stair lift

Abstract

To provide a stair ascending and descending device which can be used as an electric wheelchair and allows a subject to move by ascending and descending stairs by his / her operation while the subject is seated.SOLUTION: In a travelling state as an electric wheelchair 1, a rear-wheel drive part 33 and a front-wheel drive part 43 are controlled to drive to travel in a direction and at a speed according to operation by a subject. In moving from the travelling state to an ascending and descending state of stairs, a front side rotation drive part 42A, 42B and a front side linear motion drive part 44A, 44B are controlled to move a pair of front wheel parts 40A, 40B backward for keeping a seat part 11 horizontal when a lower end of a second frame 10B is grounded, and simultaneously, an ascending and descending drive part 20 is controlled to move a supporting shaft 21 together with a pair of rear side arm parts 31A, 31B and a pair of rear wheel parts 30A, 30B to an upper end of a third frame 10C.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention proposes a stair climbing device that can be used in combination with an electric wheelchair and allows a subject person to ascend and descend desired stairs one step at a time while seated. [Background technology]

[0002] Many stair lifts capable of carrying a person up and down stairs have been proposed. For example, a stair lift device capable of ascending and descending spiral staircases without the need for guide rails has been proposed (see Patent Document 1).

[0003] This stair climbing device has an arm mechanism that can rotate and move parallel to the stair tread surface in a two-dimensional plane horizontally, allowing it to ascend and descend stairs not only on straight stairs but also on stairs with curved paths such as spiral staircases.

[0004] A stair-climbing device that supports and assists people and objects going up and down stairs has also been proposed (see Patent Document 2). This stair-climbing device has a circulating movement mechanism that enables the mounting unit and the lifting unit to perform translational movement that circulates relative to each other along a trajectory, and is designed to allow the object to ascend and descend stably and safely not only left and right but also forward and backward while being supported by the surface of the stair treads.

[0005] Furthermore, an electric wheelchair has been proposed in which a foldable support rod is swung up and down so that the wheelchair can ascend and descend stairs like an endless track wheelchair (see Patent Document 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-235229 [Patent Document 2] Japanese Patent Application Publication No. 2019-127197 [Patent Document 3] Japanese Patent Publication No. 2022-95277 Summary of the Invention [Problem to be solved by the invention]

[0007] The stairlift device in Patent Document 1 can ascend and descend spiral staircases, such as spiral staircases, but because the vertical heights of the support members of the front and rear linear motion devices must be the same, it is extremely difficult to apply it to staircases where the elevation heights of each step are not uniform. Furthermore, because the front and rear linear motion devices are raised and lowered one step at a time by ball screw drive, there is also the problem that it takes a significantly long time to ascend and descend the stairs.

[0008] Furthermore, in the stair climbing device of Patent Document 2 mentioned above, the circulating movement mechanism has a moving body that moves along a predetermined closed trajectory driven by a single drive source, and this moving body and mounting part are connected and move relative to each other along the trajectory. As a result, not only is the range of movement limited by the shape and length of the movement trajectory, but the load distribution to the entire device is uneven due to the support structure that uses a rod-shaped arm as a fulcrum, making it insufficient for practical use in terms of safety.

[0009] Furthermore, the electric wheelchair of Patent Document 3 mentioned above has a stair climbing mechanism using a support rod instead of an endless track, but because the seat is tilted and the support rod is pressed against the nosing of the stair to slide, there remains the problem that the safety of the person sitting on the seat is not sufficiently ensured.

[0010] The present invention has been made in consideration of the above points, and aims to propose a stair climbing device that can be used in combination with an electric wheelchair and allows the user to move up and down stairs by operating it themselves while remaining seated. [Means for solving the problem]

