover plates 10, 10 are removably locked on the upper end of a so that they face each other with a gap in between, and are flush with the road surface of the conveyance path 1 that covers the pit with both cover plates 10, 10. A central slit 1b is formed which communicates with the pit between the two cover plates 10, 10.

The track frame 8 is made of extruded material, with an upward groove 8b formed in the flange portion at the upper end of each side plate 8a, and a successor piece 10a that engages with the groove 8b on the lower surface of each cover plate 10. A plurality of lid plates 10 are attached at appropriate intervals to lock each lid plate 10 to each side plate 8a, and a lifting bar 1 is attached to an appropriate position of each lid plate 10.
0b, and pull up the bar 10b to remove each cover plate 10, and channel grooves 8c, 8 with convex cross-sections opening upward on both sides of the bottom of the track frame 8.
c, and when burying the track frame 8, a plurality of nuts 11 are inserted in advance into each channel groove 8c from the longitudinal end of the track frame 8, and the guide rail 9 is inserted into the flange at the lower end. After the clamp piece 12 is seated on the bottom surface of the track frame 8 via the shim plate 9b at 9a, the clamp piece 12 is engaged with the flange 9a.
The guide rail 9 is tightened and fixed by screwing the bolt 12a inserted into the nut 11 into the nut 11. Further, a longitudinal dovetail groove 8d is formed on the inner surface of the side plate 8a of the track frame 8, so that the front and rear track frames 8,
8, is provided with a dovetail joint member 13 that engages with the dovetail grooves 8d of both track frames 8, 8, as shown in the fourth figure, and the joint member 13 is provided with a groove bottom of each dovetail groove 8d. A tightening bolt 13a that can come into contact with the bolt 13a is screwed in, and the joint member 13 is pressed against the inner surface of each dovetail groove 8d by the tightening reaction force of the bolt 13a, and the front and rear track frames 8, 8 are moved vertically and horizontally. I made it possible to match and connect them.

The trolley body 3 has a movable frame 1 at the center of its front part that is vertically swingable as shown in FIGS. 5 to 7.
4, and the movable frame 14 is equipped with a bearing 1.
5, a steering frame 16 which is rotatable around a vertical steering axis is pivotally supported, and within a housing-shaped casing 16a fixed to the lower surface of the steering frame 16, a steering frame 16 is mounted approximately directly below the steering axis. A traveling motor 1 that pivotally supports the drive wheel 7 so as to be in contact with the track 1a and rotates the drive wheel 7 on one side in the lateral direction of the casing 16a.
7 and a brake 18 on the other side.

The movable frame 14 is pivoted at its rear end on a horizontal pivot 14a provided on the cross frame 3a of the truck body 3, and the movable frame 14 is pivoted at a tongue piece 14b extending from its front end. A biasing means 14c made of a coil spring is used to urge the driving wheel 7 downwardly so as to apply an appropriate grounding load to the drive wheel 7 so as not to cause it to slip, and an operating member made of a bolt screwed onto the tongue piece 14b. 14d
is provided, and the movable frame 1 is rotated by the rotation of the operating member 14d.
4, the drive wheel 7 is pulled up against the biasing means 14c.
It was made possible to levitate from orbit 1a. Further, the movable frame 14 is pivotally supported on the pivot shaft 14a via an elastic member 14e made of a rubber bushing, and the bogie body 3
Even if the wheels 6 attached to the wheels 6 pick up the undulations of the road surface of the conveyance path 1 and the truck body 3 tilts in the width direction, the tilt of the truck body 3 is absorbed by the elastic deformation of the elastic member 14e, and the width of the movable frame 14 increases. The drive wheels 7 are prevented from tilting in the width direction, and are stably grounded on the track 1a without tilting in the width direction. 14f is movable frame 1
The cover plate attached to the top surface of 4 is shown.

