JPH1072194A - Article conveying vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an article conveying vehicle decreasing a turn radius as small as possible at running time further with capability of stably holding a car body at cargo transfer loading time by protruding/retreating a fork. SOLUTION: A pair of right/left driven wheels 7 supporting a load of car body 1 to be provided in the intermediate of car body longitudinal direction, drive wheel 6 provided to one side of longitudinal direction from the driven wheel 7 to support a load of the car body 1 to make it run and a fork 4 capable of protruding/retreating in the longitudinal direction are provided on the other side in the longitudinal direction, the drive wheel 6 is constituted to be capable of turning around a vertical axial center P1. A pair of right/left idling wheels 19 are provided to the other side of longitudinal direction from the driven wheel 7 to be capable of moving in a vertical direction to be energized to move downward, a wheel lock means limiting movement in the upward of the idling wheel 19 is provided, to be constituted capable of switching to a locking condition and unlocking condition associated with protruding/retreating of the fork 4, so as to switch to the locking condition in the case of the fork 4 protruding from the car body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pair of right and left driven wheels provided at the center of the vehicle body in the front-rear direction for supporting the load of the vehicle body, supporting the load of the vehicle body, and running the vehicle body. Drive wheels provided closer to one side in the vehicle longitudinal direction than the driven wheels, and are configured to be able to move back and forth along the vehicle longitudinal direction to transfer loads on the other side in the vehicle longitudinal direction. And a fork, wherein the drive wheel is configured to be rotatable around a vertical axis along a vertical direction in order to steer the vehicle body.

[0002]

2. Description of the Related Art Such an article transport vehicle is used for transporting various articles in a warehouse or a factory, and it is desired to make the turning radius as small as possible so that the vehicle can travel with a small turn. In order to reduce the turning radius of the vehicle body, it is necessary to minimize the distance between the driven wheel and the driven wheel that are rotatable around the longitudinal axis in order to steer the vehicle body. When the distance between the wheels is reduced, the stability of the vehicle body is impaired accordingly. In particular, when a load is supported by a protruding fork at the time of transfer of the load, the load of the load acts as a force for tilting the vehicle body toward the fork, which is a problem particularly at the time of transfer of the load. .

[0003] Conventionally, in order to stabilize the vehicle body when a load is transferred, as disclosed in Japanese Patent Application Laid-Open No. 6-297927, idle wheels are provided which can be moved up and down, and a fork is extended and retracted to move the load. 2. Description of the Related Art There is known an article carrier that restricts upward movement of idle wheels when transferring a vehicle and stabilizes a vehicle body by idle wheels.

[0004]

However, the article transport vehicle disclosed in the above publication has a pair of drive wheels provided in the front-rear direction of the vehicle body, and a pair of idle wheels also provided in the left-right direction of the vehicle body. However, there is a problem that the turning radius of the vehicle body is inevitably increased. In other words, when trying to reduce the turning radius during traveling, the vehicle body becomes unstable when transferring loads, and conversely, when trying to stabilize the vehicle body, the turning radius during traveling increases, reducing the turning radius. And stabilization of the vehicle body at the time of load transfer are mutually contradictory, and there has not yet been an article carrier satisfying both.

The present invention solves such a conventional problem. The object of the present invention is to minimize the turning radius of the vehicle body during traveling and to reduce the load when the fork is moved in and out. An object of the present invention is to provide an article transport vehicle that can stably hold a vehicle body during transfer.

[0006]

According to the first aspect of the present invention, a pair of left and right driven wheels for supporting a load on a vehicle body are provided at an intermediate position in a longitudinal direction of the vehicle body.
A drive wheel is provided closer to one side in the vehicle longitudinal direction than the driven wheel, and the drive wheel is configured to be rotatable about the vertical axis, so that the drive wheel is rotated about the vertical axis,
By turning the vehicle body around the driven wheel side,
The vehicle body can be turned with a relatively small radius, and the turning radius of the vehicle body can be made as small as possible by shortening the distance between the drive wheel and the driven wheel.

