WO2008001523A1 - Walk assistance device - Google Patents

Abstract

A walk assistance device where force generated by a leg link (5) is transmitted to the body trunk of the user through a load transmission section (1). The leg link has an upper first link section (6) connected to the load transmission section via a first joint section (3), a lower second link section (7) connected to a foot sole installation section (2) via a second joint section (4), an intermediate third joint section (8) for connecting the first link section and the second link section so that the distance between the first joint section and the second joint section is variable, and a drive source (9) for driving the third joint section. Inertia moment about the first joint section of the leg link is reduced to decrease a load acting on a leg of the user during walking. The drive source (9) is placed above the third joint section (8) of the first link section (6) to position the center of gravity of the entire leg link (5) above the third joint section (8). Also, when the drive source (9) is constructed from an electric motor (91) and a reduction gear (92), the electric motor (91) is placed above the reduction gear (92).

Description

 Specification

 Walking assist device

 Technical field

 The present invention relates to a walking assistance device that assists a user's walking.

 Background art

 Conventionally, as this type of walking assist device, a trunk mounting portion to be mounted on a user's trunk and a hip mounting portion corresponding to a human hip joint are connected to the trunk mounting portion, and A thigh attachment part that is attached to the thigh of the leg, a thigh attachment part that is connected to the thigh attachment part via a knee joint part corresponding to a human knee joint, and is attached to the leg of the user's leg; and a thigh attachment part And a foot attachment portion that is connected to a user's foot, and is driven coaxially with each joint portion. Are known (see, for example, Japanese Patent Laid-Open No. 2003-220102). In this device, an assist moment from the hip joint drive source is applied to the user's thigh via the thigh attachment part, and an assist moment from the knee joint drive source is provided to the user's lower leg via the thigh attachment part. In addition, an assist moment from the ankle joint drive source can be applied to the user's foot via the foot mounting portion to assist walking.

 [0003] The above conventional example can assist all movements of the user's thigh, lower leg, and foot, but on the other hand, the thigh and lower leg are restrained by the thigh attachment part and the lower leg attachment part, and the sense of binding is strong. Become. In addition, it is necessary to provide drive sources for the joints of the hip joint, knee joint, and ankle joint, which increases the cost.

[0004] In order to solve such a problem, the walking assist device includes a load transmitting unit, a foot mounting unit mounted on the user's foot, and a leg link between the load transmitting unit and the foot mounting unit. It is also conceivable that the force generated by the leg link is transmitted to the user's trunk through the load transmission unit. According to this, it is possible to reduce the load acting on the user's leg by the force from the leg link transmitted to the user's trunk via the load transmitting unit, and assist walking. Further, the leg link can be free with respect to the user's leg, and the sense of restraint can be eliminated. In this case, the upper first link where the leg link is connected to the load transmitting portion via the first joint portion. And a lower second link portion connected to the foot attachment portion via the second joint portion, and the first link portion so that the distance between the first joint portion and the second joint portion is variable. If the third joint portion is connected to the second link portion and a drive source that drives the third joint portion, the first joint portion and the first joint portion are connected to the third joint portion by the drive source. The load acting on the user's leg can be reduced by generating a force that extends the distance between the two joints.

[0005] Here, the leg link is free with respect to the user's leg, but the leg link on the user's free leg (the leg from which the foot leaves the floor) follows the swinging of the free leg forward. Then swing forward with the first joint as a fulcrum. If the moment of inertia around the first joint of the leg link increases, the user's leg will feel heavy due to the moment of inertia of the leg link during walking.

 Disclosure of the invention

 Problems to be solved by the invention

 [0006] In view of the above, the present invention has an object to provide a walking assist device that can reduce the load acting on the leg of the user by reducing the moment of inertia of the leg link. Means for solving the problem

 [0007] In order to achieve the above object, the present invention provides a load transmitting unit, a foot mounting unit mounted on a user's foot, and a leg link between the load transmitting unit and the foot mounting unit. The walking assist device is configured to transmit the force generated by the leg link to the user's trunk via the load transmission unit, and the leg link is connected to the load transmission unit via the first joint unit. The distance between the upper first link portion, the lower second link portion connected to the foot attachment portion via the second joint portion, and the first joint portion and the second joint portion is variable. In this way, the center of gravity of the entire leg link is the third center of the third joint that connects the first link and the second link, and the drive source that drives the third joint. It is located above the joint part.

