JP2010167999A - Steering damping mechanism of motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering damping mechanism of a motorcycle for evenly affecting a magnetic field to magnetic fluid. <P>SOLUTION: The steering damper (steering damping mechanism) includes a steering shaft 5 rotating together with rotation of a handlebar 4 and supported to a hollow part 2a of a head pipe 2 to rotate freely, an oil chamber 14 formed between the head pipe 2 and the steering shaft 5 to surround the periphery of the steering shaft 5 and filled with the magnetic fluid of which the viscosity becomes larger by the effect of the magnetic field, and a coil part 17 disposed to surround the periphery of the oil chamber 14 and applying the magnetic field to the magnetic fluid in the oil chamber 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a steering buffer mechanism for a motorcycle, and more particularly to a steering buffer mechanism for a motorcycle including a liquid chamber filled with a magnetic fluid.

  2. Description of the Related Art Conventionally, a steering buffer mechanism for a motorcycle including a liquid chamber filled with a magnetic fluid is known (see, for example, Patent Document 1). Patent Document 1 is filled with an MR fluid (Magneto-Rheological Fluid, magnetic fluid) which is formed in a fan-shaped box shape in plan view and whose shear resistance (apparent viscosity) changes due to the action of a magnetic field. An MR fluid rotary damper with a structured body is disclosed. This MR fluid type rotary damper is further provided with coils that are attached to both side surfaces of a fan-shaped body and generate a magnetic field in a strip shape within the body. In addition, the MR fluid rotary steer damper is pivotally attached in the vicinity of the center portion of the fan-shaped body, and pivots from one side surface to the other side surface around the pivot shaft. And a vane. When the vane rotates in the body, a flow resistance is generated due to the Newtonian fluid characteristic of the MR fluid in a state where no magnetic field is applied, and a resistance force against the rotation of the vane is generated. Further, when a magnetic field is generated in the body by the coil, the shear resistance of the MR fluid in the body increases. Accordingly, when the vane rotates, a stronger flow resistance is generated than when no magnetic field is generated, and a greater resistance force is generated against the rotation of the vane.

JP 2005-172096 A

  However, in the MR fluid rotary steer damper disclosed in Patent Document 1, the coils are attached to both side surfaces of the fan-shaped body that are separated from each other. For this reason, there is a difference in the magnitude of the applied magnetic field between the portion in the vicinity of the coil and the central portion between the two coils, and it is difficult to uniformly apply the magnetic field to the MR fluid. There is a problem.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a steering buffer mechanism for a motorcycle that can uniformly apply a magnetic field to a magnetic fluid. Is to provide.

Means for Solving the Problems and Effects of the Invention

  A steering buffer mechanism for a motorcycle according to an aspect of the present invention includes a handle, a cylindrical head pipe having a hollow portion therein, and rotates as the handle rotates and rotates in the hollow portion of the head pipe. A steering shaft that is movably supported; a first liquid chamber that is formed between the head pipe and the steering shaft so as to surround the periphery of the steering shaft; and is filled with a magnetic fluid that increases in viscosity by the action of a magnetic field; A magnetic field application unit arranged to surround the first liquid chamber and applying a magnetic field to the magnetic fluid in the first liquid chamber.

  In the steering shock absorbing mechanism of the motorcycle according to this aspect, as described above, the first liquid chamber filled with the magnetic fluid whose viscosity is increased by the action of the magnetic field is provided so as to surround the periphery of the steering shaft. At the same time, a magnetic field application unit is provided that surrounds the first liquid chamber and applies a magnetic field to the magnetic fluid in the first liquid chamber. As a result, a magnetic field is applied circumferentially to the magnetic fluid in the first liquid chamber by the magnetic field applying unit that surrounds the first liquid chamber. As a result, the magnetic field can be applied uniformly to the magnetic fluid in the first liquid chamber.

  Further, by applying a magnetic field to a magnetic fluid whose viscosity is increased by the action of the magnetic field, a resistance force can be generated against the rotation of the steering shaft even before the steering shaft is rotated. Can be suppressed.

