JP3903725B2 - Goods transport vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an article transport vehicle that transports articles.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as this kind of article transport vehicle, there is one in which a vehicle body is provided with a plurality of driving wheels and driven wheels, as disclosed in, for example, JP-A-6-297927. Among these, the driven wheel is supported by a wheel support frame, and the wheel support frame is provided on the vehicle body frame side and is configured to be swingable up and down around the horizontal axis, and by an elastic body (coil spring). A downward biasing force is given. The elastic body is mounted between the upper part of the inner race of the bearing and the upper part of the wheel support frame.
[0003]
Further, a wheel lock means for limiting the upward swing of the wheel support frame is provided, and the wheel lock means has a rod body that can move up and down following the vertical swing of the wheel support frame. And a valve device for switching the fluid pressure cylinder device between a locked state and an unlocked state. The rod body of the fluid pressure cylinder device is inserted through the elastic body (coil spring).
[0004]
According to this, by switching to the unlocked state by the valve device, fluid supply to and discharge from the fluid pressure cylinder device is permitted, and the rod body can be moved up and down. As a result, the elastic body (coil spring) expands and contracts according to the unevenness of the traveling floor surface, and the wheel support frame swings up and down, so that the driven wheel moves up and down and reliably contacts the traveling floor surface. As a result, the ground pressure of the drive wheel can be kept substantially constant, and the slip of the drive wheel can be prevented.
[0005]
[Problems to be solved by the invention]
However, in the above conventional type, as shown in FIG. 9, when the wheel support frame 81 swings up and down, the elastic body 82 (coil spring) expands and contracts, and the lower portion of the elastic body 82 extends horizontally from the upper portion. Since it changes in the radial direction D perpendicular to the center 83 (the center of swinging of the wheel support frame 81), the inner peripheral portion of the elastic body 82 interferes with the rod body 85 of the fluid pressure cylinder device 84 as shown in FIG. As a result, the elastic body 82 and the rod body 85 are damaged.
[0006]
An object of the present invention is to provide an article transport vehicle that can prevent damage to an elastic body and a rod.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the first aspect of the present invention is an article transport vehicle that can travel through a drive wheel and a driven wheel,
The vehicle body is provided with a wheel support member that can swing up and down, and a swing fixing means that restricts the swing of the wheel support member upward.
The driven wheel is supported by a wheel support member,
The swing fixing means includes a fluid pressure cylinder device having a rod body that can move up and down following the vertical swing of the wheel support member, and a switch for switching the fluid pressure cylinder device between a fixed operation state and a fixed release state. Means and
In the fixed action state, the upward movement of the rod body is prevented, and the swing of the wheel support member is fixed,
In the above unlocked state, the rod body can be moved up and down in the vertical direction, and the wheel support member can swing up and down,
Two elastic bodies for applying a downward urging force to the wheel support member are provided at predetermined intervals on both sides of the rod body of the fluid pressure cylinder device ,
The rod body is located outside the elastic body and located between the elastic bodies .
[0008]
According to this, by switching the fluid pressure cylinder device to the unlocked state by the switching means, the wheel support member can swing up and down, and during running, each elastic body expands and contracts according to the unevenness of the running floor surface, thereby supporting the wheel. Since the member swings up and down, the driven wheel moves up and down and reliably contacts the traveling floor. At this time, the rod body of the fluid pressure cylinder device moves up and down following the vertical swing of the wheel support member.
[0009]
Further, when the wheel support member is swung up and down, together with the two elastic material expands and contracts, the lower portion of the elastic body is displaced in the radial direction orthogonal to the pivot axis of the wheel support member with respect to the upper The two elastic bodies are provided at predetermined intervals on both sides of the rod body of the fluid pressure cylinder device, and the rod body is outside the elastic body and located between both elastic bodies , The problem that the elastic body interferes with the rod can be prevented.
[0010]
Further, since the vertical swing of the wheel support member is fixed by switching the fluid pressure cylinder device to the fixed action state by the switching means, the driven wheel does not move up and down against the urging force of each elastic body. Fixed to. Therefore, when an article is transferred to or from the vehicle body, the vehicle body can be prevented from tilting even if the position of the center of gravity changes greatly, and the vehicle body can be prevented from shaking when traveling in the lateral direction of the vehicle body. It can also be prevented.
[0011]
In the second aspect of the invention, the wheel support member is configured to be rotatable around the longitudinal axis.
The axial center of the rod body of the fluid pressure cylinder device coincides with the vertical axis.
According to this, the wheel is turned in the left-right direction by rotating the wheel support member around the longitudinal axis.
[0012]
In the third invention, the driven wheel is constituted by a pair of left and right wheels arranged in the direction of the rotation axis,
The pair of left and right wheels are supported by one wheel support member,
One elastic body located on one side of the rod body is provided above the left and right wheels,
The other elastic body located on the other side of the rod body is provided above the left and right other wheels.
