JP2015189310A - steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering device in which a bending load applied to an output shaft is suppressed and an arrangement space required for a controller is saved.SOLUTION: A steering arm 161 comprises a hole for an output shaft into which an output shaft 22 is fitted, two holes 172 for tie rods to which tie rods 8 are attached respectively and two abutting surfaces 176 which are abutted on a stopper 162. The stopper comprises two abutting surfaces 186, where an angle θst1 formed by two contacting surfaces of the stopper is larger than an angle θar1 formed by the two abutting surfaces of the steering arm and equal to 90° or more.

Description

  The present invention relates to a steering device.

  For example, a straddle-type vehicle such as an ATV (All Terrain Vehicle) has a steering device (particularly an electric power steering device) between a steering shaft on a steering wheel side and a steering member on a wheel (front wheel) side. It is intervened. The electric power steering device is a device that assists the steering force applied by the driver to the steering wheel by the torque generated by the electric motor.

  The electric power steering apparatus incorporates members such as an input shaft, a torsion bar, and an output shaft. The input shaft is connected to the steering shaft on the handle side. The torsion bar connects the input shaft and the output shaft. A steering arm is attached to the output shaft (see, for example, Patent Document 1).

  The steering arm is a steering member on the wheel (front wheel) side. The steering arm is configured to rotate about the output shaft. The steering arm is provided with a tie rod hole to which a tie rod is attached. Wheels are connected to the tie rod.

  The electric power steering device needs to regulate the turning of the steering wheel so that the vehicle does not roll over when the driver tries to turn the steering wheel beyond the maximum turning angle in the clockwise direction or the counterclockwise direction. is there. In addition, even when the vehicle is not driven by the driver, the external force is input to the electric power steering device and the handle through the wheel (front wheel) by a projection (projection) on the road surface when traveling on a rough road. May try to rotate beyond the maximum steering angle. Also in this case, the electric power steering apparatus needs to regulate the rotation of the handle so that the vehicle does not roll over. The electric power steering apparatus is provided with an arm stopper mechanism that restricts the turning angle of the steering arm with a stopper.

  The stopper is provided so as to protrude downward from the lower surface side of the housing of the electric power steering apparatus. When the driver tries to turn the steering wheel beyond the maximum turning angle in the clockwise direction or counterclockwise direction, or when the external force is input through the wheel (front wheel), the steering wheel will turn beyond the maximum steering angle. In this case, the abutment surface provided on the steering arm abuts against the contact surface of the stopper. Accordingly, the arm stopper mechanism restricts the turning angle of the steering arm by the stopper, and accordingly, restricts the turning of the handle.

  In such an electric power steering apparatus, when the bending load applied to the output shaft becomes large, an excessive load may be applied to the bearing supporting the output shaft and the surrounding housing. Therefore, it is desirable for the electric power steering device to suppress a bending load applied to the output shaft.

JP 2007-196927 A (FIG. 2)

  However, as described below, the conventional electric power steering apparatus is not configured to suppress the bending load applied to the output shaft by the conventional arm stopper mechanism, so that a relatively large bending load is output. There was a problem that it might be applied to the shaft.

  For example, when the abutting surface on one side of the steering arm and the abutting surface on one side of the stopper are abutting, the bending load vector applied to the output shaft and bending the output shaft is input from the wheel side via the tie rod. And a combined vector value obtained by synthesizing the abutting load vector applied from the stopper to the abutting surface of the steering arm.

  Therefore, the bending load vector increases as the angle between the direction of the input load vector and the direction of the abutting load vector decreases, and conversely, the direction of the input load vector and the direction of the abutting load vector The value tends to decrease as the angle formed by increases.

  Therefore, for example, when the angle formed between the direction of the input load vector and the direction of the abutting load vector is an acute angle (0 to less than 90 °), the bending load vector is calculated as follows. The value is larger than the value of the combined vector when it is orthogonalized. On the other hand, if the angle between the direction of the input load vector and the direction of the abutting load vector is an obtuse angle (90 to 180 °), the bending load vector temporarily makes the input load vector and the abutting load vector orthogonal to each other. The value is less than or equal to the value of the combined vector.

  The direction of the input load vector is determined by the mounting direction of the tie rod mounted in the tie rod hole when the abutting surface of the steering arm and the contact surface of the stopper are in contact. The direction of the abutting load vector is a direction perpendicular to the abutting surface of the steering arm (or the contact surface of the stopper). The position where the abutting load vector is applied is the center position of the part where the abutting surface of the steering arm and the abutting surface of the stopper abut (hereinafter referred to as “abutting center position”).

  Here, an imaginary straight line extending in the front-rear direction of the vehicle through a center point in the width direction of the vehicle is referred to as a “center line of the entire vehicle”, and the straight lines virtually arranged along the two contact surfaces are The point on the center line of the entire vehicle that intersects will be described as the “starting point of the contact surface”.

  By the way, in the conventional arm stopper mechanism, the angle formed between the two contact surfaces of the stopper (the angle between the two contact surfaces and the angle formed inside the stopper (for example, FIG. 19B) Is an angle formed by two abutting surfaces of the steering arm (an angle between the two abutting surfaces, and an angle formed inside the steering arm (for example, FIG. 18B)). For example, the angle formed between the two abutting surfaces of the steering arm is set to 180 °, and the angle formed between the two abutting surfaces of the stopper is set to 90 ° so that the angle is smaller than the angle θar)). It was set to °.

  In the conventional arm stopper mechanism, since the angle between the two contact surfaces of the stopper is set to 90 °, the two abutting center positions are centered on the “starting point of the contact surface” and “the entire vehicle It is provided at a position of 45 ° to the left and right from the “center line”.

  In such a conventional arm stopper mechanism, when the abutting surface on one side of the steering arm and the abutting surface on one side of the stopper are abutting, the abutting load vector is 45 ° from the “center line of the entire vehicle”. Takes its abutment center position in the direction. In addition, the conventional arm stopper mechanism has a tie rod mounting direction around the tie rod hole so that the input load vector is at an acute angle (0 to less than 90 °) with the abutment load vector. Such (see FIG. 20).

  Such a conventional arm stopper mechanism is not configured in consideration of the angle formed by the direction of the input load vector and the direction of the abutting load vector as described above. Therefore, the conventional electric power steering apparatus using the conventional arm stopper mechanism may have a relatively large bending load applied to the output shaft. In this case, the bearing supporting the output shaft and the surrounding housing In some cases, an excessive load was applied.

  In this regard, the inventor of the present invention has a configuration in which the bending load vector is a combined vector of the input load vector and the abutting load vector, so that the input load vector and the abutting load vector act so as to cancel each other. It was thought that the bending load could be suppressed if it was made.

  Then, the inventor of the present invention makes the relationship between the angle formed by the two contact surfaces of the stopper and the angle formed by the two abutment surfaces of the steering arm reverse to the relationship in the conventional arm stopper mechanism. (In other words, the angle formed between the two abutment surfaces of the stopper is larger than the angle formed between the two abutment surfaces of the steering arm). It was considered that if the arm stopper mechanism is configured such that the angle between the contact surfaces is set to be equal to or greater than the angle (90 °) of the conventional arm stopper mechanism, the bending load can be suppressed.

  In the conventional electric power steering apparatus, as shown in FIG. 22, a controller 122 that controls the electric motor 121 is attached to a vehicle (not shown) as a separate body at a position away from the electric motor 121. The controller 122 controls the electric motor 121 based on the detected torque signal from the torque sensor 124 housed in the housing 123 of the electric power steering device. The controller 122 is connected to the electric motor 121 and the torque sensor 124 via a motor harness 125 and a detection signal harness 126, respectively. The controller 122 is also connected to the battery and the vehicle body side control device.

  As described above, conventionally, since the controller 122 is located away from the electric motor 121, the wiring space for the motor harness 125 and the detection signal harness 126 is increased, and there is a problem that the wiring work of the harness tends to be troublesome. Further, since a separate protective housing for the controller 122 is required, there is a problem in that the arrangement space for the controller 122 is increased and the weight is increased accordingly.

  The present invention has been made in order to solve the above-described problems, and it is a main object of the present invention to provide a steering device capable of suppressing a bending load applied to an output shaft and saving the arrangement space required for a controller. And

  To achieve the above object, the present invention provides an input shaft connected to a steering shaft coupled to a steering handle, an output shaft connected to the input shaft, a sensor for detecting a steering state of the steering handle, and a motor A controller that controls the motor based on a detection signal from the sensor, a torque transmission mechanism that transmits torque generated by the motor to the output shaft, a wheel that rotates about the output shaft, and a wheel A steering arm to which two tie rods connected to each other are attached, and a stopper that is provided around the output shaft and regulates a rotation angle of the steering arm. An output shaft that is provided on the center line and fitted with the output shaft is a virtual straight line extending in the front-rear direction of the vehicle through the output shaft. A hole, two tie rod holes provided at positions on the left and right of the center line and behind the hole for the output shaft, to which the tie rods are respectively attached, and a position on the left and right of the center line and the output Two abutting surfaces provided behind the shaft hole and abutted against the stopper, wherein the stopper is positioned on the left and right of the center line and the There are provided two contact surfaces that are provided at positions in the rotational direction and respectively contact the abutting surface, and an angle formed by the two contact surfaces of the stopper is determined by the two protrusions of the steering arm. It is larger than an angle formed between the surfaces for the time being and is 90 ° or more, and the controller is housed in the casing of the motor.

  The bending load vector is a combined vector of the input load vector and the abutting load vector. Therefore, the bending load can be suppressed by causing the input load vector and the abutting load vector to cancel each other. The configuration in which the input load vector and the abutting load vector cancel each other is realized by increasing the angle formed by the direction of the input load vector and the direction of the abutting load vector. The configuration that increases the angle between the direction of the input load vector and the direction of the abutment load vector is the angle between the centerline of the steering arm and the abutment surface (the angle between the centerline of the steering arm and the abutment surface). Thus, by reducing the angle formed inside the steering arm, for example, the angle θ176 shown in FIG. 8B, and the angle formed by the center line of the stopper and the contact surface relative thereto, This can be realized by increasing the angle between the center line of the stopper and the contact surface, which is formed inside the stopper (for example, the angle θ186 shown in FIG. 9B). .

  In the steering device according to the present invention, the angle formed between the two contact surfaces of the stopper is set to be larger than the angle formed between the two contact surfaces of the steering arm and 90 ° or more. With such a configuration, the direction of the input load vector and the abutting load vector can be made to cancel each other. As a result, the steering device according to the present invention can suppress the value of the bending load vector applied to the output shaft, and thus can suppress the bending load applied to the output shaft. Thereby, the steering device according to the present invention can reduce the load applied to the bearing supporting the output shaft and the surrounding housing.

And since the controller is accommodated in the housing of the motor, a space for arranging the controller separately from the motor as in the prior art becomes unnecessary. Therefore, the space required for the controller can be saved. Since the controller is protected by the motor housing, it is not necessary to provide a separate protective housing for the controller, and the weight can be reduced accordingly.
Further, since the connecting portion between the controller and the motor is housed in the housing, the motor harness for connecting the controller and the motor is not exposed to the outside as in the conventional case. Therefore, the wiring work of the motor harness becomes unnecessary. Since the motor harness is not exposed to the outside, for example, when the present invention is applied to a saddle riding type vehicle, the problem of damage to harnesses under severe use conditions of the saddle riding type vehicle can be reduced.
Further, the detection signal harness for connecting the controller and the sensor can be shortened as compared with the conventional case, so that the detection signal harness can be easily routed.