1 is a side view showing a front portion of a motorcycle according to a first embodiment of the present invention. FIG. 2 is a diagram for explaining a configuration of a steering damper of the motorcycle according to the first embodiment shown in FIG. 1. FIG. 3 is a cross-sectional view taken along the line 100-100 shown in FIG. It is a graph for demonstrating the characteristic of the magnetic fluid in the state to which the magnetism of the steering damper of 1st Embodiment shown in FIG. 2 was acted. 2 is a flowchart for illustrating a control operation of a control unit of the motorcycle according to the first embodiment shown in FIG. FIG. 6 is a diagram for explaining a configuration of a steering damper of a motorcycle according to a second embodiment of the present invention. It is sectional drawing along the 200-200 line | wire shown in FIG. FIG. 7 is a graph for explaining characteristics in a state where the magnetism of the magnetic fluid of the steering damper of the motorcycle of the second embodiment shown in FIG. 6 is not acted on. FIG. 6 is a diagram for illustrating a configuration of a steering damper of a motorcycle according to a third embodiment of the present invention. FIG. 10 is a cross-sectional view taken along line 300-300 illustrated in FIG. 9. Fig. 10 is a graph for illustrating the characteristics of the steering damper of the motorcycle according to the third embodiment shown in Fig. 9.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
In the first embodiment of the present invention, a steering damper provided in a head pipe will be described as an example of a steering buffer mechanism of a motorcycle according to the present invention. In the figure, an arrow FWD indicates the front in the traveling direction of the motorcycle. Hereinafter, the structure of the steering damper of the motorcycle 1 according to the first embodiment of the present invention will be described in detail with reference to FIGS.

  In the motorcycle 1 according to the first embodiment of the present invention, a main frame 3 is disposed behind the head pipe 2 as shown in FIG. Further, a handle 4 is rotatably provided on the upper portion of the head pipe 2. The head pipe 2 has a cylindrical shape having a hollow portion 2a therein, and a steering shaft 5 that rotates together with the handle 4 is rotatably inserted into the hollow portion 2a of the head pipe 2. Yes. A front fork 6 is disposed in front of the head pipe 2 (in the direction of the arrow FWD). A front wheel 7 is rotatably attached to the lower end portion of the front fork 6. An under bracket 8 for fixing the steering shaft 5 and the front fork 6 is disposed below the head pipe 2.

  As shown in FIGS. 1 and 2, bearings 9 and 10 for smoothly rotating the steering shaft 5 are disposed at the upper end portion and the lower end portion of the head pipe 2, respectively. Further, as shown in FIG. 2, an iron inner cylinder member 11 is fixed to the steering shaft 5 by being press-fitted. A flange portion 11 a that prevents the outer cylinder member 12 from falling by supporting an outer cylinder member 12 described later from below is formed at the lower end of the inner cylinder member 11. The inner cylinder member 11 is an example of the “inner cylinder part” in the present invention, and the flange part 11a is an example of the “support part” in the present invention. The flange portion 11a is configured to support the outer cylinder member 12 from below while rotating as the steering shaft 5 rotates.

  An outer cylinder member 12 is fixed to the inner peripheral surface 2 b of the hollow portion 2 a of the head pipe 2. The outer cylinder member 12 is an example of the “outer cylinder portion” in the present invention. The outer peripheral surface 12a of the outer cylinder member 12 has a coil storage portion 12b that is formed in a circumferential shape and a concave shape. Further, between the flange portion 11 a of the inner cylinder member 11 and the outer cylinder member 12, the flange portion 11 a of the inner cylinder member 11 that rotates together with the steering shaft 5 is smoothly rotated with respect to the outer cylinder member 12. The thrust washer 13 is arranged. Further, the outer cylinder member 12 holds a coil portion 17 described later by the outer peripheral surface 12a, and holds a magnetic fluid in the oil chamber 14 described later by the inner peripheral surface 12c.

  Here, in the first embodiment, as shown in FIG. 3, an oil chamber 14 surrounding the periphery of the steering shaft 5 is formed between the head pipe 2 and the steering shaft 5. The oil chamber 14 is an example of the “first liquid chamber” in the present invention. The oil chamber 14 is formed between the inner peripheral surface 12 c of the cylindrical outer cylinder member 12 and the outer peripheral surface 11 b of the cylindrical inner cylinder member 11. The oil chamber 14 has a magnetic powder that changes its shear resistance (apparent viscosity) due to the action of a magnetic field generated by a coil portion 17 to be described later, and generates a resistance force against the rotation of the steering shaft 5. The magnetic fluid which consists of hydraulic fluid containing is filled. This magnetic fluid has Newtonian fluid properties when no magnetic field is applied, while it has Bingham plastic fluid properties when a magnetic field is applied. Here, the Newtonian fluid characteristic is a characteristic of a viscous fluid in which the flow resistance increases as the flow velocity increases from the zero state. The Bingham plastic fluid characteristic is a characteristic that generates a large flow resistance even when the flow rate is zero.