[0011] In order to solve this problem, the present invention provides a stair climbing device that can be used with an electric wheelchair and allows a seated person to ascend and descend desired stairs one step at a time. The device comprises a frame structure in which a first frame that horizontally supports the seat of the electric wheelchair is used as a reference, and a second frame that supports a footrest and a third frame that supports a backrest are fixed at a predetermined inclination angle to the front and rear ends of the first frame, and a support shaft that is provided at the rear end of the first frame and engaged so as to slide freely along the longitudinal direction of the third frame is held horizontally relative to the third frame. a rear rotation drive unit that rotates and drives one end of a pair of rear arm units that are rotatably connected to both ends of the support shaft around the central axis of the support shaft; a rear wheel drive unit that rotates and drives a pair of rear wheel units that are connected to the other ends of the pair of rear arm units around a drive shaft provided at the other end of the pair of rear arm units; and a pair of rear arm units that are configured so that one end of each of the pair of rear arm units is extendable along the longitudinal direction with the other end as a reference, and a drive shaft that drives and drives the pair of rear arm units so as to extend or shorten together with the corresponding rear wheel units. a front rotation drive unit that rotates one end of a pair of front arm units connected to both sides of the front end of the first frame around a rotation axis that is coaxial with the rear rotation drive unit; a front wheel drive unit that rotates a pair of front wheel units connected to the other ends of the pair of front arm units around a drive shaft provided at the other end of the pair of front arm units; and a pair of front arm units that are configured so that one end of each of the pair of front arm units is extendable along the longitudinal direction, and linearly drives the pair of front arm units so as to be extended or shortened together with the corresponding front wheel units. and an integrated control unit that collectively controls the lifting drive unit, rear rotating drive unit, rear wheel drive unit, rear linear drive unit, front rotating drive unit, front wheel drive unit and front linear drive unit, and when in a running state as an electric wheelchair, the integrated control unit controls the rear wheel drive unit and front wheel drive unit to drive the wheelchair in a direction and at a speed according to the operation of the user, and when transitioning from the running state to a stair climbing state, controls the front rotating drive unit and front linear drive unit to move the pair of front wheels backward so as to maintain the seat horizontal even when the lower end of the second frame touches the ground, and at the same time controls the lifting drive unit,The support shaft is moved to the upper end of the third frame together with the pair of rear arm portions and the pair of rear wheel portions.

[0012] As a result, with the stair climbing device, when a subject in an electric wheelchair approaches a staircase, the subject can operate the device themselves while remaining seated and begin preparing to ascend or descend the stairs.

[0013] Furthermore, the present invention includes a first distance measurement unit provided at the rear end of the first frame that measures the proximity of the rear end of the first frame to the treads and risers of the stairs, and when preparing to ascend the stairs, the subject drives the device backward in response to their operation so that the pair of rear wheels abuts against the risers of the stairs, and the integrated control unit calculates the height of each stair step based on the measurement results from the first distance measurement unit and controls the rear pivot drive unit, rear linear drive unit, front pivot drive unit, and front linear drive unit in conjunction with each other so that the lower end surface of the first frame abuts against the treads of the stairs one by one. As a result, the stair climbing device allows the subject to ascend and descend the stairs one step at a time while remaining seated.

[0014] Furthermore, the present invention includes a second distance measurement unit provided at the lower end of the second frame for measuring the proximity of the lower end of the second frame to the stair treads and risers, and when descending the stairs, the second frame is moved forward in response to operation by the subject so that the lower end of the second frame is positioned just before the stair nosing, and the integrated control unit calculates the height of each stair step in accordance with the measurements by the first distance measurement unit and the second distance measurement unit, while interlockingly controlling the rear pivot drive unit, rear linear drive unit, front pivot drive unit, and front linear drive unit so that the lower outer surface of the first frame successively abuts the stair tread. As a result, the stair climbing device allows the subject to descend the stairs one step at a time while remaining seated.

[0015] Furthermore, the present invention further includes an angle detection unit that detects the horizontal state of the first frame, and the integrated control unit independently controls the rear rotation drive unit, rear linear drive unit, front rotation drive unit, and front linear drive unit based on the detection result of the angle detection unit when ascending or descending stairs so that the first frame always maintains a parallel relationship with the stair treads. As a result, in the stair climbing device, the seat surface is always kept flat when ascending or descending stairs, allowing the subject to ascend and descend stairs while seated in a stable position.

[0016] Furthermore, in the present invention, when going up or down stairs, when the lower end surface of the first frame moves from a landing state in which it is in contact with the stair tread to the tread of the next step, the integrated control unit controls the rear pivoting drive unit, the rear linear drive unit, the front pivoting drive unit and the front linear drive unit so that the pair of rear wheel units and the pair of front wheel units all move away from the tread.

[0017] As a result, in the stair climbing device, when the first frame supporting the seat is in a stable state in contact with the stair treads, the pair of rear wheels and the pair of front wheels can all be detached from the stair treads, thereby applying the subject's weight to the stair treads and reducing the load during ascending and descending operation accordingly, thereby significantly improving driving efficiency.

[0018] Furthermore, in the present invention, the lifting drive unit, rear pivoting drive unit, rear linear drive unit, front pivoting drive unit, and front linear drive unit each have a locking mechanism, and even if the power supply to the entire device is turned off in the lifting state, the locking mechanisms fix and hold the support shaft, the pair of rear arms, and the pair of front arms in the positions when the power supply is turned off. As a result, the stair climbing device can always ensure the safety of the subject when going up or down stairs, even if the power supply is turned off.