In the steering device according to the present invention, preferably, an angle formed by the two contact surfaces of the stopper is 180 ° or more.
The steering device having this configuration rotates the steering arm around the output shaft within a range where there is no stopper. Therefore, the steering apparatus has an angle of 360 ° in the entire circumferential direction centering on the output shaft, an angle formed by the two contact surfaces of the stopper (see, for example, the angle θst1 shown in FIG. 7), and 2 of the steering arm. The total angle (for example, shown in FIG. 7) of the angle between the two abutting surfaces (see, for example, the angle θar1 shown in FIG. 7), the maximum turning angle in the clockwise direction of the steering arm and the maximum turning angle in the counterclockwise direction. The angle θdr1).
For this reason, when the angle formed between the two contact surfaces of the stopper is increased, the steering device is configured to decrease the angle formed between the two abutting surfaces of the steering arm. It can be configured in a small size.
In the steering device having this configuration, the angle formed between the two contact surfaces of the stopper is increased to 180 ° or more, and therefore, the angle formed between the two contact surfaces of the steering arm is further reduced. As a result, the steering device having this configuration can further reduce the size of the steering arm.
Further, in the steering device having this configuration, since the steering arm is further reduced in size, the portion to which the abutting load vector is applied (that is, the central position of the portion where the abutting surface of the steering arm and the abutting surface of the stopper abut) is arranged. The input load vector can be brought close to the periphery of the tie rod hole. Therefore, the steering device with this configuration can efficiently suppress vibration.

In the steering device according to the present invention, preferably, a total value of an angle formed between the two contact surfaces of the stopper and an angle formed between the two abutting surfaces of the steering arm is 270 ° or less. .
By satisfying this condition, the steering device with this configuration can ensure an angle of 90 ° or more as the total angle of the maximum turning angle in the clockwise direction and the maximum turning angle in the counterclockwise direction of the steering arm.

  According to the present invention, a bending load applied to the output shaft can be suppressed. Further, the space required for the controller can be saved.

It is a mimetic diagram showing a schematic structure of a saddle riding type vehicle. It is a schematic block diagram of the electric power steering device provided with the arm stopper mechanism according to the first embodiment, viewed from the side surface direction. It is a schematic block diagram inside the electric power steering device provided with the arm stopper mechanism according to the first embodiment. It is a schematic block diagram between the steering arm of the arm stopper mechanism which concerns on 1st Embodiment, and a front wheel seen from the upper surface direction. It is explanatory drawing which shows typically the operation | movement relationship between the steering arm of the arm stopper mechanism which concerns on 1st Embodiment, and a front wheel seen from the lower surface direction. It is explanatory drawing of the load vector concerning a steering arm of the arm stopper mechanism which concerns on 1st Embodiment. It is a schematic block diagram of the arm stopper mechanism which concerns on 1st Embodiment seen from the lower surface direction. It is a schematic block diagram of the steering arm of the arm stopper mechanism which concerns on 1st Embodiment seen from the lower surface direction. It is a schematic block diagram of the stopper of the arm stopper mechanism which concerns on 1st Embodiment seen from the lower surface direction. It is a schematic diagram which shows the ideal structure of each site | part of the steering arm of the arm stopper mechanism which concerns on 1st Embodiment. It is explanatory drawing of the load vector concerning the principal part of the arm stopper mechanism which concerns on 1st Embodiment. It is a schematic block diagram of the arm stopper mechanism which concerns on 2nd Embodiment seen from the lower surface direction. It is a schematic block diagram of the steering arm of the arm stopper mechanism which concerns on 2nd Embodiment seen from the lower surface direction. It is a schematic block diagram of the stopper of the arm stopper mechanism which concerns on 2nd Embodiment seen from the lower surface direction. It is explanatory drawing of the load vector concerning the principal part of the arm stopper mechanism which concerns on 2nd Embodiment. It is a schematic block diagram of the electric power steering device provided with the arm stopper mechanism which concerns on the comparative example seen from the side surface direction. It is a schematic block diagram of the arm stopper mechanism which concerns on the comparative example seen from the lower surface direction. It is a schematic block diagram of the steering arm of the arm stopper mechanism which concerns on the comparative example seen from the lower surface direction. It is a schematic block diagram of the stopper of the arm stopper mechanism which concerns on the comparative example seen from the lower surface direction. It is explanatory drawing of the load vector concerning the principal part of the arm stopper mechanism which concerns on a comparative example. It is a schematic diagram which shows the relationship between an input load vector, an abutting load vector, and a bending load vector. It is a block diagram of the power steering apparatus which shows the example of arrangement | positioning of the conventional controller.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings. Each figure is only schematically shown so that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated example. Moreover, in each figure, the same code | symbol is attached | subjected about the common component and the same component, and those overlapping description is abbreviate | omitted.

  Here, the directions of “up”, “down”, “front”, “rear”, “left”, and “right” are based on the direction of the vehicle. In addition, in the drawings, there are drawings having a configuration as viewed from the lower side of the vehicle. In these drawings, it appears as if the directions of “left” and “right” are reversed. However, since the “left” and “right” directions are directions in the configuration viewed from the lower side of the vehicle, they are as shown in the drawings.

<< First Embodiment >>
Hereinafter, the configuration of the arm stopper mechanism 160 (see FIG. 2) of the steering device according to the first embodiment will be described. Here, in order to explain the features of the arm stopper mechanism 160 according to the first embodiment in an easy-to-understand manner, description will be given in the following order.
1: Schematic configuration of saddle riding type vehicle and electric power steering device 2: Schematic configuration between steering arm and wheel (front wheel) 3: Load vector applied to steering arm 4-1: Configuration of arm stopper mechanism according to comparative example 4-2: Load vector applied to main part of arm stopper mechanism according to comparative example 5: Relationship between input load vector and abutting load vector and bending load vector 6-1: Configuration of arm stopper mechanism according to first embodiment 6-2: Load vector applied to the main part of the arm stopper mechanism according to the first embodiment

<1: Schematic configuration of straddle-type vehicle and electric power steering device>
First, a schematic configuration of the saddle riding type vehicle 100 will be described with reference to FIG. FIG. 1 is a schematic diagram showing a schematic configuration of the saddle riding type vehicle 100. The straddle-type vehicle 100 is a vehicle on which the electric power steering device 101 provided with the arm stopper mechanism 160 according to the first embodiment is mounted.

As shown in FIG. 1, the saddle riding type vehicle 100 is a vehicle used as an ATV (All Terrain Vehicle) such as a buggy or snowmobile, and has a steering system 1001. A steering system 1001 includes a bar handle 2, a handle stay 3, a steering shaft 4, left and right tie rods 8, left and right wheels (front wheels) 9, and an electric power steering device (steering device) 101. .
In the steering system 1001, a handle stay 3 provided with a bar handle 2 that is a steering handle is fixed to the steering shaft 4. The steering shaft 4 is rotatably supported by a support member (not shown) on the vehicle body side. An electric power steering device 101 is interposed between the steering shaft 4 and the left and right tie rods 8 connected to the left and right wheels (front wheels) 9. The electric power steering apparatus 101 is an apparatus that assists the steering force applied by the driver to the bar handle 2 with the torque generated by the electric motor 24.
The electric power steering apparatus 101 includes an arm stopper mechanism 160 (see FIG. 2) according to the first embodiment. The arm stopper mechanism 160 includes a steering arm 161 and a stopper 162, and is a mechanism that regulates the rotation angle of the steering arm 161 by the stopper 162.

  As shown in FIGS. 2 and 3, the electric steering device 101 is input via the input shaft 21 connected to the steering shaft 4 coupled to the steering handle (bar handle 2), the torsion bar 27, and the torsion bar 27. An output shaft 22 connected to the shaft 21, a torque sensor 23 as a sensor for detecting the steering state of the bar handle 2, an electric motor 24, and a controller for controlling the electric motor 24 based on a detection signal from the torque sensor 23 (Also referred to as an ECU (ELECTRONIC CONTROL UNIT)) 25, a torque transmission mechanism 26 that transmits torque generated by the electric motor 24 to the output shaft 22, a housing 113, and an arm stopper mechanism 160. The input shaft 21, the torsion bar 27, and the output shaft 22 are disposed on the same central axis CL.

  In FIG. 3, the housing 113 includes a first housing 113a, a second housing 113b, and a third housing 113c in order from the top. The input shaft 21 is connected to the steering shaft 4 via the joint 5, and is rotatably supported by the first housing 113a via the bearing 31. The output shaft 22 is rotatably supported by the second housing 113b and the third housing 113c via bearings 32A and 32B. A steering arm 161 of an arm stopper mechanism 160 is attached near the lower end of the output shaft 22. The upper end of the torsion bar 27 is inserted into the hollow portion of the input shaft 21 and serrated, and the lower end of the torsion bar 27 is inserted into the hollow portion of the output shaft 22 and connected by the connecting pin 27A.

  The torque sensor 23 includes two detection coils 23A and 23B surrounding the cylindrical core 23C engaged with the input shaft 21 and the output shaft 22 in the first housing 113a. The core 23C includes a vertical groove 23E that engages with the guide pin 23D of the output shaft 22, is movable only in the axial direction, and includes a spiral groove 23G that engages with the slider pin 23F of the input shaft 21. . As a result, the steering torque applied to the bar handle 2 (FIG. 1) is applied to the input shaft 21, and a relative displacement in the rotational direction occurs between the input shaft 21 and the output shaft 22 due to elastic torsional deformation of the torsion bar 27. Then, the displacement in the rotational direction of the input shaft 21 and the output shaft 22 displaces the core 23C in the axial direction. The inductances of the detection coils 23A and 23B change due to magnetic changes around the detection coils 23A and 23B due to the displacement of the core 23C. That is, when the core 23C moves toward the input shaft 21, the inductance of the detection coil 23A closer to the core 23C increases, and the inductance of the detection coil 23B farther away from the core 23C decreases. Torque can be detected.

  As shown in FIG. 2, the electric motor 24 is attached to the motor attachment seat 113 d of the second housing 113 b by the attachment bolt 30. In FIG. 3, the torque transmission mechanism 26 includes a worm 28 attached to the output shaft 24 </ b> B of the electric motor 24, and a worm wheel 29 attached to the output shaft 22 and meshing with the worm 28.

  In the electric steering apparatus 101 having the above configuration, when the steering torque applied to the bar handle 2 is detected by the torque sensor 23, the controller 25 controls the electric motor 24 based on the detection signal from the torque sensor 23. To do. Torque generated by the electric motor 24 is transmitted to the output shaft 22 via the worm 28 and the worm wheel 29. Thereby, the torque generated by the electric motor 24 is transmitted to the output shaft 22 as an auxiliary force for the steering force applied to the bar handle 2 by the driver.

