Wheel unit

Abstract

To provide a wheel unit capable of accurately detecting operation force, while compactly arranging a detection device for detecting the operation force when pushing an object attached with a wheel, with a simple constitution.SOLUTION: A wheel driving device includes a wheel, an attachment portion that enables the wheel to be attached to an object including another wheel, a link mechanism that is provided between the wheel and the attachment portion, a detection sensor that detects an operation force in a traveling direction of the wheel acting on the object by detecting a swing amount of the link mechanism, a motor that drives the wheel, and a control unit.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a wheel unit that is detachably attached to an object such as a traveling carriage and has a detection device that detects an operating force that pushes the object along the traveling direction. [Background technology]

[0002] Conventionally, there have been known transport assist devices that assist the movement of an object by retrofitting motor-driven wheels to the object. For example, Patent Document 1 discloses a transport assist device that includes multiple Mecanum wheels attached to a medical bed as the object, a motor that drives each Mecanum wheel, a first sensor that detects a force applied to the object, and a control unit that controls the driving of the motor, and the control unit drives the Mecanum wheels via the motor so as to propel the object in the direction in which the object receives the force based on a detection signal from the first sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-186415 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the transport assistance device described in Patent Document 1, by retrofitting it to a medical bed, the movement of the medical bed can be assisted by motor-driven Mecanum wheels. Meanwhile, a first sensor reflects the magnitude of distortion generated based on the relative distance between the medical bed and the transport assistance device in a detection signal, and a control device inputs a control signal to the motor to drive each Mecanum wheel at any time after the force applied to the Mecanum wheels exceeds the static friction force based on the detection signal from the first sensor. This presents a problem: the device cannot assist the start of movement until the static friction force is exceeded, which is when the transport assistance force is most needed. Furthermore, because the first sensor must be installed on the object, the installation process is time-consuming and the wiring is complicated, resulting in an increase in the overall size of the device.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a wheel unit that has a simple and compact detection sensor and link mechanism that detect the operating force when pushing an object to which the wheel is attached, while accurately detecting the operating force and enabling assistance with the operating force at the required timing. [Means for solving the problem]

[0006] The above object of the present invention is achieved by the following configuration [1].

[0007] [1] Wheels and a mounting portion that allows the wheel to be mounted on an object having other wheels; a link mechanism provided between the wheel and the mounting portion; a detection sensor that detects an amount of swing of the link mechanism to detect an operating force in the traveling direction of the wheel acting on the object; a motor that drives the wheels; a control unit, the control unit assists driving of the wheel via the motor when the operation force is detected by the detection sensor. Wheel unit. [Effects of the Invention]

[0008] The wheel unit of the present invention allows a detection device to be provided that is simple and compact and that detects the operating force when pushing an object to which a wheel is attached. Furthermore, the operating force can be detected with high accuracy, taking the weight of the object into consideration. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a traveling unit to which a wheel unit of the present invention is applied. [Figure 2] FIG. 2 is a block diagram of the control unit. [Figure 3] FIG. 3 is a schematic diagram showing the link mechanism. [Figure 4] FIG. 4 is a schematic diagram showing the link mechanism when an operating force is applied. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be specifically described, but the present invention is not limited to the embodiments described below.

[0011] Fig. 1 is a schematic diagram showing a traveling unit to which the wheel unit of the present invention is applied, and Fig. 2 is a block diagram of the control unit. A traveling unit 1, which may be a traveling cart, a wheelchair, an autonomous traveling robot, or the like, includes a body 2 and a wheel unit 10 that is detachably attached to the underside of the body 2. The body 2 is provided with wheels (not shown) in addition to the wheel unit 10, and the caster-type wheel unit 10 is attached to the underside of the body 2, thereby forming a traveling unit 1.

[0012] The wheel unit 10 has a wheel 11, an axle 12 that supports the wheel 11, a mounting portion 13 that detachably mounts the wheel 11 to the underside of an object that becomes the vehicle body 2, a bearing 14 that supports the wheel 11 on the mounting portion 13 so that the wheel 11 can rotate, a drive motor 15 that drives the wheel 11, a detection device 20 that is provided between the wheel 11 and the mounting portion 13, and a control unit 50. The detection device 20 detects the operating force acting on the vehicle body 2 (wheels 11) when the user pushes the vehicle body 2 to move. In other words, the detection device 20 detects the operating force acting on the vehicle body 2 in the traveling direction of the wheels 11. The traveling unit 1 has a battery (not shown) connected to the drive motor 15, the control unit 50, etc., on the vehicle body 2 side or the wheel unit 10 side.

