JP2556095Y2 - Torque detector for electric power steering - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric power steering mounted on a vehicle. In a conventional electric power steering, for example, a steering wheel 21 is rotatably mounted on a vehicle body as shown in FIG. 6, and the input shaft 1 is fixed to the steering wheel 21 and a steering force transmission gear 20 is attached to the input shaft 1. Is fixed, and a steering gear 16 fixed to a power transmission device 18 of a steering and driving wheel 19 is engaged with the steering force transmission gear 20, and the steering force is transmitted from the steering wheel 21 to the input shaft 1, the steering force transmission gear 20, The structure was such that the power was transmitted to the steering and driving wheels 19 via the steering gear 16 and the power transmission device 18. Further, a servo motor 15 is disposed on the vehicle body, and a steering force transmission gear 20 is provided on an output shaft of the servo motor 15 with a steering / drive wheel 19.
And a servo motor 15 according to a detection signal of a torque detector (not shown) fixed to the input shaft 1.
Are driven to assist the steering force via the steering gear 16. As described above, in the conventional electric power steering device, the steering force transmission gear 20 of the input shaft 1 and the steering gear 16 of the power transmission device 18 transmit power at a fixed position. Therefore, when the vehicle travels on a large uneven road surface or a curb on a road shoulder, a phenomenon called kickback in which the steering reaction force is directly transmitted to the steering wheel 21 occurs. twenty one
Accident was hit by the. In the present invention. The input shaft 1 for inputting the steering force is the first rotary power transmission element, the output shaft 2 for outputting the steering force is the fourth rotary power transmission element, the first floating shaft 10 is the second rotary power transmission element, The idler shaft 11 is provided with a third rotary power transmission element, respectively, the first rotary power transmission element and the second rotary power transmission element, the second rotary power transmission element and the third rotary power transmission element, the third rotary power transmission element, The fourth rotary power transmission element is connected to each other, and the input shaft 1 and the first floating shaft 10, the first floating shaft 10 and the second floating shaft 11, and the second floating shaft 11 and the output shaft 2 are connected by a link, A second rotation power transmission element and a third rotation are provided by a link mechanism having the input shaft 1, the output shaft 2, the first floating shaft 10, and the second floating shaft 11 as connection points, and a spring 12 for holding the link at a fixed position. Holding the power transmission element, the second rotary power transmission element surrounds the first rotary power transmission element, Rotating power transmission element is an electric power steering, characterized in that revolves around the fourth rotating power transmission element respectively,
The above problem has been solved. An embodiment of the present invention will be described with reference to the drawings in a first embodiment in which a rotary power transmission element is a gear. FIG. 1 is a plan view of the first embodiment of the present invention, and FIG. FIG. 2 is a front view of the first embodiment. A steering wheel is provided on the input shaft 1 for transmitting the steering force.
21 is connected by a chain 22 or the like, and transmits the rotation direction and magnitude to the input shaft 1 by rotating the steering wheel 21. A first large gear 3 is fixed to a lower portion of the input shaft 1, and a second large gear 4 is fixed to the output shaft 2 so as not to mesh with the steering wheel 21. The first small gear 5 is fixed to the first floating shaft 10, the first small gear 5 meshes with the first large gear 3, and the first floating shaft 10 is connected to the input shaft 1 by the first link 7. Is held. The second small gear 6 is fixed to the second floating shaft 11, the second small gear 6 meshes with the second large gear 4, and the second floating shaft 11 is connected to the input shaft 1 by the third link 9. Is held. The first small gear 5 and the second small gear 6 mesh with each other, and
The first floating shaft 10 and the second floating shaft 11 are linked by a second link 8, and are a link mechanism that forms a quadrilateral with a plurality of gears and links. A spring 12 is provided at the center of the second link 8 and serves as a restoring force of the link mechanism. With these structures, the steering force applied to the steering wheel 21 is transmitted from the input shaft 1 to the first large gear 3, the first small gear 5, the second small gear 6, the second large gear 4, and the output shaft 2. The steering and driving wheels 19 are steered. Further, when the vehicle passes over large irregularities on the road surface or curbs on the road shoulder during traveling, the first small gear 5 surrounds the first large gear 3 and the second small gear 6 surrounds the second large gear 4. Revolves around
The quadrilateral composed of a plurality of gears and links has a structure in which kickback is absorbed by a deformable link mechanism. When deformed, the amount of deformation is detected by the torque detector 13, a command is issued from the controller 14 to the servomotor 15, and the motor is driven until the deformation returns. In addition to the above, in the present embodiment, as an electric power steering device, a servo motor 15 is arranged inside the vehicle body to assist the steering force of the steering and driving wheels 19, and the servo motor 15 is connected to a torque detector 13 described later. Is rotated via the controller 14 in accordance with the detected value of the second wheel 4 to rotate, for example, the second large gear 4 to assist the rotation of the steering and driving wheels 19. As shown in FIG. 2, the torque detector 13 in this embodiment is disposed on the input shaft 1 and the like, and in addition to the torque detector 13b for detecting the shaft rotational force, as shown in FIG. And two torque detectors 13a fixed to the second floating shaft 11 and detecting a torque force by deformation of a quadrilateral formed by a plurality of gears and links, and may be installed according to the space inside the vehicle body. it can. FIG. 3 shows an example in which the output shaft 2 in the first embodiment of the present invention is a power transmission device 18 in which the steering and driving wheels 19 are arranged at the lower part. Next, the rotary power transmission element will be described with reference to the drawings in a second embodiment using a sprocket wheel and a chain 22. FIG. 4 is a plan view of the second embodiment of the present invention, and FIG. It is a front view of two examples. A steering wheel is provided on the input shaft 1 for transmitting the steering force.