  The oil chamber 14 is formed so as to extend in the axial direction of the steering shaft 5, as shown in FIG. In addition, ring-shaped oil seals 15 and 16 provided to prevent the magnetic fluid from flowing out of the oil chamber 14 are disposed at the upper and lower portions of the oil chamber 14, respectively. The oil seals 15 and 16 are examples of the “first seal member” in the present invention. In addition, a seal holding portion 12 d formed in a groove shape for holding the oil seal 15 is provided on the upper portion of the outer cylinder member 12. Further, a seal holding portion 12e formed in a groove shape for holding the oil seal 16 is provided at the lower portion of the outer cylinder member. The seal holding portions 12d and 12e are examples of the “holding portion” in the present invention.

  In the first embodiment, the coil portion 17 is disposed in a space formed by the coil housing portion 12 b of the outer cylinder member 12 and the inner peripheral surface 2 b of the head pipe 2. The coil unit 17 is an example of the “magnetic field application unit” in the present invention. As shown in FIG. 2 and FIG. 3, the coil portion 17 is disposed so as to surround substantially the entire area in the vertical direction (X direction) with the outer cylinder member 12 sandwiched around the cylindrical oil chamber 14. ing. In addition, the coil portion 17 is disposed so as to surround the oil chamber 14, generates a magnetic field when an electric current is applied, and is amplified by the iron inner cylinder member 11. 14 has a function of applying a magnetic field. At this time, the apparent viscosity of the magnetic fluid filled in the oil chamber 14 increases due to an increase in shear resistance. In the first embodiment, the oil damper 14 filled with the magnetic fluid and the coil portion 17 constitute a steering damper.

  Specifically, the magnetic powder floating in the oil chamber 14 has a property of aggregating along the applied magnetic field when a magnetic field is applied by the coil portion 17. Then, due to the interaction of the magnetic powder aggregated in the oil chamber 14, the shear resistance of the portion subjected to the magnetic field action of the magnetic fluid is increased, so that the apparent viscosity can be increased. In this case, the relationship between the rotation speed of the steering shaft 5 and the rotation resistance generated when the steering shaft 5 rotates is that the magnetic fluid to which the magnetic field is applied has Bingham plastic fluid characteristics. The relationship is as shown in the graph. That is, even when the rotation speed of the steering shaft 5 is 0, a flow resistance of at least a predetermined value (yield value) occurs in the magnetic fluid in the oil chamber 14. Thereby, even in a state before the steering wheel 4 (see FIG. 1) is operated by the occupant, it is possible to generate a resistance force against the rotation of the steering shaft 5. Further, the magnetic fluid in the oil chamber 14 has a property that the yield value increases as the applied magnetic field increases, and the shear resistance (apparent viscosity) increases.

  As shown in FIG. 2, an applied current control unit 18 that controls a current applied to the coil unit 17 is connected to the coil unit 17. The applied current control unit 18 is an example of the “current application unit” in the present invention. An accelerator position sensor 19, a vehicle speed sensor 20, a gear position sensor 21, an acceleration sensor 22, a steering wheel angle sensor 23, and an engine speed sensor 24 are connected to the applied current control unit 18. . The accelerator position sensor 19, the vehicle speed sensor 20, the gear position sensor 21, the acceleration sensor 22, the steering wheel steering angle sensor 23, and the engine speed sensor 24 are respectively disposed at predetermined positions of the motorcycle 1 (see FIG. 1). ing. The applied current control unit 18 is configured to control the current applied to the coil unit 17 based on the detection results of these sensors 19 to 24. Specifically, the applied current control unit 18 controls to apply a small current to the coil unit 17 so that a weak magnetic field is applied to the magnetic fluid in the oil chamber 14 when a main switch (not shown) is turned on. Is configured to do. In addition, the applied current control unit 18 is configured so that a strong magnetic field is applied to the magnetic fluid in the oil chamber 14 when the detection values of the various sensors 19 to 24 are each equal to or greater than a predetermined value. 17 is configured to perform control to apply a large amount of current. This will be described in detail in the control operation of the applied current control unit 18 described later.

  FIG. 5 is a flowchart illustrating the operation of the applied current control unit that applies current to the coil unit according to the first embodiment of the present invention. Next, a control operation of the applied current control unit 18 when applying a current to the coil unit 17 will be described with reference to FIGS. 1 and 5.