[0019] Furthermore, in the present invention, the pair of rear wheel sections are each composed of an endless track body with an endless belt stretched around a drive wheel and at least one driven wheel, and the rear wheel drive section drives the pair of drive wheels connected to the other ends of the pair of rear arm sections to rotate around a drive shaft provided at the other end of the pair of rear arm sections, thereby driving the pair of endless track bodies to run.

[0020] As a result, in the stair climbing device, by changing the pair of rear wheel sections from point contact with the wheels to surface contact with the non-electrical track body, the possibility of the rear wheel sections slipping against the tread surface when going up or down the stairs (especially when moving up the stairs) can be significantly reduced.

[0021] Furthermore, in the present invention, the pair of front wheel sections are each composed of an endless track body with an endless belt stretched around a drive wheel and at least one driven wheel, and the front wheel drive section drives the pair of drive wheels connected to the other ends of the pair of front arm sections to rotate around a drive shaft provided at the other end of the pair of front arm sections, thereby driving the pair of endless track bodies to run.

[0022] As a result, in the stair climbing device, by changing the pair of front wheel sections from point contact of the wheels to surface contact of the non-electrical track body, the possibility of the front wheel sections slipping against the tread surface when going up and down the stairs (especially when going down the stairs) can be significantly reduced. [Effects of the Invention]

[0023] According to the present invention, it is possible to realize a stair climbing device that allows a subject to climb and descend stairs safely and stably by operating it themselves while remaining seated. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a perspective view showing the external configuration of a stair climbing device according to an embodiment of the present invention; [Figure 2] 1 is a block diagram showing the internal configuration of a stair climbing device according to an embodiment of the present invention; [Figure 3]2 is a schematic diagram showing a running state of the stair climbing device shown in FIG. 1 and a state of ascending and descending stairs. [Figure 4] 10A and 10B are schematic diagrams illustrating the operation of the stair climbing device when ascending stairs. [Figure 5] 10A and 10B are schematic diagrams illustrating the operation of the stair climbing device when ascending stairs. [Figure 6] 10A and 10B are schematic diagrams illustrating the operation of the stair climbing device when ascending stairs. [Figure 7] 10A and 10B are schematic diagrams illustrating the operation of the stair climbing device when descending stairs. [Figure 8] 10A and 10B are schematic diagrams illustrating the operation of the stair climbing device when descending stairs. [Figure 9] 10A and 10B are schematic diagrams illustrating the operation of the stair climbing device when descending stairs. [Figure 10] FIG. 10 is a perspective view showing the external configuration of a stair climbing device according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of the present invention will be described in detail below with reference to the drawings.

[0026] (1) Configuration of the stair climbing device according to this embodiment 1(A) and 1(B) show the external configuration of the stair climbing device 1 according to this embodiment. The stair climbing device 1 can also be used as a four-wheel drive electric wheelchair that moves on the floor in response to operation by the subject, and allows the subject to move up and down the desired stairs one step at a time while seated.

[0027] The stair climbing device 1 has a frame structure 10 in which a first frame 10A, a second frame 10B, and a third frame 10C are connected together so as to be integrated. This frame structure 10 is based on the first frame 10A, which supports the seat 11 of the electric wheelchair horizontally, and the second frame 10B, which supports the footrest 12, and the third frame 10C, which supports the backrest 13, are fixed to the front and rear ends of the first frame 10A at predetermined inclination angles, respectively.

[0028] An elevation drive unit 20 is provided at the rear end of the first frame 10A, and a support shaft 21, which is engaged so as to slide freely along the longitudinal direction of the third frame 10C, is slidably moved while maintaining a horizontal position relative to the third frame 10C.

[0029] The lifting drive unit 20 has a drive actuator (not shown) and converts the rotational motion of a ball screw (not shown) engaged with the output shaft of the drive actuator into linear motion of the support shaft 21, causing the support shaft 21 to slide along the longitudinal direction of the third frame 10C.

[0030] At both ends of the support shaft 21, a pair of rear arm portions 31A, 31B, each having rear wheel portions 30A, 30B at its tip, are integrally engaged with the corresponding drive mechanism systems (rear rotary drive portions 32A, 32B, rear wheel drive portions 33A, 33B (see Figure 2), rear linear drive portions 34A, 34B), with the third frame 10C sandwiched between them.

[0031] The rear rotation drive units 32A and 32B respectively drive one ends of a pair of rear arm units 31A and 31B rotatably connected to both ends of the support shaft 21 to rotate around the central axis of the support shaft 21 as the rotation center.

[0032] The rear wheel drive units 33A, 33B respectively rotate the pair of rear wheel units 30A, 30B connected to the other ends of the pair of rear arm units 31A, 31B, around the drive shaft provided at the other end of the pair of rear arm units 31A, 31B as the rotation center.

