JP2016026105A - Drive device of joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive device and a wearable motion assisting device having the same which can transmit torque excellently over a wide operation range of an output link (for example, an angle of the output link relative to a fixed link ranges from 0° to 140°), and can achieve further downsizing.SOLUTION: A drive device 8 comprises: a five-joint link mechanism 10 in which five links including an input link 11, a fixed link 12, an intermediate link 13, an output link 14, and a medium link 15 are connected sequentially and rotatably; a freedom degree limitation mechanism 23 for limiting the degree of freedom of the five-joint link mechanism 10 to 1 by restraining relative displacement of the fixed link 12 and the intermediate link 13 and relative displacement of the intermediate link 13 and the output link 14 at a predetermined ratio; and an actuator 9 for applying a rotational driving force to the input link 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive device including a five-bar linkage mechanism and a wearable motion support device including the drive device.

  2. Description of the Related Art In recent years, an operation support device that is worn on a user's body and supports the user's operation has been developed. For example, a wearable motion support device having a lower-body exoskeleton shape for assisting movement of a hip joint and a knee joint when a user walks or stands is known. Such a wearable movement support device is generally composed of a waist mounting part to be worn on the waist of the wearer, a thigh wearing part to be worn on the thigh, a lower leg wearing part to be worn on the lower leg, a waist wearing part and a thigh wearing part. There are provided wearing tools composed of actuators and the like disposed respectively at the hip joint part and the knee joint part between the thigh attachment part and the lower leg attachment part. However, if an actuator is placed near the knee joint of the wearer, the inertia of the wearer around the knee joint will increase due to the weight of the actuator, and the wearer's light walking will be hindered or worn. There has been a problem that the load on the actuator increases in order to correct the movement of the tool.

  Therefore, in the limb body assisting device described in Patent Document 1, the wearer is provided with a four-node parallel link mechanism including a thigh attachment portion and a crus attachment portion, which is applied to the wearer due to the weight of the knee joint actuator. The moment of inertia is reduced. Specifically, the limb assist device includes a closed four-joint link mechanism in which a first link part, a thigh link part, a crus link part, and a second link part are sequentially and rotatably connected, And an actuator for a knee joint that drives the link portion. Among the actuators included in the limb assisting device, the actuator for the knee joint, which is particularly heavy, is arranged in the trunk (trunk) direction from the user's knee joint.

  Based on Patent Literature 1, for example, as shown in FIG. 14 (a), an input link 99a, a fixed link 99b, an output link 99c, and an intermediate link 99d are sequentially connected to the lower limbs of the wearing tool of the motion support device. Thus, a four-bar parallel link mechanism 99 is provided. It is known that the human knee joint has a wide movement range of about 140 ° when changing posture from upright to heel. Therefore, when the output link 99c is aligned with the fixed link 99b in the four-bar parallel link mechanism 99 as 0 °, and the output link 99c is moved to 140 ° from here, as shown in FIG. 14 (b). In addition, when the angle of the output link 99c is a value within 0-140 °, the four-bar parallel link mechanism 99 becomes a thought point. When the four-bar parallel link mechanism 99 becomes a point of thinking, it is also when the wearer's knee is bent greatly and support by external power is particularly necessary. However, torque transmission from the input link 99a to the output link 99c becomes unstable at the thought point. For these reasons, if a four-joint parallel link mechanism is provided in the lower limb portion of the wearing tool of the movement support device, it is difficult to cope with a wide movement range of the human knee joint.

  Further, when the lower limb part of the wearing tool of the motion support device is configured by the four-bar parallel link mechanism, the torque transmission rate from the input link to the output link is always 1. However, when standing or standing upright, it is desirable that the torque transmission ratio from the input link to the output link in the wearing tool is small so as not to apply an extra load to the knee joint. In the posture of the heel, the torque transmission ratio from the input link to the output link in the wearing tool is used to strongly assist the wearer's movement while supporting the weight of the wearer when shifting from the heel posture to the upright posture. Is desirable to be large. That is, it is desirable that the torque transmission ratio from the input link to the output link is small in the upright posture and large in the heel posture in the wearing tool of the motion support device.

  Therefore, in Patent Document 2, a four-node non-parallel link mechanism is provided in the lower limb portion of the wearing tool of the movement support device, and the link length ratio is adjusted to cope with a wide movement range of the human knee joint and output from the input link. The torque transmission ratio to the link can be suitably adjusted. Specifically, the powered walking support apparatus described in Patent Document 2 includes a closed four-bar non-parallel link mechanism in which an input link, a fixed link, an output link, and an intermediate link are sequentially connected in a freely rotatable manner. ing. Of the four-bar linkage mechanism, the fixed link is fixed to the thigh, the output link is fixed to the lower leg, and power is input to the input link. Each link length is determined so that the sum of the link length ratios of the opposed links is substantially equal.

JP 2006-334200 A JP 2008-23234 A

  According to the powered walking support device described in Patent Document 2, it is possible to cope with a wide range of motion of the human knee joint, but when the link moves following the knee joint flexion, the input link and the intermediate link A connection part will protrude largely back, and an installation tool will enlarge. An increase in the size of the wearing tool leads to an increase in weight of the wearing tool and a decrease in wearing feeling.

  The present invention has been made to solve the above-described problems, and can transmit torque well over a wide operating range as compared with the four-link parallel link mechanism of the output link. An object of the present invention is to provide a drive device and a wearable motion support device including the drive device.

  The drive device according to the present invention includes a five-bar link mechanism in which five links of an input link, a fixed link, an intermediate link, an output link, and an intermediate link are connected so as to be sequentially rotatable, and a relative relationship between the fixed link and the intermediate link. A degree-of-freedom limiting mechanism that limits the degree of freedom of the five-bar linkage mechanism to 1 by constraining a displacement and a relative displacement of the intermediate link and the output link to a predetermined ratio; and a fixed link with respect to the input link And an actuator for applying a rotational driving force around the connecting portion.

  According to the drive device having the above configuration, the intermediate link exists between the fixed link and the output link, so that the operation range is wider than the four-link parallel link mechanism of the output link (for example, output relative to the fixed link). Even if the output link and the fixed link are arranged in the same plane over the range of the link angle from 0 ° to 140 °, it is possible to prevent the links from interfering with each other. Further, it is possible to adopt a configuration that does not pass the thought point over the wide operating range of the output link, and it is possible to perform stable torque transmission from the input link to the output link in the wide operating range. Further, when the fixed link, the intermediate link, and the output link are arranged in a straight line, the input link and the intermediate link can be formed along the straight line, and the drive device can be reduced in size. Furthermore, when the output link is operated from the state where the fixed link, the intermediate link and the output link are arranged in a straight line, the input link and the intermediate link can be formed along these links. Miniaturization can be achieved.

  In the drive device, the degree-of-freedom limiting mechanism may be a meshing gear provided on each of the fixed link and the output link.

  The wearable motion support device according to the present invention is a wearable motion support device that assists or substitutes for the wearer's muscular strength, and is provided on the thigh wearing portion to be worn on the wearer's thigh and on the wearer's lower leg. A lower limb frame having at least a lower limb mounting portion to be mounted; and the driving device provided on the lower limb frame, wherein the thigh mounting portion is provided with the fixed link, and the crus mounting portion is provided with the output link. The thigh mounting part is provided with the actuator.

  According to the wearable motion support apparatus having the above configuration, the intermediate link exists between the fixed link and the output link, so that the operation range is wider than that of the four-link parallel link mechanism of the output link (for example, the fixed link). Even if the output link and the fixed link are arranged in the same plane over the range of the angle of the opposed output links from 0 ° to 140 °, it is possible to configure such that these links do not interfere with each other. If the output link and the fixed link can be arranged in the same plane, the amount of protrusion of the lower limb frame to the side can be suppressed, which can contribute to the downsizing of the wearable motion support device. Further, it is possible to adopt a configuration that does not pass the thought point over the wide operating range of the output link, and it is possible to perform stable torque transmission from the input link to the output link in the wide operating range. As a result, the wearable motion support device can cope with a wide motion range of 140 ° of the human knee joint. In addition, when the fixed link, the intermediate link, and the output link are arranged in a straight line, the input link and the intermediate link can be formed along the straight line, and the wearable motion support device can be downsized. Can do. Furthermore, when the output link operates from a state where the fixed link, the intermediate link and the output link are arranged in a straight line, the input link and the intermediate link can be formed along these links, and the wearable operation The support device can be downsized. Furthermore, by providing the actuator in the thigh attachment part above the knee joint of the wearer, the inertial force caused by the actuator acting on the wearer during walking is reduced compared to the case where the actuator is provided near the knee joint. It is possible to provide a comfortable walking by the wearer.

  In the wearable motion support device, the link length ratio of the input link, the fixed link, the intermediate link, the output link, and the intermediate link is such that the angle of the output link relative to the fixed link is 0 ° to 140 °. It is preferable that the torque transmission ratio increases as the angle of the output link increases.

  Furthermore, in the wearable motion support device, the link length ratio of the input link, the fixed link, the intermediate link, the output link and the intermediate link is such that the angle of the output link relative to the fixed link is 0 °. From 0 to 140 °, it is preferable that the torque transmission ratio is smaller than 1 at 0 °, and the torque transmission ratio is 1 or more at 90 ° or more.

  According to the above configuration, the torque transmission ratio is small when the wearer walks in an upright posture, and the torque transmission ratio is large when the wearer stands up from the heel posture, which is more comfortable than not placing a burden on the wearer's lower limb. Gait and powerful assistance when the wearer stands up from the heel posture.

  In the wearable motion support device, the lower limb frame includes a foot mounting portion to be mounted on the wearer's foot, and the thigh mounting portion has a locking tool for mooring to the wearer's thigh, It is preferable that the lower leg mounting portion has a translational degree of freedom that can be extended in the translation direction, and the foot mounting portion has a locking tool for mooring to the wearer's foot.

Alternatively, in the wearable motion support device, the lower limb frame includes a foot mounting portion that is mounted on the foot of the wearer, and the thigh mounting portion has a degree of freedom of translation that can be extended in a translational direction, and the lower leg mounting portion. Preferably has a locking tool for mooring to the lower leg of the wearer, and the foot mounting portion has a locking tool for mooring to the foot of the wearer.

  According to the above configuration, when one of the thigh wearing part or the lower thigh wearing part is moored to the wearer's body, the other has a degree of translational freedom. Such a wearable movement support device can follow the movement of the wearer's body well when the wearer flexes and stretches the knee, and can support the movement without giving the wearer a sense of incongruity.

  In the wearable motion support apparatus, the fixed link and the output link may be arranged on the same sagittal plane. With this configuration, the wearable motion support device can be further downsized.

  In the wearable motion support device, when the wearer is in an upright posture, the upper end of the thigh mounting part, the lower end of the lower leg mounting part, and the connecting part of the fixed link and the intermediate link are substantially in sagittal view. It is good to arrange | position on the same straight line. With this configuration, the thigh attachment part and the crus attachment part of the wearable movement support device are arranged substantially in a straight line, and the lower limb frame including the thigh attachment part and the crus attachment part can be further downsized.

  According to the present invention, the operating range of the output link is wider than the configuration including the four-bar parallel link mechanism (for example, the angle of the output link relative to the fixed link is 0 ° to 140 °). It can be. The torque can be stably transmitted from the input link to the output link over a wide operating range of the output link. Further, the drive device and the wearable motion support device can be reduced in size while ensuring such a wide operation range.

