INCORPORATION BY REFERENCE

The disclosures of Japanese Patent Applications No. 2018-33292 and No. 2018-164901 respectively filed on Feb. 27, 2018 and Sep. 3, 2018, each including the specification, drawings and abstract, are incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a walking assist device.

2. Description of the Related Art

In order for a user that can walk on his/her own to walk with better quality, it is very important to swing his/her arms correctly in synchronization with his/her legs in a correct posture with his/her body trunk straight without leaning on a walker.

Japanese Patent Application Publication No. 2017-12546 (JP 2017-12546 A), for example, describes a hand cart (corresponding to the walking assist device) that generates an assist force for assisting movement of the hand cart in a travel direction in accordance with the magnitude and the direction of a handle force which is a force with which a user pushes the hand cart while grasping handlebars (corresponding to the fixed handles). The hand cart has a rotational angle sensor and an inclination angle sensor, and can travel while driving wheels such that the user can walk stably by pushing the hand cart on the basis of information such as the travel direction and the inclination angle of the vehicle body in various use situations.

The hand cart described in JP 2017-12546 A drives the wheels in accordance with a force applied to the hand cart on the assumption that the user “pushes” or “pulls” the hand cart. That is, the hand cart travels while assisting a force applied to the hand cart by the user. Thus, the user always receives assist from the hand cart during use of the hand cart, which alleviates a load on his/her body due to the hand cart. A hand cart with such a walking assist function is often used in the case where elderly people or people that need assistance to walk, in particular. While such a hand cart increases opportunities to walk and facilitates activities, however, the hand cart gradually decreases the physical strength of the user by weakening his/her muscle strength, since the hand cart alleviates a physical load on the user by assisting a force applied to the hand cart by the user.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a walking assist device that can assist a user in walking and maintain the physical strength of the user by applying a moderate load.

An aspect of the present invention provides a walking assist device including:a frame;an arm portion provided on the frame and having a grasp portion that is graspable by a user,a plurality of wheels provided at a lower end of the frame and including at least one drive wheel;a drive unit that drives the drive wheel to cause the walking assist device to travel forward or rearward;a battery that serves as a power source for the drive unit;a drive control unit that controls the drive unit; andan operation mode switching unit.

The walking assist device travels forward or rearward together with the user who walks while grasping the grasp portion.

The operation mode switching unit switches between a training mode, in which a load is applied to operation of a body of the user performed as the user walks, and an assist mode, in which a load on operation of the body of the user performed as the user walks is alleviated.

With the walking assist device according to the aspect described above, in the case where the operation mode of the walking assist device is switched to the training mode and in the case where the walking assist device is caused to travel forward or rearward with the user grasping the grasp portion, the walking assist device can apply a load to operation (walk and arm swing) of the body of the user performed during walk. In the case where the operation mode of the walking assist device is switched to the assist mode and in the case where the walking assist device is caused to travel forward or rearward with the user grasping the grasp portion, the walking assist device can alleviate the load on operation (walk) of the body of the user performed during walk. Consequently, it is possible to assist the user in walking, and to suppress a decrease in (maintain) the physical strength of the user by applying a moderate load at the same time.

The walking assist device according to the aspect described above may further include:

a state detection unit that detects at least one of a state of the grasp portion, a state of the walking assist device, a body state of the user, and an atmospheric state around the user; and

a load amount and assist amount change unit that changes a magnitude of the load on the basis of a detection signal from the state detection unit in the training mode, and that changes a magnitude of an assist force on the basis of the detection signal from the state detection unit in the assist mode.

With the aspect described above, the walking assist device has the state detection unit, and can acquire information on at least one of the state of the user grasping the grasp portion, the state of the walking assist device, the body state of the user, and the atmospheric state around the user. The walking assist device can change the magnitude of the load in the training mode, and the magnitude of the assist force in the assist mode, through the load amount and assist amount change unit on the basis of the acquired information. Consequently, the walking assist device can assist the user in walking appropriately in accordance with various states, and can suppress a decrease in physical strength.