  The controller 25 includes, for example, a CPU board portion on which a microcomputer and its peripheral circuits are mounted, a power supply board portion on which power supply elements are mounted, a connector portion connected to the outside, and the like. In the present invention, the controller 25 is housed in a housing 24A of the electric motor 24 as shown in FIG. The controller 25 is also connected to a battery and vehicle body side control equipment (not shown).

  Since the controller 25 is accommodated in the housing 24 </ b> A of the electric motor 24, a space for disposing the controller 25 separately from the electric motor 24 as in the related art becomes unnecessary. Therefore, the arrangement space required for the controller 25 can be saved. Since the controller 25 is protected by the casing 24A of the electric motor 24, it is not necessary to provide a separate protective casing for the controller 25, and the weight can be reduced accordingly.

  Further, since the connecting portion between the controller 25 and the electric motor 24 is accommodated in the housing 24A, the motor harness for connecting the controller 25 and the electric motor 24 is not exposed to the outside as in the prior art. Therefore, the wiring work of the motor harness becomes unnecessary. Since the motor harness is not exposed to the outside, the problem of damage to the harnesses under severe use conditions of the saddle riding type vehicle 100 can also be reduced.

  In addition, since the detection signal harness (not shown) for connecting the controller 25 and the torque sensor 23 can be shortened as compared with the prior art, the detection torque signal harness can be easily routed.

  The steering arm 161 is a steering member on the wheel (front wheel) 9 side. A tie rod 8 to which the wheel 9 is connected is attached to the steering arm 161. The tie rod 8 is disposed so as to extend in the width direction of the vehicle. One end of the tie rod 8 is connected to the steering arm 161 near the center in the width direction of the vehicle, and the other end is connected to the wheel (front wheel) 9. The steering arm 161 is spline-fitted to the output shaft 22 and is configured to rotate about the output shaft 22.

  The electric power steering device 101 is used when the driver tries to turn the bar handle 2 beyond the maximum turning angle in the clockwise direction or the counterclockwise direction or when driving on a rough road. The rotation of the bar handle 2 is restricted so that the vehicle does not roll over when the bar handle 2 is about to turn more than the maximum turning angle by external force being input through the wheel (front wheel) 9 due to the above. There is a need. The electric power steering apparatus 101 includes the arm stopper mechanism 160 described above as a mechanism for that purpose.

  The stopper 162 protrudes downward from the lower surface side of the housing 113 (third housing 113 c) of the electric power steering apparatus 101 and is provided around the output shaft 22. The arm stopper mechanism 160 is used when the driver tries to turn the bar handle 2 beyond the maximum turning angle in the clockwise direction or the counterclockwise direction or when an external force is input through the wheel (front wheel) 9. 2 is to turn more than the maximum turning angle, the abutment surface 176 (see FIG. 8A) provided on the steering arm 161 is the contact surface 186a of the stopper 162 (see FIG. 9A). I hit it. As a result, the arm stopper mechanism 160 restricts the rotation angle of the steering arm 161 by the stopper 162, and accordingly restricts the rotation of the bar handle 2.

<2: Schematic configuration between the steering arm and the wheel (front wheel)>
Next, a schematic configuration between the steering arm 161 and the wheel (front wheel) 9 will be described with reference to FIG. FIG. 4 is a schematic configuration diagram between the steering arm 161 and the wheel (front wheel) 9 of the arm stopper mechanism 160 according to the first embodiment, viewed from the upper surface direction.

  As shown in FIG. 4, the wheel (front wheel) 9 is suspended from the vehicle body 500 by a front wheel suspension device 501. The front wheel suspension device 501 includes a front cushion 507 that has an upper end connected to the vehicle body frame 500 and extends downward, a knuckle support member 502 that extends downward from the lower portion of the front cushion 507, and a lower portion of the knuckle support member 502 that extends in the vehicle width direction. A lower arm 503 connected to the frame 500, a knuckle 505 that is rotatably attached to the knuckle support member 502 around the kingpin axis 504, supports the wheel (front wheel) 9, and extends in the vehicle width direction to rotate the knuckle 505 around the kingpin axis 504. It consists of a tie rod 8. The knuckle 505 is provided with a hole through which the drive shaft 506 passes. The drive shaft 506 rotates the wheel (front wheel) 9 around the axle 510.

  Next, the operational relationship between the steering arm 161 and the wheel (front wheel) 9 will be described with reference to FIG. FIG. 5 is an explanatory view schematically showing an operational relationship between the steering arm 161 and the wheel (front wheel) 9 of the arm stopper mechanism 160 according to the first embodiment, as viewed from the lower surface direction.

  FIG. 5A shows a state when the bar handle 2 is not rotated (that is, when the saddle type vehicle 100 is moved straight while the bar handle 2 is maintained in a neutral state). On the other hand, FIG. 5B shows a state when the bar handle 2 is rotated counterclockwise by the maximum turning angle (that is, when the saddle riding type vehicle 100 is turned to the maximum left). .

  As is clear from the difference between FIG. 5A and FIG. 5B, the steering wheel when the bar handle 2 is rotated counterclockwise by the maximum turning angle (see FIG. 5B). The arm 161 rotates counterclockwise around the output shaft 22. At this time, the right tie rod 8 pushes the right wheel (front wheel) 9 leftward, and the left tie rod 8 pulls the left wheel (front wheel) 9 leftward. As a result, the two wheels (front wheels) 9 face leftward. At this time, the abutting portion 176 on the right side of the steering arm 161 collides with the abutting portion 186 on the right side of the stopper 162 (see FIGS. 7 and 11).

  If the bar handle 2 is rotated clockwise by the maximum turning angle, the steering arm 161 rotates clockwise around the output shaft 22. At this time, the right tie rod 8 pushes the right wheel (front wheel) 9 in the right direction, and the left tie rod 8 pulls the left wheel (front wheel) 9 in the right direction. As a result, the two wheels (front wheels) 9 face rightward. At this time, the left abutting portion 176 of the steering arm 161 collides with the left abutting portion 186 of the stopper 162.

<3: Load vector applied to the steering arm>
In the straddle-type vehicle 100, an input load is input to the steering arm 161 from the outside in a state where the abutting portion 176 of the steering arm 161 collides with the abutting portion 186 of the stopper 162 (see FIG. 5B). (See FIG. 6).

  Temporarily, the saddle riding type vehicle 100 is not the electric power steering apparatus 101 provided with the arm stopper mechanism 160 according to the first embodiment, but, for example, the electric power provided with the arm stopper mechanism 60 according to a comparative example described later. In the case where the steering device 1 (see FIGS. 16 and 17) is mounted, the arm stopper mechanism 60 according to the comparative example is configured to suppress the value of the bending load vector Wt applied to the output shaft 22. Since there is no (refer to the section <5: Relationship between Input Load Vector and Impact Load Vector and Bending Load Vector> described later), a relatively large bending load may be applied to the output shaft 22. As a result, in this case, the bearings 32A and 32B (see FIG. 3) supporting the output shaft 22 and the bearing 31 supporting the input shaft 21 connected to the output shaft 22 via the torsion bar 27 are supported. There is a possibility that an excessive load is applied to the housing 113 (see FIG. 3) around them (see FIG. 3).

  Hereinafter, the load vector applied to the steering arm 161 will be described with reference to FIG. FIG. 6 is an explanatory diagram of a load vector applied to the steering arm 161. FIG. 6 shows the following state of the saddle riding type vehicle 100.

  That is, the saddle riding type vehicle 100 may move up and down violently by traveling on a rough road, and in some cases, the wheel (front wheel) 9 may jump (leave) from the road surface. Then, at the timing immediately before the wheel (front wheel) 9 jumps up from the road surface or immediately after the wheel jumps up, for example, as shown in FIG. 6, when the driver rotates the bar handle 2 counterclockwise by the maximum turning angle, The left and right wheels (front wheels) 9 land from the side surface direction. At this time, for example, when the rear side of the left wheel (front wheel) 9 collides with a hard protrusion 511 such as a rock, the left wheel (front wheel) 9 receives a strong reaction force from the protrusion 511. FIG. 6 shows the state of the saddle riding type vehicle 100 at this time.

  At this time, a strong reaction force is applied to the left tie rod hole 172 of the steering arm 161 (see FIGS. 7 and 8A) as an input load vector Wh via the left wheel (front wheel) 9 and the left tie rod 8. ).

At this time, since the right abutting portion 176 of the steering arm 161 collides with the right abutting portion 186 of the stopper 162, the abutting load vector Wb in a direction perpendicular to the right abutting portion 186 is obtained. Is input from the right abutting portion 186 to the right abutting portion 176.
In the state where the abutting portion 176 of the steering arm 161 does not collide with the abutting portion 186 of the stopper 162, the abutting portion 176 of the steering arm 161 is caused by the collision of the wheel (front wheel) 9 with the protrusion 511. Also in the case of a collision with the contact portion 186 of the stopper 162, the load vector applied to the steering arm 161 is the same as that shown in FIG.

  In addition, when the driver rotates the bar handle 2 in the clockwise direction by the maximum turning angle immediately before the wheel (front wheel) 9 jumps from the road surface or immediately after the wheel bounces, the input load vector Wh and the collision The load vector Wb is opposite to the left and right of the state shown in FIG. That is, the input load vector Wh is input to the right tie rod hole 172 (see FIGS. 7 and 8A) of the steering arm 161, while the abutting load vector Wb is applied from the left abutting portion 186 to the left side. It is input to this department 176.

<4-1: Configuration of Arm Stopper Mechanism According to Comparative Example>
Next, in order to explain the features of the arm stopper mechanism 160 according to the first embodiment in an easy-to-understand manner, the configuration of the arm stopper mechanism 60 according to the comparative example will be described with reference to FIGS. FIG. 16 is a schematic configuration diagram of the electric power steering apparatus 1 provided with the arm stopper mechanism 60 according to the comparative example as seen from the side surface direction. FIG. 17 is a schematic configuration diagram of the arm stopper mechanism 60 viewed from the lower surface direction. FIG. 18 is a schematic configuration diagram of the steering arm 61 of the arm stopper mechanism 60 viewed from the lower surface direction. FIG. 19 is a schematic configuration diagram of the stopper 62 of the arm stopper mechanism 60 as viewed from the lower surface direction.

  The electric power steering apparatus 1 according to the comparative example shown in FIG. 16 is the same apparatus as the electric power steering apparatus 101 according to the first embodiment, and instead of the arm stopper mechanism 160 according to the first embodiment, a comparison is made. An arm stopper mechanism 60 according to the example is provided on the lower surface side of the housing 13.

  FIG. 17 shows the configuration of the arm stopper mechanism 60 as viewed from the lower surface direction. As shown in FIG. 17, the arm stopper mechanism 60 includes a steering arm 61 that rotates about the output shaft 22.

  In the example shown in FIG. 17, in the arm stopper mechanism 60, the angle θar formed by the abutment surfaces 76a and 76b (see FIG. 18) provided on the steering arm 61 is set to 180 °. Further, an angle formed between the contact surfaces 86a and 86b (see FIG. 19) provided on the stopper 62 (an angle between the two contact surfaces 86a and 86b and formed inside the stopper 62). θst is set to 90 °. Further, the total angle θdr of the maximum turning angle in the clockwise direction and the maximum turning angle in the counterclockwise direction of the steering arm 61 is 90 ° (that is, the maximum turning angle in the clockwise direction is 45 ° and the left The maximum turning angle in the circumferential direction is set to 45 °.