It is a figure which shows schematic structure of the drive device which concerns on this invention. It is a figure which shows the state which increased the output link angle of the drive device of FIG. It is a figure which shows the whole schematic structure of a mounting | wearing type | mold movement assistance apparatus. It is a front view which shows the lower left part of a mounting | wearing type | mold movement assistance apparatus. It is a side view which shows the lower left part of a mounting | wearing type | mold movement assistance apparatus. It is a side view which shows the lower left part of the mounting | wearing type | mold movement assistance apparatus of the attitude | position which bent the knee. It is an enlarged side view of a 1st translational freedom degree mechanism. It is an enlarged side view of a 2nd translational freedom degree mechanism. It is a figure explaining the link length ratio and torque transmission ratio of the five-bar link mechanism with which an operation support device is provided. It is a figure which shows the state which increased the output link angle of the five-bar linkage mechanism shown in FIG. It is a figure which shows the state which tethered the thigh frame of the mounting | wearing type movement assistance apparatus to the wearer's thigh with a fastener, (a) is a figure which shows the mode of an upright posture, (b) is the time of the posture of a heel FIG. It is a figure which shows the example which applied the drive device which concerns on this invention to the arm of a working vehicle, Comprising: (a) is the figure which lowered | hung the arm, (b) is the figure which raised the arm. It is a figure which shows the example which applied the drive device based on this invention to the arm of an industrial robot, Comprising: (a) is the figure which lowered | hung the arm, (b) is the figure which raised the arm. It is a figure which shows the conventional four-bar parallel link mechanism, (a) has shown the state when an output link angle is 0 degree, (b) has shown the state when an output link angle is 140 degrees. .

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.

[Driver]
First, a drive device according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a schematic configuration of a drive device according to the present invention, and FIG. 2 is a diagram showing a state where an output link angle of the drive device of FIG. 1 is increased. As shown in FIG. 1, the drive device 8 includes a five-bar link mechanism 10 and an actuator 9 that supplies power to the five-bar link mechanism 10.

The five-bar link mechanism 10 is a closed link mechanism in which five links of an input link 11, a fixed link 12, an intermediate link 13, an output link 14, and an intermediate link 15 are connected so as to be sequentially rotatable. Specifically, the input link 11 and the fixed link 12 are rotatably connected by an input shaft 16, and the fixed link 12 and the intermediate link 13 are rotatably connected by a connecting shaft 17. And the output link 14 are rotatably connected by a connecting shaft 18, the output link 14 and the intermediate link 15 are rotatably connected by a connecting shaft 19, and the intermediate link 15 and the input link 11 are connected. The shaft 20 is rotatably connected. In the example shown in FIGS. 1 and 2, the input shaft 16 and the connecting shafts 17, 18, 19, and 20 are parallel. Hereinafter, the inclination of the long axis direction H ₁₄ of the output link ₁₄ with respect to the long axis direction H ₁₂ of the fixed link 12 is referred to as “output link angle Q”. Output link angle Q, when the long axis direction H ₁₄ of the output link 14 and the long axis direction H ₁₂ of the fixed link 12 is aligned to (Figure 1) and 0 °. An imaginary straight line connecting the centers of the input shaft 16 and the connecting shaft 17 is referred to as a “fixed link line H _L2 ”. In the example shown in FIGS. 1 and 2, the major axis direction H ₁₂ of the fixed link ₁₂ and the fixed link line H _L2 overlap, but depending on the mode of the fixed link 12, they may not overlap. Further, a virtual straight line connecting between the centers of the connecting shaft 17 and the connecting shaft 18 is referred to as “intermediate link line H _L3 ”, and a virtual curve connecting between the connecting shaft 18 and the center of the connecting shaft 19 is referred to as “output link line H _L4 ”. . In the example shown in FIGS. 1 and 2, the long axis direction H ₁₄ of the output link ₁₄ and the output link line H _L4 do not overlap, but they may overlap depending on the form of the output link 14.

The five-bar link mechanism 10 includes a degree-of-freedom limiting mechanism 23 for setting the relative displacement between the fixed link 12 and the intermediate link 13 and the relative displacement between the intermediate link 13 and the output link 14 to a predetermined ratio. Here, the relative displacement between the fixed link 12 and the intermediate link 13 means a change in the angle formed by the fixed link line H _L2 and the intermediate link line H _L3 . The relative displacement between the intermediate link 13 and the output link 14 means a change in the angle formed by the intermediate link line intermediate link line H _L3 and the output link line H _L4 . The operations of the fixed link 12, the intermediate link 13, and the output link 14 are mutually restrained by the degree-of-freedom limiting mechanism 23, and the degree of freedom of the five-bar link mechanism 10 is 1.

  The degree-of-freedom limiting mechanism 23 according to the present embodiment includes a pair of meshing gears, one provided on the fixed link 12 and the other provided on the output link 14. Specifically, the first gear 21 is provided at the end of the fixed link 12 that is connected to the intermediate link 13, and the first gear 21 is provided at the end of the output link 14 that is connected to the intermediate link 13. Two gears 22 are provided, and the first gear 21 and the second gear 22 mesh with each other. The gear ratio between the first gear 21 and the second gear 22 is not limited to 1: 1, and gears having different numbers of teeth may be used for the first gear 21 and the second gear 22. Further, the gear ratio of the first gear 21 and the second gear 22 is not limited to a constant value, and may change while rotating. Further, it is not necessary that teeth are provided on the entire circumference of the first gear 21 and the second gear 22, and the teeth 21 and 22 are engaged so that the gears 21 and 22 mesh at least in the movable range of the output link 14 relative to the fixed link 12. Is sufficient, and the others may be smooth. The degree-of-freedom limiting mechanism 23 is not limited to one composed of a pair of gears. For example, a cam can be used in place of one or both of the first gear 21 and the second gear 22.

  In the five-bar link mechanism 10 having the above-described configuration, the fixed link 12 and the output link 14 are each fixed to an appropriate support structure (not shown) or constitute a part of the support structure. When the input link 11 receives a rotational driving force around the input shaft 16 from the actuator 9, the rotational driving force is output from the output link 14 through the intermediate link 15 at a predetermined reduction ratio. When the input link 11 rotates counterclockwise around the input shaft 16 from the state shown in FIG. 1 in the five-bar link mechanism 10, the output is output via the intermediate link 15 connected to the input link 11 as shown in FIG. The link 14 rotates counterclockwise about the connecting shaft 18, and the intermediate link 13 rotates counterclockwise about the connecting shaft 17. Here, the relative displacement between the fixed link 12 and the intermediate link 13 and the relative displacement between the intermediate link 13 and the output link 14 are constrained to a predetermined ratio (for example, 1) by the action of the freedom degree limiting mechanism 23. With the operation of the input link 11, not only the output link 14 but also the intermediate link 13 operates.

  The five-bar link mechanism 10 of the drive device 8 having the above configuration has a large operating range as compared with the four-bar parallel link mechanism. Specifically, when the output link angle Q of the five-bar linkage 10 changes from 0 ° to a large angle (for example, 140 °), the intermediate link 13 is interposed between the fixed link 12 and the output link 14. Even if the fixed link 12 and the output link 14 are arranged in the same plane, the links 12 and 14 can be configured not to interfere with each other. Further, when the output link angle Q of the five-bar link mechanism 10 changes from 0 ° to a large angle (for example, 140 °), the operation range can be configured not to include a thought point. In other words, the five-bar link mechanism 10 is provided from the input link 11 to the output link 14 over the wide operating range of the output link 14 (for example, the range where the output link angle Q is 0 ° to 140 °) due to the presence of the intermediate link 13. The torque transmission of is not unstable.

  In the five-bar linkage 10 of the drive device 8, as described above, the presence of the intermediate link 13 makes it possible to arrange the fixed link 12 and the output link 14 in the same plane. In addition, as shown in FIG. 1, when the fixed link 12, the intermediate link 13 and the output link 14 are arranged in a straight line, the input link 11 and the intermediate link 15 may be formed along the straight line. Is possible. In this way, the five-bar link mechanism 10 can be further reduced in size, that is, formed into an elongated shape along the fixed link 12. Furthermore, in this five-bar link mechanism 10, when the output link 14 moves from the state where the fixed link 12, the intermediate link 13 and the output link 14 are arranged in a straight line (FIG. 1) to the direction where the output link angle Q increases. (FIG. 2), the input link 11 and the intermediate link 15 can be formed along these links 12, 13, and 14, and the drive device 8 can be reduced in size.

[Wearable motion support device]
Next, a wearable motion support device (hereinafter simply referred to as a motion support device) provided with the drive device 8 will be described. The motion support device 30 according to the present embodiment has a lower-body exoskeleton shape, is worn on the human body regardless of the elderly, the physically disabled, and the healthy person, and the muscle strength of the lower limb mainly of the wearer. The operation of the wearer is supported by assisting or acting on the device.

FIG. 3 is a diagram showing an overall schematic configuration of the wearable motion support apparatus. As shown in FIG. 3, the operation support apparatus 30 includes a mounting tool 31, a backpack 32 loaded on the mounting tool 31, a battery 33 and a controller 34 housed in the backpack 32. The wearing tool 31 includes a lumbar frame 40 that is worn around the waist (pelvis) of the wearer, a back frame 41 that is worn on the back of the wearer, and left and right lower limb frames 42 that are worn on the lower limbs of the wearer. 42. Although the backpack 32 is detachably stacked on the back frame 41, the backpack 32 may be configured integrally with the back frame 41. Hereinafter, the configuration of the wearing tool 31 will be described in detail with reference to FIGS. 4 to 6 in addition to FIG. 3. 4 is a front view showing the lower left portion of the wearable motion support device, FIG. 5 is a side view showing the lower left portion of the wearable motion support device, and FIG. 6 is a lower left portion of the wearable motion support device in a posture in which the knee is bent. FIG. In the following, “left-right direction” refers to the shoulder width direction of the wearer, “front-rear direction” refers to the front-rear direction of the wearer, and “sagittal plane” refers to a plane that cuts the wearer's body symmetrically. A plane parallel to this is referred to as “frontal plane”, which is a plane that cuts the wearer's body back and forth and is perpendicular to the sagittal plane.

(Lumbar frame 40)
The waist frame 40 has a substantially U shape in plan view so as to cover the back side and the left and right sides of the wearer's waist (pelvis). Specifically, the waist frame 40 includes a base 45 that is elongated in the left-right direction and is located on the back side of the wearer's waist, and side portions 46, 46 that protrude forward from both left and right ends of the base 45. ing. The waist frame 40 is provided with a locking tool (not shown) such as a belt or a hook for mooring around the waist of the wearer, and the waist frame 40 is anchored to the waist of the wearer.

(Lower limb frame 42)
The left and right lower limb frames 42 and 42 have substantially the same configuration, and are provided symmetrically on the left and right lines with the left and right center of the waist frame 40 as the symmetry axis. Therefore, only the structure of one (left side) lower limb frame 42 will be described in detail below, and the description of the other will be omitted. The lower limb frame 42 includes a thigh arm 51 that is a thigh attachment portion, an intermediate arm 52 that is disposed in the vicinity of the knee joint, a crus arm 53 that is a crus attachment portion, and a foot arm 54 that is a foot attachment portion. . The thigh arm 51, the lower leg arm 53, and the lower arm 54 are provided with a locking tool (not shown) such as a belt or a hook for mooring to the wearer's body.