Further, a fork is provided on the other side of the vehicle body in the front-rear direction along the front-rear direction of the vehicle body, and a pair of left and right idle wheels can be moved in the vertical direction near the other side on which the fork is provided. And, provided in a state of being urged to move downward, provided with a wheel lock means for restricting the upward movement of the idle wheel, when the fork protrudes from the vehicle body, the wheel lock means to the lock action state, Since the upward movement of the idle wheels is restricted, the load is supported by a protruding fork, and even if the load of the load tries to incline the vehicle body, a pair of left and right idlers whose upward movement is restricted. Since the rolling wheels prevent the vehicle body from tilting and stably hold the vehicle body, it is possible to stably transfer the load.

According to the second aspect of the present invention, since the drive wheels are provided at the center in the left-right direction of the vehicle body, when the vehicle body is turned around the driven wheel side as described above, Since it is possible to make a small turn with a relatively small radius in both the left and right directions, and its driving wheels are composed of a pair of driving wheels that can be driven forward and reverse respectively, a pair of driving wheels By rotating the body at different speeds from each other, or by rotating in the opposite direction, it is possible to rotate the drive wheel composed of a pair of drive wheels around the vertical axis center, and to rotate the drive wheel. The same driving source can also be used for the rotation operation about the vertical axis.

According to the third aspect of the present invention, the vehicle body of the carrier is composed of a pair of left and right extending portions along the vehicle longitudinal direction and a main body portion connecting the extending portions on one side in the vehicle longitudinal direction. The main body portion is provided with drive wheels, and idle wheels are provided at the tip sides of a pair of left and right extending portions. At the time of transfer, the left and right extension parts can be reliably and stably held by the idler wheels provided on the tip side of the left and right extension parts, and even if the fork can be raised and lowered vertically, By raising and lowering the fork in the middle of the portion, the fork can be lowered close to the traveling road surface of the transport vehicle. In addition, since the tip of the fork is located inside the tip of the extending portion when the fork is retired, the tip of the fork is moved to another position by retreating the fork. It is less likely to come into contact with the vehicle, and the vehicle can travel safely.

According to the fourth aspect of the present invention, an optical sensor for detecting an obstacle is provided between the distal ends of the extending portions, and when the optical sensor detects the obstacle, the rotation of the drive wheels is stopped. With such a configuration, there is little danger that another object may enter between the two extended portions and come into contact with the tip of the fork during traveling, and the vehicle can travel more safely.

According to the fifth aspect of the present invention, the fork is configured to be able to move up and down in a vertical direction from above and below the upper surface of the extending portion, and to load the upper surface of the extending portion. Because it is configured on the surface, by running while placing the load on the loading surface on the upper surface of the extension part,
For example, compared to traveling with a load placed on a fork, the load can be loaded more stably, the traveling itself is stabilized, and a mechanism to prevent the collapse of the load has been added to the loading surface. In this case, the traveling speed can be increased.

According to the invention described in claim 6, a bumper for buffering an obstacle is provided on each of the outer portion and the tip portion of the pair of left and right extending portions constituting the vehicle body, and the outer portion of the main body portion. Therefore, not only can the vehicle be safely driven by retreating the fork as described above, but also if the vehicle body tries to contact another object, regardless of the direction of the vehicle body, the bumper for buffering obstacles As a result, the impact is buffered, and the vehicle can travel more safely.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an article carrier according to the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 10, the article transport vehicle automatically travels mainly along a travel path formed by the guide line L and transports the load A between the stations ST. Body 1
As shown in FIG. 2, the vehicle body 1 includes a pair of left and right extending portions 2 extending in the front-rear direction of the vehicle body 1 and a main body portion 3 connecting the extending portions 2 on the front side of the vehicle body 1. It is configured to be U-shaped. As shown in FIG. 3, a fork 4 that can protrude to the rear of the
Is provided so as to be able to move back and forth along the front-rear direction of the vehicle body 1 and to be able to move up and down in the vertical direction. The rear portion of the vehicle body 1 is opposed to each station ST, and the fork 4 is moved up and down and moved up and down to load A. Is configured to be transferred.