  FIG. 18 shows a specific configuration of the steering arm 61. 18A shows the configuration of each part of the steering arm 61, and FIG. 18B shows the arrangement position of each part of the steering arm 61.

A portion (hereinafter referred to as “main body”) to which the tie rod 8 of the steering arm 61 is attached is formed in a plate shape as shown in FIG.
As shown in FIG. 18, the steering arm 61 is provided with one output shaft hole 71 and two tie rod holes 72a and 72b. The output shaft hole 71 is a circular hole into which the output shaft 22 is fitted. The tie rod holes 72a and 72b are circular holes to which the tie rod 8 is attached. Hereinafter, the tie rod holes 72a and 72b are collectively referred to as “tie rod holes 72”.

  The output shaft hole 71 is fitted into the output shaft hole 71 so that the center point thereof coincides with the center point O22 of the output shaft 22. Hereinafter, the center point of the output shaft hole 71 may be referred to as a “center point O22”.

  The tie rod holes 72 a and 72 b are arranged at equal positions on the left and right of the center line L 61 of the steering arm 61. In the example shown in FIG. 18, each of the tie rod holes 72 a and 72 b has a center point O 72 at a distance T 72 rearward from the center point O 22 of the output shaft hole 71 and a center line L 61 of the steering arm 61. From left to right at a distance H72.

  Here, it is assumed that “the center line L61 of the steering arm 61” is a virtual straight line extending in the front-rear direction through the center point O22 of the output shaft hole 71. “Center line L61 of steering arm 61” coincides with “center line L62 of stopper 62 (see FIG. 19)” described later when the steering angle of bar handle 2 is 0 ° in the neutral state. become. The “center line L62 of the stopper 62” is also a virtual straight line (hereinafter referred to as “the center line of the entire vehicle”) extending in the vehicle front-rear direction through the center point in the vehicle width direction.

  The steering arm 61 includes portions (hereinafter referred to as “butting portions”) 74 a and 74 b that abut against the stopper 62. The abutting portions 74a and 74b are provided in the vicinity of both sides of the output shaft hole 71 in the main body of the steering arm 61 formed in a plate shape (a portion to which the tie rod 8 is attached). The abutting portions 74 a and 74 b are formed as flat surfaces (hereinafter referred to as “abutting surfaces”) 76 a and 76 b whose end surfaces are abutted against the stopper 62. Hereinafter, the abutting portions 74a and 74b are collectively referred to as “abutting portions 74”. The abutting surfaces 76a and 76b are collectively referred to as “abutting surface 76”.

  In the steering arm 61, an angle θ76 formed by the center line L61 of the steering arm 61 and the abutting surface 76 is set to 90 °. Therefore, the abutting surface 76a and the abutting surface 76b are set to an angle (the angle between the two abutting surfaces 76a and 76b and formed inside the steering arm 61) θar of 180 °. Yes.

  In FIG. 18, a line L76a indicates a straight line that is virtually arranged along the abutting surface 76a. A line L76b indicates a straight line that is virtually disposed along the abutting surface 76b. The line L76a and the line L76b intersect at the center point O22 of the output shaft hole 71. The length H76 indicates the distance from the center point O22 of the output shaft hole 71 of the steering arm 61 to the end of the abutting surface 76.

  The steering arm 61 includes an arc portion 78 that surrounds the output shaft hole 71 in an arc shape. The arc portion 78 is formed to be continuous with the abutting portions 74a and 74b. In FIG. 18, the length H78 indicates the distance from the center point O22 of the output shaft hole 71 of the steering arm 61 to the end of the arc portion 78.

  FIG. 19 shows a specific configuration of the stopper 62. FIG. 19A shows the configuration of each part of the stopper 62, and FIG. 19B shows the arrangement position of each part of the stopper 62.

  As shown in FIG. 16, the stopper 62 is provided so as to protrude downward from the lower surface side of the housing 13 of the electric power steering apparatus 1. As shown in FIG. 19, the stopper 62 has the center point O22 of the output shaft 22 as a vertex and the width of the bottom side so that the shape seen from the lower side is uniform on the left and right of the center line L62 of the stopper 62. A fan-shaped notch 81 (see FIG. 19A) having a radius H81 is formed at the apex portion of the isosceles triangle with respect to an isosceles triangle having a hypotenuse width of (H81 + H86). Yes.

  Here, it is assumed that “the center line L62 of the stopper 62” is a virtual straight line extending in the front-rear direction through the center point O22 of the output shaft 22. The “center line L62 of the stopper 62” is also the center line of the entire vehicle.

  The stopper 62 includes two flat surfaces 86a and 86b located at the oblique sides of the isosceles triangle, and the flat surfaces 86a and 86b function as contact surfaces that contact the contact surfaces 76a and 76b of the steering arm 61. . Hereinafter, the flat surface 86a is referred to as a “contact surface 86a”, and the flat surface 86b is referred to as a “contact surface 86b”. The contact surfaces 86a and 86b are collectively referred to as “contact surfaces 86”.

  In the stopper 62, an angle θ86 formed by the center line L62 of the stopper 62 and the contact surface 86 is set to 45 °. Accordingly, the abutment surface 86a and the abutment surface 86b have an angle between them (the angle between the two abutment surfaces 86a and 86b and formed inside the stopper 62) θst is set to 90 °. Has been.

  In FIG. 19, a line L86a indicates a straight line that is virtually arranged along the contact surface 86a. A line L86b indicates a straight line that is virtually arranged along the contact surface 86b. The line L86a and the line L86b intersect at the center point O22 of the output shaft 22.

<4-2: Load vector applied to main part of arm stopper mechanism according to comparative example>
Next, with reference to FIG. 20, the load vector concerning the principal part of the arm stopper mechanism 60 which concerns on a comparative example is demonstrated. FIG. 20 is an explanatory diagram of a load vector applied to the main part of the arm stopper mechanism 60.

  Here, the load vector from the wheel 9 (see FIG. 16) input to the steering arm 61 from the tie rod hole 72 is “input load vector Wh”, and the abutting surface of the steering arm 61 from the contact surface 86 of the stopper 62. A load vector applied to the output shaft 22 will be described as “abutting load vector Wb”, and a load vector applied to the output shaft 22 fitted in the output shaft hole 71 (see FIG. 18A) will be described as “bending load vector Wt”.

  Also, here, the center position of the portion where the abutting surface 76 of the steering arm 61 and the abutting surface 86 of the stopper 62 abut is defined as “abutting center position O76”, and the abutting load vector Wb is the abutting center position O76. It will be described as a matter of the above. In the example shown in FIG. 20, the abutting center position O76 is set at a position of a distance R from the center point O22 of the output shaft 22.

  Further, here, as the saddle riding type vehicle 100 is traveling, in order to turn the saddle riding type vehicle 100 to the maximum left, the bar handle 2 is rotated counterclockwise by the maximum turning angle as a result of FIG. As shown in FIG. 5, the right abutting surface 76 of the steering arm 61 is in contact with the right abutting surface 86 of the stopper 62, and the rear side of the side surface of the left wheel (front wheel) 9 is a projection 511 (see FIG. 6), the case will be explained. In this case, according to the principle described in the section <3: Load vector applied to the steering arm>, as shown in FIG. 20, the arm stopper mechanism 60 applies the input load vector Wh around the left tie rod hole 72. The abutting load vector Wb is applied to the abutting center position O76. Further, a bending load vector Wt that is a combined vector of the input load vector Wh and the abutting load vector Wb is applied to the output shaft 22.

  When the value of the bending load vector Wt increases, the bearings 32A and 32B (see FIG. 3) supporting the output shaft 22 and the input shaft 21 connected to the output shaft 22 via the torsion bar 27 are supported. There is a possibility that an excessive load is applied to the existing bearings 31 (see FIG. 3) and the surrounding housing 113 (see FIG. 3). The output shaft 22 is connected to the bar handle 2 via the torsion bar 27, the input shaft 21, and the steering shaft 4. For this reason, when the value of the bending load vector Wt increases, the bending load propagates to the bar handle 2 as a strong reaction force, and as a result, it becomes difficult to control.

  In such a configuration, the value of the bending load vector Wt is a value of a combined vector obtained by combining the input load vector Wh and the abutting load vector Wb. The direction of the input load vector Wh is the direction of the tie rod 8 (see FIG. 16) attached to the tie rod hole 72 when the abutment surface 76 of the steering arm 61 and the contact surface 86 of the stopper 62 are in contact. It depends on the mounting direction. Further, the direction of the abutting load vector Wb is a direction perpendicular to the abutting surface 76 of the steering arm 61.

<5: Relationship between input load vector and abutting load vector and bending load vector>
Next, the relationship between the input load vector Wh, the abutting load vector Wb, and the bending load vector Wt will be described with reference to FIGS. FIG. 21 is a schematic diagram illustrating the relationship between the input load vector Wh, the abutting load vector Wb, and the bending load vector Wt. FIG. 21A is a schematic diagram of the comparative example of FIG. b) and FIG. 21 (c) are schematic diagrams of other study examples. Here, as shown in FIG. 20, the description will be made assuming that the right abutting surface 76 of the steering arm 61 abuts against the right abutting surface 86 of the stopper 62.

  FIG. 21 shows a case where the abutting surface 76 on the right side of the steering arm 61 abuts against the abutting surface 86 on the right side of the stopper 62 as shown in FIG. It shows how the value of the bending load vector Wt changes when the arrangement direction of the 62 abutting surfaces 86 is changed. In FIGS. 21A to 21C, the center point O72 of the tie rod hole 72, the abutting center position O76, and the center point O22 of the output shaft 22 are in the positional relationship shown in FIG. ing.

  FIG. 21A shows a state where the arrangement direction of the abutting surface 76 of the steering arm 61 and the contact surface 86 of the stopper 62 shown in FIG. 20 is not changed. That is, FIG. 21A shows an example in which the angle θ76 formed by the center line L61 of the steering arm 61 and the abutting surface 76 of the steering arm 61 is set to 90 °. In other words, FIG. 21A shows an example in which the angle θ86 formed by the center line L62 of the stopper 62 and the contact surface 86 of the stopper 62 is set to 45 °.

  FIG. 21B shows the arrangement direction of the abutting surface 76 of the steering arm 61 from the state shown in FIG. 21A so that the direction of the input load vector Wh and the direction of the abutting load vector Wb are orthogonal to each other. A state is shown when tilted by an angle θb1 toward the center line L61. That is, FIG. 21B shows an example in which the angle θ76 formed by the center line L61 of the steering arm 61 and the abutting surface 76 of the steering arm 61 is set to (90−θb1) ° smaller than 90 °. Show. In other words, FIG. 21B shows an example in which the angle θ86 formed by the center line L62 of the stopper 62 and the contact surface 86 of the stopper 62 is set to (45 + θb1) ° larger than 45 °. ing.