[0033] The pair of rear arm portions 31A, 31B are configured so that one end thereof can be used as a reference and the other end thereof can be extended in the longitudinal direction. The rear linear drive portions 34A, 34B linearly drive the pair of rear arm portions 31A, 31B so as to extend or shorten them together with the corresponding rear wheel portions 30A, 30B.

[0034] On both sides of the front end of the first frame 10A, a pair of front arm portions 41A, 41B, each with front wheel portions 40A, 40B at its tip, are integrally engaged with the corresponding drive mechanism system (front rotational drive portions 42A, 42B, front wheel drive portions 43A, 43B (see Figure 2), front linear drive portions 44A, 44B), sandwiching the first frame 10A between them.

[0035] The front rotation drive units 42A, 42B rotate one end of a pair of front arm units 41A, 41B connected to both sides of the front end of the first frame 10A, respectively, around a rotation axis that is coaxial with the above-mentioned rear rotation drive units 32A, 32B.

[0036] The front wheel drive units 43A, 43B respectively rotate the pair of front wheel units 40A, 40B connected to the other ends of the pair of front arm units 41A, 41B, around the drive shaft provided at the other end of the pair of front arm units 41A, 41B as the rotation center.

[0037] The pair of front arm portions 41A, 41B are configured so that one end thereof is extendable along the longitudinal direction, with the other end being a reference point. The front linear drive portions 44A, 44B linearly drive the pair of front arm portions 41A, 41B so as to extend or retract together with the corresponding front wheel portions 40A, 40B.

[0038] The second frame 10B in the frame structure 10 is fixed at a predetermined inclination angle relative to the first frame 10A, but the length from the connection point with the first frame 10A to the bottom end can be freely adjusted to fit the rise of the stairs, and the footrest portion 12 supported at the bottom end can be freely rotated to fit the tread of the stairs.

[0039] 2 shows the circuit configuration of the control system of the stair climbing device 1. The stair climbing device 1 has a built-in general control unit 50 consisting of an MCM (Multi-Chip Module) equipped with a CPU (Central Processing Unit) and memory inside the third frame 10C, which is configured to comprehensively control the lifting drive unit 20, rear rotation drive units 32A, 32B, rear wheel drive units 33A, 33B, rear linear drive units 34A, 34B, front rotation drive units 42A, 42B, front wheel drive units 43A, 43B, and front linear drive units 44A, 44B.

[0040] The lifting drive unit 20, rear rotation drive units 32A, 32B, rear wheel drive units 33A, 33B, rear linear drive units 34A, 34B, front rotation drive units 42A, 42B, front wheel drive units 43A, 43B and front linear drive units 44A, 44B each have a drive actuator (not shown), and are configured to drive each drive actuator to transmit output according to control by the integrated control unit 50.

[0041] When the electric wheelchair is running as shown in Figure 3(A), the integrated control unit 50 independently controls the pair of rear wheel drive units 33A, 33B and the pair of front wheel drive units 43A, 43B, causing the wheelchair to move forward or backward by rotating the rear wheel units 30A, 30B and the front wheel units 40A, 40B forward or backward, and by directing the forward direction of the rear wheel units 30A, 30B and the front wheel units 40A, 40B in the desired direction in response to the user's operation, the wheelchair moves forward at the desired speed and to the right or left.

[0042] In addition, when transitioning from a running state as shown in Figure 3(B) to a stair climbing state, the integrated control unit 50 controls the front pivoting drive units 42A, 42B and the front linear drive units 44A, 44B to move the pair of front wheel units 40A, 40B rearward so as to maintain the seat horizontal even when the lower end of the second frame 10B touches the ground, and at the same time controls the lifting drive unit 20 to move the support shaft 21 together with the pair of rear arm units 31A, 31B and the pair of rear wheel units 30A, 30B to the upper end of the third frame 10C.

[0043] In this way, with the stair climbing device 1, when a subject in an electric wheelchair approaches a staircase, the subject can operate the device themselves while remaining seated and begin preparing to ascend or descend the stairs.

[0044] 2, the first distance measurement unit 60 is provided at the rear end of the first frame 10A and measures the proximity distance of the rear end of the first frame 10A to the treads and risers of the stairs. The second distance measurement unit 61 is provided at the bottom end of the second frame 10B and measures the proximity distance of the bottom end of the second frame 10B to the treads and risers of the stairs. Furthermore, the angle detection unit 62 detects the horizontal state of the first frame 10A.

[0045] Furthermore, the stair climbing device 1 has a relatively large capacity drive battery 63, consisting of a secondary battery or capacitor, built into the first frame (below the seat 11) 10A, which is capable of supplying power to each of the drive actuators of the lifting drive unit 20, rear pivoting drive units 32A, 32B, rear wheel drive units 33A, 33B, rear direct drive units 34A, 34B, front pivoting drive units 42A, 42B, front wheel drive units 43A, 43B and front direct drive units 44A, 44B.