 [0008] According to the present invention, the center of gravity of the entire leg link approaches the first joint, and the moment of inertia around the first joint of the leg link is reduced. Therefore, when the user swings the swing leg forward, the load acting on the swing leg due to the moment of inertia of the leg link can be reduced.

[0009] In addition, the center of gravity of the entire leg link is located above the third joint part is that the mass of the first link part (the mass including the accessory equipment installed in the first link part) is Mass (second link part It means that it is larger than the mass including incidental equipment. Here, the thigh of a person's leg is heavier than the lower leg. Then, by positioning the center of gravity of the entire leg link above the third joint part, the mass ratio of the first link part and the second link part of the leg link approaches the mass ratio of the thigh and the lower leg of the human leg. It will be. For this reason, the total natural frequency of the user's free leg and the leg link that moves following this will be close to the natural frequency of the free leg alone, and there will be no sense of incongruity in the operation of the free leg.

 [0010] In the present invention, it is desirable that the drive source is installed so that the center of gravity is located in a portion above the third joint portion of the first link portion. According to this, even if the mass of the first link part itself is not intentionally increased, the weight of the entire leg link can be positioned above the third joint part by the large mass of the drive source. Therefore, the mass of the entire leg link does not increase, and the moment of inertia of the leg link can be reasonably reduced.

[0011] When the drive source is composed of an electric motor and a speed reducer, the electric motor and the speed reducer may not be arranged on the same axis due to the limitation on the thickness of the leg link. In this case, it is desirable to install an electric motor above the speed reducer. In other words, the moment of inertia of the leg link can be effectively reduced by setting the position of the electric motor, which is generally heavier than the speed reducer, closer to the first joint portion than the speed reducer. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, a walking assistance device according to an embodiment of the present invention will be described. As shown in Figs. 1 and 2, the walking assist device is composed of a seating member 1 that is a load transmission unit on which a user P sits and a pair of left and right feet that are attached to the left and right feet of the user. A pair of left and right parts connected to the mounting parts 2, 2 and the seating member 1 via the first joint part 3 at the upper end and connected to both foot mounting parts 2, 2 via the second joint part 4 at the lower end, respectively. Leg links 5 and 5 are provided.

[0013] Each leg link 5 is composed of a flexible link that can change the distance between the first joint portion 3 and the second joint portion 4. That is, each leg link 5 is connected to the seating member 1 via the first joint part 3 and the upper first link part 6 connected to the foot mounting part 2 via the second joint part 4. The lower second link portion 7 is configured to be connected to bendable and extendable by a rotary third joint portion 8. Each leg link 5 is equipped with a drive source 9 for the third joint 8. The distance between the first joint part 3 and the second joint part 4 is set to each leg link 5 by driving the third joint part 8 by the drive source 9. Supports at least a part of the user's body weight (hereinafter referred to as weight-loading assist force) by measuring the force in the direction of extending the separation, that is, the force in the direction of extending each leg link 5 Let me. The weight unloading assist force generated at each leg link 5 is transmitted to the trunk of the user P via the seating member 1, and the load acting on the leg of the user P is reduced.

 [0014] The walking assist device of the present embodiment can be used simply by mounting the foot mounting portion 2 on the foot of the user P and sitting on the seating member 1, and hardly receives a sense of restraint. In addition, since the first joint 3 and the leg link 5 are located in the crotch of the user P, it is possible to swing the arm freely so that the hand does not hit the first joint 3 or the leg link 5 when swinging the arm while walking. Become. Furthermore, the device becomes smaller and can be used even in a narrow space. Combined with the reduction of the feeling of restraint and the freedom of arm swing, the usability is remarkably improved.

 [0015] The seating member 1 includes a saddle-shaped seat portion la on which the user P is seated, and a lower support frame lb that supports the seat portion la. Each first joint portion 3 for each leg link 5 includes an arcuate guide rail 31 that is provided on the lower side of the seating member 1 and that is long in the front-rear direction. Then, the leg links 5 are movably engaged with the guide rails 31 via a plurality of rollers 62 that are pivotally attached to a slider 61 fixed to the upper end of the first link portion 6. As a result, each leg link 5 swings in the front-rear direction around the center of curvature of the guide rail 31, and the swing support point in the front-rear direction of each leg link 5 becomes the center of curvature of the guide rail 31.