  The thigh arm 51 is connected to the front end of the side portion 46 of the waist frame 40 via a hip joint actuator 61 and a hip joint 62. The hip joint actuator 61 is provided so as to protrude outward from the front end portion of the side portion 46 of the waist frame 40. The hip joint actuator 61 includes, for example, a motor and a reduction gear. As shown in detail in FIG. 7, the output shaft 61 a of the hip joint actuator 61 is fixed to a first joint 621 that is a component of the hip joint 62, and is driven by the hip joint actuator 61 with respect to the waist frame 40. Thus, the first joint 621 rotates on the sagittal plane. Note that “rotate on the sagittal plane” means that the axis rotates around the axis perpendicular to the sagittal plane while maintaining parallelism with the sagittal plane.

  The hip joint 62 includes a first joint 621, a second joint 622 connected to the upper portion of the thigh arm 51, and a pivot 623 that rotatably connects the first joint 621 and the second joint 622 on the frontal plane. And. Note that “rotate on the front frame” means to rotate while maintaining parallel to the front frame about an axis perpendicular to the front frame.

The upper end of the intermediate arm 52 is rotatably connected to the lower end of the thigh arm 51 via the connecting shaft 17. The lower end of the intermediate arm 52 is rotatably connected to the upper end of the lower leg arm 53 via the connecting shaft 18. The first gear 21 is provided at the lower end of the thigh arm 51, and the second gear 22 is provided at the upper end of the lower leg arm 53, and the meshing gears 21, 22 constitute the degree-of-freedom limiting mechanism 23. The thigh arm 51, the intermediate arm 52, and the crus arm 53 connected in this way constitute a part of the five-bar linkage mechanism 10. The thigh arm 51 corresponds to the fixed link 12, the intermediate arm 52 corresponds to the intermediate link 13, and the crus arm 53 corresponds to the output link 14. The knee joint actuator 63 that applies rotational power to the five-bar linkage mechanism 10 is fixed to the thigh arm 51 via a bracket 63a and the like. The knee joint actuator 63 includes, for example, a motor and a reduction gear. As described above, the knee joint actuator 63 is disposed on the waist side away from the wearer's knee joint, so that the knee joint actuator 63 is disposed in the vicinity of the wearer's knee joint. The moment of inertia applied to the wearer due to the weight of the knee joint actuator 63 during walking can be reduced.

  One end of the input link 11 is fixed to the output shaft of the knee joint actuator 63, that is, the input shaft 16 to the five-bar linkage mechanism 10. The other end of the input link 11 is rotatably connected to one end of the intermediate link 15 via the connecting shaft 20. The other end of the intermediate link 15 is connected to the lower leg arm 53 via the connecting shaft 19 so as to be rotatable. As described above, the drive device 8 including the five-joint link mechanism 10 and the knee joint actuator 63 (actuator 9) is provided around the knee joint portion of the lower limb frame 42. When the input link 11 receives a rotational driving force around the input shaft 16 from the knee joint actuator 63, the lower leg arm 53 is connected to the connecting shaft via the intermediate link 15 connected to the input link 11, as shown in FIG. The intermediate arm 52 rotates about the connecting shaft 17. Here, due to the action of the degree-of-freedom limiting mechanism 23, the relative displacement between the thigh arm 51 and the intermediate arm 52 and the relative displacement between the intermediate arm 52 and the crus arm 53 are constrained to a predetermined ratio (for example, 1), and the input link 11 In accordance with the operation, not only the lower leg arm 53 but also the intermediate arm 52 operates.

  The length (dimension in the major axis direction) of the thigh arm 51 is adjusted to approximately match the length of the wearer's thigh. The length of the thigh arm 51 adjusted in this way is referred to as the “reference length of the thigh arm”. The reference length of the thigh arm is also the minimum length of the thigh arm 51. The thigh arm 51 includes a first translational degree-of-freedom mechanism 55 that enables the thigh arm 51 to extend in the translation direction (long axis direction) by 1-30 mm from the reference length. As shown in FIG. 7, the first translational degree-of-freedom mechanism 55 includes a connection pin 55 a extending in the translational direction from the second joint 622 at the connection portion between the thigh arm 51 and the second joint 622 of the hip joint 62. The connecting pin 55a provided on the thigh arm 51 is slidably inserted into the connecting hole 55b, and the compression spring 55c is fitted on the connecting pin 55a. The connection pin 55a is longer than the connection hole 55b, the lower end of the connection pin 55a projects downward from the connection hole 55b, and a flange is formed at the lower end. The opening edge of the connection hole 55b and the flange portion of the connection pin 55a are spaced apart in the translational direction, and a compression spring 55c is provided between the opening edge of the connection hole 55b of the connection pin 55a and the flange portion of the connection pin 55a. . The connection pin 55a and the thigh arm 51 are a sliding pair, and the thigh arm 51 extends in the translational direction when a slip occurs between the connection pin 55a and the connection hole 55b. Further, the connection pin 55a can be rotated in the radial direction (around the axis of the connection pin 55a) in the connection hole 55b, thereby allowing the thigh arm 51 to rotate freely (one degree of freedom of rotation around the axis of the connection pin 55a). ) Is given. The extension allowance E1 of the thigh arm 51 in the translation direction is the length of the connection pin 55a that appears between the lower end of the second joint 622 and the upper end of the thigh arm 51. The expansion margin E1 is 0 when the lower end of the second joint 622 and the upper end of the thigh arm 51 are in contact with each other, and the connection pin 55a is urged by the compression spring 55c so that the expansion margin E1 becomes zero. Yes. When a tensile load is applied to the thigh arm 51, the extension pin E1 increases as the connection pin 55a moves in the connection hole 55b against the urging force of the compression spring 55c.

Further, the length (dimension in the long axis direction) of the lower leg arm 53 is adjusted to match the length of the wearer's lower leg. The length of the lower leg arm 53 adjusted in this way is referred to as “reference length of the lower leg arm”. The reference length of the lower leg arm is also the minimum length of the lower leg arm 53. The crus arm 53 includes a second translational degree-of-freedom mechanism 57 that enables the crus arm 53 to extend in the translational direction (long axis direction) by 1-30 mm from the reference length. As shown in FIG. 8, the second translational freedom degree mechanism 57 is provided in the first joint 641 at a connection portion between the lower end of the crus arm 53 and a first joint 641 of an ankle joint 64 described later. The prism portion 57a extending in the translational direction, the rectangular tube portion 57b into which the rectangular column portion 57a provided on the crus arm 53 is slidably inserted, and the direction in which the rectangular column portion 57a is accommodated in the rectangular tube portion 57b. And a tension spring 57c as an urging member. The rectangular column part 57a and the crus arm 53 are sliding pairs, and the crus arm 53 extends in the translational direction when the prismatic part 57a slides in the translational direction in the rectangular tube part 57b. In the above configuration, the extension E2 in the translational direction of the crus arm 53 is the length of the prism portion 57a that appears between the lower end of the crus arm 53 and the upper end of the first joint 641. The extension E2 is 0 when the lower end of the crus arm 53 and the upper end of the first joint 641 are in contact with each other, and the tension spring 57c urges the prism 57a so that the extension E2 becomes 0. Yes. Then, when a tensile load is applied to the crus arm 53, the extension allowance E2 increases as the prism 57a moves in the rectangular tube 57b against the urging force of the tension spring 57c.

  As described above, the reference lengths of the thigh arm 51 and the lower leg arm 53 are adjusted so as to match the dimensions of the wearer's thigh and lower leg, respectively. Not much accuracy is required. In addition to the thigh arm 51 and the lower leg arm 53 each having a degree of freedom of translation, the provision of the intermediate arm 52 between them allows a slight dimensional error.

  The lower leg arm 53 and the lower arm 54 are connected via an ankle joint 64. The ankle joint 64 pivots the first joint 641 connected to the lower end of the lower leg arm 53, the second joint 643 connected to the upper end of the lower arm 54, and the first joint 641 and the second joint 643. And a pivot shaft 642. The first joint 641 is loosely fitted to the pivot shaft 642, and the first joint 641 can rotate on the sagittal plane about the pivot shaft 642 and can swing on the frontal plane. A sole plate 531 constituting the foot arm 54 is connected to the lower portion of the second joint 643. The sole plate 531 has an integral shape that covers at least the wearer's heel.

(Back frame 41)
The back frame 41 is a so-called backpack. The back frame 41 is provided with a side belt for anchoring to the shoulder and chest of the wearer, a locking device (not shown) such as a shoulder strap and a hook. A backpack 32 is loaded on the back frame 41. The battery 33 stored in the backpack 32 supplies electricity to the hip joint actuator 61, the knee joint actuator 63, and the controller 34. Further, the controller 34 stored in the backpack 32 receives a detection signal from a sensor (not shown) provided in each part of the wearing tool 31 so that the wearing tool 31 assists or substitutes the operation of the wearer. The hip joint actuator 61 and the knee joint actuator 63 are controlled. The sensor is a sensor that detects a physical quantity such as a change in the center of gravity of the member or a load applied to the member. Instead of or in addition to these, a biosignal sensor that detects a wearer's biosignal is used. It may be used. If the biological signal sensor is used, the actuators 61 and 63 can generate power according to the wearer's intention.

  In the operation support device 30 configured as described above, the link length ratio of the five links of the five-bar link mechanism 10 is set so that the optimum torque transmission ratio can be exhibited as the operation support device 30. That is, the link length ratio is adjusted so that even if the knee joint actuator 63 has a constant output, the torque transmission ratio is such that a strong assist force is exerted in the heel posture and an agile back drive is secured in the upright posture. Yes. Such a torque transmission ratio has a characteristic that the output link angle Q increases as the output link angle Q increases when the output link angle Q is in the range of 0 to 140 °. Further, such torque transmission ratio is less than 1 when the output link angle Q is 0 ° in the range of the output link angle Q of 0-140 °, and is less than 1 when the output link angle Q is 90 ° or more. It is preferable to have a characteristic of increasing. In particular, it is desirable that the torque transmission ratio be a small value close to 0 when the output link angle Q is near 0 °. Thus, power is effectively transmitted from the knee joint actuator 63 to the crus arm 53 as an output link in a heel posture that requires particularly strong assistance.

FIG. 9 is a diagram for explaining the link length ratio and the torque transmission ratio of the five-bar link mechanism provided in the operation support device, and FIG. 10 is a diagram showing a state in which the output link angle of the five-bar link mechanism shown in FIG. 9 is increased. It is. 9 and 10, the distance between the centers of the input shaft 16 and the connecting shaft 20 is the link length L 1 of the input link 11. Similarly, the distance between the centers of the input shaft 16 and the connecting shaft 17 is the link length L2 of the fixed link 12. The distance between the centers of the connecting shaft 17 and the connecting shaft 18 is the link length L3 of the intermediate link 13. The distance between the centers of the connecting shaft 18 and the connecting shaft 19 is the link length L4 of the output link 14. The distance between the centers of the connecting shaft 19 and the connecting shaft 20 is the link length L5 of the intermediate link 15. Further, Lin is the length of a perpendicular drawn from the center of the input shaft 16 to the intermediate link line H _L5, and is defined as an input perpendicular distance Lin. Here, the intermediate link line H _L5 is an imaginary straight line that connects between the centers of the connecting shaft 19 and the connecting shaft 20. Lout is the length of the perpendicular drawn to the mediating link line H _L5 from the engagement point P3 between the first gear 21 and second gear 22, and outputs the perpendicular distance Lout. The input perpendicular distance Lin and the output perpendicular distance Lout are the five link lengths L1, L2, L3, L4.
The value depends on L5. A value obtained by dividing the output normal distance Lout by the input normal distance Lin is the torque transmission ratio (= Lout / Lin).

