JP6893804B2 - Power assist device - Google Patents

Description

The present invention relates to a power assist device, and more particularly to a device that is attached to a human body and supplements the muscular strength of the arm by the rotational force of a motor to reduce work labor.

In recent years, there have been proposals for devices that are attached to the human body to supplement muscular strength and reduce work labor. Such power assist devices are desired to be put into practical use in various fields involving physical labor such as agricultural work, civil engineering construction sites, and long-term care, and are expected to be widely used in the future from the social aspect of labor shortage and aging. ing.

Further, there are the following patent documents as a proposal for such a power assist device.

Japanese Unexamined Patent Publication No. 2011-251507 Japanese Unexamined Patent Publication No. 2013-52192

By the way, conventional power assist devices, including the inventions described in the above patent documents, require a complicated device structure and control, and lack simplicity.

For example, the device of Patent Document 1 includes an angle sensor that detects the movement of joints such as the user's shoulder, elbow, hip, and knee, and a pressure sensor that detects the pressure of muscles when each joint is operated. The arithmetic processing unit calculates the drive amount of the motor based on the detection results from various sensors such as the torque sensor that detects the driving force transmitted from the motor of the drive mechanism to each joint, and the motor attached to each part of the body. With complex controls to drive each.

Further, in the device of Patent Document 2, the first angle detecting unit for detecting the rotation angle of the upper arm, the second angle detecting unit for detecting the rotation angle of the thigh, and the weight applied to the toes and heels of the toes, respectively. It is equipped with a floor reaction force detection unit that detects it and a three-dimensional acceleration sensor that detects the inclination of the upper body, and from the detection results from these sensors, the rotational torque required to move the body in various working postures of the wearer is complicated. It is calculated by mechanical calculation and an assist torque is applied to the whole body.

In this way, the conventional power assist device involves a large-scale device structure and complicated control, and although it cannot be said that there is no possibility of use depending on the purpose of use and the field, it is intended to be widely used in a wider range of fields. Is desired to provide a device capable of reducing labor with a simpler mechanism from the viewpoint of cost.

Therefore, an object of the present invention is to make it possible to reduce the labor of an operator by a simple mechanism without requiring a large-scale device structure or complicated control.

In order to solve the above problems and achieve the object, the power assist device according to the present invention is a power assist device that is attached to the body of a worker to supplement the muscle strength of the worker and assist the movement involving raising and lowering the arm. The direction in which the operator swings his arm forward is the "swing direction", and the direction in which the worker swings his arm forward in the opposite direction to the swing direction is the "swing direction". When the rotation in the direction is referred to as "vertical rotation", a motor that generates a rotational force that assists the operator's movement and a motor that transmits the rotational force of the motor to the operator's arm in the swinging direction. It is provided with an arm that applies the force of the above to the operator, and a speed reducer that is interposed between the motor and the arm to reduce the rotation of the motor and transmit it to the arm.

Further, the arm extends from the position near the shoulder of the operator along the arm and is supported so as to be capable of vertical rotation (rotation in the swing-up direction and the swing-down direction) around the shoulder side base end. An operator at an arm body, a power receiving portion that receives the rotational force of the motor and transmits the rotational force to the shoulder-side base end portion of the arm body, and a tip portion of the arm body that is spaced away from the power receiving portion. It has an arm engaging portion that transmits the rotational force of the motor to the worker's arm by engaging with the arm of the motor. Further, the motor is provided to supply a rotational force in the swing direction to the arm.

Further, the power assist device further includes a one-way clutch interposed between the speed reducer and the power receiving unit. This one-way clutch transmits rotational force in the first rotation state in which the motor side rotates relative to the swing direction and the arm side rotates relative to the swing direction, while the motor side rotates relative to the swing direction and the arm side rotates relative to the swing direction. In the second rotational state, it slips and cuts off the transmission of rotational force. The contents of the "first rotation state" and the "second rotation state" will be described in detail later.

The power assist device of the present invention supplements the muscular strength of the arm of the worker when performing work using the arm, for example, lifting an object using the arm or holding the lifted object at that position. When performing such work, the worker's arm is rotated so as to swing forward around the shoulder. Therefore, in the device of the present invention, the movement of swinging up the arm by the arm extending from the shoulder portion along the arm and the movement of holding the raised arm are assisted.