  FIG. 21C shows a state in which the arrangement direction of the abutting surface 76 of the steering arm 61 is inclined toward the center line L61 by an angle θb2 (where angle θb2> angle θb1) from the state shown in FIG. Indicates the state. That is, in FIG. 21C, the angle θ76 formed by the center line L61 of the steering arm 61 and the abutting surface 76 of the steering arm 61 is smaller than the angle (90−θb1) ° in the state shown in FIG. An example in the case where (90−θb2) ° is set is shown. In other words, FIG. 21C shows a case where the angle θ86 formed by the center line L62 of the stopper 62 and the contact surface 86 of the stopper 62 is set to (45 + θb2) ° which is larger than (45 + θb1) °. An example is shown.

  As described above, the value of the bending load vector Wt is a value of a combined vector obtained by combining the input load vector Wh and the abutting load vector Wb. Therefore, when it is assumed that the mounting direction of the tie rod 8 to the steering arm 61 when the steering arm 61 collides with the stopper 62 is the same, that is, the direction of the input load vector Wh that is the mounting direction of the tie rod 8 is the same. Assuming that the bending load vector Wt increases as the angle θhb between the direction of the input load vector Wh and the direction of the abutting load vector Wb decreases, conversely, the direction of the input load vector Wh As the angle θhb formed by the direction of the abutting load vector Wb increases, the value tends to decrease.

  In the example shown in FIG. 21A, the angle θhb formed by the direction of the input load vector Wh and the direction of the abutting load vector Wb is an acute angle (0 to less than 90 °). In the example shown in FIG. 21B, the angle θhb formed by the direction of the input load vector Wh and the direction of the abutting load vector Wb is a right angle (90 °). In the example shown in FIG. 21C, the angle θhb formed by the direction of the input load vector Wh and the direction of the abutting load vector Wb is an obtuse angle (90 to 180 °).

  Therefore, in the example shown in FIG. 21A, the bending load vector Wt is the value of the combined vector when the input load vector Wh and the abutting load vector Wb are orthogonal (the bending in the state shown in FIG. 21B). The value is larger than the value of the load vector Wt. On the other hand, in the example shown in FIG. 21C, the bending load vector Wt is the value of the combined vector when the input load vector Wh and the abutting load vector Wb are orthogonal (the bending in the state shown in FIG. 21B). The value is smaller than the value of the load vector Wt.

  Therefore, as shown in FIG. 21C, the arm stopper mechanism 60 increases the angle θhb between the direction of the input load vector Wh and the direction of the abutting load vector Wb, and the direction of the input load vector Wh. By causing the load vector Wb to cancel each other, the value of the bending load vector Wt applied to the output shaft 22 can be suppressed.

  Here, as described above, FIG. 21A shows an example in which the angle θ76 formed by the center line L61 of the steering arm 61 and the abutting surface 76 of the steering arm 61 is set to 90 °, that is, the stopper 62. An example is shown in which the angle θ86 formed by the center line L62 and the contact surface 86 of the stopper 62 is set to 45 °.

  FIG. 21B shows an example in which the angle θ76 formed by the center line L61 of the steering arm 61 and the abutting surface 76 of the steering arm 61 is set to (90−θb1) ° smaller than 90 °. That is, an example is shown in which the angle θ86 formed by the center line L62 of the stopper 62 and the contact surface 86 of the stopper 62 is set to (45 + θb1) ° larger than 45 °.

  In FIG. 21C, the angle θ76 formed by the center line L61 of the steering arm 61 and the abutting surface 76 of the steering arm 61 is set to (90−θb2) ° which is smaller than (90−θb1) °. In other words, an example in which the angle θ86 formed by the center line L61 and the contact surface 86 of the stopper 62 is set to (45 + θb2) ° larger than (45 + θb1) ° is shown.

  Therefore, from the relationship shown in FIGS. 21A to 21C, as the angle θ76 formed between the center line L61 and the abutting surface 76 becomes smaller and relative to this, the center line L61 and the stopper 62 are increased. It can be seen that the angle θhb between the direction of the input load vector Wh and the direction of the abutting load vector Wb increases as the angle θ86 formed with the contact surface 86 increases.

  Therefore, the arm stopper mechanism 60 reduces the angle θ76 formed between the center line L61 of the steering arm 61 and the abutting surface 76 (that is, increases the angle θ86 formed between the centerline L61 and the contact surface 86 of the stopper 62). By doing so, the angle θhb formed by the direction of the input load vector Wh and the direction of the abutting load vector Wb can be increased. As a result, the arm stopper mechanism 60 can cause the direction of the input load vector Wh and the abutting load vector Wb to cancel each other. As a result, the value of the bending load vector Wt applied to the output shaft 22 can be reduced. Can be suppressed.

  However, the arm stopper mechanism 60 according to the comparative example suppresses the value of the bending load vector Wt applied to the output shaft 22 by causing the direction of the input load vector Wh and the abutting load vector Wb to cancel each other. It is not the structure which considered that. Therefore, the arm stopper mechanism 60 may be subjected to a relatively large bending load on the output shaft 22. In this case, the bearings 32 A and 32 B (see FIG. 3) supporting the output shaft 22 and the torsion bar 27 are installed. There is a possibility that an excessive load is applied to the bearing 31 (see FIG. 3) supporting the input shaft 21 connected to the output shaft 22 through the housing 113 (see FIG. 3) around them. Further, in this case, the bending load is propagated to the bar handle 2 as a strong reaction force, and as a result, the steering becomes difficult.

<6-1: Configuration of Arm Stopper Mechanism According to First Embodiment>
From this point of view, the arm stopper mechanism 160 (see FIGS. 2 and 7) according to the first embodiment is shown in FIG. 21 (c) in order to suppress the value of the bending load vector Wt applied to the output shaft 22. Like the arm stopper mechanism according to the illustrated example, the angle θhb (see FIG. 11) formed by the direction of the input load vector Wh and the direction of the abutting load vector Wb is the angle θhb ( 21 (see FIG. 21A)) (preferably an obtuse angle).

  That is, for example, as shown in FIG. 6, the arm stopper mechanism 160 according to the first embodiment is configured so that the steering arm 161 stops the stopper 162 in order to make the riding type vehicle 100 make a maximum turn while the riding type vehicle 100 is traveling. When the abutting load vector Wb is input to the steering arm 161, a projection (rock, etc.) 511 collides with the turning inner wheel (front wheel) 9 and the input load vector via the tie rod 8. When Wh is input to the steering arm 161, the bending load vector Wt (see FIG. 11) that acts on the output shaft 22 from the steering arm 161 to bend the output shaft 22 is reduced.

  Specifically, as shown in FIG. 8, the arm stopper mechanism 160 according to the first embodiment is configured such that the angle θ176 formed by the center line L161 of the steering arm 161 and the abutting surface 176 has an arm stopper mechanism according to the comparative example. The angle θ186 formed by the center line L162 of the stopper 162 and the contact surface 186 relative to the angle θ76 so as to be smaller than the angle θ76 of 60 (see FIG. 21A) is relative to the arm according to the comparative example. The stopper mechanism 60 is configured to be larger than the angle θ86 (see FIG. 21A).

  Hereinafter, the configuration of the arm stopper mechanism 160 according to the first embodiment will be described with reference to FIGS. 7 to 10. FIG. 7 is a schematic configuration diagram of the arm stopper mechanism 160 viewed from the lower surface direction. FIG. 8 is a schematic configuration diagram of the steering arm 161 of the arm stopper mechanism 160 as viewed from the lower surface direction. FIG. 8A shows the configuration of each part of the steering arm 161, and FIG. 8B shows the arrangement position of each part of the steering arm 161. FIG. 9 is a schematic configuration diagram of the stopper 162 of the arm stopper mechanism 160 as viewed from the lower surface direction. FIG. 9A shows the configuration of each part of the stopper 162, and FIG. 9B shows the arrangement position of each part of the stopper 162. FIG. 10 is a schematic diagram showing an ideal arrangement relationship of each member of the arm stopper mechanism 160.

  As shown in FIG. 7, the arm stopper mechanism 160 is different from the arm stopper mechanism 60 according to the comparative example in that the shapes of the steering arm 161 and the stopper 162 are different.

FIG. 7 shows the configuration of the arm stopper mechanism 160 as seen from the bottom surface direction. As shown in FIG. 7, the arm stopper mechanism 160 includes a steering arm 161 that rotates about the output shaft 22 and a stopper 162.
Note that the steering arm 161 is spline-coupled to the output shaft 22, and is integrated with the output shaft 22 so as to rotate around the center point O22 (center axis) of the output shaft 22.

The main body of the steering arm 161 (part to which the tie rod 8 is attached) is formed in a plate shape as a whole as shown in FIG. As shown in FIGS. 7 and 8, the steering arm 161 has a shape viewed from the lower side in the shape of a fan whose central angle is developed at an acute angle. The shape is refracted.
That is, the steering arm 161 is gradually widened from the proximal end side toward the distal end side. The steering arm 161 has a symmetrical shape with respect to the center line L161. Both side surfaces of the steering arm 161 are bent from the base end side toward the outer side in the circumferential direction at a substantially intermediate portion in the radial direction.
Further, as shown in FIG. 8, in the steering arm 161, the output shaft hole 171 is arranged at the position of the sector shape (central axis), and the two tie rod holes 172a and 172b are in the vicinity of the sector free end ( The outer peripheral edge) is arranged at an arbitrary position. Hereinafter, the tie rod holes 172a and 172b are collectively referred to as “tie rod holes 172”.
That is, an output shaft hole 171 having a circular cross section is formed through the proximal end portion of the steering arm 161, and tie rod holes 172a and 172b are formed through the distal end portion.

  The output shaft hole 171 is in a state where its center point coincides with the center point O22 of the output shaft 22 by fitting the output shaft 22 therein. Hereinafter, the center point of the output shaft hole 171 is referred to as “center point O22”.

  The tie rod holes 172a and 172b are arranged at equal positions on the left and right of the center line L161 of the steering arm 161. The center line L161 is a virtual line that extends in the radial direction through the center point O22 of the output shaft hole 171 and bisects the substantially fan-shaped steering arm 161 in the circumferential direction. That is, the center line L161 is a symmetrical center line of the steering arm 161 in the circumferential direction. In the example shown in FIG. 8, each of the tie rod holes 172a and 172b has a center point O172 at a distance T172 rearward from the center point O22 of the output shaft hole 171 and the center line L161 of the steering arm 161. From left to right at a distance H172.

  Here, it is assumed that “the center line L161 of the steering arm 161” is a virtual straight line extending in the front-rear direction through the center point O22 of the output shaft hole 171. “Center line L161 of steering arm 161” coincides with “center line L162 of stopper 162 (see FIG. 9)” described later when the steering angle of bar handle 2 is 0 ° in the neutral state. become. The “center line L162 of the stopper 162” is also the center line of the entire vehicle (virtual straight line extending in the front-rear direction of the vehicle through the center point in the vehicle width direction).

  The steering arm 161 includes an arc portion 178 having a radius H178 that surrounds the output shaft hole 171 in an arc shape. The steering arm 161 includes portions 174a and 174b that refract outward in the circumferential direction from the middle portions of both fan-shaped wings, and the portions 174a and 174b project against the stopper 162. It functions as the headquarters. Hereinafter, the part 174a is referred to as “abutting part 174a”, and the part 174b is referred to as “abutting part 174b”. The abutting portions 174a and 174b are collectively referred to as “abutting portions 174”.