  First, as shown in FIG. 5, in step S1, the applied current control unit 18 applies a small current to the coil unit 17 so that a weak magnetic field is applied to the magnetic fluid in the oil chamber 14, and the process proceeds to step S2. To do. In step S2, it is determined whether the detected value of the accelerator position sensor 19 is equal to or greater than a predetermined value. In step S2, the acceleration intention of the occupant is detected by detecting the turning state of an accelerator (not shown) by the occupant. This makes it possible to determine whether or not to apply a strong magnetic field to the magnetic fluid in the oil chamber 14 before the vehicle speed increases. If the vehicle speed increases, the influence of the minute swing of the handle 4 (see FIG. 1) on the traveling motorcycle 1 (see FIG. 1) also increases, so that a large resistance force to the steering shaft 5 is necessary. It is. If it is determined in step S2 that the detected value of the accelerator position sensor 19 is equal to or greater than a predetermined value, the process proceeds to step S10 so that a strong magnetic field is applied to the magnetic fluid in the oil chamber 14. Then, control is performed so that a large amount of current is applied to the coil unit 17, and the process is terminated. If it is determined in step S2 that the detected value of the accelerator position sensor 19 is less than the predetermined value, the process proceeds to step S3.

  In step S3, it is determined whether or not the rate of change of the detected value of the accelerator position sensor 19 is equal to or greater than a predetermined value. In step S3, the intention of acceleration by the occupant is detected by calculating the rate of change of the detected value of the accelerator position sensor 19. Thus, it is possible to determine whether or not to apply a strong magnetic field to the magnetic fluid in the oil chamber 14 before the acceleration of the motorcycle 1 (see FIG. 1) increases. If it is determined in step S3 that the rate of change of the detected value of the accelerator position sensor 19 is equal to or greater than a predetermined value, the process proceeds to step S10 so that a strong magnetic field is applied to the magnetic fluid in the oil chamber 14. In addition, control for applying a large amount of current to the coil unit 17 is performed, and the process is terminated. If it is determined in step S3 that the change rate of the detected value of the accelerator position sensor 19 is less than the predetermined value, the process proceeds to step S4.

  In step S4, it is determined whether or not the vehicle speed (detected value of the vehicle speed sensor 20) is equal to or greater than a predetermined value. In step S4, when it is determined that the vehicle speed is equal to or higher than the predetermined value, the process proceeds to step S10, and a large magnetic field is applied to the coil unit 17 so that a strong magnetic field is applied to the magnetic fluid in the oil chamber 14. The current is applied. Thus, when the vehicle speed is equal to or higher than a predetermined value, it is possible to apply a strong magnetic field to the magnetic fluid in the oil chamber 14 before the handle 4 (see FIG. 1) rotates. And a process is complete | finished after the control in step S10. If it is determined in step S4 that the vehicle speed is less than the predetermined value, the process proceeds to step S5.

  Then, in step S5, it is determined whether or not the acceleration (detected value of the acceleration sensor 22) of the motorcycle 1 (see FIG. 1) is equal to or greater than a predetermined value. In step S5, the acceleration state of the motorcycle 1 is detected by detecting the acceleration of the motorcycle 1 (see FIG. 1). This makes it possible to determine whether or not to apply a strong magnetic field to the magnetic fluid in the oil chamber 14 before the vehicle speed increases. If it is determined in step S5 that the acceleration is equal to or greater than the predetermined value, the process proceeds to step S10, and the coil portion 17 is increased so that a strong magnetic field is applied to the magnetic fluid in the oil chamber 14. Is applied, and the process is terminated. If it is determined in step S5 that the acceleration is less than the predetermined value, the process proceeds to step S6.

  In step S6, it is determined whether or not the rotation speed of the handle 4 (see FIG. 1) is equal to or higher than a predetermined value. The rotation speed of the handle 4 is calculated from the detection result of the handle rudder angle sensor 23. In this step S 6, whether a strong resistance force is generated by applying a strong magnetic field to the magnetic fluid in the oil chamber 14 against a sudden operation of the handle 4 by an occupant and a large shake of the handle 4 due to a road surface condition. It is determined whether or not. If it is determined in step S7 that the rotation speed of the handle 4 is equal to or higher than the predetermined value, the process proceeds to step S10 so that a strong magnetic field is applied to the magnetic fluid in the oil chamber 14. Control is performed so that a large amount of current is applied to the coil unit 17, and the process is terminated. In step S6, when it is determined that the rotation speed of the handle 4 is less than the predetermined value, the process proceeds to step S7, and control is performed so that a small current is continuously applied to the coil unit 17, Processing is terminated.