This arm receives the rotational force transmitted from the motor via the speed reducer to the shoulder side base end portion via the power receiving portion, and rotates around the shoulder side base end portion. The tip of the arm is provided with an arm engaging portion, and the operator receives the rotational force of the motor on the arm through the arm engaging portion. The rotation direction of the motor is the swing-up direction (the direction in which the arm is swung forward), and the labor of the operator is reduced by receiving the force in the swing-up direction via the arm.

On the other hand, when the worker lowers his arm (for example, lowers a lifted object), the motor receives a rotational force in the swing direction from the arm fixed to the worker's arm and changes to the original drive direction (swing direction). Will be rotated in the opposite direction, but even at this time, the motor continues to output the rotational force in the swinging direction, and the operator continues to receive the force in the swinging direction (the direction in which the arm is raised), and the labor is reduced. It will be reduced. When the object is lifted and held in that state (the arm is in the stopped state), the rotational force of the motor in the swinging direction is also received, and the labor of the operator is reduced.

Further, in the device of the present invention, a one-way clutch is provided between the speed reducer and the power receiving portion of the arm. As described above, this one-way clutch transmits rotational force in the first rotation state, while idling in the second rotation state, which is a rotation state in the opposite direction to the first rotation state. "Rotation state" and "second rotation state" are concepts that indicate the relative rotation state between the motor side (output shaft of the speed reducer) and the arm side (power receiving part that receives the rotational force from the motor). Specifically, it is as follows.

The motor has a state of rotating (or trying to rotate) in the swing direction and a state of being stopped, and an arm (power receiving part) has a state of rotating in the swing direction and a state of being stopped. There is a state where it rotates in the downward direction.

Therefore, in the "first rotation state", (1) the motor tries to rotate in the swing-up direction (actually, it rotates in the swing-down direction in response to the rotation of the arm in the swing-down direction) and the arm moves in the swing-down direction. Both the rotating state, (2) the motor trying to rotate in the swing direction (actually, it cannot rotate because the arm is stopped) and the arm is stopped, and (3) both the motor and the arm are stopped. It rotates in the swing direction, but includes a state in which the rotation speed of the arm is slower than the rotation speed of the motor (rotation speed of the motor output via the speed reducer), and in these states (1) to (3), the motor The rotational force of is transmitted to the arm to provide support.

On the other hand, in the "second rotation state", (4) the motor is stopped and the arm rotates in the swing direction, and (5) both the motor and the arm rotate in the swing direction, but the arm rotates. Including the state where the speed is faster than the rotation speed of the motor (the rotation speed of the motor output via the reducer), in these states (4) and (5), the one-way clutch idles and the rotational force of the motor is the arm. Not transmitted to.

In the present invention, the one-way clutch prevents the drive unit (motor and speed reducer) from interfering with the movement of the operator to quickly raise the arm (prevents the load from being applied to the arm side by idling / for example, lifting). (It is possible that the object is light and does not require support.) On the other hand, the rotational force of the motor is transmitted for the action of slowly raising the arm to lift the object and the action of stopping with the arm raised. And fulfill the function of providing support. As described above, according to the present invention, by providing a relatively simple mechanism called a one-way clutch, it is possible to easily and appropriately support the work without involving a complicated control mechanism.

In a preferred embodiment, the power assist device has a base portion that can be carried by the operator, and a motor is installed on the base portion, while the vertical rotation axis of the arm body is the vertical rotation of the upper arm of the operator. A power receiving portion is provided so as to be located on the side surface portion of the shoulder of the operator so as to substantially coincide with the shaft, and further has a power transmitting means for transmitting the rotational force of the motor to the power receiving portion.

By aligning the vertical rotation axis of the arm body with the vertical rotation axis of the worker's upper arm and rotating both coaxially and integrally, the arm can be operated smoothly and the worker can rotate the arm without discomfort. This is to be able to do it.

The power transmission means is, for example, hung between the first sprocket provided on the motor side, the second sprocket provided on the power receiving portion side, and the first sprocket and the second sprocket to transmit the rotational force of the motor. It can be composed of a chain that transmits from the first sprocket to the second sprocket. In addition to such a sprocket and a chain, the power transmission means may be composed of, for example, a pulley (belt wheel) and a belt, or a gear.