The abutting portions 174a and 174b are formed as flat surfaces 176a and 176b on the side surfaces of the body (the portion to which the tie rod 8 is attached) of the steering arm 161 formed in a plate shape, and the flat surfaces 176a and 176b are stoppers. It functions as an abutment surface that is abutted against 162.
That is, on both side surfaces of the steering arm 161, the abutting surfaces 176a and 176b are formed at the positions closer to the tip than the intermediate portion in the radial direction.
Hereinafter, the flat surface 176a is referred to as “abutting surface 176a”, and the flat surface 176b is referred to as “abutting surface 176b”. The abutting surfaces 176a and 176b are collectively referred to as “abutting surfaces 176”.

  In FIG. 8, a line L176a indicates a straight line that is virtually arranged along the abutting surface 176a. A line L176b indicates a straight line that is virtually arranged along the abutting surface 176b. The length H176 indicates the distance from the point O162 where the line L176a and the line L176b of the steering arm 161 intersect to the end of the abutting surface 176.

  On the other hand, as shown in FIG. 2, the stopper 162 is provided so as to protrude downward from the lower surface side of the housing 113 of the electric power steering apparatus 101. As shown in FIG. 9, the stopper 162 has a trapezoidal part 162a having a substantially trapezoidal shape when viewed from below, and a rectangular part 162b having a substantially rectangular shape, with the bottom of the trapezoidal part 162a and the long side of the rectangular part 162b. The shape is joined (combined).

  The trapezoidal part 162a and the rectangular part 162b are disposed so as to intersect the center line L162 of the stopper 162 perpendicularly, and extend in the left-right direction. Here, it is assumed that “the center line L162 of the stopper 162” is a virtual straight line extending in the front-rear direction passing over the center point O22 of the output shaft 22. “Center line L162 of stopper 162” is also the center line of the entire vehicle.

The trapezoidal part 162a and the rectangular part 162b are arranged such that the center point of the lower base of the trapezoidal part 162a and the center point of the long side of the rectangular part 162b coincide with the center point O22 of the output shaft 22. The stopper 162 has a 1/2 circular cutout 181 (see FIG. 9A) that is recessed toward the front side so as to surround the front half of the output shaft 22 with the center point O22 of the output shaft 22 as the center. Is formed.
That is, the notch 181 is a semicircular recess formed at the center in the left-right direction of the rear edge of the stopper 162 and opened rearward. The notch 181 is a part through which the output shaft 22 is inserted, and the center point O22 of the output shaft 22 is disposed in the notch 181.

  The stopper 162 is configured such that the amount of protrusion from the lower surface side of the housing 113 increases from the front end side of the trapezoidal portion 162a toward the rear end side of the rectangular portion 162b. In addition, contact surfaces 186a and 186b are formed on the left and right sides of the cutout portion 181 on the rear end surface of the rectangular portion 162b. The stopper 162 is configured such that only the contact surface 186 contacts the steering arm 161.

  In the example shown in FIG. 9, the trapezoidal portion 162a is formed in a shape in which the width of the upper base is H162a, the width of the lower base is H162b, and the height is T162a. The rectangular portion 162b is formed in a shape in which the long side width is H162b and the short side width is T162b.

  The short side of the rectangular portion 162b is configured to have a width T162b having the same value as the separation distance T176 (see FIG. 8B) set in the steering arm 161. The separation distance T176 is a distance between a parallel surface parallel to the abutting surface 176 passing over the center point O22 of the output shaft hole 171 of the steering arm 161 and the abutting surface 176. The rectangular portion 162b functions as a contact surface on which the flat surfaces 186a and 186b located on the long side not joined to the trapezoidal portion 162a come into contact with the abutting surface 176 of the steering arm 161 (see FIG. 8A). . Hereinafter, the flat surface 186a is referred to as “contact surface 186a”, and the flat surface 186b is referred to as “contact surface 186b”. The contact surfaces 186a and 186b are collectively referred to as “contact surfaces 186”.

  In the stopper 162, an angle θ186 formed by the center line L162 of the stopper 162 and the contact surface 186 is set to 90 °. Therefore, the contact surface 186a and the contact surface 186b have an angle between them (the angle between the two contact surfaces 186a and 186b and formed inside the stopper 162) θst1 is set to 180 °. Has been. That is, the contact surfaces 186a and 186b are opened at an angle of 180 ° with the intermediate position (point O186) in the left-right direction of the rear edge of the rectangular portion 162b as the center.

  In FIG. 9, a line L186a indicates a straight line that is virtually arranged along the contact surface 186a. A line L186b indicates a straight line that is virtually disposed along the contact surface 186b. A point O186 indicates a point where the line L186a and the line L186b of the stopper 162 intersect. In the example shown in FIG. 9, the line L186a and the line L186b are in an overlapping state because the angle θst1 is set to 180 °.

  In such an arm stopper mechanism 160, each part of the steering arm 161 is preferably configured as shown in FIG. FIG. 10 is a schematic diagram showing an ideal configuration of each member of the arm stopper mechanism 160. FIG. 10A shows the arrangement position of each part of the steering arm 161, and FIG. 10B shows the angle in the arrangement direction of the abutting surfaces 176a and 176b of the steering arm 161.

  Here, the arrangement position of the abutting surface 176 (see FIG. 8A) of the steering arm 161 will be mainly described. A stopper 162 (see FIGS. 2 and 7) against which the abutting surface 176 of the steering arm 161 is abutted has a configuration in which each part corresponds to the steering arm 161.

  In FIG. 10, a line L161 indicates the center line of the steering arm 161. A point O22 indicates the center point of the output shaft hole 171 (see FIG. 8A) of the steering arm 161 and the center point of the output shaft 22. A point O172 indicates the center point of the tie rod hole 172 of the steering arm 161 (see FIG. 8A). Further, the point O176 corresponds to the abutting center position of the steering arm 161 (that is, the abutting surface 176 of the steering arm 161 according to the first embodiment and the abutting surface 186 of the stopper 162 (see FIG. 9A)). The center position of the part which touches is shown. The length H172 indicates the distance from the center line L161 of the steering arm 161 to the center point O172 of the tie rod hole 172.

  The arm stopper mechanism 160 is based on the characteristics of the arm stopper mechanism 60 according to the comparative example shown in FIG. 21 (a) and the arm stopper mechanisms according to the first and second examination examples shown in FIGS. 21 (b) and 21 (c). As can be seen, by reducing the angle θ176 formed by the center line L161 of the steering arm 161 and the abutment surface 176, and in relation to this, the angle θ186 formed by the center line L162 of the stopper 162 and the contact surface 186, respectively. Is increased, the angle θhb formed by the direction of the input load vector Wh and the direction of the abutting load vector Wb can be increased. As a result, the arm stopper mechanism 160 can act so that the direction of the input load vector Wh and the abutting load vector Wb cancel each other. As a result, the value of the bending load vector Wt applied to the output shaft 22 can be reduced. Can be suppressed.

  Therefore, in the steering arm 161 of the arm stopper mechanism 160, the angle θ176 formed by the center line L161 of the steering arm 161 and the abutting surface 176 is the angle θ76 of the steering arm 61 of the arm stopper mechanism 60 according to the comparative example (FIG. It is set to be smaller than (see)). That is, in the stopper 162 of the arm stopper mechanism 160, the angle θ186 formed by the center line L162 of the stopper 162 and the contact surface 186 is the angle θ86 of the stopper 62 of the arm stopper mechanism 60 according to the comparative example (see FIG. 21A). ) Is set to be larger than.

  However, the arm stopper mechanism 160 needs to prevent the bar handle 2 from turning more than the maximum turning angle so that the vehicle does not roll over. For this reason, the steering arm 161 of the arm stopper mechanism 160 is designed so that, for example, the ideal optimum arrangement angle of the angle θ176 is 45 ° and the angle θ176 is designed in order to define the maximum turning angle of the bar handle 2. An angle θα (for example, 10 °) is set as an allowable angle (hereinafter referred to as “allowable tilt angle”).

The arm stopper mechanism 160 is configured so that the abutting surfaces 176a and 176b of the steering arm 161 are centered on an arbitrary point O162 on the center line L161 of the steering arm 161 so as to satisfy these conditions. In the opposite direction, it is inclined at an angle of (45 ± θα) °. That is, the abutting surfaces 176a and 176b of the steering arm 161 have an angle (arranged between the two abutting surfaces 176a and 176b and formed inside the steering arm 161) θar1 (90 ± 2). Xθα) ° is set.
Thus, the abutting surfaces 176a and 176b are open at an angle of (90 ± 2 × θα) ° with the point O162 on the center line L186 as the center.

  For example, FIG. 7 shows a configuration of the arm stopper mechanism 160 when the allowable inclination angle θα is 0 °. In the example shown in FIG. 7, the angle θar1 formed by the abutting surfaces 176a and 176b (see FIG. 8) provided on the steering arm 161 is set to 90 °. Further, an angle θst1 formed between the contact surfaces 186a and 186b (see FIG. 9) provided on the stopper 162 is set to 180 °. Further, the total angle θdr1 of the maximum turning angle in the clockwise direction and the maximum turning angle in the counterclockwise direction of the steering arm 161 is 90 ° (that is, the maximum turning angle in the clockwise direction is 45 ° and the left The maximum turning angle in the circumferential direction is set to 45 °.

<6-2: Load vector applied to the main part of the arm stopper mechanism according to the first embodiment>
Next, with reference to FIG. 11, the load vector applied to the main part of the arm stopper mechanism 160 according to the first embodiment will be described. FIG. 11 is an explanatory diagram of a load vector applied to the main part of the arm stopper mechanism 160.

  Here, the load vector from the wheel 9 (see FIG. 2) input to the steering arm 161 from the tie rod hole 172 is “input load vector Wh”, and the abutment surface of the steering arm 161 from the contact surface 186 of the stopper 162. A load vector applied to the output shaft 22 fitted in the output shaft hole 171 (see FIG. 8A) will be described as a “bending load vector Wt”.

  Further, here, the center position of the portion where the abutting surface 176 of the steering arm 161 and the abutting surface 186 of the stopper 162 abut is defined as “abutting center position O176”, and the abutting load vector Wb is the abutting center position O176. It will be described as a matter of the above. In the example shown in FIG. 11, the abutting center position O176 is a distance R1 on the right side from the center point O22 of the output shaft 22, and a distance T162b (that is, a distance T176 (FIG. 8 (b) )))) Is set.

  In addition, here, as the straddle type vehicle 100 travels, the bar handle 2 is rotated counterclockwise by the maximum turning angle in order to turn the straddle type vehicle 100 to the maximum left. As shown in FIG. 5, the right abutting surface 176 of the steering arm 161 abuts against the right abutting surface 186 of the stopper 162, and the rear side of the side surface of the left wheel (front wheel) 9 is a projection 511 (FIG. 6), the case will be explained. In this case, according to the principle described in the chapter <3: Load vector applied to the steering arm>, as shown in FIG. 11, the arm stopper mechanism 160 applies the input load vector Wh around the left tie rod hole 172. The abutting load vector Wb is applied to the abutting center position O176. Further, a bending load vector Wt that is a combined vector of the input load vector Wh and the abutting load vector Wb is applied to the output shaft 22.

