JP7480932B2 - Conveyor - Google Patents

Description

The present invention relates to a transport device that holds and transports loads.

One type of transport device that holds and transports a load is one that detects the presence or absence of a load and adjusts the pressure of the drive wheels against the road surface (see, for example, Patent Document 1).

The transport device of Patent Document 1 supports two drive wheels 3 on a vehicle body 2 with springs 10, and fixes an idler wheel 1. The vehicle body 2 is provided with a detection cylinder 12 having a piston rod 12a protruding from the top surface of the vehicle body 2. The detection cylinder 12 detects the presence or absence of a load on the loading platform 11, and when a load is placed on the loading platform, the piston rod 12a descends to act on the fluid to drive the operating cylinder 7.

In other words, when the piston rod 12a moves down due to the weight of the load, the pressure is transmitted to the operating cylinder 7 via the fluid in the detection cylinder 12 and the piping 13, causing the piston 8 of the operating cylinder 7 to move down. The piston 8 moves down, compressing the spring 10, thereby increasing the pressure of the drive wheels 3 against the road surface.

When the load is removed from the loading platform 11, the piston rod 12a of the detection cylinder 12 rises to its original position and pressure is no longer transmitted to the operating cylinder 7. The spring 10 returns to its original length due to its restoring force, and the pressure applied to the drive wheels 3 decreases to the state it was in before the load was placed on the loading platform 11.

Japanese Patent Application Laid-Open No. 59-140111

In order for a transport device that holds and transports a load to run stably, it needs a driving force that matches the running weight (the weight of the transport device itself plus the weight of the load) and frictional force between the drive wheels and the ground.
If sufficient frictional force is not generated at the drive wheels when the conveying device holds a load, the drive wheels will slip.

According to the above-mentioned configuration of the transport device in Patent Document 1, when a load is placed on the loading platform 11 from an empty state, as described above, the pressure of the drive wheels 3 against the road surface becomes higher than when there is no load on the loading platform 11, so a frictional force that transmits a driving force commensurate with the running weight (the weight of the transport device + the weight of the load) can be obtained. Then, when the load is removed from the loading platform 11, as described above, the pressure applied to the drive wheels 3 decreases to the state before the load was placed on the loading platform 11.

However, to detect the presence or absence of a load, the vehicle body 2 is provided with a detection cylinder 12 having a piston rod 12a protruding from the top surface of the vehicle body 2, and the detection cylinder 12 contains the piston rod 12a that moves up and down, and a fluid. Providing such a detection cylinder 12 increases manufacturing costs and makes it difficult to make the conveying device compact and low-floor. Furthermore, it is necessary to connect the detection cylinder 12 and the drive cylinder 7 with piping 13 and fill and seal the space between the piston rod 12a and the piston 8 with fluid, which increases maintenance costs.

The present invention aims to provide a transport device that holds and transports a load, and can adjust the pressure of the drive wheels against the road surface depending on whether or not there is a load, while suppressing increases in manufacturing and maintenance costs and providing a structure suitable for compact size and low floor construction.

In order to solve the above problems, the conveying device according to the present invention comprises:
A conveying device comprising at least a main body having a drive wheel and a load holding part for holding a load,
The main body portion is
a suspension portion that suspends the drive wheel on a base body of the main body portion;
A biasing member that applies a biasing force against a running surface to the drive wheel via the suspension portion;
a biasing force adjustment unit that adjusts the biasing force by pressing the biasing member;
Equipped with
a displacement operation unit that displaces the load holding unit between a holding state in which the load holding unit holds the load and a non-holding state in which the load holding unit does not hold the load,
The biasing force adjustment unit is
a motion transmission member having one end and an other end,
The motion transmission member is
The support is supported at a predetermined position other than the one end and the other end, and oscillates in a seesaw manner relative to a base of the main body portion,
The one end is linked to the displacement of the load retaining portion , whereby the motion transmission member swings and the other end adjusts the biasing force.

With this type of transport device configuration, the force adjustment unit adjusts the force applied to the traveling surface in conjunction with the displacement of the load holding unit, so that sufficient frictional force is obtained at the drive wheels when the transport device holds a load, eliminating the inconvenience of the drive wheels slipping due to an inability to obtain frictional force commensurate with the traveling weight.