Furthermore, the direction in which the operator spreads the arms (widens the distance between the arms) is the "spreading direction", and the direction in which the arms are narrowed (narrowing the distance between the arms) is the "squeezing direction". When the rotation in the direction is referred to as "horizontal rotation", the rotation connecting portion that connects the power receiving portion and the arm body so that the arm body can rotate laterally around the shoulder side base end portion is referred to as a power receiving portion. It is preferable to provide it between the arm body. By configuring the arm body to rotate not only vertically but also horizontally, the distance between the arms can be freely changed so that various work objects (lifted objects) can be flexibly handled. A more specific configuration is, for example, as follows.

The rotary connecting portion includes a connecting plate that connects the power receiving portion and the arm body. Further, when considering three orthogonal axes consisting of a front-rear axis extending in the front-rear direction, a left-right axis extending in the left-right direction, and an up-down axis extending in the up-down direction when viewed from the operator, the connecting plate is A vertical plate portion that extends parallel to the plane including the vertical axis and is provided so as to be located on the side surface of the operator's shoulder, and the left-right axis and the vertical axis in the initial state orthogonal to the vertical plate portion and with the arm body lowered. It is an L-shaped plate-shaped member including a horizontal plate portion that extends parallel to a plane including and is provided so as to be located on the front surface portion of the operator's shoulder. Further, the vertical plate portion is fixed to the power receiving portion so that the connecting plate rotates vertically, and the shoulder-side base end portion of the arm body is installed on the horizontal plate portion so as to be rotatable horizontally.

The structure of the rotary connecting portion is not limited to the above structure, and may be a hinge or other structure as in the second embodiment described later, for example.

Further, in the power assist device of the present invention, an output control unit that changes the magnitude of the rotational force output by the motor and an input operation unit that instructs the output control unit the magnitude of the rotational force are further provided. It is desirable to prepare.

This is so that the operator can freely adjust the optimum support force corresponding to the weight of the work object on site.

The specific configuration of the input operation unit is not particularly limited. For example, it may be a slide volume or volume knob that can be operated at hand, a volume with a switch, a dial, or the like, or it can be input by voice (so that it can be input by a voice emitted by an operator).

Further, in a typical aspect of the present invention, each of the above configurations (motor, speed reducer, one-way clutch and arm / hereinafter, these) is provided for both the left and right arms so that both the left arm and the right arm can be supported as in the embodiment described later. However, the present invention does not exclude a structure in which the device main body is provided only for one arm, for example, a power assist device for the left arm or a power assist device for the right arm. Can also be configured based on the present invention.

According to the power assist device according to the present invention, work labor can be reduced by a simple structure and control without using a large-scale device structure or a complicated control mechanism.

Other objects, features and advantages of the present invention will be clarified by the following description of embodiments of the present invention described with reference to the drawings. In each figure, the same reference numerals indicate the same or corresponding parts.

FIG. 1 is a perspective view conceptually showing an example of a usage state of the power assist device according to the first embodiment of the present invention. FIG. 2 is a plan view conceptually showing the power assist device according to the first embodiment. FIG. 3 is a side view conceptually showing the power assist device according to the first embodiment. FIG. 4 is a front view conceptually showing the power assist device according to the first embodiment. FIG. 5 is a rear view conceptually showing the power assist device according to the first embodiment. FIG. 6 is a perspective view showing a device main body portion (a state in which the arm is lowered to the initial position) of the power assist device according to the first embodiment. FIG. 7 is a perspective view showing a device main body portion (a state in which the arm is swung up substantially horizontally) of the power assist device according to the first embodiment. FIG. 8 is an exploded perspective view showing a device main body portion (a state in which the arm is swung up substantially horizontally) of the power assist device according to the first embodiment. FIG. 9 is a block diagram illustrating drive control of a motor in the power assist device according to the first embodiment. FIG. 10 is a perspective view conceptually showing an example of a usage state of the power assist device according to the second embodiment of the present invention. FIG. 11 is a plan view conceptually showing the power assist device according to the second embodiment. FIG. 12 is a side view conceptually showing the power assist device according to the second embodiment. FIG. 13 is a rear view conceptually showing the power assist device according to the second embodiment.