  The following formulas 1 and 2 are conditional expressions for which the five-joint link mechanism 10 included in the motion support device 30 is a pondering point. By designing the five-bar link mechanism 10 within a range not satisfying the mathematical expressions 1 and 2, it is possible to avoid the five-bar link mechanism 10 included in the operation support device 30 from being a wonder point.

In Equations 1 and 2, Q _L0 and Q _Lf are angles formed by the fixed link line H _L2 and the output link line H _L4 . Q _L0 is an angle formed by the fixed link line H _L2 and the output link line H _L4 when the wearer's knee joint is most extended (upright posture), and Q _Lf is when the wearer's knee joint is bent most (蹲踞Angle) formed by the fixed link line H _L2 and the output link line H _L4 . R is 1 / (1 + ny). Here, ny is the ratio of the relative displacement between the fixed link 12 and the intermediate link 13. When gears 21 and 22 that mesh with each other are used as the degree of freedom limiting mechanism 23 as in the present embodiment and the gear ratio is 1: 1, ny = 1.

A method for obtaining the link length ratio using Equations 1 and 2 will be described below with reference to a specific example (not shown) in the case of determining the intermediate link length L5. First, link lengths (L1, L2, L3, L4) other than the intermediate link length L5 are determined in accordance with the wearer's body dimensions. For example, the input link length L1 = 60 mm, the fixed link length L2 = 210 mm, the intermediate link length L3 = 40 mm, and the output link length L4 = 50 mm. Then, the values of ny, Q _L0 , and Q _Lf are determined according to the configuration of the operation support device 30. For example, ny = 1, Q _L0 = 0 °, and Q _Lf = 140 °. By substituting these numerical conditions into Equation 1 and Equation 2, the intermediate link length L5 is obtained. Then, in Formula 1, the mediation link length L5 = 240 mm is calculated, and in Formula 2, the mediation link length L5 = 258 mm. As described above, a value that is the intermediate link length L5 is selected from the values that are larger than the lower limit and smaller than the upper limit of the intermediate link length L5 calculated by using Equations 1 and 2. Here, for example, the intermediate link length L5 = 250 mm is selected between the solution of Equation 1 and the solution of Equation 2. Torque transmission with the link length ratio (input link length L1 = 60 mm, fixed link length L2 = 210 mm, intermediate link length L3 = 40 mm, output link length L4 = 50 mm, intermediate link length L5 = 250 mm) obtained as described above. The ratio is as shown in Table 1.

  In the change of the torque transmission ratio with respect to the output link angle shown in Table 1, the torque transmission ratio is a sufficiently small value close to 0 when the output link angle is 0 °, and when the output link angle is 90 ° or more, the torque transmission ratio is Greater than 1. The torque transmission ratio increases with an increase in the output link angle, and has a maximum value at the maximum output link angle (140 °) shown in Table 1. Thus, the torque transmission ratio of the five-bar link mechanism 10 included in the motion support device 30 is set to be suitable for the motion support device 30 based on the link length ratio determined by the above method.

  The motion support device 30 according to the present embodiment described above includes the drive device 8 including the five-bar linkage mechanism 10 so that a wide motion range (for example, the output link angle Q) of the crus arm 53 (the output link 14) is provided. Over the range of 0-140 °), even if the thigh arm 51 and the lower leg arm 53 are arranged in the same plane, these arms 51 and 53 do not interfere with each other and do not become a thought point. Therefore, torque is stably transmitted to the lower leg arm 53 over the wide operating range of the lower leg arm 53. Thereby, the movement support apparatus 30 can respond to a wide movement range of 0-140 ° of the human knee joint.

  Furthermore, the operation support apparatus 30 according to the present embodiment can be further reduced in size while ensuring the wide operation range by including the drive device 8. Specifically, the increase in the thickness of the lower limb frame 42 in the left-right direction is suppressed by arranging the lower leg arm 53 and the upper leg arm 51 on substantially the same sagittal plane. In addition, the upper end P1 of the thigh arm 51, the lower end P2 of the crus arm 53, and the connecting shaft 17 of the thigh arm 51 and the intermediate arm 52 in the sagittal view (FIG. 5) when the wearer is standing upright. Are arranged on substantially the same straight line, an increase in the thickness of the lower limb frame 42 in the front-rear direction is suppressed. In FIG. 5, the upper end P <b> 1 of the thigh arm 51 indicates a connection portion between the waist frame 40 and the lower limb frame 42.

  As shown in FIG. 5, the upper end P1 of the thigh arm 51 is located on the side of the wearer's hip joint, and the lower end P2 of the lower leg arm 53 is located on the side of the wearer's heel. In the sagittal view, a straight line connecting these points (P1 and P2) passes through the back side of the knee joint of the wearer, and the connecting shaft 17 and the connecting shaft 18 are approximately located on this straight line. By arranging the connecting shafts 17 and 18 in this way, the basic portion of the lower limb frame 42 composed of the thigh arm 51, the intermediate arm 52, and the lower leg arm 53 has a substantially linear shape. In this way, the basic portion of the lower limb frame 42 has a substantially linear shape, so that the load positioned above the knee joint portion (intermediate arm 52) of the lower limb frame 42 is passively supported by the basic portion of the lower limb frame 42. be able to. Then, it is possible to form the input link 11 and the intermediate link 15 along the thigh arm 51, the intermediate arm 52, and the crus arm 53 that are arranged in a straight line as described above. Furthermore, it is possible to form the input link 11 and the intermediate link 15 along the thigh arm 51 in a state where the output link angle is increased. As a result of forming the five-bar link mechanism 10 in this way, the lower limb frame 42 and a part thereof do not protrude greatly forward or backward of the wearer in both the upright posture and the heel posture, and the lower limb frame 42 It becomes compact along the wearer's lower limbs.

In addition, in a conventional motion support device in which a thigh arm and a lower leg arm are connected by a knee joint axis, when the knee joint axis is arranged on the back side of the wearer's knee joint, the wearer bends the knee. The distance from the body part of the wearer where the knee joint axis is arranged to the wearer's heel decreases. This change in distance causes problems such as a deviation between the wearer's body and the wearing tool. On the other hand, in the operation support apparatus 30 according to the present embodiment, the above problem is avoided or reduced. As shown in FIG. 5, when the wearer is in an upright posture, the connecting shaft 18, the meshing point P <b> 3 of the gears 21 and 22, and the lower end P <b> 2 of the crus arm 53 are aligned substantially in a straight line. As shown in FIG. 6, as the wearer flexes the knee, the connecting shaft 18 moves away from the straight line connecting the meshing point P3 of the gears 21 and 22 and the lower end P2 of the crus arm 53. The length of the line segment connecting the meshing point P3 and the lower end P2 of the lower leg arm 53 decreases. That is, when the wearer bends the knee, the meshing of the gears 21 and 22 is reduced as the distance from the body part of the wearer where the meshing point P3 of the gears 21 and 22 is disposed to the wearer's heel is decreased. Since the length of the line segment connecting the point P3 and the lower end P2 of the crus arm 53 is also reduced, the displacement between the wearer's body and the wearing tool is avoided or reduced.

In addition, in the wearing tool 31 of the motion support device 30 according to the present embodiment, the thigh arm 51 and the lower thigh arm 53 are locked to the wearer's body and a translational freedom degree mechanism (first Are provided with a translational freedom degree mechanism 55 and a second translational degree of freedom mechanism 57). However, the configuration may be such that the wearing tool 31 is provided with a translational degree-of-freedom mechanism on one of the thigh arm 51 and the lower leg arm 53 and the other is moored on the wearer's body. Regardless of the wearing device 31, it is possible to provide the movement of the lower limb with less discomfort for the wearer while eliminating the need for strict adjustment of the longitudinal dimension of the thigh arm 51 and the lower leg arm 53 with respect to the wearer's skeleton structure. it can. FIG. 11 is a view showing a state in which the thigh frame of the wearable motion support device is moored to the wearer's thigh with a locking tool, (a) is a view showing the upright posture, and (b) is a view. It is a figure which shows the mode at the time of the posture of a heel. As shown in FIGS. 11 (a) and 11 (b), when the thigh arm 51 is moored to the wearer's thigh by the locking device 75 and the foot arm 54 is moored to the wearer's foot by the locking device 76, It is sufficient if the lower leg arm 53 is provided with the second translational freedom degree mechanism 57. Such a wearing form is suitable for the motion support apparatus 30 used to support the wearer's walking. Further, when the intermediate arm 52 is anchored to the wearer's lower leg by the locking tool and the foot arm 54 is moored to the wearer's foot by the locking tool, the first translational degree of freedom mechanism is added to the thigh arm 51 55 is enough. Such a mounting form is suitable for the operation support apparatus 30 used to support the load handling of the wearer.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. is there.

  For example, the driving device 8 according to the present invention can be applied not only to the wearable motion support device 30 having the lower body exoskeleton shape described above but also to other wearable motion support devices. For example, the wearable movement support device may support only the bending and stretching of the wearer's knee. In this case, the wearing tool of the motion support device includes a thigh attachment part (fixed link 12), a knee joint part (intermediate link 13), a crus attachment part (output link 14), an input link 11, and an intermediate link 15. A drive device 8 including a five-bar linkage mechanism 10 and an actuator 9 that applies power to the input link 11 is provided. Further, for example, the wearable movement support device may support bending and stretching of the wearer's elbow. In this case, the wearing tool of the motion support apparatus is a free one comprising an upper arm wearing part (fixed link 12), an elbow joint part (intermediate link 13), a lower arm wearing part (output link 14), an input link 11 and an intermediate link 15. A drive device 8 including a five-joint link mechanism 10 and an actuator 9 that applies power to the input link 11 is provided.

Furthermore, the drive device 8 can be applied to any device or machine having a bending arm in addition to the wearable motion support device. FIG. 12 is a view showing an example in which the drive device according to the present invention is applied to an arm of a work vehicle, in which (a) is a view in which the arm is lowered, and (b) is a view in which the arm is raised. . 12 (a) and 12 (b), the drive device 8 is applied to an arm provided in a bulldozer that is a work vehicle. Specifically, the bulldozer arm has a one-degree-of-freedom five-joint link mechanism 10 in which five links of an input link 11, a fixed link 12, an intermediate link 13, an output link 14, and an intermediate link 15 are connected so as to be sequentially rotatable. It consists of The actuator 9 can move the bulldozer arm up and down by applying a rotational driving force to the input link 11.

FIG. 13 is a view showing an example in which the drive device according to the present invention is applied to an arm of an industrial robot, where (a) is a view in which the arm is lowered, and (b) is a view in which the arm is raised. It is. 13A and 13B, the drive device 8 is applied to the arm of an industrial robot. Specifically, the arm of an industrial robot is a one-degree-of-freedom five-joint link in which five links of an input link 11, a fixed link 12, an intermediate link 13, an output link 14, and an intermediate link 15 are sequentially connected to be rotatable. The mechanism 10 is configured. Then, by applying a rotational driving force to the input link 11 by the actuator 9, the arm of the industrial robot can be bent and stretched.

  The drive device according to the present invention is useful for further miniaturization while ensuring a wide movable range as compared with a case where a four-bar parallel link mechanism is provided in any device or machine having a bending joint. .

