JP5252215B2 - Steering system for transport cart - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a system for steering a transport carriage that is intended for a transport carriage that is mounted with an object to be transported and can be moved in an arbitrary direction on a floor surface by an operator's boosting operation.

  As this kind of transport cart, for example, a stretcher and a moving bed used when transporting patients in medical facilities, or a simple transport used when transporting various items in the field at various work sites and logistics facilities. A typical handcart or the like is representative, but since all of this type of transport cart does not have a steering mechanism, the operator has only to change the direction by adjusting the moving direction while pushing back.

  On the other hand, there are proposals for various types of steering mechanisms and control systems as disclosed in Patent Documents 1 to 7, for example, for automatically driving various vehicles and carts.

JP-A-7-81602 Japanese Patent Laid-Open No. 8-249062 JP-A-9-282033 JP 11-105728 A JP 2003-276628 A JP 2008-26928 A International Publication No. 97/36217 Pamphlet

  When transporting a long transport cart like a stretcher or moving bed, or when a heavy article is mounted on a wheelbarrow, you can freely change the direction or slightly change the direction of movement while pushing it alone. Since it is not always easy to make adjustments, in such a case, two or more operators must cooperate and steer as necessary to improve the efficiency and labor saving of the transportation work. Not preferred above.

  Although it is conceivable that these transport carts can be automatically steered as shown in Patent Literatures 1 to 7, such a complicated and advanced automatic control technology for a simple transport cart that is moved by a pushing operation. It is not realistic to apply a steering mechanism that applies to the above, and if such a mechanism is mounted on a simple transport cart such as a stretcher, a bed, or a wheelbarrow, the operator can perform a free boosting operation. It becomes impossible to do so, and the original simplicity, mobility, and versatility are impaired, which is not preferable.

  In view of the above circumstances, an object of the present invention is to provide an effective and appropriate steering system for performing steering for a simple transport carriage.

The present invention is directed to a transport cart that has a caster that can change its direction in an arbitrary direction and that can carry an object to be transported and can be moved in an arbitrary direction on a floor surface by a push-up operation by an operator. Is a steering system for guiding in a desired moving direction based on predetermined destination guidance information when moving on the floor surface by the operator's back-pressing operation , wherein the transport carriage includes the destination guidance information And a steering wheel that is controlled based on the detection result of the detector and moves the transport carriage along the destination guidance information.

  In the present invention, the steering wheel is retractably provided at the bottom of the transport carriage, and when the steered wheel is in the retracted state, the transport carriage is supported on the floor surface by the caster so that the direction can be freely changed in any direction. When the steering wheel is used, a part of the caster is lifted on the floor surface, and the transfer carriage is supported on the floor surface by the steering wheel in a steerable manner instead of the caster. Preferably there is.

In addition, it is preferable that a speed detecting unit that detects a moving speed of the transport carriage is provided, and the steered wheels are controlled according to the moving speed detected by the speed detecting unit.
The destination guidance information may be a line provided on the floor or an image marker provided on the ceiling.
It is also conceivable that an auxiliary drive mechanism that assists the boosting operation by the operator and reduces the pushing force forward is mounted on the transport carriage.

  According to the system of the present invention, the operator simply pushes the carriage, and the carriage moves in that direction while reading the destination guidance information by itself. The operation of finely adjusting the moving direction or forcibly changing the direction in order to go to the destination can be unnecessary or sufficiently reduced. Therefore, even a single person can efficiently transport the transport cart, and there is no need to transport another operator with another operator at the front of the transport cart for the purpose of steering as in the past. Thus, it is possible to sufficiently save labor required for conveyance.

  In addition, the system of the present invention does not automatically drive the transport carriage simply by reducing the steering operation by the operator. Therefore, the transport carriage is simply configured to simply read the destination guidance information and control the direction of the steering wheel. Since it is sufficient to install a simple mechanism, it is not necessary to have a complicated and sophisticated control system like the conventional various automatic vehicle driving systems, and it is possible to use the conventional one as it is. Yes, it is possible to adopt the system easily and inexpensively, and it can be applied to existing facilities without requiring major modifications.

It is a schematic block diagram (figure seeing through the bottom part of the stretcher as a conveyance trolley) which shows the steering system of the conveyance trolley which is an embodiment of the present invention.

  An embodiment of the present invention will be described with reference to FIG. This embodiment is an example of application to a system for transporting a patient transport stretcher frequently used in medical facilities.

The stretcher 1 as a transport carriage in the system of the present embodiment is basically provided with casters 2 that can freely rotate in arbitrary directions at the bottom four corners of a horizontally long vehicle body in the same manner as a normal stretcher. The nurse or caregiver becomes an operator 3 and pushes it forward from behind to move it forward. However, in the present embodiment, in addition to the four-wheel caster 2, the tretcher 1 is provided on the front side. A steering unit 4 is provided at the center of the bottom.
And the line 8 as destination guidance information for guiding the movement of the stretcher 1 is displayed in advance on the floor surface in the facility where the stretcher 1 should be transported, and the steering system of this embodiment is the above-described steering system. The steering unit 4 reads the position of the line 8 and steers so that the stretcher 1 is moved along the line 8.