Furthermore, because the biasing force adjustment unit adjusts the biasing force against the traveling surface in conjunction with the displacement of the load retaining unit, there is no need to provide a piston rod that moves up and down, or a member that detects the presence of a load, such as the detection cylinder in Patent Document 1, which contains a fluid. This makes it possible to suppress increases in manufacturing and maintenance costs, and also makes it easier to make the conveying device smaller and lower in size.
Furthermore, a motion transmission member that swings in a seesaw manner relative to the base of the main body is used, with one end of the motion transmission member linked to the displacement of the load retaining part and the other end of the motion transmission member adjusting the biasing force. The motion transmission member with a simple structure that swings in a seesaw manner can improve the reliability and certainty of the operation of the biasing force adjustment part that is linked to the displacement of the load retaining part.

Here, the load retaining portion is
The load is supported from below to achieve the held state,
In a preferred embodiment, the load is released from the load by being moved downward.

With this type of transport device configuration, the load holding section slides under the load and supports the load from below, thereby holding the load. As described above, the load holding section of the transport device, which is easy to make small and has a low floor, can slide under the load, thereby increasing the load storage efficiency.

Furthermore, it is an even more preferred embodiment that the load holding portion is displaced to hold the load, and the biasing force adjustment portion presses the biasing member after a predetermined load is applied to the load holding portion.

With this type of conveying device configuration, the biasing force adjustment unit presses the biasing member after a predetermined load is applied to the load holding unit. Therefore, when no load is applied to the load holding unit, the biasing force adjustment unit does not press the biasing member, and no biasing force is increased by the biasing force adjustment unit. This prevents the free wheel on one side from lifting up due to an increase in biasing force by the biasing force adjustment unit when no load is applied to the load holding unit, and prevents problems such as the load holding unit unexpectedly coming into contact with the load or the sensor malfunctioning.

As described above, the conveying device according to the present invention holds and conveys a load, and can adjust the pressure of the drive wheels against the road surface depending on whether or not a load is present. Since the biasing force adjustment unit adjusts the biasing force against the running surface in conjunction with the displacement movement of the load holding unit, there is no need to provide a member to detect the presence of a load. This prevents increases in manufacturing and maintenance costs, and makes it easier to make the conveying device smaller and lower-floor.

1 is a perspective view of a conveying device according to an embodiment of the present invention, showing a state in which a lift table serving as a load holding section is lowered. FIG. 2 is a perspective view of the conveying device, showing a state in which a lift table serving as a load holding section is lifted. FIG. 2 is a front view showing the drive wheels and the swivel wheels and the surrounding area, with the lift table, which is the load holding section, lowered. FIG. 2 is a front view showing the drive wheels and the swivel wheels and the surrounding area, illustrating the state in which the lift table, which is the load holding section, is raised. FIG. FIG. 4 is an enlarged front view of the main part around the drive wheels, showing the lift table, which is the load holding part, in the lowered state. FIG. 2 is an enlarged front view of the main part around the drive wheels, showing the state at the moment when the lift table, which is the load holding part, is raised and a load is placed on it. FIG. 2 is an enlarged front view of the main part around the drive wheels, showing the lift table, which is a load holding part with a load placed thereon, in the most elevated state. 1 is an enlarged longitudinal sectional view of a main portion seen from the front, showing the suspension portion, the biasing member, the biasing force adjustment portion, and the load holding portion, in a state in which the lift table, which is the load holding portion, is lowered. FIG. 10A and 10B are explanatory diagrams of a mechanism for releasing the connection of the force adjustment part, in which FIG. 10A is a perspective view showing a state in which the connection of the force adjustment part has not been released by the mechanism, and FIG. 10B is a perspective view showing a state in which the connection of the force adjustment part has been released by the mechanism.

The following describes an embodiment of the present invention with reference to the drawings.

In the following embodiment, the forward direction of the conveying device (arrow H in the figure) is defined as the front, left and right are defined as looking forward, and a view from the left is a front view.