DESCRIPTION OF SYMBOLS 8 Drive apparatus 9 Actuator 10 Five-bar link mechanism 11 Input link 12 Fixed link 13 Intermediate link 14 Output link 15 Intermediary link 16 Input shaft 17, 18, 19, 20 Connection shaft 21, 22 Gear 23 Degree of freedom restriction mechanism 30 Operation support device DESCRIPTION OF SYMBOLS 31 Wearing tool 32 Backpack 33 Battery 34 Controller 40 Lumbar frame 41 Back frame 42 Lower limb frame 51 Thigh arm 52 Middle arm 53 Lower leg arm 54 Lower leg arm 63 Knee joint actuator

The present invention relates to a joint drive device for two structures connected to each other so as to be bendable and provided with a five-bar linkage mechanism.

  2. Description of the Related Art In recent years, an operation support device that is worn on a user's body and supports the user's operation has been developed. For example, a wearable motion support device having a lower-body exoskeleton shape for assisting movement of a hip joint and a knee joint when a user walks or stands is known. Such a wearable movement support device is generally composed of a waist mounting part to be worn on the waist of the wearer, a thigh wearing part to be worn on the thigh, a lower leg wearing part to be worn on the lower leg, a waist wearing part and a thigh wearing part. There are provided wearing tools composed of actuators and the like disposed respectively at the hip joint part and the knee joint part between the thigh attachment part and the lower leg attachment part. However, if an actuator is placed near the knee joint of the wearer, the inertia of the wearer around the knee joint will increase due to the weight of the actuator, and the wearer's light walking will be hindered or worn. There has been a problem that the load on the actuator increases in order to correct the movement of the tool.

  Therefore, in the limb body assisting device described in Patent Document 1, the wearer is provided with a four-node parallel link mechanism including a thigh attachment portion and a crus attachment portion, which is applied to the wearer due to the weight of the knee joint actuator. The moment of inertia is reduced. Specifically, the limb assist device includes a closed four-joint link mechanism in which a first link part, a thigh link part, a crus link part, and a second link part are sequentially and rotatably connected, And an actuator for a knee joint that drives the link portion. Among the actuators included in the limb assisting device, the actuator for the knee joint, which is particularly heavy, is arranged in the trunk (trunk) direction from the user's knee joint.

  Based on Patent Literature 1, for example, as shown in FIG. 14 (a), an input link 99a, a fixed link 99b, an output link 99c, and an intermediate link 99d are sequentially connected to the lower limbs of the wearing tool of the motion support device. Thus, a four-bar parallel link mechanism 99 is provided. It is known that the human knee joint has a wide movement range of about 140 ° when changing posture from upright to heel. Therefore, when the output link 99c is aligned with the fixed link 99b in the four-bar parallel link mechanism 99 as 0 °, and the output link 99c is moved to 140 ° from here, as shown in FIG. 14 (b). In addition, when the angle of the output link 99c is a value within 0-140 °, the four-bar parallel link mechanism 99 becomes a thought point. When the four-bar parallel link mechanism 99 becomes a point of thinking, it is also when the wearer's knee is bent greatly and support by external power is particularly necessary. However, torque transmission from the input link 99a to the output link 99c becomes unstable at the thought point. For these reasons, if a four-joint parallel link mechanism is provided in the lower limb portion of the wearing tool of the movement support device, it is difficult to cope with a wide movement range of the human knee joint.

  Further, when the lower limb part of the wearing tool of the motion support device is configured by the four-bar parallel link mechanism, the torque transmission rate from the input link to the output link is always 1. However, when standing or standing upright, it is desirable that the torque transmission ratio from the input link to the output link in the wearing tool is small so as not to apply an extra load to the knee joint. In the posture of the heel, the torque transmission ratio from the input link to the output link in the wearing tool is used to strongly assist the wearer's movement while supporting the weight of the wearer when shifting from the heel posture to the upright posture. Is desirable to be large. That is, it is desirable that the torque transmission ratio from the input link to the output link is small in the upright posture and large in the heel posture in the wearing tool of the motion support device.

  Therefore, in Patent Document 2, a four-node non-parallel link mechanism is provided in the lower limb portion of the wearing tool of the movement support device, and the link length ratio is adjusted to cope with a wide movement range of the human knee joint and output from the input link. The torque transmission ratio to the link can be suitably adjusted. Specifically, the powered walking support apparatus described in Patent Document 2 includes a closed four-bar non-parallel link mechanism in which an input link, a fixed link, an output link, and an intermediate link are sequentially connected in a freely rotatable manner. ing. Of the four-bar linkage mechanism, the fixed link is fixed to the thigh, the output link is fixed to the lower leg, and power is input to the input link. Each link length is determined so that the sum of the link length ratios of the opposed links is substantially equal.

JP 2006-334200 A JP 2008-23234 A

  According to the powered walking support device described in Patent Document 2, it is possible to cope with a wide range of motion of the human knee joint, but when the link moves following the knee joint flexion, the input link and the intermediate link A connection part will protrude largely back, and an installation tool will enlarge. An increase in the size of the wearing tool leads to an increase in weight of the wearing tool and a decrease in wearing feeling.

The present invention has been made to solve the above-described problems, and can transmit torque well over a wide operating range as compared with the four-link parallel link mechanism of the output link. It is an object of the present invention to provide a joint drive device that can be realized.

A joint driving device according to the present invention is the joint driving device in two structures connected by a bending joint,
An input link, a fixed link provided on one of the two structures , an intermediate link, an output link provided on the other of the two structures, and an intermediary link are sequentially connected to be rotatable. A five-bar linkage mechanism,
And freedom limiting mechanism that limits the freedom of the five festivals link mechanism 1 by restraining the relative displacement of the intermediate link and the output link and relative displacement of said intermediate link and said fixed link at a predetermined ratio,
It is characterized in that it comprises an actuator providing rotational driving force of the connecting portion around the fixed link with respect to the input link.

According to the joint drive device having the above-described configuration, the intermediate link exists between the fixed link and the output link, so that the operation range is wider than the four-link parallel link mechanism of the output link (for example, relative to the fixed link). Even if the output link and the fixed link are arranged in the same plane over the range of the angle of the output link to be performed in the range from 0 ° to 140 °, it is possible to configure such that these links do not interfere. Further, it is possible to adopt a configuration that does not pass the thought point over the wide operating range of the output link, and it is possible to perform stable torque transmission from the input link to the output link in the wide operating range. Further, when the fixed link, the intermediate link, and the output link are arranged in a straight line, the input link and the intermediate link can be formed along the straight line, and the joint drive device can be downsized. it can. Furthermore, when the output link operates from a state where the fixed link, the intermediate link and the output link are arranged in a straight line, the input link and the intermediate link can be formed along these links, and the drive of the joint The size of the apparatus can be reduced.

In the driving device of the joint, the degrees of freedom limiting mechanism, the fixed link and the gear that rotates together with the fixed link is provided in a connecting part between the intermediate link, the connecting portion between the intermediate link and the output link to the gear which rotates together with the output link which is provided, it may be a gear mutually in mesh.

In the joint drive device , the link length ratio of the input link, the fixed link, the intermediate link, the output link and the intermediate link is such that the angle of the output link relative to the fixed link is from 0 ° to 140 °. in the range, it may have a relationship that the torque transmission ratio increases with increasing angle of the output link.

Furthermore, in the joint drive device , the link length ratio of the input link, the fixed link, the intermediate link, the output link and the intermediate link is such that the angle of the output link relative to the fixed link is 0 °. in the range of up to 140 °, 0 torque transmission ratio when ° is smaller than 1, may have a relationship that the torque transmission ratio of 1 or more than 90 °.

According to the above arrangement, a small torque transmission ratio when the joint is extended, the torque transmission ratio becomes greater when extending the joint, it is possible to realize a strong assist when extending the joint.

In the joint drive device , the fixed link and the output link may be disposed on the same sagittal plane. With this configuration, the joint driving device can be further downsized.

According to the present invention, the operation range of the output link is set to a wider range (for example, the angle of the output link relative to the fixed link is in the range of 0 ° to 140 °) compared to the four-bar parallel link mechanism. Can do. The torque can be stably transmitted from the input link to the output link over a wide operating range of the output link. Furthermore, the joint drive device can be reduced in size while ensuring such a wide operating range.

It is a figure which shows schematic structure of the drive device of the joint which concerns on one Embodiment of this invention. It is a figure which shows the state which increased the output link angle of the drive device of the joint of FIG. 1 is a diagram illustrating an overall schematic configuration of a wearable motion support apparatus to which a joint drive device according to an embodiment of the present invention is applied . It is a front view which shows the lower left part of a mounting | wearing type | mold movement assistance apparatus. It is a side view which shows the lower left part of a mounting | wearing type | mold movement assistance apparatus. It is a side view which shows the lower left part of the mounting | wearing type | mold movement assistance apparatus of the attitude | position which bent the knee. It is an enlarged side view of a 1st translational freedom degree mechanism. It is an enlarged side view of a 2nd translational freedom degree mechanism. It is a figure explaining the link length ratio and torque transmission ratio of the five-bar link mechanism with which an operation support device is provided. It is a figure which shows the state which increased the output link angle of the five-bar linkage mechanism shown in FIG. It is a figure which shows the state which tethered the thigh frame of the mounting | wearing type movement assistance apparatus to the wearer's thigh with a fastener, (a) is a figure which shows the mode of an upright posture, (b) is the time of the posture of a heel FIG. It is a figure which shows the example which applied the drive device of the joint which concerns on one Embodiment of this invention to the arm of a working vehicle, Comprising: (a) is the figure which lowered | hung the arm, (b) raised the arm FIG. It is a figure which shows the example which applied the drive device of the joint which concerns on one Embodiment of this invention to the arm of an industrial robot, Comprising: (a) is the figure which lowered | hung the arm, (b) raised the arm FIG. It is a figure which shows the conventional four-bar parallel link mechanism, (a) has shown the state when an output link angle is 0 degree, (b) has shown the state when an output link angle is 140 degrees. .

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.

[Driver]
First, a joint drive device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a schematic configuration of a joint driving device according to the present invention, and FIG. 2 is a diagram showing a state where an output link angle of the joint driving device of FIG. 1 is increased. As shown in FIG. 1, the joint drive device 8 includes a five-bar link mechanism 10 and an actuator 9 that supplies power to the five-bar link mechanism 10.

The five-bar link mechanism 10 is a closed link mechanism in which five links of an input link 11, a fixed link 12, an intermediate link 13, an output link 14, and an intermediate link 15 are connected so as to be sequentially rotatable. Specifically, the input link 11 and the fixed link 12 are rotatably connected by an input shaft 16, and the fixed link 12 and the intermediate link 13 are rotatably connected by a connecting shaft 17. And the output link 14 are rotatably connected by a connecting shaft 18, the output link 14 and the intermediate link 15 are rotatably connected by a connecting shaft 19, and the intermediate link 15 and the input link 11 are connected. The shaft 20 is rotatably connected. In the example shown in FIGS. 1 and 2, the input shaft 16 and the connecting shafts 17, 18, 19, and 20 are parallel. Hereinafter, the inclination of the long axis direction H ₁₄ of the output link ₁₄ with respect to the long axis direction H ₁₂ of the fixed link 12 is referred to as “output link angle Q”. Output link angle Q, when the long axis direction H ₁₄ of the output link 14 and the long axis direction H ₁₂ of the fixed link 12 is aligned to (Figure 1) and 0 °. An imaginary straight line connecting the centers of the input shaft 16 and the connecting shaft 17 is referred to as a “fixed link line H _L2 ”. In the example shown in FIGS. 1 and 2, the major axis direction H ₁₂ of the fixed link ₁₂ and the fixed link line H _L2 overlap, but depending on the mode of the fixed link 12, they may not overlap. Further, a virtual straight line connecting between the centers of the connecting shaft 17 and the connecting shaft 18 is referred to as “intermediate link line H _L3 ”, and a virtual curve connecting between the connecting shaft 18 and the center of the connecting shaft 19 is referred to as “output link line H _L4 ”. . In the example shown in FIGS. 1 and 2, the long axis direction H ₁₄ of the output link ₁₄ and the output link line H _L4 do not overlap, but they may overlap depending on the form of the output link 14.