The steering unit 4 in this embodiment includes a pair of steered wheels 6 that are steered left and right by a steering mechanism 5, a sensor 7 as a detector that detects the above-described line 8 formed on the floor, and detection thereof. Control means (not shown) for controlling the direction of the steered wheel 6 based on the result, and the direction of the steered wheel 6 is controlled momentarily so as to follow the position while detecting the position of the line 8 by the sensor 7. It has become.
Therefore, when the line 8 is a straight line as shown in FIG. 1 (a), the steered wheels 6 are controlled to face forward, and the stretcher 1 goes straight, and the line 8 is directed as shown in FIG. 1 (b). In the case of turning, the steering wheel 6 is directed in that direction, and the stretcher 1 naturally changes direction, and in any case, the stretcher 1 moves along the line 8 without deviating from the line 8. It has become.

According to this system, the operator 3 who conveys the stretcher 1 simply places the stretcher 1 on the predetermined line 8 corresponding to the destination at the start of conveyance, and then pushes the stretcher 1 forward. As described above, the stretcher 1 naturally moves along the line 8 toward the destination. Therefore, it is not necessary for the operator 3 to finely adjust the moving direction while pushing the stretcher 1 as in the prior art, and the operator 3 is forced to change each time because the direction is changed to the destination. The operation of changing the direction is unnecessary or can be sufficiently reduced.
As a result, according to the present system, even one person can efficiently transport the stretcher 1 without any trouble, and another operator is arranged at the front of the stretcher 1 for the purpose of steering as in the past. Thus, there is no need for two people to carry and the labor saving required for carrying the stretcher 1 can be sufficiently achieved.

  Further, the system of the present embodiment is based on the premise that the movement of the stretcher 1 is performed only by the operator's back-up, and does not cause the stretcher 1 itself to self-run. The steering unit 4 provided in the stretcher 1 is a simple mechanism that simply reads the line 8 and directs the steering wheel 6 in its direction, and the direction of the steering wheel 6 is used as a power source. It is sufficient to mount a battery with a small capacity that can be changed. Naturally, a complicated and sophisticated control system for automatically driving a vehicle as disclosed in Patent Documents 1 to 7 is also unnecessary. Therefore, it is possible to adopt the present system sufficiently inexpensively and simply by adding a simple steering unit 4 to the general-purpose stretcher 1 and displaying the line 8 on the floor surface. It can also be applied without requiring major renovation.

The basic embodiments of the present invention have been described above. Supplementary explanations and application examples are listed below.
-Conveying cart In the system of the above-described embodiment, the stretcher 1 is steered. However, the system of the present invention is not limited to the stretcher 1 as long as the operator 3 pushes and moves it. For example, the present invention can be similarly applied to various types of transport carts such as a mobile bed, a distribution car, and a wheelbarrow for transporting various articles.
Of course, this system is not limited to medical facilities that use a lot of stretchers, mobile beds, or barges, but also various facilities that carry various goods using various transport carts, such as work sites and logistics facilities. Naturally, it can be widely applied to facilities of various uses.

-Destination guidance information In the system of the above embodiment, the destination guidance information is displayed as a line 8 on the floor surface, and the line 8 is detected by the sensor 7 to steer, but more specifically, the line 8 is displayed. It is preferable to perform the steering by forming the magnetic tape and using the sensor 7 as a magnetic sensor and detecting the magnetism of the line 8 by the magnetic sensor.
However, the present invention is not limited to such a magnetic guidance system. For example, the destination guidance information is electromagnetically recorded on the line 8, or the destination guidance information is displayed according to the color classification or line type of the line 8. Steering can also be performed by optical detection, and destination guidance information and detectors suitable for these methods may be adopted.
Further, instead of displaying the destination guidance information as the line 8 on the floor as in the above embodiment, image markers are installed at predetermined intervals on the ceiling surface, and the image markers are detected by a detector provided on the transport carriage. A guidance method using an image marker that performs steering while detecting can also be adopted. In that case, it is not necessary to form a line on the floor surface, and it is possible to guide each transport cart to each destination by programming the destination and travel route in advance for each transport cart, You can also change destinations and travel routes on the program.