Referring to FIG. 1, the center of curvature of guide rail 31, that is, the swing fulcrum 3 a of each leg link 5 in each first joint 3 in the front-rear direction is located above seating member 1. Here, the user! ³ leans forward on the upper body and the action point of the weight of the upper body of the user P with respect to the seating member 1 is shifted to the front of the swinging fulcrum 3a in the front-rear direction of each leg link 5. Member 1 tilts forward. If the seating member 1 continues to incline as it is, the seating member 1 will be displaced backward with respect to the user P. However, in this embodiment, as the seating member 1 leans forward and downward, the weight action point is displaced rearward below the swinging fulcrum 3a, and the distance in the front-rear direction between the fulcrum 3a and the weight action point is the same. The rotational moment acting on the seating member 1 is also reduced. Then, when the weight application point is displaced to a position just below the swing fulcrum 3a, the rotational moment applied to the seating member 1 becomes zero, and the seating member 1 is stabilized in this state. In this way Since the seating member 1 automatically converges to a stable state, the seating member 1 can be prevented from shifting in the front-rear direction at the crotch of the user P.

 [0017] Further, the slider 61 at the upper end of each leg link 5 has a third joint 8 of each leg link 5 and a swing fulcrum 3a in the longitudinal direction of each leg link 5 (the center of curvature of the guide rail 31). The guide rail 31 is located behind the line connecting the two. As a result, a forward swinging stroke of each leg link 5 following the forward swinging of each leg of the user P can be ensured without increasing the length of the guide rail 31 to the left.

 [0018] Further, the guide rails 31 for the left and right leg links 5 are pivotally supported on the support frame lb of the seating member 1 via the support shaft 32 in the front-rear direction. Accordingly, each guide rail 31 is connected to the seating member 1 so as to be swingable in the lateral direction. Therefore, the leg link 5 is allowed to swing in the lateral direction, and the leg of the user P can be abducted.

 Each foot mounting portion 2 includes a shoe 21 and a connecting member 22 that protrudes upward from the inside of the shoe 21. The second link portion 7 of each leg link 5 is connected to the connecting member 22 via the second joint portion 4. The second joint portion 4 is configured in a three-axis structure having a first shaft 41 in the lateral direction, a second shaft 42 in the vertical direction, and a third shaft 43 in the front-rear direction. In addition, a biaxial force sensor 44 is incorporated in the second joint portion 4. Here, the weight unloading assist force is determined by the swing support 3a in the front / rear direction of the leg link 5 at the first joint 3 and the front / rear direction of the leg link 5 at the second joint 4 as viewed from the side. It acts on a line (hereinafter referred to as a reference line) L connecting the first axis 41, which is the swing fulcrum. Then, the actual weight relief assist force acting on the reference line L (more precisely, the resultant force of the weight relief assist force and the force due to the weight of the seating member 1 and each leg link 5) is detected by the force sensor 44. It is calculated based on the detected value of the force in two axes.

In addition, as shown in FIG. 1, loads acting on the middle phalangeal joint (MP joint) portion and the heel portion of the foot of the user P are applied to the lower surface of the insole 23 provided in the shoe 21. A pair of pressure sensors 24 and 24 for detection are installed. When assisting walking, first calculate the ratio of the applied load of each foot to the total load acting on both feet of the user based on the detection values of both pressure sensors 24, 24 of each foot mounting part 2. To do. Next, a value obtained by multiplying a preset weight-load assist force set value by the load ratio of each foot is calculated as a control target value of the weight-free assist force to be generated at each leg link 5. Based on the detection value of the force sensor 44, The drive source 9 is controlled so that the actual weight-free assist force calculated in this way becomes the control target value.

 Here, the drive source 9 is a force disposed on the leg link 5. Since the drive source 9 is heavy, the drive source 9 and the pivot point 3a in the front-rear direction of the leg link 5 at the first joint 3 are The distance between the center of gravity of the entire leg link 5 including the drive source 9 and the swing fulcrum 3a also increases. As a result, the moment of inertia of the leg link 5 around the oscillating fulcrum 3a increases, and the moment of inertia of the leg link 5 is increased when the user P's free leg (the leg from which the foot leaves the floor) is swung forward. As a result, the load acting on the free leg increases. Therefore, in the present embodiment, the drive source 9 is arranged so that the center of the drive source 9 is located above the third joint portion 8 of the first link portion 6, and the center of gravity of the entire leg link 5 including the drive source 9 is set. Is positioned above the third joint 8. As a result, the distance between the center of gravity of the entire leg link 5 and the swing fulcrum 3a is shortened, and the moment of inertia of the leg link 5 around the swing fulcrum 3a is reduced, acting on the free leg of the user P. To reduce the load.