[0046] (2) Operation when ascending stairs using a stair-climbing device The operation of the stair climbing device 1 will be described below, from a traveling state as an electric wheelchair to a state of preparation for climbing stairs, and then climbing stairs one step at a time.

[0047] In the stair climbing device 1, the overall control unit 50 moves the device backward in response to the operation of the subject, and prepares to ascend the stairs from a running state so that the pair of rear wheels 30A, 30B come into contact with the rise surface of the first step of the stairs (Figure 4(A)).

[0048] The integrated control unit 50 controls the front rotation drive units 42A, 42B and the front linear drive units 44A, 44B to move the pair of front wheel units 40A, 40B rearward so that the seat 11 remains horizontal even when the lower end of the second frame 10B touches the ground, and abuts the riser surface of the first step of the stairs, and at the same time controls the lifting drive unit 20 to move the support shaft 21 together with the pair of rear arm units 31A, 31B and the pair of rear wheel units 30A, 30B to the upper end of the third frame 10C (Figure 4(B)).

[0049] Next, the integrated control unit 50 calculates the height of each step of the stairs based on the measurement results from the first distance measurement unit 60, and controls the front rotational drive units 42A, 42B and the front linear drive units 44A, 44B in conjunction with each other to bring the pair of front wheel units 40A, 40B into contact with the rise surface of the next step that corresponds to approximately the same height position (Figure 4(C)).

[0050] In a four-point support state using a pair of rear wheel sections 30A, 30B and a pair of front wheel sections 40A, 40B, the integrated control unit 50 controls the rear pivoting drive sections 32A, 32B, rear linear drive sections 34A, 34B, front pivoting drive sections 42A, 42B and front linear drive sections 44A, 44B in coordination so that the lower end surface of the first frame 10A abuts against the tread of a staircase at approximately the same height position (Figure 5(A)).

[0051] After landing on the first tread (first step) of the stairs, from the second step onwards, the integrated control unit 50 calculates the height of ascent and descent for each step of the stairs based on the measurement results from the first distance measurement unit 60, and controls the rear pivoting drive units 32A, 32B, rear linear drive units 34A, 34B, front pivoting drive units 42A, 42B and front linear drive units 44A, 44B in conjunction with each other so that the lower end surface of the first frame 10A sequentially abuts against the treads of the stairs (Figures 5(B) to 6(B)).

[0052] When ascending such stairs, when the lower end surface of the first frame 10A moves from a landing state in which it abuts the stair tread to the tread of the next step, the integrated control unit 50 controls the rear pivoting drive units 32A, 32B, rear linear drive units 34A, 34B, front pivoting drive units 42A, 42B and front linear drive units 44A, 44B so that the pair of rear wheel units 30A, 30B and the pair of front wheel units 40A, 40B all move away from the tread (so that they are in a lifted-up state with four-point support) (Figures 5(B) and 6(B)).

[0053] As a result, in the stair climbing device 1, when the first frame 10A supporting the seat 11 is in a stable state in which it is in contact with the stair tread, the pair of rear wheel sections 30A, 30B and the pair of front wheel sections 40A, 40B can all be detached from the stair tread, thereby applying the subject's weight to the stair tread, thereby reducing the load during the ascending and descending drive and significantly improving the drive efficiency.

[0054] Furthermore, when ascending stairs, the integrated control unit 50 independently controls the rear rotational drive units 32A, 32B, rear linear drive units 34A, 34B, front rotational drive units 42A, 42B, and front linear drive units 44A, 44B based on the detection results of the angle detection unit 62 so that the first frame 10A is always kept parallel to the stair treads (FIGS. 4(C), 5(B), and 6(B)). As a result, in the stair climbing device 1, the seat surface is always kept flat when ascending stairs, allowing the subject to ascend the stairs while sitting stably.

[0055] In stair climbing device 1, lifting drive unit 20, rear pivoting drive units 32A, 32B, rear linear drive units 34A, 34B, front pivoting drive units 42A, 42B, and front linear drive units 44A, 44B each have a locking mechanism (not shown), and even when the power supply to the entire device is turned off in the ascending state, each locking mechanism fixes and holds support shaft 21, the pair of rear arm units 31A, 31B, and the pair of front arm units 41A, 41B in the orientation when power is turned off. As a result, stair climbing device 1 can always ensure the safety of the subject when ascending stairs, even when the power supply is turned off.

[0056] In this way, with the stair climbing device 1, the subject can move from a traveling state as an electric wheelchair to a state of preparation for climbing stairs, and then climb the stairs one step at a time while remaining seated.