<Conveyor device>
A conveying device 1 according to an embodiment of the present invention, shown in the perspective views of Figures 1 and 2, the front views of Figures 3 and 4, and the plan view of Figure 5, comprises a main body 2 and a load holding unit 3. The main body 2 is equipped with left and right drive wheels 4, front, rear, left and right free-wheeling wheels 5, a geared motor M for driving the drive wheels 4, etc. The load holding unit 3 holds a load W (Figure 4), such as a lift table L. A drive control device for the geared motor M and a drive control device for a displacement operation unit 9, which will be described later, are provided within a base 2A of the main body 2.

The load holding unit 3 is not limited to the lift table L, but may be a unit that holds the load W by scooping it up with forks like a forklift, or a unit that holds the load W by gripping or clamping it.

The main body 2 includes a suspension section 6 that suspends the drive wheel 4 on the base 2A of the main body 2, a biasing member 7 that applies a biasing force against the running surface G to the drive wheel 4 via the suspension section 6, and a biasing force adjustment section 8 that adjusts the biasing force by pressing the biasing member 7.

The main body 2 is equipped with a displacement unit 9 that displaces the load holding unit 3 between a holding state A (FIG. 4) in which the load holding unit 3 holds a load W, and a non-holding state B (FIG. 3) in which the load holding unit 3 does not hold a load W. The displacement unit 9 is, for example, as shown in FIGS. 3 and 4, composed of a lifting geared motor 12 and an eccentric cam 13 fixed to the output shaft 12A of the lifting geared motor 12, and the eccentric cam 13 raises and lowers the lifting table L, which is the load holding unit 3.

<Carrying out cargo using conveying equipment>
The empty conveying device 1 with the lift table L lowered as shown in Fig. 3 travels by itself along a predetermined route to a predetermined discharge location in the shelf system. When the conveying device 1 reaches the predetermined discharge location, it places the load W at the predetermined discharge location on the lift table L by lifting the lift table L as shown in Fig. 4. The conveying device 1 with the load W loaded thereon travels by itself along the predetermined route to discharge the load.

<Carrying in cargo using conveying equipment>
As shown in Fig. 4, the conveying device 1 loaded with the load W travels on its own along a predetermined route to a predetermined loading point in the rack system. When the conveying device 1 reaches the predetermined loading point, it places the load W at the predetermined loading point by lowering the lift table L. The empty conveying device 1 travels on its own along the predetermined route.

As described above, the lift table L, which is the load holding unit 3 in this embodiment, is in a holding state A (Figs. 4, 7, and 8) in which it holds the load W by supporting the load W from below, and in a non-holding state B (Figs. 3 and 6) in which it does not hold the load W by moving away from the load W below.

<Adjustment of biasing force by biasing force adjustment unit>
Reference will be made primarily to Figs. 6, 7 and 8 which are enlarged front views of the essential parts, and Fig. 9 which is an enlarged longitudinal sectional view of the essential parts as viewed from the front.

The running wheels 4 are supported by a suspension 6 that swings up and down around a support shaft 6A in the left-right direction relative to the base 2A of the main body 2, and can therefore move up and down relative to the base 2A. The lower end surface of the vertical compression coil spring S, which is the biasing member 7, abuts against the upper surface of the support plate 6B of the suspension 6.

As described above, the displacement unit 9 displaces the lift table L, which is the load holding unit 3, between a holding state A (FIG. 4) in which the load holding unit 3 holds a load W, and a non-holding state B (FIG. 3) in which the load holding unit 3 does not hold a load W. The fixed member C and receiving member D shown in FIGS. 3 to 9 are integral with the lift table L and move up and down together with the lift table L.

The link-shaped motion transmission member 10 that constitutes the biasing force adjustment section 8 has a roller R1 at one end 10A and a roller R2 at the other end 10B. The motion transmission member 10 is supported on the base 2A via a support member 11 by a support shaft 10C provided at a predetermined position other than the one end 10A and the other end 10B. Therefore, the motion transmission member 10 oscillates in a seesaw manner relative to the base 2A.

A roller R1 provided on one end 10A of the motion transmission member 10 rests on the upper surface of the receiving member D, which rises and falls together with the lift table L, which is the load holding section 3. A receiving member E abuts against the upper surface of the compression coil spring S.