[First Embodiment]
As shown in FIGS. 1 to 9, the power assist device 11 (hereinafter, may be referred to as “assist device” or simply “device”) according to the first embodiment of the present invention is carried on the back of the worker 1 The base portion 12 for fixing the device 11 to the back of the worker 1, the device main body portions 21 and 21a installed on the base portion 12, and the device main body portions 21 and 21a are driven and controlled. It is provided with a control unit (output control unit) 41, an input operation unit 45 for the operator 1 to operate the apparatus 11, and a power supply (battery) 42. The input operation unit 45 is not shown in the drawings other than FIG.

Further, as shown in FIG. 1, the apparatus 11 of the present embodiment holds, for example, an induction heating coil 2 (weight is about 10 to 20 kg / hereinafter simply referred to as "coil") for bending a metal tube in a factory with both hands. It is possible to support the work of lifting and holding it during processing, but in the present invention, the object of work, the place of use, the purpose of use, the field of use, etc. of the device are various. Of course, it's good.

The base portion 12 includes a back plate 13, a shoulder strap 14, and a waist harness (waist belt) 15 so that the worker 1 can carry the device 11 of the present embodiment on his back like a backpack. The worker 1 carries the base portion 12 on his back by hanging the shoulder straps 14 on both shoulders, and fixes the base portion 12 on his back by tightening the waist harness 15 on his back. A back pad (not shown) is provided on the inside of the back plate 13 (a portion corresponding to the back) so as to fit the back of the worker 1. The device main body portions 21 and 21a, the control unit 41, and the battery 42 are installed on the back plate 13 of the base portion 12.

The device main body portions 21 and 21a are composed of a power generating unit (motor 22 and speed reducer 23 described later) that generates a rotational force that supports the arm of the worker 1, an arm 31 that supports the arm of the worker 1, and a power generating unit. A power transmission unit (sprocket 38a, 38b, chain 39, which will be described later) that transmits the generated rotational force to the arm 31 is interposed between the power generation unit and the power transmission unit, and the rotational force is applied only for rotation in one direction. It has a one-way clutch 25 for transmission. The device 11 is provided with a total of two device main bodies 21 and 21a, one on each side so as to support both arms, but the device main body 21a for the left arm is also the device main body 21 for the right arm. Since it has the same configuration and performs the same function for the left arm by performing the same control, only the device main body 21 for the right arm will be described below, and the device main body 21a for the left arm will be a considerable part. The same reference numerals will be given and duplicate description will be omitted.

The power generation unit includes a motor 22 that generates a rotational force and a speed reducer 23 that decelerates the rotation of the motor 22 to increase torque, and is between the speed reducer 23 and the power transmission unit (rear sprocket 38a described later). Together with the intervening one-way clutch 25, it is installed on the surface of the back plate 13 of the base portion 12 which is the back side of the worker 1. In the figure, reference numeral 27 indicates an output shaft of the motor 22 to the speed reducer 23, and reference numeral 28 indicates an output shaft of the speed reducer 23 to the one-way clutch.

On the other hand, the arm 31 has a power receiving unit 33 that receives the rotational force generated by the power generating units 22 and 23 on the side surface of the shoulder of the worker 1, and the front surface and the side surface of the upper arm from the front surface of the shoulder of the worker 1. The arm body 32 extending to the vicinity of the elbow along the upper arm so as to surround the arm body, and the tip portion (end on the elbow side) of the arm body 32 abuts on the rear surface of the upper arm of the worker 1 and the power generating portions 22 and 23. It includes an arm engaging portion 35 that transmits the generated rotational force to the arm, and a connecting plate 51 that connects the arm body 32 and the power receiving portion 33.

Further, the arm 31 is installed on the support side plate 37 so that it can rotate vertically (rotate in the swing-up direction and the swing-down direction) around the shoulder side surface portion (power receiving portion 33) of the worker 1. The support side plate 37 is fixed to the back plate 13 via the power generating portions 22 and 23, and is horizontal forward from the side surface portion of the power generating portions 22 and 23 installed on the back plate 13 to the side surface portion of the shoulder of the worker 1. The arm 31 (power receiving portion 33) is vertically rotatably supported at the front end portion via the bearing 36b.