[0057] (3) Operation when descending stairs using a stair-climbing device The operation of the stair climbing device 1 will be described below, from a traveling state as an electric wheelchair, through a state of preparation for descending stairs, and then descending the stairs one step at a time.

[0058] In the stair climbing device 1, the overall control unit 50 moves the device forward in response to the operation of the subject, and prepares to descend the stairs from a running state so that the lower end of the second frame 10B is positioned just before the nosing of the stairs (Figure 7(A)).

[0059] The integrated control unit 50 controls the front rotational drive units 42A, 42B and the front linear drive units 44A, 44B to move the pair of front wheel units 40A, 40B forward and downward so that the seat 11 remains horizontal even when the lower end of the second frame 10B touches the ground, and abuts it against the tread of the first step of the stairs (Figure 7(B)).

[0060] Next, the integrated control unit 50 controls the front rotation drive units 42A, 42B and the front linear drive units 44A, 44B to move the pair of front wheel units 40A, 40B rearward so that the seat 11 remains horizontal even when the lower end of the second frame 10B touches the ground, and abuts the riser surface of the first step of the stairs, and at the same time controls the lifting drive unit 20 to move the support shaft 21, together with the pair of rear arm units 31A, 31B and the pair of rear wheel units 30A, 30B, to the upper end of the third frame 10C (Figure 7(C)).

[0061] Next, the integrated control unit 50 calculates the height of each staircase step based on the measurement results from the first distance measurement unit 60 and the second distance measurement unit 61, and controls the front rotational drive units 42A, 42B and the front linear drive units 44A, 44B in conjunction with each other to bring the pair of front wheels 40A, 40B into contact with the tread of the next step below (FIG. 8(A)). At the same time, the integrated control unit 50 controls the rear linear drive units 34A, 34B to extend the pair of rear arms 31A, 31B and bring the pair of rear wheels 30A, 30B into contact with the ground (FIG. 8(A)).

[0062] After landing on the floor, from the first step onwards, the integrated control unit 50 calculates the height of each step of the stairs based on the measurement results from the first distance measurement unit 60 and the second distance measurement unit 61, and controls the rear pivoting drive units 32A, 32B, rear linear drive units 34A, 34B, front pivoting drive units 42A, 42B and front linear drive units 44A, 44B in conjunction with each other to bring the pair of front wheel units 40A, 40B into contact with the tread of the next step below and to position the pair of rear wheel units 30A, 30B in front of the nosing of the staircase (Figure 8(B)).

[0063] In a four-point support state using a pair of rear wheels 30A, 30B and a pair of front wheels 40A, 40B, the integrated control unit 50 controls the rear pivoting drive units 32A, 32B, rear linear drive units 34A, 34B, front pivoting drive units 42A, 42B and front linear drive units 44A, 44B in conjunction with one another so that the lower end surface of the first frame 10A abuts against the tread of a staircase at approximately the same height (Figures 9(A) and (B)).

[0064] When descending such stairs, when the lower end surface of the first frame 10 moves from a landing state in which it abuts the stair tread to the tread of the next step, the integrated control unit 50 controls the rear pivoting drive units 32A, 32B, rear linear drive units 34A, 34B, front pivoting drive units 42A, 42B and front linear drive units 44A, 44B so that the pair of rear wheel units 30A, 30B and the pair of front wheel units 40A, 40B all move away from the tread (so that they are in a lifted-up state with four-point support) (Figure 9(A)).

[0065] As a result, in the stair climbing device 1, when the first frame 10A supporting the seat 11 is in a stable state in which it is in contact with the stair tread, the pair of rear wheel sections 30A, 30B and the pair of front wheel sections 40A, 40B can all be detached from the stair tread, thereby applying the subject's weight to the stair tread, thereby reducing the load during the ascending and descending drive and significantly improving the drive efficiency.

[0066] Furthermore, when descending stairs, the integrated control unit 50 independently controls the rear rotational drive units 32A, 32B, rear linear drive units 34A, 34B, front rotational drive units 42A, 42B, and front linear drive units 44A, 44B based on the detection results of the angle detection unit 62 so that the first frame 10A is always kept parallel to the treads of the stairs (FIG. 9(A)). As a result, in the stair climbing device 1, the seat surface is always kept flat when descending stairs, allowing the subject to descend the stairs while sitting stably.

[0067] In the stair climbing device 1, the lifting drive unit 20, rear pivoting drive units 32A, 32B, rear linear drive units 34A, 34B, front pivoting drive units 42A, 42B, and front linear drive units 44A, 44B each have a locking mechanism (not shown), and even when the power supply to the entire device is turned off in the descending state, the respective locking mechanisms fix and hold the support shaft 21, the pair of rear arm units 31A, 31B, and the pair of front arm units 41A, 41B in the positions when the power supply is turned off. As a result, the stair climbing device 1 can always ensure the safety of the subject even when the power supply is turned off when descending stairs.