When the lift table L rises from the lowered state (unheld state B) as shown in FIG. 6 to the state shown in FIG. 7 and FIG. 8, the fixed member C and the receiving member D rise together with the lift table L. As a result, the roller 10A rises due to the receiving member D, so the motion transmission member 10 swings. Therefore, the roller R2, which is located on the opposite side of the support shaft 10C from the roller R1, descends.

When the roller R2 at the other end 10B of the motion transmission member 10 constituting the biasing force adjustment unit 8 descends, the roller R2 presses down on the receiving member E as shown in FIG. 8. This causes the compression coil spring S to be compressed, and the biasing force F, which is increased by the biasing force adjustment unit 8, acts on the running surface G. The greater the upward displacement of the fixed member C and the receiving member D, the greater the amount by which the compression coil spring S is compressed, and the greater the biasing force F.

When the lift table L descends from the state shown in FIG. 8 to the state shown in FIG. 7 and then to the state shown in FIG. 6, the fixed member C and receiving member D descend together with the lift table L. As a result, the state changes from one in which the roller R2 presses down on the receiving member E, compressing the compression coil spring S, and the biasing force F increased by the biasing force adjustment unit 8 is acting (e.g., FIG. 8) to one in which the roller R2 does not press down on the receiving member E, does not compress the compression coil spring S, and the biasing force F increased by the biasing force adjustment unit 8 is not acting (e.g., FIG. 6).

As described above, the force adjustment unit 8 adjusts the force applied to the running surface G by increasing or decreasing the force F that is increased by the force adjustment unit 8 in response to the displacement operation of the load holding unit 3.

With this configuration, the load holding unit 3 is displaced by the displacement unit 9, and the biasing force adjustment unit 8 adjusts the biasing force against the running surface G in conjunction with the displacement of the load holding unit 3. This ensures that sufficient frictional force is obtained at the drive wheels 4 when the conveying device 1 holds the load W, and therefore prevents the drive wheels from slipping due to an inability to obtain frictional force commensurate with the running weight (the weight of the conveying device 1 plus the weight of the load W).

In addition, because the biasing force adjustment unit 8 adjusts the biasing force against the traveling surface G in conjunction with the displacement of the load holding unit 3, there is no need to provide a piston rod that moves vertically, or a component that detects the presence of a load, such as the detection cylinder in Patent Document 1, which contains a fluid. This makes it possible to suppress increases in manufacturing and maintenance costs, and also makes it easier to make the conveying device 1 smaller and lower in size.

Furthermore, the load holding portion 3 slides under the load W and supports the load W from below, resulting in a holding state A in which the load W is held. As described above, the load holding portion 3 of the conveying device 1, which can be easily made small and has a low floor, slides under the load W, thereby increasing the storage efficiency of the load W.

In addition, a motion transmission member 10 that swings in a seesaw manner relative to the base 2A of the main body 2 is used, with one end 10A of the motion transmission member 10 linking with the displacement motion of the load holding part 3 and the other end 10B of the motion transmission member 10 adjusting the biasing force. The motion transmission member 10, which has a simple structure that swings in a seesaw manner, can improve the reliability and certainty of the operation of the biasing force adjustment part 8 that links with the displacement motion of the load holding part 3.

Figure 7 shows the state at the moment when the lift table L, which is the load holding unit 3, rises and places a load W on it. In this state, the lift table L is in a holding state A holding the load W, but the compression coil spring S is not compressed by the motion transmission member 10 constituting the force adjustment unit 8, so the biasing force F increased by the force adjustment unit 8 does not act. When the lift table L rises from the state in Figure 7, and the fixed member C and receiving member D rise together with the lift table L to the range shown in Figure 8, the motion transmission member 10 swings and the roller R2 presses down the receiving member E, compressing the compression coil spring S, so that the biasing force F acts.

In other words, the lift table L, which is the load holding unit 3, is displaced by the displacement operation unit 9, so that the lift table L holds the load W, and after a predetermined load is applied to the lift table L, the motion transmission member 10 constituting the force adjustment unit 8 presses the compression coil spring S, causing the force adjustment unit 8 to apply an increasing force F.