Further, inside the support side plate 37, a power transmission unit is provided along the support side plate 37. The power transmission unit includes a sprocket 38a (referred to as a “rear sprocket”) connected to the output shaft 28 of the speed reducer 23 via a one-way clutch 25, and a sprocket 38b (“front sprocket”) fixed to the power receiving unit 33 of the arm 31. ”) And the chain 39 (the figure shows only the intermediate portion between the two sprockets) extending between the rear sprocket 38a and the front sprocket 38b.

The rotational force generated by the power generating units 22 and 23 is transmitted to the power receiving unit 33 of the arm 31 via the one-way clutch 25 and the power transmitting unit (sprocket 38a, 38b and the chain 39), and the power receiving unit 33 receives the power receiving unit 33. By rotating, the arm 31 (connecting plate 51, arm body 32, and arm engaging portion 35) rotates vertically. In the figure, reference numeral X1 is the rotation axis of the power generating units 22 and 23 and the rear sprocket 38a, reference numeral X2 is the rotation axis (vertical rotation axis) of the front sprocket 38b and the power receiving unit 33, and reference numeral Y is the arm body 32. The rotation axes (horizontal rotation axes described below) are shown, reference numeral A indicates rotation in the upswing direction, reference numeral B indicates rotation in the downswing direction, reference numeral C indicates rotation in the expansion direction, and reference numeral D indicates rotation in the expansion direction. The rotation in the constriction direction is shown respectively.

The arm 31 is further provided with a connecting plate 51, which enables not only the vertical rotations A and B but also horizontal rotations, that is, rotation C in the expansion direction and rotation D in the narrowing direction. The connecting plate 51 has a vertical plate portion 51a fixed to the power receiving portion 33 and vertically rotating together with the power receiving portion 33, and an initial state in which the arm body 32 is lowered at right angles to the vertical plate portion 51a (FIGS. 2 and 2). (See FIG. 6 and the like), it is an L-shaped plate-shaped member composed of a horizontal plate portion 51b arranged on the front surface side of the shoulder of the worker 1. The arm main body 32 can rotate laterally because its base end portion (shoulder side end portion) is fixed to the horizontal plate portion 51b of the connecting plate 51 via the bearing 36c. Note that this lateral rotation is performed by the operator's own force, and the operator 1 can freely spread or narrow his arms according to the size and width of the work object 2.

The motor 22 rotates by receiving power supplied from the battery 42 via a drive circuit 44 (see FIG. 9). The rotation direction of the motor 22 is a direction in which the arm 31 (arm) is swung forward (swing direction / see arrow A in FIG. 3), and the rotational force in this direction is the speed reducer 23, the one-way clutch 25, and power transmission. It is transmitted to the power receiving portion 33 of the arm 31 through the portions (rear sprocket 38a, chain 39 and front sprocket 38b).

The rotation of the motor 22 is controlled by the control unit 41. As shown in FIG. 9, the control unit 41 includes a device control unit 43 and a motor drive circuit 44, and the operator 1 operates the input operation unit 45 to turn the device 11 (motor 22) on and off (start and turn). In addition to (stop), the output of the motor 22, that is, the support force by the arm 31 (rotational force of the motor 22) can be increased or decreased. The device control unit 43 adjusts the output of the motor 22 via the drive circuit 44 based on the input from the input operation unit 45. The input operation unit 45 may be connected to the device control unit 43 by wire (cord / signal line), or may be wirelessly connected. Further, the input operation unit 45 can be configured by, for example, a slide volume, a volume knob, a volume with a switch, or the like, or may be capable of inputting by voice input.

Further, in the present embodiment, the device main body portions 21 and 21a are provided with a torque sensor 24 for detecting the rotational force transmitted to the arm 31 and an arm rotation angle detection unit 26 for detecting the rotation angle of the arm 31. The arm rotation angle detection unit 26 is composed of an encoder, and shows how far forward (in the direction of arrow A in the figure) the arm 31 is swung up from the initial position (for example, the arm shown in FIG. 3 is suspended vertically downward). Detect the angle.