Reference numeral 19 denotes a guide member that engages with the guide rail 9 through a pair of guide rollers 19a at the front and rear, and as shown in FIG. The connecting piece 19b is connected to a bracket 16b protruding from the front surface of the casing 16a of the steering frame 16, and the steering frame 16 is connected to the steering frame 16 by the guide rail 9 via the guide member 19. Turning,
That is, the driving wheels 7 are steered, and a power supply path 20 is provided on the lower side surface of the guide rail 9, and a current collector 21 is provided in the guide member 19 in sliding contact with the power supply path 20, and the current is collected from the power supply path 20. 21 and coupler 22
Electric power is supplied to the traveling motor 17 and a drive motor (not shown) of the X-link mechanism 4 through the drive motor 17 and the drive motor (not shown) of the X-link mechanism 4.

Here, the connecting piece 19b is connected to the bracket 16b by a pair of bolts 23, 23 with nuts 23a pivotally attached to the upper part of the bracket 16b so as to be able to swing freely in the horizontal direction.
The guide member 19 can be separated from the steering frame 16 by loosening the bolts 3a and swinging each bolt 23 laterally outward toward the opening side.

In the illustrated example, the center of the arrangement pitch of the guide rollers 19a, 19a before and after the guide member 19 coincides with the steering axis.
9 may be engaged with the guide rail 9 on the leading side or the trailing side of the steering axis.

Referring to FIGS. 9 and 10, reference numeral 24 indicates a link chain that engages with the slit 1b, and a link chain 24a at the front end of the chain 24 is removably engaged with the rear part of the truck body 3 from above. A member 25 is provided so that the chain 24 is dragged by the conveyance vehicle 2 and moves along the slit 1b, and when the following conveyance vehicle 2 approaches, the stopper 24b connected to the rear end of the chain 24 is attached to the stopper 24b connected to the rear end of the chain 24. A stopper 19c attached to the front end of the guide member 19 connected to the steering frame 16 of the transport vehicle 2 comes into contact with the guide member 19 to prevent the following transport vehicle 2 from approaching any further, and the vehicle is mounted on the front and rear transport vehicles 2, 2. The vehicle bodies W that move are now prevented from colliding with each other. In the figure, reference numeral 24c indicates a guide roller attached to the chain 24 so as to roll on the upper surface of the guide rail 9. Note that the engagement member 25 is connected to the truck body 3.
It is configured so that it can be engaged and disengaged not only from the top side but also from the left and right sides via the link mechanism 25a.

Next, the operation of this embodiment will be explained.

The conveyance cart 2 moves on the conveyance path 1 by rotation of the drive wheels 7 by the travel motor 17, and in the curved portion of the conveyance path 1, the drive wheels 7 are moved by the guide rails 9 via the guide member 19 and the steering frame 16. The bogie body 3 is steered to face in the tangential direction of the track 1a, and a propulsive force along the track 1a acts on the front part of the bogie body 3 via the drive wheels 7, and the rear part of the bogie body 3 engages with the engagement member 25. The carriage 2 is guided to the slit 1b via the link chain 24, and thus the carriage 2 runs smoothly along the curved section.

When the transport vehicle 2 breaks down, the guide member 19
is separated from the steering frame 16, and then the movable frame 14 is pulled up by the operating member 14d to levitate the drive wheel 7, and the engaging member 25 is pulled up to separate from the link chain 24. According to this, the transport vehicle 2
can be moved freely, and since the transport path 1 is formed flat over its entire width including the track 1a, the transport cart 2 can be easily pushed to the side of the transport path 1 without getting caught. be able to.

In the above embodiment, the link chain 24 for collision prevention is also used as the second guide member for guiding the transport vehicle 2, but instead of the link chain 24, a link chain 24 dedicated to engaging with the slit 1b and the guide rail 9 is used. A guide member may be provided.

(Effects of the Invention) As is clear from the above description, according to the invention of claim 1, the steerability of the transport vehicle is improved, and the transport vehicle can run smoothly even on curved portions of the transport path. Moreover, the conveyance path is formed flat over its entire width, so that the conveyance path can be effectively used as a work space.

Further, according to the invention of claim 2, construction of the conveyance path becomes easy, and maintenance work in the pit where the guide rail is laid becomes easy.