The five-bar link mechanism 10 includes a degree-of-freedom limiting mechanism 23 for setting the relative displacement between the fixed link 12 and the intermediate link 13 and the relative displacement between the intermediate link 13 and the output link 14 to a predetermined ratio. Here, the relative displacement between the fixed link 12 and the intermediate link 13 means a change in the angle formed by the fixed link line H _L2 and the intermediate link line H _L3 . The relative displacement between the intermediate link 13 and the output link 14 means a change in the angle formed by the intermediate link line intermediate link line H _L3 and the output link line H _L4 . The operations of the fixed link 12, the intermediate link 13, and the output link 14 are mutually restrained by the degree-of-freedom limiting mechanism 23, and the degree of freedom of the five-bar link mechanism 10 is 1.

  The degree-of-freedom limiting mechanism 23 according to the present embodiment includes a pair of meshing gears, one provided on the fixed link 12 and the other provided on the output link 14. Specifically, the first gear 21 is provided at the end of the fixed link 12 that is connected to the intermediate link 13, and the first gear 21 is provided at the end of the output link 14 that is connected to the intermediate link 13. Two gears 22 are provided, and the first gear 21 and the second gear 22 mesh with each other. The gear ratio between the first gear 21 and the second gear 22 is not limited to 1: 1, and gears having different numbers of teeth may be used for the first gear 21 and the second gear 22. Further, the gear ratio of the first gear 21 and the second gear 22 is not limited to a constant value, and may change while rotating. Further, it is not necessary that teeth are provided on the entire circumference of the first gear 21 and the second gear 22, and the teeth 21 and 22 are engaged so that the gears 21 and 22 mesh at least in the movable range of the output link 14 relative to the fixed link 12. Is sufficient, and the others may be smooth. The degree-of-freedom limiting mechanism 23 is not limited to one composed of a pair of gears. For example, a cam can be used in place of one or both of the first gear 21 and the second gear 22.

  In the five-bar link mechanism 10 having the above-described configuration, the fixed link 12 and the output link 14 are each fixed to an appropriate support structure (not shown) or constitute a part of the support structure. When the input link 11 receives a rotational driving force around the input shaft 16 from the actuator 9, the rotational driving force is output from the output link 14 through the intermediate link 15 at a predetermined reduction ratio. When the input link 11 rotates counterclockwise around the input shaft 16 from the state shown in FIG. 1 in the five-bar link mechanism 10, the output is output via the intermediate link 15 connected to the input link 11 as shown in FIG. The link 14 rotates counterclockwise about the connecting shaft 18, and the intermediate link 13 rotates counterclockwise about the connecting shaft 17. Here, the relative displacement between the fixed link 12 and the intermediate link 13 and the relative displacement between the intermediate link 13 and the output link 14 are constrained to a predetermined ratio (for example, 1) by the action of the freedom degree limiting mechanism 23. With the operation of the input link 11, not only the output link 14 but also the intermediate link 13 operates.

  The five-bar link mechanism 10 of the drive device 8 having the above configuration has a large operating range as compared with the four-bar parallel link mechanism. Specifically, when the output link angle Q of the five-bar linkage 10 changes from 0 ° to a large angle (for example, 140 °), the intermediate link 13 is interposed between the fixed link 12 and the output link 14. Even if the fixed link 12 and the output link 14 are arranged in the same plane, the links 12 and 14 can be configured not to interfere with each other. Further, when the output link angle Q of the five-bar link mechanism 10 changes from 0 ° to a large angle (for example, 140 °), the operation range can be configured not to include a thought point. In other words, the five-bar link mechanism 10 is provided from the input link 11 to the output link 14 over the wide operating range of the output link 14 (for example, the range where the output link angle Q is 0 ° to 140 °) due to the presence of the intermediate link 13. The torque transmission of is not unstable.

In the five- joint link mechanism 10 of the joint drive device 8 described above, the presence of the intermediate link 13 makes it possible to arrange the fixed link 12 and the output link 14 in the same plane. In addition, as shown in FIG. 1, when the fixed link 12, the intermediate link 13 and the output link 14 are arranged in a straight line, the input link 11 and the intermediate link 15 may be formed along the straight line. Is possible. In this way, the five-bar link mechanism 10 can be further reduced in size, that is, formed into an elongated shape along the fixed link 12. Furthermore, in this five-bar link mechanism 10, when the output link 14 moves from the state where the fixed link 12, the intermediate link 13 and the output link 14 are arranged in a straight line (FIG. 1) to the direction where the output link angle Q increases. (FIG. 2), the input link 11 and the intermediate link 15 can be formed along these links 12, 13, and 14, and the joint drive device 8 can be downsized.

[Wearable motion support device]
Next, a wearable movement support apparatus (hereinafter simply referred to as a movement support apparatus) provided with the joint drive apparatus 8 will be described. The motion support device 30 according to the present embodiment has a lower-body exoskeleton shape, is worn on the human body regardless of the elderly, the physically disabled, and the healthy person, and the muscle strength of the lower limb mainly of the wearer. The operation of the wearer is supported by assisting or acting on the device.

FIG. 3 is a diagram showing an overall schematic configuration of the wearable motion support device 30 to which the joint drive device 8 according to one embodiment of the present invention is applied . As shown in FIG. 3, the operation support apparatus 30 includes a mounting tool 31, a backpack 32 loaded on the mounting tool 31, a battery 33 and a controller 34 housed in the backpack 32. The wearing tool 31 includes a lumbar frame 40 that is worn around the waist (pelvis) of the wearer, a back frame 41 that is worn on the back of the wearer, and left and right lower limb frames 42 that are worn on the lower limbs of the wearer. 42. Although the backpack 32 is detachably stacked on the back frame 41, the backpack 32 may be configured integrally with the back frame 41. Hereinafter, the configuration of the wearing tool 31 will be described in detail with reference to FIGS. 4 to 6 in addition to FIG. 3. 4 is a front view showing the lower left portion of the wearable motion support device, FIG. 5 is a side view showing the lower left portion of the wearable motion support device, and FIG. 6 is a lower left portion of the wearable motion support device in a posture in which the knee is bent. FIG. In the following, “left-right direction” refers to the shoulder width direction of the wearer, “front-rear direction” refers to the front-rear direction of the wearer, and “sagittal plane” refers to a plane that cuts the wearer's body symmetrically. A plane parallel to this is referred to as “frontal plane”, which is a plane that cuts the wearer's body back and forth and is perpendicular to the sagittal plane.

(Lumbar frame 40)
The waist frame 40 has a substantially U shape in plan view so as to cover the back side and the left and right sides of the wearer's waist (pelvis). Specifically, the waist frame 40 includes a base 45 that is elongated in the left-right direction and is located on the back side of the wearer's waist, and side portions 46, 46 that protrude forward from both left and right ends of the base 45. ing. The waist frame 40 is provided with a locking tool (not shown) such as a belt or a hook for mooring around the waist of the wearer, and the waist frame 40 is anchored to the waist of the wearer.

(Lower limb frame 42)
The left and right lower limb frames 42 and 42 have substantially the same configuration, and are provided symmetrically on the left and right lines with the left and right center of the waist frame 40 as the symmetry axis. Therefore, only the structure of one (left side) lower limb frame 42 will be described in detail below, and the description of the other will be omitted. The lower limb frame 42 includes a thigh arm 51 that is a thigh attachment portion, an intermediate arm 52 that is disposed in the vicinity of the knee joint, a crus arm 53 that is a crus attachment portion, and a foot arm 54 that is a foot attachment portion. . The thigh arm 51, the lower leg arm 53, and the lower arm 54 are provided with a locking tool (not shown) such as a belt or a hook for mooring to the wearer's body.

  The thigh arm 51 is connected to the front end of the side portion 46 of the waist frame 40 via a hip joint actuator 61 and a hip joint 62. The hip joint actuator 61 is provided so as to protrude outward from the front end portion of the side portion 46 of the waist frame 40. The hip joint actuator 61 includes, for example, a motor and a reduction gear. As shown in detail in FIG. 7, the output shaft 61 a of the hip joint actuator 61 is fixed to a first joint 621 that is a component of the hip joint 62, and is driven by the hip joint actuator 61 with respect to the waist frame 40. Thus, the first joint 621 rotates on the sagittal plane. Note that “rotate on the sagittal plane” means that the axis rotates around the axis perpendicular to the sagittal plane while maintaining parallelism with the sagittal plane.

  The hip joint 62 includes a first joint 621, a second joint 622 connected to the upper portion of the thigh arm 51, and a pivot 623 that rotatably connects the first joint 621 and the second joint 622 on the frontal plane. And. Note that “rotate on the front frame” means to rotate while maintaining parallel to the front frame about an axis perpendicular to the front frame.

  The upper end of the intermediate arm 52 is rotatably connected to the lower end of the thigh arm 51 via the connecting shaft 17. The lower end of the intermediate arm 52 is rotatably connected to the upper end of the lower leg arm 53 via the connecting shaft 18. The first gear 21 is provided at the lower end of the thigh arm 51, and the second gear 22 is provided at the upper end of the lower leg arm 53, and the meshing gears 21, 22 constitute the degree-of-freedom limiting mechanism 23. The thigh arm 51, the intermediate arm 52, and the crus arm 53 connected in this way constitute a part of the five-bar linkage mechanism 10. The thigh arm 51 corresponds to the fixed link 12, the intermediate arm 52 corresponds to the intermediate link 13, and the crus arm 53 corresponds to the output link 14. The knee joint actuator 63 that applies rotational power to the five-bar linkage mechanism 10 is fixed to the thigh arm 51 via a bracket 63a and the like. The knee joint actuator 63 includes, for example, a motor and a reduction gear. As described above, the knee joint actuator 63 is disposed on the waist side away from the wearer's knee joint, so that the knee joint actuator 63 is disposed in the vicinity of the wearer's knee joint. The moment of inertia applied to the wearer due to the weight of the knee joint actuator 63 during walking can be reduced.

One end of the input link 11 is fixed to the output shaft of the knee joint actuator 63, that is, the input shaft 16 to the five-bar linkage mechanism 10. The other end of the input link 11 is rotatably connected to one end of the intermediate link 15 via the connecting shaft 20. The other end of the intermediate link 15 is connected to the lower leg arm 53 via the connecting shaft 19 so as to be rotatable. As described above, the joint drive device 8 including the five-joint link mechanism 10 and the knee joint actuator 63 (actuator 9) is provided around the knee joint portion of the lower limb frame 42. When the input link 11 receives a rotational driving force around the input shaft 16 from the knee joint actuator 63, the lower leg arm 53 is connected to the connecting shaft via the intermediate link 15 connected to the input link 11, as shown in FIG. The intermediate arm 52 rotates about the connecting shaft 17. Here, due to the action of the degree-of-freedom limiting mechanism 23, the relative displacement between the thigh arm 51 and the intermediate arm 52 and the relative displacement between the intermediate arm 52 and the crus arm 53 are constrained to a predetermined ratio (for example, 1), and the input link 11 In accordance with the operation, not only the lower leg arm 53 but also the intermediate arm 52 operates.