 [0022] In addition, positioning the center of gravity of the entire leg link 5 above the third joint portion 8 means that the mass of the first link portion 6 is larger than the mass of the second link portion 7. Here, the thigh of a person's leg is heavier than the lower leg. Then, by positioning the center of gravity of the entire leg link 5 above the third joint part 8, the mass ratio between the first link part 6 and the second link part 7 of the leg link 5 is increased. It approaches the mass ratio. Further, the length ratio between the first link part 6 and the second link part 7 is substantially equal to the length ratio between the thigh and the lower leg of a human leg. For this reason, the total natural frequency of the user's free leg and the leg link 5 that moves following this will be close to the natural frequency of the free leg alone, and there will be no sense of incongruity in the operation of the free leg. ,.

In the present embodiment, the drive source 9 includes an electric motor 91 and a planetary gear type speed reducer 92. In this case, it is conceivable that the electric motor 91 and the speed reducer 92 are arranged coaxially so as to be positioned near the upper end of the first link portion 6. However, the lateral thickness of the leg link 5 is limited to avoid interference with the user P's leg. If the electric motor 91 and the speed reducer 92 are arranged coaxially, the thickness of the arrangement portion of the drive source 9 exceeds the thickness limit of the leg link 5, and the drive source 9 hits the leg of the user P. there is a possibility. Therefore, in the present embodiment, the electric motor 91 and the speed reducer 92 are disposed above the speed reducer 92 in the first link portion 6. Is placed so that According to this, the electric motor 91, which is heavier than the speed reducer 92, approaches the swing fulcrum 3a. Therefore, the inertia moment of the leg link 5 around the swing fulcrum 3a can be effectively reduced.

 The third joint portion 8 is driven by the electric motor 91 via the speed reducer 92 and the power transmission mechanism 10. This will be described in detail with reference to FIG. The third joint portion 8 is configured to pivotally attach the upper end portion of the second link portion 7 to the lower end portion of the first link portion 6 via a lateral joint shaft 81. The power transmission mechanism 10 includes a first crank arm portion 101 provided on the output side of the speed reducer 92, a second crank arm portion 102 integrated with the second link portion 7 extending upward from the joint shaft 81, and both clutches. It is comprised with the rod 103 which connects the link arm parts 101 and 102. According to this, the rotational output of the speed reducer 92 is transmitted to the second crank arm portion 102 via the first crank arm portion 101 and the rod 103, and the second link portion 7 is transmitted to the first link portion 6. It swings around the joint shaft 81, and the leg link 5 bends as shown in FIG. 4 from the extended state shown in FIG.

 [0025] By the way, if the leg link 5 is bent while the leg of the user P is straight, the third joint 8 protrudes forward from the knee joint of the user P, and the user P Give a sense of incongruity. Therefore, in the state where the leg of the user P is straightened, the joint axis 81 of the third joint portion 8 is positioned on the reference line L as shown in FIG. It is desired that Θ is 0 °, that is, the leg link 5 is extended.

 [0026] Here, when the leg link 5 is a simple flexion-extension link, the length of the line segment connecting the swing fulcrum 3a of the leg link 5 in the first joint 3 and the first axis 41 of the second joint 4 The expansion / contraction speed of the leg link 5 obtained by differentiating the length with the bending angle Θ of the third joint 8 becomes 0 when the bending angle Θ becomes 0 °. Therefore, when the bending angle Θ becomes 0 °, controllability in the direction in which the leg link 5 is extended, that is, the direction in which the seating member 1 is pushed up is lost. Therefore, even if the user P shifts from standing on both legs to standing on one leg and the weight-carrying assist force that should be generated on the leg link 5 on the standing leg side increases, the standing leg remains straight. If the bending angle Θ of the third joint 8 of the leg link 5 on the standing leg side is 0 °, the body weight assist force cannot be controlled properly.

Therefore, in the present embodiment, the second link portion 7 of the leg link 5 is connected to the third joint portion 8 with a cylindrical upper half 71, and the upper half 71 is slidably supported by sliding. Stretchable with lower half 72 Further, an interlocking mechanism 11 that contracts and expands the second link portion 7 in conjunction with the increase and decrease of the bending angle Θ of the third joint portion 8 is provided. Then, the interlocking mechanism 11 is set to 0 even when the expansion / contraction speed of the second link portion 7 obtained by differentiating the length of the second link portion 7 by the bending angle Θ of the third joint portion 8 makes the bending angle Θ 0 °. It is configured not to be.