Steering unit The steering unit 4 mounted on the transport carriage (in the above case, the stretcher 1) reads the destination guidance information (in the above case, the line 8) by the detector (in the above case, the sensor 7) and follows it. As long as the steering wheel 6 is controlled, the configuration of the steering unit 4 is arbitrary, and various modifications and applications are possible.
In particular, it is possible to switch between a mode that is used as a simple stretcher without performing a steering operation and a mode in which a steering operation is performed by a steering unit. In the former normal mode, the steered wheels 6 are stored in the bottom part of the transport carriage. Thus, it is preferable that the steering wheel 6 be pulled out and used only in the latter steering mode.
In that case, if the steered wheels 6 are stored in the normal mode and floated on the floor surface, the transport carriage is supported on the floor surface only by the four-wheel casters 2 and can freely move in any direction. Therefore, the excellent mobility, which is the original function of the transport carriage, is not impaired at all. For example, when the transport carriage is placed at a fixed position, it is advantageous to finely adjust the positioning. .
On the other hand, when the transport carriage is moved over a long distance, the steering wheel 6 is pulled out to perform the steering operation using the steering unit 4 by switching to the steering mode, whereby the front part of the transport carriage is driven by the steering wheel 6. By supporting the side and lifting the caster 2 of the front side two wheels on the floor surface, thereby substantially forming a three-wheeled vehicle type with the steering wheel 6 of the front wheel and the caster 2 of the rear two wheels It is possible to perform the steering operation more smoothly and reliably.
However, in the normal mode, if the steering wheel 6 can be freely rotated in any direction as in the case of the caster 2, there is no fear of impairing the mobility in the normal mode. Absent. In the steering mode, if there is no concern that the caster 2 affects the steering, it is not always necessary to lift the caster 2. In such a case, the steering wheel 6 and the four-wheel caster 2 as a whole always support the transport carriage. It does not matter even if it is set as the structure to do.

Steering wheel direction control In this system, the direction of the steering wheel 6 is controlled momentarily based on the destination guidance information detected by the detector. At this time, the direction of the steering wheel 6 is determined according to the moving speed of the transport carriage. It is preferable to adjust the control speed. That is, in this system, since the transport carriage is moved by the operator's boosting operation, the movement speed changes variously, but when the movement speed of the transport carriage is high, the control of the direction of the steering wheel 6 is slow, Or, conversely, if the direction of the steered wheels is rapidly controlled when the moving speed of the transport carriage is slow, there is a concern that sufficient followability to the destination guidance information cannot be secured and the movement direction may be shifted. By optimally controlling the direction control speed of the steered wheels 6 according to the moving speed at that time, it is possible to always ensure sufficient follow-up without causing such a shift.

-Auxiliary drive mechanism This system does not require or reduce the steering by the operator and does not cause the carriage to move itself. Therefore, a drive source for causing the carriage to self-run is unnecessary. Equipped with an auxiliary drive mechanism to assist the boosting operation in order to reduce the labor of the operator, assuming that the transported object is heavy and it is difficult for one operator to push out the transport cart. It is also possible to do.
However, in that case, mounting a large-capacity drive source on the transport carriage and making it a system that can run unattended will also take the gist of the present invention to reduce steering, in which case As with various automatic driving systems, it is inevitable that the entire system will become highly complex, and the carriage will also become complicated and heavy, impairing the original mobility and versatility. A simple power assist mechanism should be installed so that it can operate for the first time and auxiliary driving force can be obtained.

1 Stretcher (transport cart)
2 Caster 3 Operator 4 Steering unit 5 Steering mechanism 6 Steering wheel 7 Sensor (detector)
8 lines (destination guide information)

Claims (6)

For a transport cart having a caster that can change its direction in an arbitrary direction and is capable of moving in an arbitrary direction on the floor surface by carrying an object to be transported and pushing the operator, the transport cart is used as the operator. A steering system for guiding in a desired moving direction based on predetermined destination guidance information when moving on the floor surface by a back pushing operation ,
The transport carriage includes a detector that detects the destination guidance information, and a steering wheel that is controlled based on a detection result by the detector and moves the transport carriage along the destination guidance information. This is a steering system for transport carts. A steering system for a transport carriage according to claim 1,
The steerable wheel is retractably provided at the bottom of the transport carriage, and when the steerable wheel is in the retracted state, the transport carriage is supported on the floor by the caster so that the direction of the steerable wheel can be freely changed in any direction. When the vehicle is used, a part of the caster is lifted on the floor surface, and instead of the caster, the transport carriage is supported on the floor surface so as to be steerable by the steering wheel. Steering system for transport cart. It is the steering system of the conveyance trolley of Claim 1 or 2,
A steering system for a transport carriage, comprising speed detection means for detecting the travel speed of the transport carriage, wherein the steered wheels are controlled according to the travel speed detected by the speed detection means. It is a steering system of the conveyance trolley of Claim 1, 2, or 3,
The destination guidance information is a line provided on a floor surface. It is a steering system of the conveyance trolley of Claim 1, 2, or 3,
The destination information is an image marker provided on a ceiling surface. It is a steering system of a conveyance cart given in any 1 paragraph of Claims 1-5,
The conveyance carriage steering system according to claim 1, wherein the conveyance carriage is equipped with an auxiliary drive mechanism that assists a boosting operation by an operator and reduces a forward pushing force.

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