According to the third aspect of the invention, it is possible to apply an appropriate ground load to the driving wheels so as to prevent them from slipping.
Furthermore, according to the fourth aspect of the invention, the driving wheels can be stably grounded on the track, and the transport vehicle can be stably self-propelled by the rotation of the driving wheels.

Further, according to the invention of claim 5, when the transport vehicle breaks down, the transport vehicle can be easily removed from the transport path,
The line can be restarted without stopping for a long time.

Furthermore, according to the sixth aspect of the present invention, even if the conveyance path is complicatedly curved, the conveyance cart can be accurately driven along it, which has the effect of increasing the degree of freedom in designing the conveyance path.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an example of the device of the present invention, Fig. 2 is a side view thereof, Fig. 3 is a cross-sectional view of the conveyance path, Fig. 4 is a perspective view of the main part of the joint part of the track frame, Figure 5 is a longitudinal cross-sectional view of the front part of the carrier, Figure 6 is a plan view thereof, Figures 7 and 8 are cross-sectional views taken along lines - and -, respectively, of Figure 5, and Figure 9 is a cross-sectional view of the carrier. A vertical cross-sectional view of the rear portion, and FIG. 10 is a cross-sectional view taken along the line -- in FIG. DESCRIPTION OF SYMBOLS 1... Conveyance path, 1a... Track, 1b... Slit, 2... Conveyance truck, 3... Dolly body, 6... Wheel, 7... Drive wheel, 8... Track frame, 8a... Side plate, 9... Guide rail, 10... Lid plate, 14...
...Movable frame, 14c...Biasing means, 14d...Operation member, 14e...Elastic member, 16...Steering frame, 1
7...Travel motor, 19...Guide member, 24...
...Link chain (second guide member), 25...
...Engagement member.

Claims (1)

[Scope of Claims] 1. In a trolley-type conveyance device in which a conveyance cart is self-propelled along a conveyance path, a pit is formed at the center in the width direction of the conveyance path, and a guide rail is laid within the pit. At the same time, forming a track flush with the road surface of the conveyance path covering the pit on the upper surface of the pit,
A slit communicating with the pit is formed in the center in the width direction of the track, and at least a front wheel of a plurality of wheels attached to the main body of the transport vehicle so as to be in contact with the road surface of the transport path is configured as a caster wheel;
A steering frame that is rotatable around a vertical steering axis is pivotally supported on the bogie body, and a driving wheel that is grounded on the track substantially directly below the steering axis is mounted on the steering frame, and the driving wheel is rotated. 1. A trolley-type conveying device, comprising: a traveling motor; further comprising: a guide member that engages with and is guided by the guide rail; and connects the guide member to the steering frame through the slit. 2. The pit is constituted by a substantially U-shaped track frame buried in the center of the width direction of the conveyance path, and the slits are formed at the upper ends of side plates on both sides of the track frame, and are opposed to each other with a gap forming the slit. 2. The trolley-type conveyance device according to claim 1, wherein a pair of cover plates are detachably engaged and the track is formed by both cover plates. 3. The trolley-type conveyance device according to claim 1, wherein the steering frame is pivotally supported by a movable frame provided on the trolley body and urged downward by a biasing means. 4. The movable frame is pivotally supported on the truck body at its front and rear ends so as to be able to swing vertically, and an elastic member is provided at the pivot portion to allow tilting of the movable frame in the width direction with respect to the truck body. The trolley-type conveyance device according to claim 3, characterized in that: 5. The trolley-type conveyance according to claim 3 or 4, characterized in that the guide member is separable from the steering frame and further includes an operating member for pulling up the movable frame against the urging means. Device. 6 All of the wheels attached to the bogie body are constructed of caster wheels, and a second guide member that engages with and is guided by the slit or the guide rail is provided, and the drive wheel is attached to the bogie body. Claim 1, characterized in that an engaging member is provided which is detachable from the second guide member and is spaced apart from the second guide member in the front-rear direction.
6. The trolley-type conveyance device according to any one of 3, 4, and 5.