[0013] The control unit 50 detects the operation force acting on the vehicle body 2 using the detection device 20, and controls the driving of the drive motor 15 based on the detected operation force. That is, when moving the body 2, the traveling unit 1 can appropriately detect the operating force acting on the body 2 (wheels 11) and assist the rotation of the wheels 11 with the driving force of the drive motor 15. This allows the traveling unit 1 to move more smoothly.

[0014] Next, the configuration of the detection device 20 provided in the wheel unit 10 will be described with reference to Figures 3 and 4. Figure 3 is a schematic diagram showing a link mechanism. Figure 4 is a schematic diagram showing the link mechanism when an operating force is applied.

[0015] The detection device 20 has a link mechanism 22 provided between the mounting portion 13 and the wheel 11 (axle 12), and a potentiometer 21 which is a detection sensor that detects the amount of swing of the link mechanism 22. Note that the detection sensor is not limited to the potentiometer 21, and any sensor that can detect the amount of swing of the link mechanism 22, such as an angle detection encoder, may be used. The link mechanism 22 has a first link member 23 connected to the mounting portion 13 and a second link member 24 connected to the axle 12 and shorter than the first link member 23.

[0016] The first link member 23 extends downward from an upper end portion fixed to the mounting portion 13, and is perpendicular to the axle 12. Furthermore, the first link member 23 inclines in the opposite direction to the traveling direction of the wheel 11 as it extends downward. The upper end of the first link member 23 is attached and fixed to the mounting portion 13 via the bearing 14, has a rotating shaft 16 journaled on the bearing 14, and is firmly fixed to the mounting portion 13 while maintaining the inclination angle. Therefore, the position of the axle 12 in a plan view is offset from the rotating shaft 16 journaled on the bearing 14, and moves around the rotating shaft 16.

[0017] The second link member 24 is a frame-like member formed shorter than the height from the axle 12 to the ground contact surface of the wheel 11. The lower end of the second link member 24 is rotatably supported on the lower end of the first link member 23 via a first pivot support portion 25. The upper end of the second link member 24 is rotatably supported on the axle 12 via a second pivot support portion 26.

[0018] The potentiometer 21 is fixedly attached to the first pivotal support portion 25 or the second pivotal support portion 26, thereby detecting the amount of swing of the second link member 24.

[0019] The bearing 14 is fixed to the lower surface of the mounting portion 13 so that the rotary shaft 16 extends vertically, and supports the upper end of the first link member 23 which extends obliquely downward. That is, the entire wheel unit 10 is rotatably supported on the rotation axis 16 of the bearing 14. At this time, the wheel 11 attached to the lower end of the wheel unit 10 is provided so that the direction of the wheel 11 always faces the rotation axis 16 of the bearing 14 in a plan view. According to this configuration, the traveling unit 1, in which the wheels 11 are fixedly attached to the car body 2, can move in any direction through 360° by rotating the caster-type wheels 11 about the bearings 14 as axes.

[0020] Next, the operation of the above-mentioned detection device 20 will be described. When the wheel unit 10 is attached and fixed to the underside of the vehicle body 2 via the attachment portion 13, the weight of the vehicle body 2 acts on the axle 12 via the link mechanism 22. This causes the second link member 24 to be stable in a stationary state extending in the vertical (up and down) direction with the axle 12 as its upper end. This configuration can be seen in FIG. 3.

[0021] When an operating force is applied to the vehicle body 2 to move the traveling unit 1 forward in the traveling direction of the wheels 11 while the traveling unit 1 is in this stationary state, the link mechanism 22 is deformed by the operating force. Specifically, an operating force acting forward in the traveling direction of the vehicle body 2 (wheel 11) acts on the second link member 24 via the first link member 23, causing the second link member 24 to swing forward around the second pivot portion 26. Similarly, when an operating force acting rearward in the traveling direction of the vehicle body 2 is applied, the second link member 24 swings rearward around the second pivot portion 26. That is, the amount of swing of the second link member 24 is detected by the potentiometer 21 and converted into an operating force that is pre-assigned to correspond to this amount of swing, thereby making it possible to detect the operating force acting on the traveling unit 1 in the forward or backward direction of travel. This configuration can be seen in FIG. 4.

[0022] With this configuration, the second link member 24 can be swung forward even when the operating force is small relative to the weight of the vehicle body 2. Therefore, even if the running resistance becomes very large due to, for example, a heavy weight of the vehicle body 2, and the operating force pushing the traveling unit 1 is barely enough to move the traveling unit 1, the operating force pushing the traveling unit 1 can move the link mechanism 22 of the wheel unit 10 instead of the traveling unit 1, so the operating force moving the traveling unit 1 in the traveling direction can be detected. In other words, by controlling the drive of the drive motor 15 in accordance with the detected operating force, the rotation of the wheel 11 can be assisted so that the traveling unit 1, which cannot move with operating force alone, can move smoothly.