At startup, the device control unit 43 has a size (referred to as "initial value") set in advance so that the arm of the worker 1 is not lifted by the arm 31 without holding the work object 2. The motor 22 is driven so that a support force (rotational force of the arm 31) is generated.

On the other hand, in the device 11 of the present embodiment, the upper limit value of the torque (rotational force) transmitted to the arm 31 and the upper limit value of the rotation angle of the arm 31 are set in advance in the device control unit 43, and the torque sensor 24 and the arm When the value input from the rotation angle detection unit 26 to the device control unit 43 reaches any of the upper limit values, the output of the motor 22 is reduced (for example, returned to the initial value). This is to prevent excessive support force from being applied to the worker 1 or excessive rotation of the arm, and to ensure safety.

The output shaft 27 of the motor 22 is connected to the speed reducer 23, a one-way clutch 25 is interposed between the output shaft 28 from the speed reducer 23 and the arm 31, and the relative rotational state of the motor 22 and the arm 31 is provided. As already mentioned, there are a first rotation state and a second rotation state.

That is, in the first rotation state, (1) the motor 22 is about to rotate in the swing direction A, but the arm 31 rotates in the swing direction B (the motor 22 is rotated in the direction opposite to the drive direction). (2) The motor 22 tries to rotate in the swing direction A but the arm 31 is stopped, and (3) the motor 22 and the arm 31 both rotate in the swing direction A, but the arm 31 When the rotational speed of the motor 22 is slower than the rotational speed of the motor 22 (the rotational speed of the output shaft 28 of the speed reducer 23), the rotational force of the motor 22 is transmitted to the arm 31 to provide support.

Therefore, for example, the operator 1 wears and drives the assist device 11, slowly lifts the coil 2 from the floor (state (3) above), and holds the coil 2 in the lifted position as shown in FIG. (The above state (2)) During the processing, the work labor is reduced by receiving the support of the assist device 11. Further, when the coil 2 held after processing is lowered to the floor (state (1) above), the support of the assist device 11 can be similarly received.

On the other hand, in the second rotation state, (4) the motor 22 is stopped, but the arm 31 rotates in the swing direction A, and (5) both the motor 22 and the arm 31 rotate in the swing direction A. However, when the rotational speed of the arm 31 is faster than the rotational speed of the motor 22 (the rotational speed of the output shaft 28 of the speed reducer 23), the one-way clutch 25 idles and the rotational force of the motor 22 is not transmitted to the arm 31.

Therefore, for example, when the work object 2 is not held or the work object 2 is very light and the arm is to be raised quickly without requiring support (the above state (5)), the one-way clutch 25 idles. By doing so, it is possible to prevent the speed reducer 23 and the motor 22 from becoming a load and interfering with the operation.

Further, as already described, when the input operation unit 45 is operated to start driving the device 11, the support force is a relatively small force (initial value) that the arm does not lift, but the input operation by the operator 1 By increasing the output of the motor 22 by the device control unit 43 based on the input from the unit 45, it is possible to obtain a support force of a size desired by the operator.

In the present embodiment, the vertical rotation axis X2 of the arm 31 coincides with the vertical rotation axis of the upper arm of the worker 1, and the arm 31 and the arm of the worker 1 rotate coaxially and integrally, so that the arm 31 operates smoothly. However, the worker 1 has an advantage that the arm can be rotated without discomfort.

[Second Embodiment]
10 to 13 show the power assist device according to the second embodiment of the present invention. As shown in these figures, the device of the present embodiment is attached to the body of the worker 1 by carrying it on the back like the device of the first embodiment, and has a motor 22 and a speed reducer 23 to rotate. It is interposed between the power generating unit that generates force, the arm 31 that supports the arm of the worker 1, and the power generating units 22, 23 and the arm 31 (between the speed reducer 23 and the power receiving unit 33). It includes a one-way clutch 25, a control unit 41 that controls a power generation unit, an input operation unit 45, a battery 42, and a base unit 12.

On the other hand, the structure of the arm 31 of the device of the present embodiment is different from that of the device of the first embodiment. Hereinafter, the apparatus of the present embodiment will be described focusing on the differences from the first embodiment.