 [0028] According to this, the expansion / contraction speed of the leg link 5 must not be 0 even when the bending angle Θ is 0 °. Therefore, even when the bending angle Θ becomes 0 °, the controllability in the direction in which the seating member 1 is pushed up is not lost, and the body weight assisting force can be appropriately controlled in accordance with the load change. As a result, it becomes possible for the bending angle of the third joint 8 to be 0 °, that is, the leg link 5 to be in the extended state while the leg of the user P is straightly extended. P can be used without feeling uncomfortable. The lower half 72 can be adjusted to an arbitrary length by a lock nut 73, and the leg link length can be adjusted according to the length of the leg of the user P.

 [0029] Here, the expansion / contraction drive source of the second link part 7 that moves the lower half part 72 of the second link part 7 up and down relative to the upper half part 71 and the bending angle Θ of the third joint part 8 are detected. It is also possible to provide a sensor and to configure the interlocking mechanism so that the lower half part 72 of the second link part 7 is moved up and down by operating the expansion / contraction drive source with a signal from the sensor. However, this increases the cost and increases the total weight of the leg links due to the influence of the expansion / contraction drive source. Therefore, in the present embodiment, the rotational motion around the third joint portion 8 of the upper half portion 71 of the second link portion 7 relative to the first link portion 6 is converted into the linear motion of the lower half portion 72 of the second link portion 7. The interlocking mechanism 11 is constituted by a mechanical mechanism to reduce the cost and to keep the increase in the total weight of the leg link 5 low.

More specifically, the interlocking mechanism 11 includes a first interlocking link 112 having one end pivotally attached to the upper half 71 of the second link part 7 by a shaft 111 and a second link part 7 having one end by a shaft 113. The second interlocking link 115 is pivotally connected to the other end of the first interlocking link 112 by the shaft 114, and the other end is pivotally connected to the first link portion 6 by the shaft 116. At the same time, it is constituted by a link mechanism comprising a third interlocking link 118 pivotally attached to the middle part of the first interlocking link 112 by the shaft 117 at the other end. According to this, the quadrangular shape connecting the joint shaft 81, the shaft 111, the shaft 117, and the shaft 116 of the third joint portion 8 is the third portion of the upper half portion 71 of the second link portion 7 with respect to the first link portion 6. Deformation is caused by the displacement of the axis 111 due to the rotational movement around the joint 8 and the angle between the line segment connecting the axis 114 and the axis 111 and the line segment connecting the axis 114 and the axis 113 is accompanied by this deformation. Changes. Due to this angle change, axis 111 and axis 113 The distance between the lower half 72 of the second link portion 7 moves linearly in the longitudinal direction (vertical direction) with respect to the upper half 71. When the bending angle Θ of the third joint portion 8 decreases, as shown in FIG. 1, the lower half 72 moves downward, the length of the second link portion 7 increases, and the bending angle Θ increases. At this time, as shown in FIG. 4, the lower half portion 72 moves upward and the length of the second link portion 7 decreases. Note that the interlock mechanism 11 can be configured not only by the link mechanism of the present embodiment but also by a cam mechanism or a rack and pinion mechanism.

 By the way, when the first joint portion 3 is configured to include the arc-shaped guide rail 31 as described above, a space between the first rail portion 3 and the guide rail 13 is formed below the seating member 1. Therefore, in order to make effective use of this space, the battery 12 for the drive source 9, the controller 13, and the motor driver 14 are placed in the space between the guide frame 31 and the support frame lb of the seating member 1. Place it.

 [0032] Here, in order to reduce the moment of inertia around the swing fulcrum 3a of the first joint 3 of the leg link 5, the driving source 9 which is a heavy load should be arranged at a height position higher than the third joint 8. Is desired. In the present embodiment, the drive source 9 is disposed above the third joint portion 8 of the first link portion 6 as described above. A heavy battery 12 is also arranged on the seating member 1 higher than the third joint 8. When the drive source 9 and the battery 12 are arranged at a high position in this manner, the weight of the drive source 9 and the battery 12 causes the leg link 5 to be connected to the second joint 4 when the user P is standing upright. A tilting moment in the front-rear direction around the single axis 41 is likely to occur, and a pushing force in the front-rear direction acts on the seating member 1 by this tilting moment.