[0023] Furthermore, the detection device 20 that detects the operating force can be efficiently concentrated and arranged in the space between the mounting portion 13 of the wheel unit 10 and the wheel 11, making it possible to make the entire wheel unit 10 compact.

[0024] Furthermore, in the above-described traveling unit 1, the amount of swing of the second link member 24 is detected by the potentiometer 21 and converted into an operating force according to this amount of swing, but the potentiometer 21 may also be used as an ON-OFF switch function that starts and stops the drive motor 15 with a predetermined angular displacement.

[0025] Furthermore, because the detection device 20 detects the operating force from the amount of swing of the second link member 24 journaled on the axle 12, it can detect the operating force no matter where the user applies the operating force by pressing on the traveling unit 1. To be more specific, for example, if the traveling unit 1 is a dolly, the detection device 20 can detect the operating force when the user presses the handle or bed of the dolly. Furthermore, unlike the prior art described in Patent Document 1, which cannot detect the operating force unless the object to be assisted is moved, the detection device 20 can detect the operating force even when the object to be assisted is stationary, improving versatility.

[0026] The present invention is not limited to the above-described embodiments, and modifications and improvements are possible as appropriate.

[0027] As described above, the present specification discloses the following: (1) Wheels and a mounting portion that allows the wheel to be mounted on an object having other wheels; a link mechanism provided between the wheel and the mounting portion; a detection sensor that detects an amount of swing of the link mechanism to detect an operating force in the traveling direction of the wheel acting on the object; a motor that drives the wheels; a control unit, the control unit assists driving of the wheel via the motor when the operation force is detected by the detection sensor. Wheel unit. According to this configuration, the detection device for detecting the operating force when pushing an object having wheels attached thereto can be provided in a simple and compact configuration, and the operating force can be detected with high accuracy.

[0028] (2) The link mechanism is a first link member having an upper end fixed to the mounting portion; a second link member whose upper end is rotatably fixed to a support shaft provided on the wheel and whose lower end is rotatably fixed to the lower end of the first link member, The detection sensor detects the swing of the second link member. The wheel unit described in (1). According to this configuration, the link mechanism and the detection sensor can be disposed together between the mounting portion and the wheel, so that the entire device can be configured more compactly.

[0029] (3) The support shaft is the axle of the wheel. (2) The wheel unit described in (2). According to this configuration, the axle is also used as a member that pivotally supports the second link member, making it possible to reduce the number of parts.

[0030] (4) The first link member extends downward from the mounting portion in a direction perpendicular to the axle and is inclined in a direction opposite to the traveling direction of the wheel, The upper end of the first link member is attached to the attachment portion via a bearing having a rotation axis extending vertically, thereby causing the wheel to turn. A wheel unit as described in (2) or (3). With this configuration, the wheels are attached so that they can pivot around the bearings, allowing the object to move 360°. Also, because the wheels and the attachment parts are offset in the planar direction, when an operating force is applied to the object, the caster-type wheels naturally pivot so that the direction of the operating force is in the direction of travel, improving operability.

[0031] (5) The detection sensor is a potentiometer. A wheel unit according to any one of (1) to (4). According to this configuration, the operating force can be detected steplessly and accurately based on the amount of swing of the link mechanism detected by the potentiometer. [Explanation of symbols]

[0032] 1. Traveling unit 2. Body 10 Wheel unit 11 wheels 12 axles 13 Mounting part 14 Bearings 15 Drive motor 16 Rotation Axis 20 Detection device 21 Potentiometer 22 Link mechanism 23 First link member 24 Second link member 25 1st axis branch 26 Second axis branch 50 control section

Claims

1. Wheels and a mounting portion that allows the wheel to be mounted on an object having other wheels; a link mechanism provided between the wheel and the mounting portion; a detection sensor that detects an amount of swing of the link mechanism to detect an operating force in the traveling direction of the wheel acting on the object; a motor that drives the wheels; a control unit, the control unit assists driving of the wheel via the motor when the operation force is detected by the detection sensor. Wheel unit.

2. The link mechanism includes: a first link member having an upper end fixed to the mounting portion; a second link member having an upper end rotatably fixed to a support shaft provided on the wheel and a lower end rotatably fixed to a lower end of the first link member, The detection sensor detects the swing of the second link member. The wheel unit according to claim 1 .

3. The support shaft is the axle of the wheel. The wheel unit according to claim 2 .

4. the first link member extends downward from the mounting portion in a direction perpendicular to the axle and is inclined in a direction opposite to a traveling direction of the wheel; An upper end of the first link member is attached to the attachment portion via a bearing having a rotation axis extending vertically, thereby causing the wheel to turn. The wheel unit according to claim 3.

5. The detection sensor is a potentiometer. The wheel unit according to claim 1 .

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