[0068] In this way, with the stair climbing device 1, the subject can move from a traveling state as an electric wheelchair to a state of preparation for descending stairs, and then descend the stairs one step at a time while remaining seated.

[0069] (4) Other embodiments As described above, in this embodiment, the pair of rear wheel sections 30A, 30B and the pair of front wheel sections 40A, 40B are each configured from wheels that can be rotated, but the present invention is not limited to this, and various running mechanisms other than wheels may be applied as long as they have the running function of an electric wheelchair.

[0070] For example, as shown in Figures 10(A) and (B), in which the same symbols are used for parts corresponding to those in Figures 1(A) and (B), the stair climbing device 70 may be configured so that the pair of rear wheel sections 80A, 80B and the pair of front wheel sections 90A, 90B are each composed of endless track bodies in which an endless belt is stretched between a drive wheel and at least one driven wheel.

[0071] In accordance with the pair of rear wheel sections 80A, 80B being constructed from endless track bodies, rear wheel drive sections 33A, 33B drive a pair of drive wheels connected to the other ends of the pair of rear arm sections 31A, 31B to rotate around a drive shaft provided at the other end of the pair of rear arm sections 31A, 31B, respectively, thereby driving the pair of endless track bodies (80A, 80B) to run.

[0072] Similarly, in response to the pair of front wheel sections 90A, 90B being constructed from endless track bodies, the front wheel drive sections 43A, 43B drive the pair of drive wheels connected to the other ends of the pair of front arm sections 41A, 41B to rotate around the drive shaft provided at the other end of the pair of front arm sections 41A, 41B, thereby driving the pair of endless track bodies (90A, 90B) to run.

[0073] In this way, in the stair climbing device 70, by changing the pair of rear wheel sections 80A, 80B and the pair of front wheel sections 90A, 90B from point contact of the wheels to surface contact of the wireless track body, the possibility of the rear wheel sections 80A, 80B and the front wheel sections 90A, 90B slipping against the tread surface when going up or down the stairs can be significantly reduced.

[0074] 10(A) and (B) are described as cases in which the pair of rear wheel sections 80A, 80B and the pair of front wheel sections 90A, 90B are all configured from caterpillars, but it is also possible to configure only the pair of rear wheel sections 80A, 80B from caterpillars and the pair of front wheel sections 40A, 40B from wheels, or it is also possible to configure only the pair of front wheel sections 90A, 90B from caterpillars and the pair of rear wheel sections 30A, 30B from wheels. Furthermore, the wheels and caterpillars may be configured as interchangeable units. [Explanation of symbols]

[0075] 1, 70... stair lift device, 10... frame structure, 10A... first frame, 10B... second frame, 10C... third frame, 11... seat portion, 12... footrest portion, 13... backrest portion, 20... lifting drive portion, 21... support shaft, 30A, 30B, 80A, 80B... rear wheel portion, 31A, 31B... rear arm portion, 32A, 32B... rear rotation drive portion, 33A, 33 B...rear wheel drive unit, 34A, 34B...rear linear drive unit, 40A, 40B, 90A, 90B...front wheel unit, 41A, 41B...front arm unit, 42A, 42B...front rotary drive unit, 43A, 43B...front wheel drive unit, 44A, 44B...front linear drive unit, 50...overall control unit, 60...first distance measurement unit, 61...second distance measurement unit, 62...angle detection unit, 63...drive battery.