Therefore, when no load is applied to the lift table L, the biasing force adjustment unit 8 does not press the compression coil spring S, and so there is no biasing force F increased by the biasing force adjustment unit 8. This prevents the free-wheel 5 on one side from lifting up due to an increase in the biasing force by the biasing force adjustment unit 8 when no load is applied to the lift table L, so there is no problem with the lift table L coming into contact with the load W or the sensor malfunctioning. Furthermore, since the free-wheel 5 on one side can be prevented from lifting up, problems such as the conveyor 1 tilting, making it impossible to maintain stopping accuracy by reading a coordinate-reading barcode or the like on the travel surface G, causing the load W to shift from its intended position, or making it difficult to use a contact-type charger do not occur.

As described above, in the conveying device 1 according to the embodiment of the present invention, the force adjustment unit 8 adjusts the force applied to the running surface G in conjunction with the displacement of the lift table L, which is the load holding unit 3. However, during test runs and inspections, the lift table L may perform lifting operations without holding a load W, so a preferred embodiment is to have a mechanism for disconnecting the force adjustment unit 8.

The perspective views of Figures 10(a) and 10(b) are explanatory diagrams showing an example of a mechanism for disconnecting the biasing force adjustment unit 8. The shaft body I rotates around a vertical axis together with the receiving member D, and a tool engagement portion J, which is, for example, a flat head screw, is provided at the upper end of the shaft body I. Then, as shown in the vertical cross-sectional view of Figure 9, the upper surface of the shaft body I is exposed on the upper surface side of the lift table L.

In the state shown in Figure 10(a), for example, if a flat head screwdriver is engaged with the tool engagement portion J and rotated as shown by arrow K1, the receiving member D will come off the roller R1 of the motion transmission member 10, which is the force adjustment portion 8, as shown in Figure 10(b), and the force adjustment portion 8 can be disconnected. Similarly, in the state shown in Figure 10(b), for example, if a flat head screwdriver is engaged with the tool engagement portion J and rotated as shown by arrow K2, the state shown in Figure 10(a) will be reached and the force adjustment portion 8 will return to the connected state.

By setting it to the state shown in FIG. 10(b), the connection of the force adjustment unit 8 is released, so even if the lift table L is lifted without holding the load W during a test run or inspection, the force adjustment unit 8 increases the force, preventing the free wheel 5 on one side from floating up. Therefore, the travel control of the conveying device 1 can be performed normally during a test run or inspection.

The above description of the embodiments is merely illustrative and is not intended to be limiting. Various improvements and modifications may be made without departing from the scope of the present invention.

1 Conveying device 2 Main body 2A Base 3 Load holding section 4 Drive wheel 5 Free wheel 6 Suspension section 6A Support shaft 6B Receiving plate 7 Pressing member 8 Pressing force adjustment section 9 Displacement operation section 10 Operation transmission member 10A One end 10B Other end 10C Support shaft 11 Support member 12 Lifting geared motor 12A Output shaft 13 Eccentric cam A Holding state B Non-holding state C Fixed members D, E Receiving member F Pressing force G increased by the pressing force adjustment section Running surface H Front I Shaft body J Tool engagement section K1, K2 Rotation direction L Lifting table M Geared motor R1, R2 Roller S Compression coil spring W Load

Claims (3)

A conveying device comprising at least a main body having a drive wheel and a load holding part for holding a load,
The main body portion is
a suspension portion that suspends the drive wheel on a base body of the main body portion;
A biasing member that applies a biasing force against a running surface to the drive wheel via the suspension portion;
a biasing force adjustment unit that adjusts the biasing force by pressing the biasing member;
Equipped with
a displacement operation unit that displaces the load holding unit between a holding state in which the load holding unit holds the load and a non-holding state in which the load holding unit does not hold the load,
The biasing force adjustment unit is
a motion transmission member having one end and an other end,
The motion transmission member is
The support is supported at a predetermined position other than the one end and the other end, and oscillates in a seesaw manner relative to a base of the main body portion,
The one end portion is linked to the displacement movement of the load retaining portion , whereby the movement transmission member swings and the other end portion adjusts the biasing force.
Conveying device. The load retaining portion is
The load is supported from below to achieve the held state,
The load is released downward to the non-retained state.
The conveying device according to claim 1 . The load holding portion is displaced to hold the load, and a predetermined load is applied to the load holding portion, and then the biasing force adjustment portion presses the biasing member.
3. A conveying device according to claim 1 or 2 .

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