At the bottom of the main body portion 3 located on the front side of the vehicle body 1, a drive wheel 6 composed of a pair of drive wheels 5 spaced apart and juxtaposed is rotatable about a vertical axis P1 along the vertical direction. And a pair of right and left idler driven wheels 7 is provided at the middle bottom in the front-rear direction of the extending portion 2 of the vehicle body 1. The drive wheel 6 and the driven wheel 7 are configured to support the load of the vehicle body 1 by three-point support,
As shown in FIGS. 4 to 6, the drive wheels 6 are each provided with an electric motor 8 by a drive wheel 5 constituting the drive wheels 6.
Are directly connected to each other so that the two driving wheel bodies 5 can be driven separately in forward and reverse rotations. By providing a difference in the rotation speed of the two driving wheel bodies 5 or by rotating them in opposite directions, It is configured such that the direction can be integrally changed around the longitudinal axis P1 located at the center of the driving wheel body 5.

That is, a connecting frame 9 is provided between the two driving wheels 5, and the connecting frame 9 connects and supports one driving wheel 5 and a motor 8 for driving the driving wheel 5 on one side. On the side, another driving wheel body 5 and a motor 8 for driving it are connected and supported. The connecting frame 9 is an annular frame 1 disposed near the lower ends of both drive wheels 5 and concentrically with respect to the longitudinal axis P1.
From 0 to the vertical frame 11 continuously provided, while being rotatably attached around the horizontal axis P2 along the horizontal direction,
The annular frame 10 is attached to the main body 3 of the vehicle body 1 via a bearing 12 so as to be rotatable around a longitudinal axis P1.

A sensor bracket 13 extends from one of the two vertical frames 11, and a guide sensor 14 is mounted on the sensor bracket 13, and the guide sensor 14 is connected to a driving wheel 6 comprising a pair of driving wheels 5. It is configured to be located in front of. The guide sensor 14
It consists of a plurality of magnetic sensors juxtaposed in the horizontal direction, and detects the magnetic field of a strip-shaped induction line L with magnetism,
It is used to detect a displacement of the vehicle body 1 with respect to the guide line L and control the steering of the vehicle body 1. A rotary encoder 15 is attached to the main body portion 3 above the drive wheel 6 in a state where the rotary encoder 15 is located on the longitudinal axis P 1, and a rotary shaft 16 of the rotary encoder 15 connects the upper portions of the two vertical frames 11. Attached to the frame 17, the rotary encoder 15 is configured to detect the direction of the drive wheel 6 turning around the vertical axis P1, that is, the steering angle.

At the bottom of the front end of the extension portion 2 on the rear side of the vehicle body 1, caster type idler wheels 19 composed of a pair of idler wheels 18 which are spaced apart and juxtaposed, have a vertical axis extending along the vertical direction. A pair of right and left is provided rotatably around the core Q1. The idler wheel 18 of each idler wheel 19 is rotatably supported by a wheel support frame 20 located between the idler wheels 18, as shown in FIG. 21, is attached movably up and down around a horizontal axis Q <b> 2 along the horizontal direction, and is urged downward by a spring 22. The wheel support bracket 21 includes an inner race 2 of a bearing 23.
4 and the outer race 2 of the bearing 23
5 is attached to the extension portion 2 of the vehicle body 1, whereby each idler wheel 19 is configured to be rotatable around the longitudinal axis Q <b> 1 which is the rotational axis of the bearing 23.