Therefore, in this embodiment, the occurrence of the tilting moment can be suppressed. This will be explained by defining the state of the leg link 5 when the user P stands upright as the reference state (the state shown in FIG. 1). The drive source 9 and the battery 12 which are heavy objects, in the reference state of the leg link 5, are surfaces that pass through the first shaft 41 of the second joint portion 4 and are parallel to the horizontal direction, i.e., the frontal surface (this embodiment) The front face is substantially aligned with the reference line L) so that it passes through the front-rear width of the drive source 9 and the front-rear width of the battery 12. According to this, the offset distance in the front-rear direction of the center of gravity of the drive source 9 and the center of gravity of the battery 12 with respect to the front frame is shortened. Therefore, in the reference state of the leg link 5, the tilt of the second joint 4 generated in the leg link 5 due to the weight of the drive source 9 and the battery 12 about the first axis 41 about the front and rear direction. The dynamic moment is reduced. As a result, in the state where the user P is standing upright, the forward and backward pushing force acting on the seating member 1 is also reduced by this tilting moment, and the stability is improved.

 It should be noted that the battery 12 can be disposed in the first link portion 6 of the leg link 5. However, if the battery 12 is arranged on the seating member 1 as in the present embodiment, the mass of the battery 12 2 is not added to the leg link 5, so that the moment of inertia of the leg link 5 can be reduced as much as possible. .

 As described above, the embodiment described with reference to the drawings for the embodiment of the present invention is not limited to this. For example, in the above embodiment, the electric motor 91 and the speed reducer 92 that constitute the drive source 9 are both disposed in a portion above the third joint portion 8 of the first link portion 6. It is possible to arrange the electric motor 91 coaxially with the three joint portions 8 and to place the electric motor 91 in a portion above the third joint portion 8 of the first link portion 6. Also in this case, the total center of gravity of the electric motor 91 and the speed reducer 92, that is, the center of gravity of the drive source 9 is positioned above the third joint portion 8 of the first link portion 6.

 [0036] In the above-described embodiment, each leg link 5 is formed of a flexible link having a pivotable third joint 8 in the middle, but has a direct-acting third joint. The leg link may be composed of an elastic link. Further, in the above-described embodiment, the first joint portion 3 is configured to have an arcuate guide rail 31, and the swing fulcrum 3 a in the front-rear direction of each leg link 5 in the first joint portion 3 is used as the seating member 1. The force that is positioned above The first joint portion 3 may be configured by a joint portion of a simple structure having a lateral shaft that pivotally supports the upper end portion of each leg link 5 so as to be swingable in the front-rear direction. Is possible. It is also possible to configure the load transmission part with a harness that is worn around the user's waist. Furthermore, in order to assist a user who is inconvenient due to a broken leg or the like on one leg, only the leg link on the leg side that is inconvenient to the user is left out of the left and right leg links 5 and 5 of the above embodiment. It is also possible to omit the other leg link. Brief Description of Drawings

 FIG. 1 is a side view of a walking assistance device according to an embodiment of the present invention.

 FIG. 2 is a front view of the walking assist device of the embodiment.

FIG. 3 is a perspective view of the vicinity of a third joint part of a leg link of the walking assistance device according to the embodiment. 4] A side view when the leg link of the walking assistance device of the embodiment is bent.

Explanation of symbols

 1 ... Seating member (load transmission part), 2 ... Foot mounting part, 3 ... First joint part, 4 ... Second joint part, 5 ... Leg link, 6 ... First link part, 7 ... Second link part, 8 ... 3rd joint part, 9 ... Drive source, 91 ... Electric motor, 92 ... Reducer.

Claims

The scope of the claims  [1] It includes a load transmission part, a foot attachment part to be attached to the user's foot, and a leg link between the load transmission part and the foot attachment part, and transmits the force generated by the leg link. A walking assistance device that is transmitted to a user's trunk through a section,  The leg link includes an upper first link portion connected to the load transmitting portion via the first joint portion, a lower second link portion connected to the foot attachment portion via the second joint portion, An intermediate third joint that connects the first link and the second link so that the distance between the joint and the second joint is variable; and a drive source that drives the third joint. In what consists of:  A walking assist device characterized in that the center of gravity of the entire leg link is located above the third joint.  [2] The walking assist device according to claim 1, wherein the driving source is installed so that a center of gravity of the driving source is positioned above a portion of the first link portion above the third joint portion.  3. The walking assist device according to claim 2, wherein the drive source includes an electric motor and a speed reducer, and the electric motor is installed at a position above the speed reducer.