  The length (dimension in the major axis direction) of the thigh arm 51 is adjusted to approximately match the length of the wearer's thigh. The length of the thigh arm 51 adjusted in this way is referred to as the “reference length of the thigh arm”. The reference length of the thigh arm is also the minimum length of the thigh arm 51. The thigh arm 51 includes a first translational degree-of-freedom mechanism 55 that enables the thigh arm 51 to extend in the translation direction (long axis direction) by 1-30 mm from the reference length. As shown in FIG. 7, the first translational degree-of-freedom mechanism 55 includes a connection pin 55 a extending in the translational direction from the second joint 622 at the connection portion between the thigh arm 51 and the second joint 622 of the hip joint 62. The connecting pin 55a provided on the thigh arm 51 is slidably inserted into the connecting hole 55b, and the compression spring 55c is fitted on the connecting pin 55a. The connection pin 55a is longer than the connection hole 55b, the lower end of the connection pin 55a projects downward from the connection hole 55b, and a flange is formed at the lower end. The opening edge of the connection hole 55b and the flange portion of the connection pin 55a are spaced apart in the translational direction, and a compression spring 55c is provided between the opening edge of the connection hole 55b of the connection pin 55a and the flange portion of the connection pin 55a. . The connection pin 55a and the thigh arm 51 are a sliding pair, and the thigh arm 51 extends in the translational direction when a slip occurs between the connection pin 55a and the connection hole 55b. Further, the connection pin 55a can be rotated in the radial direction (around the axis of the connection pin 55a) in the connection hole 55b, thereby allowing the thigh arm 51 to rotate freely (one degree of freedom of rotation around the axis of the connection pin 55a). ) Is given. The extension allowance E1 of the thigh arm 51 in the translation direction is the length of the connection pin 55a that appears between the lower end of the second joint 622 and the upper end of the thigh arm 51. The expansion margin E1 is 0 when the lower end of the second joint 622 and the upper end of the thigh arm 51 are in contact with each other, and the connection pin 55a is urged by the compression spring 55c so that the expansion margin E1 becomes zero. Yes. When a tensile load is applied to the thigh arm 51, the extension pin E1 increases as the connection pin 55a moves in the connection hole 55b against the urging force of the compression spring 55c.

  Further, the length (dimension in the long axis direction) of the lower leg arm 53 is adjusted to match the length of the wearer's lower leg. The length of the lower leg arm 53 adjusted in this way is referred to as “reference length of the lower leg arm”. The reference length of the lower leg arm is also the minimum length of the lower leg arm 53. The crus arm 53 includes a second translational degree-of-freedom mechanism 57 that enables the crus arm 53 to extend in the translational direction (long axis direction) by 1-30 mm from the reference length. As shown in FIG. 8, the second translational freedom degree mechanism 57 is provided in the first joint 641 at a connection portion between the lower end of the crus arm 53 and a first joint 641 of an ankle joint 64 described later. The prism portion 57a extending in the translational direction, the rectangular tube portion 57b into which the rectangular column portion 57a provided on the crus arm 53 is slidably inserted, and the direction in which the rectangular column portion 57a is accommodated in the rectangular tube portion 57b. And a tension spring 57c as an urging member. The rectangular column part 57a and the crus arm 53 are sliding pairs, and the crus arm 53 extends in the translational direction when the prismatic part 57a slides in the translational direction in the rectangular tube part 57b. In the above configuration, the extension E2 in the translational direction of the crus arm 53 is the length of the prism portion 57a that appears between the lower end of the crus arm 53 and the upper end of the first joint 641. The extension E2 is 0 when the lower end of the crus arm 53 and the upper end of the first joint 641 are in contact with each other, and the tension spring 57c urges the prism 57a so that the extension E2 becomes 0. Yes. Then, when a tensile load is applied to the crus arm 53, the extension allowance E2 increases as the prism 57a moves in the rectangular tube 57b against the urging force of the tension spring 57c.

  As described above, the reference lengths of the thigh arm 51 and the lower leg arm 53 are adjusted so as to match the dimensions of the wearer's thigh and lower leg, respectively. Not much accuracy is required. In addition to the thigh arm 51 and the lower leg arm 53 each having a degree of freedom of translation, the provision of the intermediate arm 52 between them allows a slight dimensional error.

  The lower leg arm 53 and the lower arm 54 are connected via an ankle joint 64. The ankle joint 64 pivots the first joint 641 connected to the lower end of the lower leg arm 53, the second joint 643 connected to the upper end of the lower arm 54, and the first joint 641 and the second joint 643. And a pivot shaft 642. The first joint 641 is loosely fitted to the pivot shaft 642, and the first joint 641 can rotate on the sagittal plane about the pivot shaft 642 and can swing on the frontal plane. A sole plate 531 constituting the foot arm 54 is connected to the lower portion of the second joint 643. The sole plate 531 has an integral shape that covers at least the wearer's heel.

(Back frame 41)
The back frame 41 is a so-called backpack. The back frame 41 is provided with a side belt for anchoring to the shoulder and chest of the wearer, a locking device (not shown) such as a shoulder strap and a hook. A backpack 32 is loaded on the back frame 41. The battery 33 stored in the backpack 32 supplies electricity to the hip joint actuator 61, the knee joint actuator 63, and the controller 34. Further, the controller 34 stored in the backpack 32 receives a detection signal from a sensor (not shown) provided in each part of the wearing tool 31 so that the wearing tool 31 assists or substitutes the operation of the wearer. The hip joint actuator 61 and the knee joint actuator 63 are controlled. The sensor is a sensor that detects a physical quantity such as a change in the center of gravity of the member or a load applied to the member. Instead of or in addition to these, a biosignal sensor that detects a wearer's biosignal is used. It may be used. If the biological signal sensor is used, the actuators 61 and 63 can generate power according to the wearer's intention.

  In the operation support device 30 configured as described above, the link length ratio of the five links of the five-bar link mechanism 10 is set so that the optimum torque transmission ratio can be exhibited as the operation support device 30. That is, the link length ratio is adjusted so that even if the knee joint actuator 63 has a constant output, the torque transmission ratio is such that a strong assist force is exerted in the heel posture and an agile back drive is secured in the upright posture. Yes. Such a torque transmission ratio has a characteristic that the output link angle Q increases as the output link angle Q increases when the output link angle Q is in the range of 0 to 140 °. Further, such torque transmission ratio is less than 1 when the output link angle Q is 0 ° in the range of the output link angle Q of 0-140 °, and is less than 1 when the output link angle Q is 90 ° or more. It is preferable to have a characteristic of increasing. In particular, it is desirable that the torque transmission ratio be a small value close to 0 when the output link angle Q is near 0 °. Thus, power is effectively transmitted from the knee joint actuator 63 to the crus arm 53 as an output link in a heel posture that requires particularly strong assistance.

FIG. 9 is a diagram for explaining the link length ratio and the torque transmission ratio of the five-bar link mechanism provided in the operation support device, and FIG. 10 is a diagram showing a state in which the output link angle of the five-bar link mechanism shown in FIG. 9 is increased. It is. 9 and 10, the distance between the centers of the input shaft 16 and the connecting shaft 20 is the link length L 1 of the input link 11. Similarly, the distance between the centers of the input shaft 16 and the connecting shaft 17 is the link length L2 of the fixed link 12. The distance between the centers of the connecting shaft 17 and the connecting shaft 18 is the link length L3 of the intermediate link 13. The distance between the centers of the connecting shaft 18 and the connecting shaft 19 is the link length L4 of the output link 14. The distance between the centers of the connecting shaft 19 and the connecting shaft 20 is the link length L5 of the intermediate link 15. Further, Lin is the length of a perpendicular drawn from the center of the input shaft 16 to the intermediate link line H _L5, and is defined as an input perpendicular distance Lin. Here, the intermediate link line H _L5 is an imaginary straight line that connects between the centers of the connecting shaft 19 and the connecting shaft 20. Lout is the length of the perpendicular drawn to the mediating link line H _L5 from the engagement point P3 between the first gear 21 and second gear 22, and outputs the perpendicular distance Lout. The input perpendicular distance Lin and the output perpendicular distance Lout are values that depend on the five link lengths L1, L2, L3, L4, and L5. A value obtained by dividing the output normal distance Lout by the input normal distance Lin is the torque transmission ratio (= Lout / Lin).

  The following formulas 1 and 2 are conditional expressions for which the five-joint link mechanism 10 included in the motion support device 30 is a pondering point. By designing the five-bar link mechanism 10 within a range not satisfying the mathematical expressions 1 and 2, it is possible to avoid the five-bar link mechanism 10 included in the operation support device 30 from being a wonder point.

In Equations 1 and 2, Q _L0 and Q _Lf are angles formed by the fixed link line H _L2 and the output link line H _L4 . Q _L0 is an angle formed by the fixed link line H _L2 and the output link line H _L4 when the wearer's knee joint is most extended (upright posture), and Q _Lf is when the wearer's knee joint is bent most (蹲踞Angle) formed by the fixed link line H _L2 and the output link line H _L4 . R is 1 / (1 + ny). Here, ny is the ratio of the relative displacement between the fixed link 12 and the intermediate link 13. When gears 21 and 22 that mesh with each other are used as the degree of freedom limiting mechanism 23 as in the present embodiment and the gear ratio is 1: 1, ny = 1.

A method for obtaining the link length ratio using Equations 1 and 2 will be described below with reference to a specific example (not shown) in the case of determining the intermediate link length L5. First, link lengths (L1, L2, L3, L4) other than the intermediate link length L5 are determined in accordance with the wearer's body dimensions. For example, the input link length L1 = 60 mm, the fixed link length L2 = 210 mm, the intermediate link length L3 = 40 mm, and the output link length L4 = 50 mm. Then, the values of ny, Q _L0 , and Q _Lf are determined according to the configuration of the operation support device 30. For example, ny = 1, Q _L0 = 0 °, and Q _Lf = 140 °. By substituting these numerical conditions into Equation 1 and Equation 2, the intermediate link length L5 is obtained. Then, in Formula 1, the mediation link length L5 = 240 mm is calculated, and in Formula 2, the mediation link length L5 = 258 mm. As described above, a value that is the intermediate link length L5 is selected from the values that are larger than the lower limit and smaller than the upper limit of the intermediate link length L5 calculated by using Equations 1 and 2. Here, for example, the intermediate link length L5 = 250 mm is selected between the solution of Equation 1 and the solution of Equation 2. Torque transmission with the link length ratio (input link length L1 = 60 mm, fixed link length L2 = 210 mm, intermediate link length L3 = 40 mm, output link length L4 = 50 mm, intermediate link length L5 = 250 mm) obtained as described above. The ratio is as shown in Table 1.

  In the change of the torque transmission ratio with respect to the output link angle shown in Table 1, the torque transmission ratio is a sufficiently small value close to 0 when the output link angle is 0 °, and when the output link angle is 90 ° or more, the torque transmission ratio is Greater than 1. The torque transmission ratio increases with an increase in the output link angle, and has a maximum value at the maximum output link angle (140 °) shown in Table 1. Thus, the torque transmission ratio of the five-bar link mechanism 10 included in the motion support device 30 is set to be suitable for the motion support device 30 based on the link length ratio determined by the above method.