[0013]
According to this, the urging forces of both elastic bodies act on both wheels of the driven wheel in a well-balanced manner.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
As shown in FIG. 7, reference numeral 1 denotes an article transport facility, which includes an article transport vehicle 4 that travels along a travel line 3 provided on the traveling floor 2 and a plurality of stations 5.
[0015]
As shown in FIG. 6, an article transfer device 9 for transferring an article 8 to the station 5, and a vehicle body frame 10 for supporting the article transfer device 9 are provided on the vehicle body 7 of the article transport vehicle 4. A pair of front and rear drive wheels 11 and a pair of left and right driven wheels 12 are provided. The article transfer device 9 includes a multi-stage fork device 14 and a lifting device 15 that lifts and lowers the fork device 14.
[0016]
As shown in FIGS. 4 and 5, the vehicle body frame 10 includes a hollow base frame 16, and the article transfer device 9, the drive wheel 11, and the driven wheel 12 are disposed on the outer surface of the base frame 16. An engaging portion 17 for assembling the components is provided.
[0017]
Each of the drive wheels 11 includes a pair of wheels 11a and 11b arranged at intervals in the direction of the rotation axis 18, and drive devices 19a and 19b such as a motor for rotating the wheels 11a and 11b separately. ing. The wheels 11a, 11b and the driving devices 19a, 19b are supported by a wheel support frame 20, and the wheel support frame 20 is arranged around a vertical axis 21 located at the center between the pair of wheels 11a, 11b. It is attached to the vehicle body frame 10 via a bearing 22 and a frame 23 so as to rotate.
[0018]
As shown in FIGS. 1 and 2, the driven wheel 12 is composed of a pair of wheels 12 a and 12 b that are arranged in the direction of the rotation axis 25 with a certain gap therebetween. The pair of wheels 12a and 12b are supported by a wheel support member 27 via an axle 26 inserted in the lateral direction. The wheel support member 27 is attached to an attachment member 28 and is configured to be swingable up and down around a horizontal axis 29 (oscillation axis) with respect to the attachment member 28.
[0019]
The mounting member 28 is suspended from an inner race 30 a of a bearing 30 provided above the wheel support member 27. Further, the outer race 30 b of the bearing 30 is attached to the vehicle body frame 10 via a frame 31. The wheel support member 27 is configured to be rotatable around the longitudinal axis 32 by the bearing 30.
[0020]
As shown in FIGS. 1 to 3, the article transport vehicle 4 is provided with a swing fixing means 34 for restricting the swing of the wheel support member 27 upward. The swing fixing means 34 includes a fluid pressure cylinder device 35 and a switching means 36 for switching the fluid pressure cylinder device 35 between a fixed action state and a fixed release state.
[0021]
The fluid pressure cylinder device 35 includes a cylindrical cylinder body 35a and a piston rod 35b (an example of a rod body) configured to move up and down along the inner wall of the cylinder body 35a so as to be freely retracted and retracted from the cylinder body 35a. And a spring 35c that is provided in the cylinder body 35a and urges the piston rod 35b in the downward projecting direction.
[0022]
The tip of the piston rod 35b is received by a receiving member 37 provided on the upper portion of the wheel support member 27, and the piston rod 35b moves up and down following the vertical swing of the wheel support member 27. The axis of the piston rod 35b is provided so as to coincide with the longitudinal axis 32.
[0023]
The switching means 36 includes a switching valve 38 and a tank 39 for storing fluid (oil or the like) supplied to the cylinder body 35a through the switching valve 38. The switching valve 38 stops the discharge of the fluid from the fluid pressure cylinder device 35 and allows the fluid pressure cylinder device 35 to supply and discharge the fluid to and from the fixed release state. It can be switched to a fixed release position B to be switched by a solenoid 38a.
[0024]
In other words, the switching valve 38 prevents the passage of fluid from the fluid pressure cylinder device 35 to the tank 39 when the piston rod 35b moves upward and backward by the check valve 38b at the fixed position A, and the fixed release position B , The passage of fluid between the fluid pressure cylinder device 35 and the tank 39 is allowed by the variable throttle 38c and the check valve 38d.
[0025]
On both sides of the piston rod 35b, coil springs 41 (an example of an elastic body) for applying a downward urging force to the wheel support member 27 are provided at a predetermined interval with respect to the piston rod 35b.
[0026]
A holding member 42 is provided on the upper portion of the inner race 30a of the bearing 30, and a through hole 43 penetrating in the vertical direction is formed at the center of the holding member 42. The piston rod 35b is inserted through the through hole 43 from above. A pair of recesses 44 that hold the upper ends of the coil springs 41 are formed on the lower surface side of the holding member 42, and the upper ends of the coil springs 41 are inserted into the recesses 44 and held. The lower ends of the coil springs 41 are pressed against the receiving member 37.