  In such a configuration, the value of the bending load vector Wt is a value of a combined vector obtained by combining the input load vector Wh and the abutting load vector Wb. The direction of the input load vector Wh is the direction of the tie rod 8 (see FIG. 2) attached to the tie rod hole 172 when the abutting surface 176 of the steering arm 161 and the contact surface 186 of the stopper 162 are in contact. It depends on the mounting direction. Further, the direction of the abutting load vector Wb is a direction perpendicular to the abutting surface 176 of the steering arm 161.

  Since the steering arm 161 and the stopper 162 are configured as described above, the arm stopper mechanism 160 acts so that the input load vector Wh and the abutting load vector Wb cancel each other. Therefore, the arm stopper mechanism 160 can lower the value of the bending load vector Wt applied to the output shaft 22 than the arm stopper mechanism 60 according to the comparative example. Therefore, the arm stopper mechanism 160 can suppress a bending load applied to the output shaft 22.

  In particular, the arm stopper mechanism 160 is configured such that the value of the bending load vector Wt applied to the output shaft 22 is equal to or less than the value of the combined vector when the input load vector Wh and the abutment load vector Wb are orthogonally crossed. Good. As a result, the arm stopper mechanism 160 can significantly reduce the value of the bending load vector Wt applied to the output shaft 22, and as a result, the bending load applied to the output shaft 22 can be efficiently suppressed.

  In such an arm stopper mechanism 160, the angle θst1 formed between the two contact surfaces 186 of the stopper 162 is set larger than the angle θar1 formed between the two abutting surfaces 176 of the steering arm 161 and set to 90 ° or more. By doing so, the direction of the input load vector Wh and the abutting load vector Wb can be made to cancel each other. As a result, the arm stopper mechanism 160 can suppress the value of the bending load vector Wt applied to the output shaft 22, and thus can suppress the bending load applied to the output shaft 22. Thereby, the arm stopper mechanism 160 has the bearings 32A and 32B supporting the output shaft 22 and the bearing 31 supporting the input shaft 21 connected to the output shaft 22 through the torsion bar 27 (FIG. 3). The load on the housing 113 (see FIG. 3) around them can be reduced. Further, since the bending load applied to the output shaft 22 is suppressed, the bending load is not propagated to the bar handle 2 as a strong reaction force, and the maneuverability can be improved.

  Moreover, the arm stopper mechanism 160 is set such that the angle θst1 formed between the two contact surfaces 186 of the stopper 162 is larger than the angle θar1 formed between the two abutting surfaces 176 of the steering arm 161 and 90 ° or more. Accordingly, since the angle θar1 of the steering arm 161 can be reduced relative to this, the steering arm 161 can be configured in a small size.

This point will be described below.
The arm stopper mechanism 160 rotates the steering arm 161 around the output shaft 22 within a range where the stopper 162 does not exist. Therefore, as shown in FIG. 7, the arm stopper mechanism 161 has an angle 360 ° in the entire circumferential direction around the output shaft 22, an angle θst1 formed by the two contact surfaces 186 of the stopper 162, and the steering arm 161 is configured to be assigned to the angle θar1 formed by the two abutting surfaces 176 and the total angle θdr1 of the maximum turning angle in the clockwise direction and the maximum turning angle in the counterclockwise direction of the steering arm 161.
Therefore, when the angle θst1 formed by the two contact surfaces 186 of the stopper 162 is increased while the arm stopper mechanism 160 maintains the left and right maximum turning angles, the two protrusions of the steering arm 161 are opposed to this. In this case, the angle θar1 formed by the 176s is reduced. As a result, the steering arm 161 becomes narrow in the circumferential direction, and the steering arm 161 can be made compact.

  In particular, the arm stopper mechanism 160 further increases the angle θar1 formed between the two abutting surfaces 176 of the steering arm 161 when the angle θst1 formed between the two contact surfaces 186 of the stopper 162 is set to 180 ° or more. The configuration is reduced. As a result, in this case, the arm stopper mechanism 160 can make the steering arm 161 smaller.

  In this case, since the steering arm 161 is further downsized, the arm stopper mechanism 160 brings the abutting center position O176 applied with the abutting load vector Wb closer to the periphery of the tie rod hole 72 applied with the input load vector Wh. be able to. Therefore, in this case, the arm stopper mechanism 160 can efficiently suppress vibration.

  The arm stopper mechanism 160 preferably secures an angle of 90 ° or more as the total angle θdr1 of the maximum turning angle in the clockwise direction and the maximum turning angle in the counterclockwise direction of the steering arm 161. Therefore, in the arm stopper mechanism 160, it is preferable that the total value of the angle θst1 formed by the two contact surfaces 186 of the stopper 162 and the angle θar1 formed by the two abutting surfaces 176 of the steering arm 161 is 270 ° or less. . When this condition is satisfied, the arm stopper mechanism 160 can ensure an angle of 90 ° or more as the total angle θdr1 of the maximum turning angle in the clockwise direction and the maximum turning angle in the counterclockwise direction of the steering arm 161. .

As described above, according to the arm stopper mechanism 160 according to the first embodiment, the value of the bending load vector Wt applied to the output shaft 22 can be suppressed. As a result, the bearings 32A and 32B supporting the output shaft 22, the bearing 31 supporting the input shaft 21 connected to the output shaft 22 via the torsion bar 27 (see FIG. 3), and their surroundings The load applied to the housing 113 (see FIG. 3) can be reduced. Further, since the bending load applied to the output shaft 22 is suppressed, the bending load is not propagated to the bar handle 2 as a strong reaction force, and the maneuverability can be improved. Further, the steering arm 161 can be made small.
Moreover, the electric power steering apparatus 101 can improve maneuverability by mounting the arm stopper mechanism 160.

<< Second Embodiment >>
The arm stopper mechanism 160 according to the first embodiment has a configuration in which the abutting surface 176 is provided on a side surface portion of the main body of the steering arm 161 (a portion to which the tie rod 8 is attached). The steering arm 161 has a configuration in which an abutting portion 174 on which an abutting surface 176 is formed projects outwardly (in the rotational direction) in order to define the maximum turning angle of the bar handle 2.

  On the other hand, in 2nd Embodiment, the arm stopper mechanism 260 comprised so that a protrusion part may not be protruded outside is provided.

<Configuration of Arm Stopper Mechanism According to Second Embodiment>
Hereinafter, the configuration of the arm stopper mechanism 260 according to the second embodiment will be described with reference to FIGS. FIG. 12 is a schematic configuration diagram of the arm stopper mechanism 260 viewed from the lower surface direction. FIG. 13 is a schematic configuration diagram of the steering arm 261 of the arm stopper mechanism 260 viewed from the lower surface direction. FIG. 13A shows the configuration of each part of the steering arm 261, FIG. 13B shows the configuration of the steering arm 261 viewed from the side, and FIG. 13C shows the steering. The arrangement position of each part of the arm 261 is shown. FIG. 14 is a schematic configuration diagram of the stopper 262 of the arm stopper mechanism 260 viewed from the lower surface direction. FIG. 14 shows the configuration of each part of the stopper 262.

  FIG. 12 shows the configuration of the arm stopper mechanism 260 as seen from the lower surface direction. As shown in FIG. 12, the arm stopper mechanism 260 includes a steering arm 261 that rotates about the output shaft 22 and a stopper 262.

  The main body of the steering arm 261 (part to which the tie rod 8 is attached) is formed in a plate shape as a whole as shown in FIG. As shown in FIGS. 12 and 13A, the steering arm 261 has a fan shape in which the central angle is developed at an acute angle when viewed from below. Further, as shown in FIG. 13, the steering arm 261 has an output shaft hole 271 disposed at the position of the fan-shaped core (center axis), and the two tie rod holes 272a and 272b are in the vicinity of the fan-shaped free end ( The outer peripheral edge) is arranged in the vicinity of both wings. Hereinafter, the tie rod holes 272a and 272b are collectively referred to as “tie rod holes 272”.

  The output shaft hole 271 is in a state where the center point thereof coincides with the center point O22 of the output shaft 22 by fitting the output shaft 22 therein. Hereinafter, the center point of the output shaft hole 271 is referred to as “center point O22”.

  The tie rod holes 272a and 272b are arranged at equal positions on the left and right of the center line L261 of the steering arm 261 in the neutral state. In the example shown in FIG. 13C, the tie rod holes 272a and 272b are such that the center point O272 is located behind the center point O22 of the output shaft hole 271 and the center line L261 of the steering arm 261. From left to right at a distance H272.

  Here, it is assumed that “the center line L261 of the steering arm 261” is an imaginary straight line extending in the front-rear direction through the center point O22 of the output shaft hole 271. “Center line L261 of steering arm 261” is “center line L262 of stopper 262 (see FIG. 14)” described later when the steering angle of bar handle 2 is 0 ° (in the neutral state). It will be in a consistent state. The “center line L262 of the stopper 262” is also the center line of the entire vehicle (virtual straight line extending in the front-rear direction of the vehicle through the center point in the vehicle width direction).

  The steering arm 261 includes an arc portion 278 that surrounds the output shaft hole 271 in an arc shape (circular shape). Further, the steering arm 261 includes a protruding portion 274 that protrudes upward near the center of the upper surface of the main body (the portion to which the tie rod 8 is attached) of the steering arm 261 (see FIGS. 13A and 13B). ), And the protruding portion 274 functions as an abutting portion that abuts against the stopper 262. Hereinafter, the protruding portion 274 is referred to as a “butting portion 274”.

  The abutting portion 274 has side surfaces formed as flat surfaces 276 a and 276 b, and the flat surfaces 276 a and 276 b function as abutting surfaces against which the stopper 262 is abutted. Hereinafter, the flat surface 276a is referred to as “abutting surface 276a” and the flat surface 276b is referred to as “abutting surface 276b”. The abutting surfaces 276a and 276b are collectively referred to as “abutting surfaces 276”.

  In FIG. 13C, a line L276a indicates a straight line that is virtually arranged along the abutting surface 276a. A line L276b indicates a straight line that is virtually disposed along the abutting surface 276b.

  On the other hand, the stopper 262 is provided so as to protrude downward from the lower surface side of the housing 213 of the electric power steering apparatus 201. As shown in FIG. 14, the stopper 262 has a substantially circular shape that is cut from a 1/3 arc-shaped cutout portion 281 that is the center point O <b> 22 of the output shaft 22. Yes. In the stopper 262, end faces 286a and 286b on the outer side in the circumferential direction cut out by the cutout portion 281 function as contact surfaces. Hereinafter, the end surface 286a is referred to as “contact surface 286a”, and the end surface 286b is referred to as “contact surface 286b”. The contact surfaces 286a and 286b are collectively referred to as “contact surfaces 286”.

  Here, it is assumed that “the center line L262 of the stopper 262” is a virtual straight line extending in the front-rear direction through the center point O22 of the output shaft 22. “Center line L262 of stopper 262” is also the center line of the entire vehicle.