  In addition, after a series of processing operation is complete | finished, it returns to step S2 and a process is repeated.

  In the first embodiment, as described above, the oil chamber 14 filled with the magnetic fluid whose viscosity is increased by the action of the magnetic field is provided so as to surround the periphery of the steering shaft 5. At the same time, a coil portion 17 is provided so as to surround the oil chamber 14 and applies a magnetic field to the magnetic fluid in the oil chamber 14. As a result, a magnetic field is applied circumferentially to the magnetic fluid in the oil chamber 14 by the coil portion 17 surrounding the oil chamber 14, so that the magnetic field is uniformly applied to the magnetic fluid in the oil chamber 14. Can act.

  Further, in the first embodiment, as described above, by applying a magnetic field to the magnetic fluid whose viscosity is increased by the action of the magnetic field in the oil chamber 14, the steering shaft 5 is in a state before the steering shaft 5 is rotated. Since a resistance force can be generated, a minute shake of the steering shaft 5 can be suppressed.

  In the first embodiment, as described above, the oil chamber 14 is configured to surround the steering shaft 5 so as to extend along the axial direction of the steering shaft 5. As a result, the area surrounding the steering shaft 5 by the oil chamber 14 can be increased in the direction of the rotational axis of the steering shaft 5, so that the area of the oil chamber 14 facing the steering shaft 5 (inner cylinder member 11) is increased. be able to. As a result, the resistance force against the rotation of the steering shaft 5 by the oil chamber 14 can be increased.

  In the first embodiment, as described above, the oil chamber 14 is fixed to the inner cylinder member 11 fixed to the outer peripheral surface of the steering shaft 5 and the inner peripheral surface 2 b of the hollow portion 2 a of the head pipe 2. It is formed between the outer cylinder members 12. Thereby, the oil chamber 14 can be easily formed between the head pipe 2 and the steering shaft 5.

  Moreover, in 1st Embodiment, the space which accommodates the coil part 17 is easily securable by providing the coil accommodating part 12b which accommodates the coil part 17 in the outer cylinder member 12 as mentioned above.

  In the first embodiment, as described above, the coil portion 17 is held by the coil storage portion 12b formed on the outer peripheral surface 12a of the outer cylinder member 12, and the oil chamber is held by the inner peripheral surface 12c of the outer cylinder member 12. 14 is configured to hold the magnetic fluid in 14. Thereby, compared with the case where the components for holding the coil part 17 and the components for holding the magnetic fluid in the oil chamber 14 are provided separately from the outer cylinder member 12, respectively, the steering damper is in the axial direction. It can suppress becoming large in the orthogonal direction.

  In the first embodiment, as described above, by providing the applied current control unit 18 that applies a current for generating a magnetic field to the coil unit 17, the current applied to the coil unit 17 can be easily changed. Can be adjusted.

  Moreover, in 1st Embodiment, the flange part 11a provided in the lower part of the inner cylinder member 11 and supporting the outer cylinder member 12 from the downward direction is provided as mentioned above. Thereby, the outer cylinder member 12 can be easily prevented from falling by the flange portion 11 a of the inner cylinder member 11 that rotates together with the steering shaft 5.

  In the first embodiment, as described above, the magnetic fluid easily flows out of the oil chamber 14 by arranging the oil seals 15 and 16 to seal the upper portion and the lower portion of the oil chamber 14. Can be prevented.

  Further, in the first embodiment, as described above, the outer cylinder member 12 is provided with the seal holding portion 12d for holding the oil seal 15 and the seal holding portion 12e for holding the oil seal 16. Accordingly, the oil seals 15 and 16 can be easily held by the outer cylinder member 12.

  Further, in the first embodiment, as described above, the coil portion 17 is disposed so as to surround a substantially entire region in the axial direction of the steering shaft 5 of the oil chamber 14. As a result, the region surrounding the steering shaft 5 by the oil chamber 14 can be made larger in the direction of the rotational axis of the steering shaft 5. Therefore, the facing area between the coil portion 14 and the steering shaft 5 (inner cylinder member 11) can be further increased. As a result, the resistance force against the rotation of the steering shaft 5 by the oil chamber 14 can be further increased.