[0027]
Further, as shown in FIG. 1, one coil spring 41 located on one side of the piston rod 35b is provided above one wheel 12a, and the other coil spring 41 located on the other side of the piston rod 35b. Is provided above the other wheel 12b.
[0028]
Hereinafter, the operation of the above configuration will be described.
When the article transport vehicle 4 travels along the travel line 3, as shown in FIG. 3, the switching valve 38 is switched to the unlocking position B by the solenoid 38a, and the fluid pressure cylinder device 35 is switched to the unlocking state. The passage of fluid between the fluid pressure cylinder device 35 and the tank 39 is allowed. As a result, the piston rod 35 b can freely move up and down, and the wheel support member 27 can swing up and down around the horizontal axis 29.
[0029]
In this state, when the article transport vehicle 4 goes straight, both the drive devices 19a and 19b rotate and drive both wheels 11a and 11b of each drive wheel 11 at the same rotation speed in the same direction. As a result, the article transport vehicle 4 travels straight, and at this time, both wheels 12a and 12b of each driven wheel 12 rotate following the wheels 11a and 11b.
[0030]
When the article transport vehicle 4 is turned left and right along the travel line 3, both the drive devices 19a and 19b are operated at different rotational speeds. Thereby, since both the wheels 11a and 11b are rotationally driven at different rotational speeds, the article transport vehicle 4 turns left and right. At this time, both the wheels 12 a and 12 b of each driven wheel 12 rotate around the vertical axis 32 integrally with the wheel support member 27 according to the turning of the article transport vehicle 4.
[0031]
Further, when traveling, as shown in FIG. 8, when the traveling floor 2 is uneven, each coil spring 41 expands and contracts according to the unevenness, and the wheel support member 27 swings up and down around the horizontal axis 29. Therefore, both the wheels 12 a and 12 b of each driven wheel 12 move up and down integrally with the wheel support member 27 and are reliably grounded to the traveling floor 2. Thereby, the ground pressure of both the wheels 11a and 11b of each drive wheel 11 can be kept substantially constant, and the slip of the wheels 11a and 11b of the drive wheel 11 can be prevented. At this time, the piston rod 35b moves up and down following the vertical swing of the wheel support member 27.
[0032]
Further, when the wheel support member 27 swings up and down, the coil spring 41 expands and contracts, and the lower part of the coil spring 41 changes in the radial direction D perpendicular to the horizontal axis 29 with respect to the upper part. As shown in FIG. 4, since the coil spring 41 is provided at a predetermined interval on both sides of the piston rod 35b of the fluid pressure cylinder device 35, it is possible to prevent the coil spring 41 from interfering with the piston rod 35b. Can do. Thereby, damage to the coil spring 41 and the piston rod 35b can be prevented.
[0033]
Further, when the article transport vehicle 4 is stopped and the article 8 is transferred to the station 5 using the article transfer device 9 as shown in FIG. 6, the switching valve 38 is fixed to the fixed position A by the solenoid 38a. The fluid pressure cylinder device 35 is switched to the fixed action state, and the passage of fluid from the fluid pressure cylinder device 35 to the tank 39 is blocked. Accordingly, the upward movement of the piston rod 35b is prevented, so that the vertical swing of the wheel support member 27 is fixed, and both the wheels 12a and 12b of each driven wheel 12 are subjected to the urging force of each coil spring 41. It is fixed without moving up and down. Therefore, when the article 8 is transferred using the article transfer device 9, the vehicle body 7 can be prevented from tilting even if the position of the center of gravity changes greatly. Furthermore, when the article transport vehicle 4 is traversed in the left-right direction, the vehicle body 7 can be prevented from shaking by fixing the vertical movements of the two wheels 12a, 12b of each driven wheel 12 as described above.
[0034]
Also, as shown in FIG. 1, of the pair of coil springs 41 provided on both sides of the piston rod 35b, one coil spring 41 is located above one wheel 12a of the driven wheel 12, and the other coil Since the spring 41 is positioned above the other wheel 12b, the urging forces of the coil springs 41 act on the wheels 12a and 12b in a well-balanced manner.
[0035]
Furthermore, when changing the setting of the spring constant of the coil spring 41 according to the weight of the vehicle body 7, since two (a pair) of coil springs 41 are provided for each driven wheel 12, coil springs having different specifications from each other. The spring constant can be adjusted by properly using one coil spring 41 and the other coil spring 41. Therefore, there is an advantage that the degree of freedom at the time of adjusting the spring constant is increased as compared to the conventional type using only one coil spring. Furthermore, by providing two (a pair of) coil springs 41, the diameter of each coil spring 41 becomes smaller than that of the conventional type, so that the coil spring 41 can easily follow the thrust force. Become.