  The arm stopper mechanism 260 is obtained from the characteristics of the arm stopper mechanism 60 according to the comparative example shown in FIG. 21A and the arm stopper mechanisms according to the first and second examination examples shown in FIGS. 21B and 21C. As can be seen, the angle θ276 (see FIG. 13C) formed by the center line L261 of the steering arm 261 and the abutting surface 276 is reduced, and relative to this, the centerline L262 of the stopper 262 is in contact with the centerline L262. By increasing the angle θ286 (see FIG. 14) formed with the contact surface 286, the angle θhb (see FIG. 15) formed between the direction of the input load vector Wh and the direction of the abutting load vector Wb can be increased. As a result, the arm stopper mechanism 260 can act so that the direction of the input load vector Wh and the abutting load vector Wb cancel each other. As a result, the value of the bending load vector Wt applied to the output shaft 22 can be reduced. Can be suppressed.

  Therefore, in the steering arm 261 of the arm stopper mechanism 260, the angle θ276 (see FIG. 13C) formed by the center line L261 of the steering arm 261 and the abutment surface 276 (see FIG. 13C) is the steering arm 61 of the arm stopper mechanism 60 according to the comparative example. Is set to be smaller than the angle θ76 (see FIG. 21C). That is, in the stopper 262 of the arm stopper mechanism 260, the angle θ286 (see FIG. 14) formed by the center line L262 of the stopper 262 and the contact surface 286 is the angle θ86 (see FIG. 14) of the stopper 62 of the arm stopper mechanism 60 according to the comparative example. 21 (a)).

  However, the arm stopper mechanism 260 needs to prevent the bar handle 2 from turning beyond the maximum steering angle so that the vehicle does not roll over. Therefore, the steering arm 261 of the arm stopper mechanism 260 determines, for example, the optimum arrangement angle of the abutting surface 276 with respect to the center line L261 and the tie rod hole 272 with respect to the center line L261 in order to define the maximum steering angle of the bar handle 2. The inclination angle θ276 of the imaginary straight lines L276a and L276b connecting the center point O272 and the center point O22 of the output shaft hole 271 is θβ (for example, 5 ° as an allowable inclination angle allowed for design with respect to the angle θ276). ) Angle is set.

  In the arm stopper mechanism 260, the abutting surfaces 276a and 276b of the steering arm 261 are opposite to each other with respect to the center line L261 about the center point O22 of the output shaft hole 271 so as to satisfy these conditions ( It is configured to be inclined at an angle of θ276 ± θβ) ° (see FIG. 13C). That is, the abutting surfaces 276a and 276b of the steering arm 261 have an angle formed between each other (an angle between the two abutting surfaces 276a and 276b and formed inside the steering arm 261) θar2 (2 × ( The angle is set to θ276 ± θβ)) °.

  For example, in FIG. 12, the inclination angle θ276 of the straight lines L276a and L276b is 15 ° (that is, the angle θar2 formed between the abutment surfaces 276a and 276b (see FIG. 13) provided on the steering arm 261 is 30 °) and the allowable inclination. The configuration of the arm stopper mechanism 260 when the angle θβ is 0 ° is shown. In the example shown in FIG. 12, in the arm stopper mechanism 260, the angle θar2 formed by the abutment surfaces 276a and 276b (see FIG. 13) provided on the steering arm 261 is set to 30 °. Further, an angle formed between the contact surfaces 286a and 286b (see FIG. 14) provided on the stopper 262 (an angle between the two contact surfaces 286a and 286b and formed inside the stopper 262). θst2 is set to 230 °. Further, the total angle θdr2 of the maximum turning angle in the clockwise direction and the maximum turning angle in the counterclockwise direction of the steering arm 261 is set to 100 °.

<Load vector applied to the main part of the arm stopper mechanism according to the second embodiment>
Hereinafter, with reference to FIG. 15, the load vector applied to the main part of the arm stopper mechanism 260 will be described. FIG. 15 is an explanatory diagram of a load vector applied to the main part of the arm stopper mechanism 260.

  Here, the load vector from the wheel 9 (see FIG. 2) input to the steering arm 261 through the tie rod hole 272 is “input load vector Wh”, and the abutment surface of the steering arm 261 from the contact surface 286 of the stopper 262. A load vector applied to H.276 will be referred to as “abutting load vector Wb”, and a load vector applied to the output shaft 22 fitted in the output shaft hole 271 (see FIG. 13A) will be described as “bending load vector Wt”.

  Here, the center position of the portion where the abutting surface 276 of the steering arm 261 and the abutting surface 286 of the stopper 262 abut is defined as “abutting center position O276”, and the abutting load vector Wb is the abutting center position O276. It will be described as a matter of the above. In the example shown in FIG. 15, the abutting center position O276 is a position between the center point O22 of the output shaft 22 and the center point O272 of the tie rod hole 272, and is a distance from the center point O22 of the output shaft 22. It is set at the position R2.

  Further, here, as the straddle-type vehicle 100 is traveling, the bar handle 2 is turned counterclockwise by the maximum turning angle in order to turn the straddle-type vehicle 100 to the maximum left, as a result of FIG. As shown in FIG. 5, the right abutting surface 276 of the steering arm 261 is in contact with the right abutting surface 286 of the stopper 262, and the rear side of the side surface of the left wheel (front wheel) 9 is a projection 511 (FIG. 6), the case will be explained. In this case, as shown in FIG. 15, in the arm stopper mechanism 260, the input load vector Wh is applied around the left tie rod hole 272, and the abutting load vector Wb is applied to the abutting center position O276. Further, a bending load vector Wt that is a combined vector of the input load vector Wh and the abutting load vector Wb is applied to the output shaft 22.

  The value of the bending load vector Wt is a value of a combined vector obtained by combining the input load vector Wh and the abutting load vector Wb. The direction of the input load vector Wh is the direction of the tie rod 8 (see FIG. 2) attached to the tie rod hole 272 when the abutting surface 276 of the steering arm 261 and the contact surface 286 of the stopper 262 are in contact. It depends on the mounting direction. The direction of the abutting load vector Wb is a direction perpendicular to the abutting surface 276 of the steering arm 261.

  Since the steering arm 261 and the stopper 262 are configured as described above, the arm stopper mechanism 260 acts so that the input load vector Wh and the abutting load vector Wb cancel each other. Therefore, the arm stopper mechanism 260 can lower the value of the bending load vector Wt applied to the output shaft 22 than the arm stopper mechanism 60 according to the comparative example. Therefore, the arm stopper mechanism 260 can suppress a bending load applied to the output shaft 22.

  In particular, such an arm stopper mechanism 260 is such that the value of the bending load vector Wt applied to the output shaft 22 is equal to or less than the value of the combined vector when the input load vector Wh and the abutting load vector Wb are orthogonally crossed. It is good to configure. As a result, the arm stopper mechanism 260 can significantly reduce the value of the bending load vector Wt applied to the output shaft 22, and as a result, the bending load applied to the output shaft 22 can be efficiently suppressed.

As described above, according to the arm stopper mechanism 260 according to the second embodiment, the value of the bending load vector Wt applied to the output shaft 22 can be suppressed, similarly to the arm stopper mechanism 160 according to the first embodiment. As a result, the bearings 32A and 32B supporting the output shaft 22, the bearing 31 supporting the input shaft 21 connected to the output shaft 22 via the torsion bar 27 (see FIG. 3), and their surroundings The load applied to the housing 113 (see FIG. 3) can be reduced. Further, since the bending load applied to the output shaft 22 is suppressed, the bending load is not propagated to the bar handle 2 as a strong reaction force, and the maneuverability can be improved.
In addition, according to the arm stopper mechanism 260, the abutting portion 274 of the steering arm 261 is configured not to protrude outward (in the rotation direction), and thus is smaller than the arm stopper mechanism 160 according to the first embodiment. Can be configured.
Moreover, the electric power steering apparatus 201 can improve maneuverability by mounting the arm stopper mechanism 260.

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the gist of the present invention.

  The steering device according to the present invention is preferably provided around a steering arm that rotates about the output shaft of the steering device and is attached with two tie rods to which wheels are connected, and the output shaft. A stopper for restricting the rotation angle of the steering arm, and the steering arm has an output shaft hole into which the output shaft is fitted, two tie rod holes to which the tie rods are respectively attached, and a stopper. Two abutting surfaces to be abutted, and the stopper includes two abutting surfaces that respectively abut against the two abutting surfaces of the steering arm, and the two abutting surfaces of the steering arm are respectively When any one of the abutment surfaces abuts against the abutment surface of the stopper, the tie on the far side Tsu input load vector and input from the de-hole and according abutting load vector on the abutting surface may be a configuration which acts to cancel each other. And the two abutment surfaces are the input load vector when the bending load vector applied to the output shaft fitted in the output shaft hole is orthogonal to the input load vector and the abutment load vector. It is good to arrange so that it may become below the value of the synthetic vector of the abutting load vector. The direction of the input load vector is determined by the mounting direction of the tie rod attached to the tie rod hole. Further, the direction of the abutting load vector is a direction perpendicular to the abutting surface of the steering arm.

21 Input shaft 22 Output shaft 23 Torque sensor (sensor)
24 Electric motor (motor)
25 Controller 26 Torque transmission mechanism 27 Torsion bar 101, 201 Electric power steering device 113, 213 Housing 160, 260 Arm stopper mechanism 161, 261 Steering arm 162, 262 Stopper 171, 271 Output shaft fitting hole 172 (172a, 172b), 272 (272a, 272b) Tie rod hole 174 (174a, 174b), 274 Abutting portion 176 (176a, 176b), 276 (276a, 276b) Abutting surface 186 (186a, 186b), 286 (286a, 286b) Abutting surface

Claims (3)

An input shaft connected to a steering shaft coupled to the steering handle;
An output shaft connected to the input shaft;
A sensor for detecting a steering state of the steering wheel;
A motor,
A controller for controlling the motor based on a detection signal from the sensor;
A torque transmission mechanism for transmitting the generated torque of the motor to the output shaft;
A steering arm that rotates about the output shaft and to which two tie rods to which wheels are connected are attached;
A stopper provided around the output shaft and restricting the rotation angle of the steering arm;
Have
In the neutral state, the steering arm has a virtual straight line extending through the output shaft in the front-rear direction of the vehicle as a center line, provided on the center line, and an output shaft hole into which the output shaft is fitted, Two tie rod holes provided on the left and right of the center line and behind the output shaft hole, to which the tie rods are respectively attached, and the left and right positions of the center line and the output shaft hole Two abutting surfaces that are provided at a rear position and are abutted against the stopper,
The stopper is provided at two positions on the left and right of the center line and at a position on the rotation direction of the abutting surface of the steering arm, and abuts against the abutting surface, respectively.
An angle formed between the two contact surfaces of the stopper is larger than an angle formed between the two abutting surfaces of the steering arm and is 90 ° or more.
A steering apparatus, wherein the controller is housed in a casing of the motor. The steering device according to claim 1, wherein an angle formed by the two contact surfaces of the stopper is 180 ° or more. The total value of the angle formed by the two contact surfaces of the stopper and the angle formed by the two abutment surfaces of the steering arm is 270 ° or less. The steering apparatus as described.

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