(Second Embodiment)
FIG. 6 is a cross-sectional view for explaining the configuration of the steering damper according to the second embodiment of the present invention. 7 and 8 are diagrams for explaining the configuration and performance of the steering damper shown in FIG. Next, the configuration of the steering damper according to the second embodiment will be described with reference to FIGS. In the second embodiment, unlike the first embodiment, an example in which the inner cylinder member 111 is provided with a vane 111c that rotates in the oil chamber 114 will be described.

  In the second embodiment, as shown in FIG. 6, the inner cylinder member 111 is fixed to the steering shaft 5 by being press-fitted. A flange portion 111 a that prevents the outer cylinder member 112 from falling by supporting an outer cylinder member 112 described later from below is formed at the lower end of the inner cylinder member 111. The inner cylinder member 111 is an example of the “inner cylinder part” in the present invention, and the flange part 111a is an example of the “support part” in the present invention.

  An outer cylinder member 112 is fixed to the inner peripheral surface 2 b of the hollow portion 2 a of the head pipe 2. The outer cylinder member 112 is an example of the “outer cylinder portion” in the present invention. The outer peripheral surface 112a of the outer cylinder member 112 has a coil storage portion 112b formed in a circumferential shape and a concave shape. In addition, a seal holding portion 112 d formed in a groove shape for holding the oil seal 15 is provided on the outer cylinder member 112. Further, a seal holding portion 112e formed in a groove shape for holding the oil seal 16 is provided at the lower portion of the outer cylinder member. Further, the outer cylinder member 112 holds the coil portion 17 by the outer peripheral surface 112a, and holds a magnetic fluid in an oil chamber 114 described later by the inner peripheral surface 112c. The seal holding portions 112d and 112e are examples of the “holding portion” in the present invention.

  Further, as shown in FIG. 7, an oil chamber 114 is formed between the head pipe 2 and the steering shaft 5 so as to surround the periphery of the steering shaft 5. The oil chamber 114 is an example of the “first liquid chamber” in the present invention. Specifically, the oil chamber 114 is formed between the inner peripheral surface 112 c of the cylindrical outer cylinder member 112 and the outer peripheral surface 111 b of the cylindrical inner cylinder member 111. In the oil chamber 114, the magnetic powder that changes the shear resistance (apparent viscosity) due to the action of a magnetic field generated by a coil unit 117, which will be described later, and generates a resistance force against the rotation of the steering shaft 5. The magnetic fluid which consists of hydraulic fluid containing is filled.

  A coil portion 117 is disposed in a space formed by the coil housing portion 112 b of the outer cylinder member 112 and the inner peripheral surface 2 b of the head pipe 2. The coil unit 117 is an example of the “magnetic field application unit” in the present invention. The coil portion 117 is disposed so as to surround the oil chamber 114, generates a magnetic field when supplied with current, and is amplified by the iron inner cylindrical member 111 in an oil chamber. 114 has a function of applying a magnetic field. At this time, the apparent viscosity of the portion corresponding to the portion where the coil portion 117 of the magnetic fluid filled in the oil chamber 114 is increased is increased by increasing the shear resistance. In addition, an applied current control unit 18 that controls a current applied to the coil unit 117 is connected to the coil unit 117.

  Here, in the second embodiment, as shown in FIGS. 6 and 7, the inner cylinder member 111 has two plate-like vanes 111 c protruding in a direction substantially orthogonal to the axial direction of the steering shaft 5. It is provided integrally. The vane 111c is an example of the “first vane member” in the present invention. The vane 111c is configured to rotate in the oil chamber 114 as the steering shaft 5 rotates. At this time, a flow resistance is generated between the vane 111c and the magnetic fluid in the oil chamber 114. Further, the vane 111 c is formed so as to extend along the axial direction of the steering shaft 5 so that the longitudinal direction is the axial direction of the steering shaft 5. The vane 111 c is provided so as to be positioned below the oil chamber 114 and is provided below the coil portion 117. In the second embodiment, a steering damper is constituted by the oil chamber 114 filled with magnetic fluid, the coil portion 117, and the vane 111c.

  In the second embodiment, when the magnetic field is not applied to the oil chamber 114, the magnetic fluid in the oil chamber 114 has Newtonian fluid characteristics, and therefore the rotational speed of the steering shaft 5 and the steering shaft 5 The relationship with the rotation resistance generated when the lens rotates is as shown in FIG. At this time, the rotation resistance generated in the steering shaft 5 is given by the flow resistance generated when the vane 111c rotates in the magnetic fluid in the oil chamber 114.