As described above, each idle wheel 19 is provided with a horizontal axis Q2.
Although it is configured to be able to move vertically around and is urged to move downward by a spring 22,
Each idler wheel 19 is provided with a wheel lock means 26 for restricting upward movement around the horizontal axis Q2. The wheel locking means 26 is composed of a hydraulic cylinder 27 that expands and contracts following the vertical movement of the idler wheel 19, and a valve device that supplies oil in the tank 28 to the hydraulic cylinder 27 or stops oil supply. I have. The hydraulic cylinder 27 is disposed on the axis of the vertical axis Q1 and its cylinder rod 29
However, the hydraulic cylinder 27 is pressed and urged to the lower wheel support frame 20 by a spring 30 provided inside, so that the cylinder rod 29 moves up and down following the up and down movement of the wheel support frame 20, whereby the hydraulic cylinder 27 is moved. It is configured to expand and contract.

The valve device includes a check valve 32 for preventing oil supply to the variable throttle 31 and the hydraulic cylinder 27;
A non-return valve 33 for preventing oil from returning to the tank 28 when the hydraulic cylinder 27 is shortened. It is configured to be switchable between an unlocked state in which the vertical movement of the idle wheel 19 is allowed and a locked state in which the hydraulic cylinder 27 is prevented from being shortened to prevent the idle wheel 19 from moving upward. The locked state and the released state of the wheel locking means 26 are switched in conjunction with the operation of the fork 4, and when the fork 4 is moved up and down and the load A is transferred, the locked state is set. 4
Is configured to be switched to the unlocked state when the load A is conveyed while being retracted. This valve device is
It is configured to switch to the unlocked state by energizing the solenoid 34. Even if the battery A mounted on the vehicle body 1 runs short of electric power or breaks during transfer of the load A, the spring 35 is used to switch to the unlocked state. It is configured to switch.

The fork 4 is vertically movable up and down along a pair of left and right posts 36 as shown in FIGS. 8 and 9, and is moved up and down by an electric motor (not shown) via a transmission mechanism such as a chain 37. It is configured to be able to.
Further, the post 36 is erected on a trolley 38 configured to be movable in the front-rear direction of the vehicle body 1, and the wheels 39 are rotated forward and reverse by an electric motor (not shown) to thereby rotate the post 36 on the trolley 38. Is moved in the front-rear direction of the vehicle body 1,
By moving the fork 4 in the longitudinal direction of the vehicle body 1,
The left and right extending portions 2 are configured to be able to protrude rearward from the distal ends thereof, or to be able to retreat inside the distal ends of the extending portions 2.

When the fork 4 is lowered to the lowermost position, the fork 4 enters into the space between the left and right extending portions 2 and can be lowered below the upper surfaces of the two extending portions 2. It is configured as follows. In other words, the fork 4 is configured to be able to move up and down over the upper surface of the extending portion 2 as a reference, and the fork 4 is moved up and down and moved up and down with the extending portion 2 side facing each station ST. The load A on the station ST side is transferred to the vehicle body 1 side, and the load placement surface 40 which is the upper surface of the extension portion 2.
It is configured such that the load A on the load mounting surface 40 can be transferred to the station ST side.

The entire circumference of the lateral portion of the vehicle body 1, that is, from the distal end portion to the outer portion of the pair of left and right extending portions 2, and from the outer portion to the outer portion of the body portion 3,
An obstacle buffer bumper 41 made of an elastic member or the like is provided, and an optical sensor 42 composed of a light projector 42a and a light receiver 42b is provided between the front ends of the left and right extending portions 2, and its light When the sensor 42 detects an obstacle, the driving of the driving wheel 6 is stopped.