[0036]
In the above embodiment, as shown in FIG. 5, the vehicle body 7 is provided with a pair of front and rear driving wheels 11 (two sets) and a pair of left and right driven wheels 12 (two sets). The number is not limited to two sets, and may be a single set or a plurality of sets of three or more sets. Further, the arrangement of the drive wheels 11 and the driven wheels 12 is not limited to the front, rear, left and right. For example, the drive wheels 11 may be provided on the left and right, and the driven wheels 12 may be provided on the front and rear.
[0037]
In the above embodiment, the drive wheel 11 is composed of a pair (two wheels) of wheels 11a and 11b, but may be composed of one wheel or three or more wheels. Similarly, although the driven wheel 12 is composed of a pair (two wheels) of wheels 12a and 12b, it may be composed of one wheel or three or more wheels.
[0038]
In the embodiment described above, the fork device 14 is used as the article transfer device 9, but is not limited to the fork device 14, and for example, a conveyor or the like may be used. Moreover, although the said article transfer apparatus 9 is provided in the article conveyance vehicle 4, you may provide in the station 5 side.
[0039]
In the above embodiment, fluid such as oil is supplied from the tank 39 to the fluid pressure cylinder device 35, but a liquid other than oil or a gas such as air may be used as the fluid.
[0040]
【The invention's effect】
According to the present invention as described above, when the wheel support member is swung up and down, perpendicular with the two elastic material expands and contracts, the pivot axis of the wheel support member lower portion of the elastic body relative to the upper However, the two elastic bodies are provided on both sides of the rod body of the fluid pressure cylinder device at a predetermined interval, and the rod body is outside the elastic body and is between the two elastic bodies. due to the position, it is possible to the elastic body is prevent a problem interferes with rod.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional front view of a driven wheel of an article transport vehicle according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional side view of a driven wheel of the article transport vehicle.
FIG. 3 is a diagram showing a configuration of a swing fixing means of the article transport vehicle.
FIG. 4 is a front view of the lower part of the article transport vehicle.
FIG. 5 is a view taken along arrow XX in FIG. 4;
FIG. 6 is a front view of the article transport vehicle, showing a state where articles are transferred to and from the station.
FIG. 7 is a schematic plan view of an article transport facility using the article transport vehicle.
FIG. 8 is a partial cross-sectional side view of the driven wheel of the article transport vehicle, in which (a) shows a state in which the driven wheel and the wheel support member swing downward, and (b) shows the driven wheel and the wheel. The support member is swung upward.
FIG. 9 is a partial cross-sectional side view of a driven wheel of a conventional article transport vehicle, in which (a) shows a state in which the driven wheel and a wheel support frame swing downward, and (b) shows a driven wheel and a wheel. The support frame is shown swinging upward.
[Explanation of symbols]
4 article transport vehicle 7 car body 8 article 9 article transfer device 11 driving wheel 12 driven wheels 12a, 12b wheel 25 rotating shaft 27 wheel support member 29 horizontal shaft center 32 vertical shaft center 34 swing fixing means 35 fluid pressure cylinder device 35b Piston rod (rod)
36 switching means 41 coil spring (elastic body)

Claims (3)

An article transporter that can travel through a driving wheel and a driven wheel,
The vehicle body is provided with a wheel support member that can swing up and down, and a swing fixing means that restricts the swing of the wheel support member upward.
The driven wheel is supported by a wheel support member,
The swing fixing means includes a fluid pressure cylinder device having a rod body that can move up and down following the vertical swing of the wheel support member, and a switch for switching the fluid pressure cylinder device between a fixed operation state and a fixed release state. Consisting of means,
In the fixed action state, the upward movement of the rod body is prevented, and the swing of the wheel support member is fixed,
In the unlocked state, the rod body can be moved up and down in the vertical direction, and the wheel support member can swing up and down.
Two elastic bodies for applying a downward urging force to the wheel support member are provided at predetermined intervals on both sides of the rod body of the fluid pressure cylinder device ,
The article transport vehicle according to claim 1, wherein the bar is located outside the elastic body and located between the elastic bodies . The wheel support member is configured to be rotatable around the longitudinal axis,
2. The article transporting vehicle according to claim 1, wherein the axis of the rod body of the fluid pressure cylinder device coincides with the longitudinal axis. The driven wheel is composed of a pair of left and right wheels arranged in the direction of the rotation axis,
The pair of left and right wheels are supported by one wheel support member,
One elastic body located on one side of the rod body is provided above the left and right wheels,
3. The article transport vehicle according to claim 1, wherein the other elastic body located on the other side of the rod body is provided above the left and right wheels.

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