  Other configurations of the second embodiment are the same as those of the first embodiment.

  In the second embodiment, as described above, the vane 111c that is configured to rotate with the steering shaft 5 and extends in the axial direction of the steering shaft 5 and whose longitudinal direction is the axial direction of the steering shaft 5 is provided. Thereby, the flow resistance generated when the vane 111c rotates in the oil chamber 114 can be easily increased. As a result, the steering shaft 5 can have a greater resistance to rotation. Further, the vane 111c is configured to rotate in the oil chamber 114. As a result, even when a magnetic field is no longer applied to the oil chamber 114 due to no current being supplied to the coil portion 117, a flow resistance is generated when the vane 111c rotates in the oil chamber 114, so that steering is performed. A resistance force against the rotation of the shaft 5 can be ensured.

  Further, in the second embodiment, as described above, the vane 111c is disposed so as to rotate below the coil portion 117 and below the oil chamber 114, so that the magnetic fluid in the oil chamber 114 is transferred to the magnetic fluid. Even when the contained magnetic powder precipitates, it can be easily stirred when the vane 111c rotates in the oil chamber 114.

  The remaining effects of the second embodiment are similar to those of the first embodiment.

(Third embodiment)
FIG. 9 is a cross-sectional view showing a steering damper according to a third embodiment of the present invention. 10 and 11 are diagrams for explaining the configuration and performance of the steering damper shown in FIG. Next, the configuration of the steering damper according to the third embodiment will be described with reference to FIGS. In the third embodiment, unlike the second embodiment, an example in which the vane 211c rotates in the oil chamber 250 filled with hydraulic oil will be described.

  In the third embodiment, as shown in FIGS. 9 and 10, the inner cylinder member 211 is fixed to the steering shaft 5 by being press-fitted. A flange portion 211a is formed at the lower end portion of the inner cylinder member 211 to prevent the outer cylinder member 112 from falling by supporting the outer cylinder member 112 described later from below. The inner cylinder member 211 is an example of the “inner cylinder part” in the present invention, and the flange part 211a is an example of the “support part” in the present invention.

  Further, an oil chamber 214 (see FIG. 9) and an oil chamber 250 surrounding the periphery of the steering shaft 5 are formed between the head pipe 2 and the steering shaft 5 in a state of being partitioned from each other. The oil chamber 214 is an example of the “first liquid chamber” in the present invention, and the oil chamber 250 is an example of the “second liquid chamber” in the present invention. Specifically, the oil chamber 214 (see FIG. 9) and the oil chamber 250 are formed between the inner peripheral surface 112c of the cylindrical outer cylinder member 112 and the outer peripheral surface 211b of the cylindrical inner cylinder member 211. ing. The oil chamber 214 is filled with a magnetic fluid that is oil containing magnetic powder, while the oil chamber 250 is filled with hydraulic oil having Newtonian fluid characteristics.

  Further, as shown in FIG. 9, an oil seal 15 that prevents the magnetic fluid from flowing out from the oil chamber 214 is attached to the upper end portion of the oil chamber 214. An oil seal 16 is attached to the lower end of the oil chamber 250 to prevent hydraulic oil from leaking out of the oil chamber 250. A ring-shaped oil seal 230 is provided between the oil chamber 214 and the oil chamber 250 to partition and seal the oil chamber 214 and the oil chamber 250. The oil seal 230 has a function of preventing the magnetic fluid in the oil chamber 214 from mixing with the hydraulic oil in the oil chamber 250. The oil seal 230 is an example of the “second seal member” in the present invention.

  Further, as shown in FIG. 10, a coil portion 217 surrounding the oil chamber 214 is disposed in the coil housing portion 112 b of the outer cylinder member 112. The coil unit 217 is an example of the “magnetic field application unit” in the present invention. The coil portion 217 is disposed so as to surround the oil chamber 214 over substantially the entire axial direction of the steering shaft 5.

  Here, in the third embodiment, the inner cylinder member 211 is integrally provided with two plate-like vanes 211 c that protrude in a direction substantially orthogonal to the axial direction of the steering shaft 5. The vane 211c is an example of the “second vane member” in the present invention. The vane 211c is configured to rotate in the hydraulic oil in the oil chamber 250 as the steering shaft 5 rotates. At this time, a flow resistance is generated between the vane 211c and the hydraulic oil in the oil chamber 250. Further, the vane 211c is formed so as to extend along the axial direction of the steering shaft 5 so that the longitudinal direction is the axial direction of the steering shaft 5. The vane 211c is provided below the coil portion 217. In the third embodiment, a steering damper is constituted by the oil chamber 214 filled with magnetic fluid, the coil portion 217, the oil chamber 250, and the vane 211c.

