JPH01247263A - Dolly - Google Patents

Abstract

PURPOSE:To prevent the body of a dolly from slippage by allowing only a clutch for driving the rear wheels to work when the body is in acceleration, and permitting another clutch for front wheels solely to operate when in deceleration. CONSTITUTION:When a dolly is run in the A direction, power is supplied only to a clutch 26 in response to a signal given by a control part 32 and a drive motor 24 is put in operation, with another clutch 27 not power supplied, so that wheels 15 are rotated through an axis 13, and the body 11 runs on a rail 33 in the A direction. When the body 11 is in acceleration, its center of gravity shifts to the back of the body 11 to cause increase of the contact resistance of the wheels 15 with rail 33, and slip is not likely to be generated between them. When decelerative condition is introduced so as to stop, a signal form the control part 32 disengages the clutch 26 and engages the one 27. Thereby the wheels 16 as front wheel are driven, and the center of gravity shifts toward the wheels 16 to cause increase of their friction resistance with the rail 33, so that the body 11 stops in specified position precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a transport vehicle whose wheels are prevented from slipping during acceleration or deceleration.

(Prior Art) Conventionally, a tracked automatic guided vehicle that runs on rails has been configured as shown in FIG. 4. In other words, 1 in the figure is a vehicle body, and a driving wheel 2 is attached to one end of the lower surface of the vehicle body 1 in the running direction.
, a driven wheel 3 is rotatably provided on the other end side,
It runs on rail 4. Also, car body 1
is provided with a drive motor 5, and the rotation of this drive motor 5 is transmitted to the drive wheels 2 via a belt 6.

By the way, in a conveyance vehicle having such a structure, the vehicle body 1
When traveling in the direction of arrow a, when the driving wheels 2 are rotationally driven, the center of gravity of the vehicle body 1 moves toward the driven wheels 3 located at the rear in the traveling direction. Then, since the weight of the vehicle body 1 applied to the driving wheels 2 is reduced, the contact resistance between the driving wheels 2 and the rails 4 is reduced, and slipping occurs in the driving wheels 2.

Furthermore, when the drive wheels 2 are driven to rotate in order to make the vehicle body 1 travel in the direction of the arrow A, which is the opposite direction to the arrow a, the center of gravity of the vehicle body 1 is added to the drive wheels 3, so that the contact between the drive wheels 3 and the rails 4 The resistance increases, making it difficult for slips to occur between them. However, when the drive wheels 2 are decelerated to stop the vehicle body 1, the center of gravity of the vehicle body 1 moves toward the driven wheels 3, and the contact resistance between the drive wheels 2 and the rails 4 decreases, causing slippage between them. will occur. Therefore, it was very difficult to stop the vehicle body tube 1 at a predetermined position.

(Problem to be solved by the invention) As described above, in conventional automated guided vehicles, the contact resistance between the drive wheels and the rail changes depending on the traveling direction of the vehicle body and whether the vehicle body is in a decelerating state or an accelerating state. As a result, slipping occurs and the vehicle body cannot be stopped at a predetermined position.

This invention was made based on the above circumstances, and its purpose is to prevent slippage of the vehicle body due to changes in running conditions such as the direction of travel of the vehicle body and whether the vehicle body is decelerating or accelerating. The objective is to provide a transport vehicle that is less likely to cause such occurrences.

[Structure of the Invention (Means and Effects for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a vehicle body having a drive source, and a vehicle body provided on the vehicle body that is driven by the drive source and in the traveling direction. a first wheel and a second wheel that become front wheels or rear wheels; a first clutch provided between the drive source and the first wheel; and a first clutch provided between the drive source and the second wheel.
a second clutch provided between the wheels of the vehicle; and a control unit that operates only a rear wheel drive clutch when the vehicle body is in an acceleration state and operates only a front wheel drive clutch when the vehicle body is in a deceleration state. Equipped with. The wheels to be driven are changed in response to changes in the running conditions of the vehicle, thereby making it difficult for the driven wheels to slip.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. The transport vehicle shown in FIG. 3 includes a vehicle body 11. Support portions 12 are provided at each of the four corners of the lower surface of the vehicle body 11.
A first axle 13 is rotatably provided on a pair of support parts 12 located at one end of the vehicle body 11, and a second axle 14 is rotatably provided on a pair of support parts 12 located at the other end. It is rotatably provided. A first wheel 15 is fitted to each end of the first axle 13, and a first wheel 15 is fitted to each end of the first axle 13.
A second wheel 16 is fitted to both ends of the wheel 4. Furthermore, a first pulley 17 is fitted in the middle of each axle 13, 14, respectively.

A support portion 18 shown in FIG. 2 is provided at the middle portion of the lower surface of the vehicle body 11 in the longitudinal direction.
is rotatably supported. This drive shaft 19 has a second
A pulley 21 is fitted. This second pulley 21
A first belt 23 is stretched between and a third pulley 22 provided on the vehicle body 11. The third pulley 2 above
2 is fitted onto a rotating shaft 25 of a drive motor 24, which is provided on the vehicle body 11 and serves as a drive source. Therefore, when the drive motor 24 operates, the first belt 23
The drive shaft 19 is rotationally driven by this.