The arm 31 extends from the back surface of the shoulder of the worker 1 to the vicinity of the elbow along the outside of the upper arm, and rotatably supports the base end, which is the end on the shoulder side, and the arm. At the base end of the main body 32 (the end on the shoulder side), the power receiving part 33 that receives the rotational force of the motor 22 and at the tip of the arm main body 32 (the end on the elbow side), the tip of the upper arm of the worker 1 It is provided with an arm engaging portion 35 that connects the tip end portion of the arm body 32 and the arm of the worker 1 by winding and transmits the rotational force of the motor 22 to the arm.

The arm engaging portion 35 is provided so as to be slidable (movable) along the length direction of the arm 31 and to be rotatable relative to the arm 31 so that the worker 1 can smoothly raise and lower the arm. (See arrows E and F in FIGS. 11 to 12). Further, the arm body 32 and the power receiving unit 33 are connected via a hinge 34 so that the arm body 32 can be swung in the left-right direction (see arrows C and D in FIG. 11). Worker 1 can change the width of both hands by bending the forearm from the elbow, but it is possible to bend (widen or narrow) the upper arm from the shoulder to the left and right, making it more flexible for work targets of various sizes. This is to be able to handle things.

Further, the output shaft 27 of the motor 22 is connected to the speed reducer 23, and the output shaft 28 from the speed reducer 23 and the power receiving unit 33 of the arm 31 are connected to each other via a one-way clutch 25 arranged inside the power receiving unit 33. It is connected. As described above, in the device of the present embodiment, the arm 31 is provided so that the base end portion (power receiving portion 33) is located on the side (back side of the worker 1) of the power generating portions 22 and 23, and the speed reducer 23 is provided. Since the output shaft 28 from the above can be directly connected to the arm 31 (power receiving unit 33) via the one-way clutch 25, the power transmission unit (sprocket 38a, 38b and the chain 39) as in the first embodiment can be used. The support side plate 37 becomes unnecessary.

The rotation direction of the motor 22, the function of the one-way clutch 25, and the relative rotation states of the motor 22 and the arm 31 include the first rotation state and the second rotation state, which are the same as those in the first embodiment. The device can also provide the worker 1 with the same support as the device of the first embodiment.

Although the embodiments of the present invention have been described above, it is clear to those skilled in the art that the present invention is not limited thereto and various modifications can be made within the scope of the claims. ..

For example, in each of the above embodiments, the same control is simultaneously performed on the left and right device main bodies 21 and 21a so that the work object can be lifted with both hands, but the right arm device main body 21 and the left arm are used. It may be possible to perform independent control separately from the device main body 21a. In this case, the input operation unit 45 may be configured so that the left and right device main bodies 21 and 21a can be independently driven.

Further, as the one-way clutch 25, for example, a cam clutch can be used, but another one-way clutch can also be used. Further, as the motor 22, for example, a servo motor or another DC motor can be used. Further, the power supply 42 is not necessarily limited to a battery, and power may be supplied from an AC power source or the like through a cord.

1 Worker (wearer of power assist device)
2 Work object (induction heating coil)
11 Power assist device 12 Base 13 Back plate 14 Shoulder strap 15 Waist harness (waist belt)
21,21a Device body 22 Motor 23 Reducer 24 Torque sensor 25 One-way clutch 26 Arm rotation angle detector (encoder)
27 Motor output shaft 28 Reducer output shaft 31 Arm 32 Arm body 33 Power receiving part 34 Hinge 35 Arm engaging part
36b, 36c Bearing 37 Support side plate 38a Rear sprocket 38b Front sprocket 39 Chain 41 Control 42 Power supply (battery)
43 Device control unit 44 Drive circuit 45 Input operation unit 51 Connection plate 51a Vertical plate 51b Horizontal plate

Claims (6)