The motion support device 30 according to the present embodiment described above includes the joint drive device 8 including the five-bar linkage mechanism 10, thereby enabling a wide motion range (for example, output link) of the crus arm 53 (output link 14). Even if the thigh arm 51 and the crus arm 53 are arranged in the same plane over an angle Q in the range of 0 to 140 °, the arms 51 and 53 do not interfere with each other and do not become a thought point. Therefore, torque is stably transmitted to the lower leg arm 53 over the wide operating range of the lower leg arm 53. Thereby, the movement support apparatus 30 can respond to a wide movement range of 0-140 ° of the human knee joint.

Furthermore, the motion support device 30 according to the present embodiment includes the joint drive device 8 and can be further downsized while ensuring the wide motion range. Specifically, the increase in the thickness of the lower limb frame 42 in the left-right direction is suppressed by arranging the lower leg arm 53 and the upper leg arm 51 on substantially the same sagittal plane. In addition, the upper end P1 of the thigh arm 51, the lower end P2 of the crus arm 53, and the connecting shaft 17 of the thigh arm 51 and the intermediate arm 52 in the sagittal view (FIG. 5) when the wearer is standing upright. Are arranged on substantially the same straight line, an increase in the thickness of the lower limb frame 42 in the front-rear direction is suppressed. In FIG. 5, the upper end P <b> 1 of the thigh arm 51 indicates a connection portion between the waist frame 40 and the lower limb frame 42.

  As shown in FIG. 5, the upper end P1 of the thigh arm 51 is located on the side of the wearer's hip joint, and the lower end P2 of the lower leg arm 53 is located on the side of the wearer's heel. In the sagittal view, a straight line connecting these points (P1 and P2) passes through the back side of the knee joint of the wearer, and the connecting shaft 17 and the connecting shaft 18 are approximately located on this straight line. By arranging the connecting shafts 17 and 18 in this way, the basic portion of the lower limb frame 42 composed of the thigh arm 51, the intermediate arm 52, and the lower leg arm 53 has a substantially linear shape. In this way, the basic portion of the lower limb frame 42 has a substantially linear shape, so that the load positioned above the knee joint portion (intermediate arm 52) of the lower limb frame 42 is passively supported by the basic portion of the lower limb frame 42. be able to. Then, it is possible to form the input link 11 and the intermediate link 15 along the thigh arm 51, the intermediate arm 52, and the crus arm 53 that are arranged in a straight line as described above. Furthermore, it is possible to form the input link 11 and the intermediate link 15 along the thigh arm 51 in a state where the output link angle is increased. As a result of forming the five-bar link mechanism 10 in this way, the lower limb frame 42 and a part thereof do not protrude greatly forward or backward of the wearer in both the upright posture and the heel posture, and the lower limb frame 42 It becomes compact along the wearer's lower limbs.

  In addition, in a conventional motion support device in which a thigh arm and a lower leg arm are connected by a knee joint axis, when the knee joint axis is arranged on the back side of the wearer's knee joint, the wearer bends the knee. The distance from the body part of the wearer where the knee joint axis is arranged to the wearer's heel decreases. This change in distance causes problems such as a deviation between the wearer's body and the wearing tool. On the other hand, in the operation support apparatus 30 according to the present embodiment, the above problem is avoided or reduced. As shown in FIG. 5, when the wearer is in an upright posture, the connecting shaft 18, the meshing point P <b> 3 of the gears 21 and 22, and the lower end P <b> 2 of the crus arm 53 are aligned substantially in a straight line. As shown in FIG. 6, as the wearer flexes the knee, the connecting shaft 18 moves away from the straight line connecting the meshing point P3 of the gears 21 and 22 and the lower end P2 of the crus arm 53. The length of the line segment connecting the meshing point P3 and the lower end P2 of the lower leg arm 53 decreases. That is, when the wearer bends the knee, the meshing of the gears 21 and 22 is reduced as the distance from the body part of the wearer where the meshing point P3 of the gears 21 and 22 is disposed to the wearer's heel is decreased. Since the length of the line segment connecting the point P3 and the lower end P2 of the crus arm 53 is also reduced, the displacement between the wearer's body and the wearing tool is avoided or reduced.

  In addition, in the wearing tool 31 of the motion support device 30 according to the present embodiment, the thigh arm 51 and the lower thigh arm 53 are locked to the wearer's body and a translational freedom degree mechanism (first Are provided with a translational freedom degree mechanism 55 and a second translational degree of freedom mechanism 57). However, the configuration may be such that the wearing tool 31 is provided with a translational degree-of-freedom mechanism on one of the thigh arm 51 and the lower leg arm 53 and the other is moored on the wearer's body. Regardless of the wearing device 31, it is possible to provide the movement of the lower limb with less discomfort for the wearer while eliminating the need for strict adjustment of the longitudinal dimensions of the thigh arm 51 and the lower leg arm 53 with respect to the skeleton structure of the wearer. it can. FIG. 11 is a view showing a state in which the thigh frame of the wearable motion support device is moored to the wearer's thigh with a locking tool, (a) is a view showing the upright posture, and (b) is a view. It is a figure which shows the mode at the time of the posture of a heel. As shown in FIGS. 11 (a) and 11 (b), when the thigh arm 51 is moored to the wearer's thigh by the locking device 75 and the foot arm 54 is moored to the wearer's foot by the locking device 76, It is sufficient if the lower leg arm 53 is provided with the second translational freedom degree mechanism 57. Such a wearing form is suitable for the motion support apparatus 30 used to support the wearer's walking. Further, when the intermediate arm 52 is anchored to the wearer's lower leg by the locking tool and the foot arm 54 is moored to the wearer's foot by the locking tool, the first translational degree of freedom mechanism is added to the thigh arm 51. 55 is enough. Such a mounting form is suitable for the operation support apparatus 30 used to support the load handling of the wearer.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. is there.

For example, the joint drive device 8 according to the present invention is not limited to the wearable motion support device 30 having the lower body exoskeleton shape described above, but can be applied to other wearable motion support devices. For example, the wearable movement support device may support only the bending and stretching of the wearer's knee. In this case, the wearing tool of the motion support device includes a thigh attachment part (fixed link 12), a knee joint part (intermediate link 13), a crus attachment part (output link 14), an input link 11, and an intermediate link 15. The joint drive device 8 including the five-bar linkage mechanism 10 and the actuator 9 for applying power to the input link 11 is provided. Further, for example, the wearable movement support device may support bending and stretching of the wearer's elbow. In this case, the wearing tool of the motion support apparatus is a free one comprising an upper arm wearing part (fixed link 12), an elbow joint part (intermediate link 13), a lower arm wearing part (output link 14), an input link 11 and an intermediate link 15. A joint drive device 8 including a five-joint link mechanism 10 and an actuator 9 for applying power to the input link 11 is provided.

Furthermore, the joint drive device 8 can be applied to any device or machine having a bending arm in addition to the wearable motion support device. FIG. 12 is a view showing an example in which the drive device according to the present invention is applied to an arm of a work vehicle, in which (a) is a view in which the arm is lowered, and (b) is a view in which the arm is raised. . 12 (a) and 12 (b), the drive device 8 is applied to an arm provided in a bulldozer that is a work vehicle. Specifically, the bulldozer arm has a one-degree-of-freedom five-joint link mechanism 10 in which five links of an input link 11, a fixed link 12, an intermediate link 13, an output link 14, and an intermediate link 15 are connected so as to be sequentially rotatable. It consists of The actuator 9 can move the bulldozer arm up and down by applying a rotational driving force to the input link 11.

  FIG. 13 is a view showing an example in which the drive device according to the present invention is applied to an arm of an industrial robot, where (a) is a view in which the arm is lowered, and (b) is a view in which the arm is raised. It is. 13A and 13B, the drive device 8 is applied to the arm of an industrial robot. Specifically, the arm of an industrial robot is a one-degree-of-freedom five-joint link in which five links of an input link 11, a fixed link 12, an intermediate link 13, an output link 14, and an intermediate link 15 are sequentially connected to be rotatable. The mechanism 10 is configured. Then, by applying a rotational driving force to the input link 11 by the actuator 9, the arm of the industrial robot can be bent and stretched.

The joint drive device according to the present invention is useful for further downsizing in any device or machine having a bending joint, while ensuring a wide movable range as compared with a case where a four-bar parallel link mechanism is provided. It is.

DESCRIPTION OF SYMBOLS 8 Drive apparatus 9 Actuator 10 Five-bar link mechanism 11 Input link 12 Fixed link 13 Intermediate link 14 Output link 15 Intermediary link 16 Input shaft 17, 18, 19, 20 Connection shaft 21, 22 Gear 23 Degree of freedom restriction mechanism 30 Operation support device DESCRIPTION OF SYMBOLS 31 Wearing tool 32 Backpack 33 Battery 34 Controller 40 Lumbar frame 41 Back frame 42 Lower limb frame 51 Thigh arm 52 Middle arm 53 Lower leg arm 54 Lower leg arm 63 Knee joint actuator

Claims (9)

A five-bar linkage mechanism in which five links of an input link, a fixed link, an intermediate link, an output link, and an intermediate link are sequentially connected to each other, and
A degree-of-freedom limiting mechanism that limits the degree of freedom of the five-bar linkage mechanism to 1 by constraining the relative displacement of the fixed link and the intermediate link and the relative displacement of the intermediate link and the output link to a predetermined ratio;
An actuator that applies a rotational driving force around a connecting portion with the fixed link to the input link;   The drive device according to claim 1, wherein the degree-of-freedom limiting mechanism is a meshing gear provided in each of the fixed link and the output link. A wearable movement support device for assisting or acting on the wearer's muscle strength,
A lower limb frame having at least a thigh attachment part attached to the thigh of the wearer and a lower leg attachment part attached to the lower leg of the wearer;
The drive device according to claim 1 or 2 provided on the lower limb frame,
The wearable motion support device, wherein the thigh mounting portion is provided with the fixed link, the crus mounting portion is provided with the output link, and the thigh mounting portion is provided with the actuator.   The link length ratio of the input link, the fixed link, the intermediate link, the output link, and the intermediate link is such that the output link relative to the fixed link is in the range of 0 ° to 140 °. The wearable motion support apparatus according to claim 3, wherein the torque transmission ratio increases as the angle increases.   The link length ratio of the input link, the fixed link, the intermediate link, the output link, and the intermediate link is 0 ° when the angle of the output link relative to the fixed link is 0 ° to 140 °. The wearable motion support device according to claim 3 or 4, wherein the torque transmission ratio is sometimes smaller than 1, and the torque transmission ratio is 1 or more at 90 ° or more. The lower limb frame includes a foot attachment portion attached to the wearer's foot,
The thigh mounting portion has a locking tool for mooring to the wearer's thigh,
The lower leg mounting part has a degree of freedom of translation that can be extended in the translation direction,
The wearing type movement support device according to any one of claims 3 to 5, wherein the foot wearing unit includes a locking tool for mooring the foot of the wearer. The lower limb frame includes a foot attachment portion attached to the wearer's foot,
The thigh mounting portion has a translational degree of freedom that can be extended in the translation direction, and the crus mounting portion has a locking tool for mooring to the wearer's crus;
The wearing type movement support device according to any one of claims 3 to 5, wherein the foot wearing unit includes a locking tool for mooring the foot of the wearer.   The wearable motion support apparatus according to any one of claims 3 to 7, wherein the fixed link and the output link are arranged on the same sagittal plane.   When the wearer is in an upright posture, the upper end of the thigh mounting portion, the lower end of the crus mounting portion, and the connecting portion of the fixed link and the intermediate link are arranged on substantially the same straight line in a sagittal view. The wearable motion support apparatus according to any one of claims 3 to 8.

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