Claims

1. A stair climbing device that can be used in combination with an electric wheelchair and allows a subject to ascend and descend desired stairs one step at a time while seated, a frame structure in which a first frame that horizontally supports the seat of the electric wheelchair is used as a reference, and a second frame that supports a footrest and a third frame that supports a backrest are fixed to the front and rear ends of the first frame at predetermined inclination angles, respectively; an elevation drive unit that slides a support shaft that is provided at a rear end of the first frame and engaged with the third frame so as to be slidable along the longitudinal direction of the third frame while maintaining the support shaft in a horizontal state relative to the third frame; a rear rotation drive unit that drives and rotates one end of a pair of rear arm units that are rotatably connected to both ends of the support shaft, with the central axis of the support shaft as a rotation center; a rear wheel drive unit that drives a pair of rear wheel units connected to the other ends of the pair of rear arm units to rotate around a drive shaft provided at the other ends of the pair of rear arm units as a rotation center; a rear linear drive unit that linearly drives the pair of rear arm units so that the pair of rear arm units are extended or shortened together with the corresponding rear wheel units, the rear arm units being configured such that the other end of each of the pair of rear arm units is extendable along the longitudinal direction relative to one end of the rear arm unit; a front rotation drive unit that rotates one end of a pair of front arm units connected to both sides of the front end of the first frame around a rotation axis that is coaxial with the rear rotation drive unit; a front wheel drive unit that drives a pair of front wheels connected to the other ends of the pair of front arms to rotate around a drive shaft provided at the other ends of the pair of front arms as a rotation center; a front linear drive unit that linearly drives the pair of front arm units so that the pair of front arm units are extended or shortened together with the corresponding front wheel units, the front arm units being configured such that the other end of each of the pair of front arm units is extendable along the longitudinal direction relative to one end of the pair of front arm units; an integrated control unit that collectively controls the lifting drive unit, the rear rotation drive unit, the rear wheel drive unit, the rear linear drive unit, the front rotation drive unit, the front wheel drive unit, and the front linear drive unit, The general control unit In the traveling state of the electric wheelchair, the rear wheel drive unit and the front wheel drive unit are controlled to drive the electric wheelchair in a direction and at a speed according to the operation of the subject person, When transitioning from the traveling state to the stair climbing state, the front rotation drive unit and the front linear drive unit are controlled to move the pair of front wheels rearward so as to maintain the seat horizontal even when the lower end of the second frame touches the ground, and at the same time, the lift drive unit is controlled to move the support shaft together with the pair of rear arm units and the pair of rear wheels to the upper end of the third frame. A stair climbing device characterized by:

2. a first distance measuring unit provided at a rear end of the first frame for measuring a proximity distance of the rear end of the first frame to a tread and a riser of the staircase; When preparing to ascend the stairs, the vehicle is driven backward in response to an operation by the subject, and the pair of rear wheels are in contact with the rise of the stairs. The integrated control unit calculates the height of each step of the stairs according to the measurement result by the first distance measurement unit, and controls the rear rotation drive unit, the rear linear drive unit, the front rotation drive unit, and the front linear drive unit in cooperation with each other so that the lower end surface of the first frame sequentially abuts against the treads of the stairs.

2. The stair climbing device according to claim 1.

3. a second distance measuring unit provided at a lower end of the second frame for measuring a proximity distance of the lower end of the second frame to the tread and riser of the staircase; When descending the stairs, the second frame is moved forward in response to an operation by the subject, and a lower end of the second frame is positioned in front of the nosing of the stairs. The integrated control unit calculates the height of each step of the stairs according to the measurement results by the first distance measurement unit and the second distance measurement unit, and controls the rear rotation drive unit, the rear linear drive unit, the front rotation drive unit, and the front linear drive unit in cooperation with each other so that the lower outer surface of the first frame comes into contact with the treads of the stairs in sequence.

3. The stair climbing device according to claim 2.

4. further comprising an angle detection unit that detects a horizontal state of the first frame; The integrated control unit independently controls the rear rotation drive unit, the rear linear drive unit, the front rotation drive unit, and the front linear drive unit based on the detection result of the angle detection unit when ascending or descending the stairs so that the first frame always maintains a parallel relationship with the stair treads.

4. A stair climbing device according to claim 1.

5. The integrated control unit controls the rear rotation drive unit, the rear linear drive unit, the front rotation drive unit, and the front linear drive unit so that, when the lower end surface of the first frame moves from a landing state in which it abuts against the tread surface of the staircase to a tread surface of the next step during ascending or descending the staircase, the pair of rear wheel units and the pair of front wheel units are all separated from the tread surface.

4. A stair climbing device according to claim 1.

6. The lifting drive unit, the rear rotation drive unit, the rear linear drive unit, the front rotation drive unit, and the front linear drive unit each have a locking mechanism, and even if the power supply to the entire device is turned off in the lifting state, the support shaft, the pair of rear arm units, and the pair of front arm units are fixed and held in the orientation when the power supply is turned off by the respective locking mechanisms.

4. A stair climbing device according to claim 1.

7. The pair of rear wheel portions are each composed of a track body having an endless belt wound around a drive wheel and at least one driven wheel, The rear wheel drive unit drives the caterpillars to travel by rotating the drive wheels connected to the other ends of the pair of rear arm units around the drive shafts provided at the other ends of the pair of rear arm units.

4. A stair climbing device according to claim 1.

8. The pair of front wheel units each comprise a track body having an endless belt wound around a drive wheel and at least one driven wheel, The front wheel drive unit drives the drive wheels connected to the other ends of the pair of front arm units to rotate around the drive shaft provided at the other ends of the pair of front arm units, thereby driving each of the endless track vehicles to travel.

4. A stair climbing device according to claim 1.

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