It is a power assist device that is attached to the body of the worker and supplements the muscle strength of the worker to assist the movement involving raising and lowering the arm.
The direction in which the worker swings his arm forward is the swing direction, the direction in which the worker swings his arm forward is the swing direction, and the rotation in these swing directions and swing directions is When referred to as vertical rotation,
The power assist device is
A motor that generates a rotational force that assists the operation,
An arm that applies a force in the swing direction to the worker by transmitting the rotational force of the motor to the worker's arm, and an arm.
It is provided with a speed reducer interposed between the motor and the arm to reduce the rotation by the motor and transmit it to the arm.
The arm
An arm body that extends along the arm from a position near the shoulder of the worker and is supported so that the vertical rotation can be performed around the shoulder side base end.
A power receiving unit that receives the rotational force of the motor and transmits the rotational force to the shoulder-side base end portion of the arm body.
It has an arm engaging portion that transmits the rotational force of the motor to the worker's arm by engaging with the worker's arm at the tip of the arm body separated from the power receiving portion.
The motor is provided so as to generate a rotational force in the swing direction and supply the rotational force to the arm.
The power assist device further includes a one-way clutch interposed between the speed reducer and the power receiving unit.
The one-way clutch transmits the rotational force of the motor in the swing direction in the first rotation state in which the motor side rotates relative to the swing direction and the arm side rotates relative to the swing direction, while the motor side transmits the rotational force in the swing direction. In the second rotation state in which the arm side rotates relative to the swing direction, it is provided so as to idle and block the transmission of the rotational force of the motor in the swing direction .
As a result, the first rotation state, (1) the motor generates the rotational force in the swing direction and the arm rotates in the swing direction, and (2) the motor swings. A state in which an upward rotational force is generated and the arm is stopped, and (3) the motor and the arm both rotate in the swing direction, and the rotation speed of the arm is via the speed reducer. Regardless of whether the motor is slower than the rotational speed of the motor, the rotational force of the motor in the swing direction is transmitted to the arm to reduce the labor of the operator, while the labor of the operator is reduced. The second rotation state, (4) the state in which the motor is stopped and the arm rotates in the swing direction, and (5) the motor and the arm both rotate in the swing direction and the arm Regardless of whether the rotation speed is faster than the rotation speed of the motor output via the speed reducer, the one-way clutch idles and the rotational force of the motor is not transmitted to the arm. A power assist device that prevents the load from being applied to the operator. The power assist device has a base portion that can be carried by an operator.
While the motor is installed on the base,
The power receiving portion is provided so as to be located on the side surface portion of the shoulder of the worker so that the vertical rotation axis of the arm body substantially coincides with the vertical rotation axis of the upper arm of the worker.
The power assist device according to claim 1, further comprising a power transmission means for transmitting the rotational force of the motor to the power receiving unit. The power transmission means
The first sprocket on the motor side and
The second sprocket on the power receiving side and
The power assist device according to claim 2, further comprising a chain that is hung between the first sprocket and the second sprocket and transmits the rotational force of the motor from the first sprocket to the second sprocket. When the operator refers to the direction in which the arm is spread as the expansion direction, the direction in which the arm is squeezed as the squeezing direction, and the rotation in these expansion direction and the squeezing direction as lateral rotation, respectively.
A claim that a rotation connecting portion for connecting the power receiving portion and the arm main body is provided between the power receiving portion and the arm main body so that the arm main body can rotate laterally about the shoulder side base end portion. The power assist device according to any one of 1 to 3. The rotary connecting portion includes a connecting plate that connects the power receiving portion and the arm body.
Considering three axes orthogonal to each other, consisting of a front-rear axis extending in the front-rear direction, a left-right axis extending in the left-right direction, and an up-down axis extending in the up-down direction when viewed from the operator.
The connecting plate is
A vertical plate portion that extends parallel to the plane including the front-rear axis and the vertical axis so as to be located on the side surface of the shoulder of the operator, and left and right in the initial state orthogonal to the vertical plate portion and with the arm body lowered. It is an L-shaped plate-shaped member composed of a horizontal plate portion that extends parallel to a plane including an axis and a vertical axis and is provided so as to be located on the front portion of an operator's shoulder.
While the vertical plate portion is fixed to the power receiving portion so that the connecting plate rotates vertically,
The power assist device according to claim 4, wherein a shoulder-side base end portion of the arm body is laterally rotatably installed on the horizontal plate portion. An output control unit that changes the magnitude of the rotational force output by the motor,
The power assist device according to any one of claims 1 to 5, further comprising an input operation unit that indicates the magnitude of the rotational force to the output control unit.

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