Although not shown, the motors 8 for driving the driving wheels 5 are provided with rotary encoders for detecting the amount of rotation, respectively, and the detection signals are used for calculating the traveling distance information. In addition, various mark sensors, ID tag readers, and the like are provided on the bottom surface side of the vehicle body 1 and various detection information including the detection information of the optical sensor 42 is input to a control device on the vehicle body 1 side. ing. Then, the traveling control of the vehicle body 1 is executed by the control device, and as shown on the right side of FIG.
Approaching the station ST in reverse and away from
As shown on the left side of FIG.
While traveling away from T, various controls such as transfer of the load A are executed, and the operation of the wheel locking means 26 is also controlled.

[Another Embodiment] In the above embodiment,
Although the example in which the wheel locking means 26 is configured by using the hydraulic cylinder 27 and the like is shown, various changes can be made in actual implementation such as mechanical locking means and electric locking means. Various changes can also be made to the configuration for moving in the front-back direction.

[Brief description of the drawings]

FIG. 1 is a plan view showing an arrangement of wheels of an article transport vehicle.

FIG. 2 is a plan view of an article carrier.

FIG. 3 is a side view of the article transport vehicle.

FIG. 4 is a plan view of a drive wheel.

FIG. 5 is a front view of a driving wheel.

FIG. 6 is a longitudinal side view of a drive wheel.

FIG. 7 is a side view of an idle wheel.

FIG. 8 is a side view showing the operation of the fork.

FIG. 9 is a side view showing the operation of the fork.

FIG. 10 is a plan view showing the operation of the article transport vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 2 Extension part 3 Main part 4 Fork 5 Drive wheel 6 Drive wheel 7 Follower wheel 19 Idling wheel 26 Wheel locking means 40 Loading surface 41 Bumper 42 Optical sensor A Load P1 Vertical axis

Claims (6)

[Claims] 1. A pair of left and right driven wheels provided at an intermediate position in the front-rear direction of the vehicle body for supporting a load on the vehicle body, and the driven wheels supporting the load on the vehicle body and running the vehicle body. A drive wheel provided closer to one side of the vehicle body front and rear direction, and a fork configured to be able to move back and forth along the vehicle body front and rear direction to transfer a load on the other side of the vehicle body front and rear direction, An article carrier, wherein the drive wheel is configured to be rotatable around a vertical axis along a vertical direction in order to steer the vehicle body, wherein the driven wheel is located closer to the other side in the vehicle longitudinal direction than the driven wheel. A pair of idle wheels is provided, and a pair of left and right idle wheels is provided so as to be movable in the vertical direction and is urged to move downward, and the upward movement of the pair of left and right idle wheels is restricted. Wheel locking means for The fork means is configured to be switchable between a locked state and an unlocked state in conjunction with the withdrawal of the fork, and the wheel locking means is switched to the locked state when the fork projects from the vehicle body. Goods carrier. 2. The vehicle according to claim 1, wherein the drive wheels are provided at a central portion of the vehicle body in the left-right direction, and each of the drive wheels is constituted by a pair of drive wheels that can be driven forward and reverse independently. Goods carrier. 3. The vehicle body comprises a pair of left and right extending portions extending in the front-rear direction of the vehicle body and a main body portion connecting the extending portions on one side in the vehicle front-rear direction. And the main body portion is provided with the drive wheel, and the pair of left and right extending portions is provided with the idle wheel at the tip end thereof. When the fork is retired, the tip of the fork is set at the tip of the extending portion. The article transport vehicle according to claim 1, wherein the article transport vehicle is configured to be located further inside. 4. An optical sensor for detecting an obstacle between the distal ends of the extending portions, wherein when the optical sensor detects an obstacle, the driving of the driving wheels is stopped. 4. The article carrier according to 3. 5. The fork is configured to be able to move up and down in a vertical direction over and below the upper surface of the extension portion, and the upper surface of the extension portion is configured as a loading surface. Item 4. The article carrier according to item 3 or 4. 6. The bumper according to claim 3, wherein an outer portion and a tip portion of a pair of left and right extending portions constituting the vehicle body and an outer portion of the main body portion are provided with bumpers for buffering obstacles, respectively. An article carrier according to any one of the preceding claims.