An electromagnetic first clutch 26 is connected to one end of the drive shaft 19.
The drive side 26a of the second clutch 27 is connected to the other end, and the drive side 27a of a second electromagnetic clutch 27 is connected to the other end. A driven shaft 28 is provided on each driven side 26b, 27b of each clutch 26, 27, and a fourth pulley 29 is fitted onto each driven shaft 28. The fourth clutch on the first clutch 26 side
The pulley 29 provided on the first axle 13, the fourth pulley 29 on the second clutch 27 side, and the second pulley 21 on the second axle 14 are provided with second pulleys, respectively. A belt 31 is stretched. Therefore, when the driven side 26a and the driving side 26b of the first clutch 26 are coupled, the rotation of the drive motor 24 is caused to rotate to the first axle 1.
3 and the drive side 27a of the second clutch 27
When the driven side 27b and the driven side 27b are coupled, the signal is transmitted to the second axle 16.

Further, the vehicle body 11 is provided with a control section 32 . This control unit 32 detects changes in the rotational direction and rotational speed of the drive motor 24 via a sensor (not shown), and operates either the first clutch 26 or the second clutch 27 as described later based on the detection signal. In other words, it is driven to a state where power is transmitted.

Note that the first wheel 15 and the second wheel 16 are provided on the rail 33 so as to be freely transferable.

Next, a case will be described in which the transport vehicle having the above configuration is caused to travel. First, when the conveyance vehicle is run in the direction shown by arrow A in FIG. The drive motor 24 is driven while the motor 27 is not energized. Then, the drive motor 24
The rotation is transmitted to the first axle 13 via the first clutch 26, thereby rotationally driving the first wheel 15 and causing the vehicle body 11 to run on the rail 33 in the direction of arrow A. .

When the vehicle body 11 is driven in this manner, when the vehicle body 11 is in an accelerated state, its center of gravity moves to the rear of the vehicle body 1. As a result, the weight of the vehicle body 11 applied to the first wheels 13 increases, so the contact resistance between the first wheels 15 and the rails 33 increases, making it difficult for slips to occur between them. Therefore, errors in the travel distance of the vehicle body 11 are prevented.

After the vehicle body 11 has traveled to a predetermined position in this way,
In order to stop, the rotation speed of the drive motor 24 decreases and shifts to a deceleration state, and when this is detected, the first clutch 26 is disengaged by a signal from the control section 32, and the second clutch 27 is disengaged. Concatenated. As a result, the second wheel 16, which is the front wheel, is driven by the drive motor 24.

When the traveling speed of the vehicle body 11 is reduced in such a state,
The center of gravity shifts to the second wheel 16, which is the front wheel. As a result, the weight of the vehicle body 11 applied to the second wheels 16 increases, so the frictional resistance between the second wheels 16 and the rails 33 increases, making it difficult for slips to occur between them.

Therefore, the vehicle body 11 can be accurately stopped at a predetermined position.

On the other hand, when the vehicle body 11 is started in the direction of arrow B, which is the opposite direction to arrow A, the second clutch 27 is connected and the first clutch 26 is disengaged, so that the second wheel 16 becomes the rear wheel. is driven.

Therefore, as the center of gravity of the vehicle body 11 moves when starting, the load that the second wheels 16 receive increases, so the frictional resistance between the second wheels 16 and the rails 33 also increases, and there is a gap between them. Slips are less likely to occur.

Further, when the speed of the vehicle body 11 is reduced to stop, the control section 32 detects this and connects the first clutch 26 and disengages the second clutch 27. As a result, the first wheel 15 serving as the front wheel is driven during deceleration, and the load applied to the first wheel 15 increases. Therefore, since the contact resistance between the first wheels 15 and the rails 33 increases, slips are less likely to occur between them, and the vehicle body 11 can be accurately stopped at a predetermined position.

That is, regardless of whether the vehicle body 11 is run in the direction of arrow A or B, it is possible to prevent the vehicle body 11 from slipping during acceleration or deceleration.

In addition, in the above embodiment, the vehicle body is run on rails, but even if the vehicle is a trackless carrier that runs directly on the floor of a factory instead of on rails, there will be problems when accelerating or decelerating. It is possible to prevent slippage from occurring.

Furthermore, the transport vehicle may be unmanned or manned.

[Effects of the Invention] As described above, the present invention provides the first clutch between the drive source and the first wheel, the second clutch between the drive source and the second wheel, and The controller operates either the first clutch or the second clutch depending on the traveling direction of the vehicle body and whether the traveling direction is in an acceleration state or a deceleration state. Therefore, the control unit can connect and drive the wheel located on the side where the center of gravity of the vehicle body moves due to a change in the running state of the vehicle body, that is, the wheel on the side where frictional resistance increases, by connecting it to the drive source. This makes it difficult for the wheels to slip, improving the stopping accuracy of the vehicle body.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a drive structure showing an embodiment of the present invention;
Figure 2 is an enlarged side view of the wheel portion of the car body, Figure 3
The same figure is a side view of the vehicle body, and FIG. 4 is a side view of a conventional vehicle body. DESCRIPTION OF SYMBOLS 11... Vehicle body, 15... First wheel, 16... Second wheel, 24... Drive motor (drive source), 26...
・First clutch, 27...Second clutch, 32・
...Control unit. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] a vehicle body having a drive source; first wheels and second wheels provided on the vehicle body and driven by the drive source and serving as front wheels or rear wheels depending on the running direction; the drive source and the first wheels; a first clutch provided between the drive source and the second wheel; and a second clutch provided between the drive source and the second wheel, and only a clutch for rear wheel drive is operated when the vehicle body is in an accelerating state. and a control unit that operates only a front wheel drive clutch when the vehicle is in a deceleration state.