The steering wheel 21 is rotated to transmit the rotation direction and magnitude to the input shaft 1 by rotating the steering wheel 21. The first large sprocket wheel is located below the input shaft 1.
33 is fixed to the output shaft 2 and the second large sprocket wheel
34 is fixed. In the second embodiment, the steering force transmitted to the output shaft 2 is the steering force transmitting gear 20, the steering gear 16,
The steering and driving wheels 19 are steered via the power transmission device 18. A first small sprocket wheel 35 is fixed to the first floating shaft 10, the first small sprocket wheel 35 is connected to the first large sprocket wheel 33 by a chain 22, and the first floating shaft 10 is It is held while being connected by one link 7. A third small sprocket wheel is fixed to the second floating shaft 11, the second small sprocket wheel is connected to the second large sprocket wheel 34 by a chain 22, and the second floating shaft 11 is connected to the input shaft 1 and the third link. 9 and held together. The second small sprocket wheel 36 and the third small sprocket wheel are connected by the chain 22, and the first idle shaft 10
And the second floating shaft 11 are linked by a second link 8, and are a link mechanism that forms a quadrilateral with a plurality of gears and links. A spring 12 is provided at the center of the second link 8 and serves as a restoring force of the link mechanism. With these structures, the steering force applied to the steering wheel 21 is changed from the input shaft 1 to the first large sprocket wheel 33, the first small sprocket wheel 35, the second small sprocket wheel 36, the second large sprocket wheel 34, and the output shaft 2 And the steering wheel 19 is steered. Furthermore, if the vehicle passes over large unevenness on the road surface or curbs on the shoulder of the road, the first small sprocket wheel 35
Is revolving around the first large sprocket wheel 33 and the second small sprocket wheel 36 revolves around the second large sprocket wheel 34, and the quadrilateral composed of multiple sprocket wheels and links is kicked by a deformable link mechanism. It is a structure that absorbs the back. When deformed, the amount of deformation is detected by the torque detector 13, a command is issued from the controller 14 to the servomotor 15, and the motor is driven until the deformation returns. That is, in the second embodiment, the gears of the first embodiment are merely replaced with sprocket wheels, and the operation is the same. Further, the servomotor 15, the controller 14, and the torque detector 13 can be installed according to the space inside the vehicle body as in the first embodiment. Thus, the first rotary power element is the first large gear 3, the second rotary power element is the first small gear 5, the third rotary power element is the second small gear 6, and the fourth rotary power element is the second large gear 4. For example, it is possible to implement by replacing with various rotary power elements. Since the present invention has the above-described configuration, even when the vehicle runs on a large uneven surface of a road or a curb on a road shoulder as in the case of the conventional electric power steering, the kickback does not occur, and the work can be performed without any kickback. The accident that the user hits the arm or the like with the steering wheel 21 is eliminated. Further, the transmission force of the kickback can be adjusted by the spring 12, and can be freely adjusted even when an operator demands a certain weak kickback for grasping the road surface condition.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention, FIG. 1 is a plan view using gears as a rotary power transmission element, FIG. 2 is a front view of FIG. 1, and FIG. FIG. 4 is a front view in which the output shaft 2 is a power transmission device 18, FIG. 4 is a plan view of a sprocket wheel and a chain 22 as rotary power transmission elements, FIG. 5 is a front view in FIG. 4, and FIG. It is a front view of an electric power steering. 1 input shaft 2 output shaft 3 first large gear 4 second large gear 5 first small gear 6 second small gear 7 first link 8 second link 9 Third link 10 First floating shaft 11 Second floating shaft 12 Spring 13 Torque detector 14 Controller 15 Servo motor 16 Steering gear 18 Power transmission Device 19: Steering and driving wheel 20: Steering force transmission gear 21: Steering wheel 22: Chain 33: First large sprocket wheel 34 ... Second large sprocket wheel 35 ... First small sprocket wheel 36 ... … Second small sprocket wheel

Claims (1)

(57) [Rules for requesting registration of utility model] The input shaft 1 for inputting the steering force is the first rotary power transmission element, the output shaft 2 for outputting the steering force is the fourth rotary power transmission element, the first floating shaft 10 is the second rotary power transmission element, The idler shaft 11 includes a third rotational power transmission element, respectively, the first rotational power transmission element and the second rotational power transmission element, the second rotational power transmission element and the third rotational power transmission element, the third rotational power transmission element, The fourth rotating power transmission element is connected to each other, and the input shaft 1 and the first floating shaft 10, the first floating shaft 10 and the second floating shaft 11, and the second floating shaft 11 and the output shaft 2 are connected by a link, A second rotation power transmission element and a third rotation are provided by a link mechanism having the input shaft 1, the output shaft 2, the first floating shaft 10, and the second floating shaft 11 as connection points, and a spring 12 for holding the link at a fixed position. Holding the power transmission element, the second rotary power transmission element around the first rotary power transmission element, An electric power steering, wherein the third rotary power transmission element revolves around the fourth rotary power transmission element.