  In the third embodiment, when no magnetic field is applied to the oil chamber 214 (when the oil chamber 214 is filled with a nonmagnetic fluid), the rotation speed of the steering shaft 5 and the steering shaft The relationship with the rotation resistance generated when the 5 rotates is as shown by the broken line A in FIG. 11 indicating the characteristics of the Newtonian fluid. In addition, when the vane 211c is not provided and a magnetic field is applied in the oil chamber 214, the rotation speed of the steering shaft 5 and the rotation generated when the steering shaft 5 rotates. The relationship with the dynamic resistance is as shown by a broken line B in FIG. 11 showing the characteristics of the Bingham plastic fluid. That is, the vane 211c is configured to rotate in the oil chamber 250 filled with hydraulic oil, and the oil chamber 214 is filled with a magnetic fluid, whereby the rotation speed of the steering shaft 5 and the steering shaft 5 are increased. The relationship between the rotation resistance generated when the lens rotates and the rotation resistance is represented by a solid line C that is a combination of the broken line A and the broken line B. Thereby, from the case where the rotation speed of the steering shaft 5 is 0 (the state before the rotation), the rotation resistance of the steering shaft 5 is reduced by the Bingham plastic fluid characteristic of the magnetic fluid in the oil chamber 214 to which the magnetic field is applied. It becomes possible to enlarge. In addition, the rotational speed of the steering shaft 5 increases as the rotational speed of the steering shaft 5 increases due to the rotational resistance of the vane 211c that rotates in the oil chamber 250 filled with hydraulic oil having Newtonian fluid characteristics. It becomes possible to increase the resistance to rotation.

  Other configurations of the third embodiment are the same as those of the first embodiment and the second embodiment.

  In the third embodiment, as described above, the oil chamber 250 is formed between the head pipe 2 and the steering shaft 5 so as to be partitioned with respect to the oil chamber 214 and filled with hydraulic oil having Newtonian fluid characteristics. The vane 211c is configured to rotate in the oil chamber 250. Thereby, in addition to the rotation resistance of the steering shaft 5 due to the magnetic fluid in the oil chamber 214 to which the magnetic field is applied, the rotation resistance when the vane 211c rotates in the oil chamber 250 is also used. The resistance to rotation can be increased. As a result, the resistance force against the rotation of the steering shaft 5 can be sufficiently increased regardless of the rotation speed of the steering shaft 5.

  Further, in the third embodiment, as described above, the oil seal 230 for partitioning and sealing the oil chamber 214 and the oil chamber 250 is provided. Thereby, it is possible to easily suppress the hydraulic oil in the oil chamber 250 from flowing out.

  The remaining effects of the third embodiment are similar to those of the first embodiment and the second embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first to third embodiments, the example in which the oil chamber is formed by filling the space formed between the inner cylinder member and the outer cylinder member with oil is shown. Not limited to this, a cylindrical member made of a magnetic material may be disposed between the head pipe and the steering shaft as an oil chamber.

  Moreover, in the said 1st-3rd embodiment, although the example which fixes an inner cylinder member by press-fitting with respect to a steering shaft was shown, this invention is not restricted to this, A thread part is provided in an inner cylinder member and a steering shaft. And a method other than press-fitting, such as a method in which the inner cylinder member and the steering shaft are fastened to each other using a bolt, and a method in which a keyway is formed in the inner cylinder member and the steering shaft. The inner cylinder member may be fixed to the steering shaft.

  Moreover, although the example which arrange | positions the vane integrally formed in the inner cylinder member was shown in the said 2nd and 3rd embodiment, this invention is not restricted to this, A vane and an inner cylinder member are mutually separated. It may be provided.

  Moreover, although the example which arrange | positions two vanes was shown in the said 2nd and 3rd embodiment, this invention is not restricted to this, You may arrange | position one or three or more vanes.

  Further, in the second and third embodiments, the example in which the vane formed in a plate shape is arranged is shown. However, the present invention is not limited to this, and an orifice having an inner diameter through which a fluid can pass is provided in the vane. Also good.

  Moreover, although the example which arrange | positions a vane below the coil part was shown in the said 3rd Embodiment, this invention is not restricted to this, You may arrange | position a vane above a coil part.

  In the third embodiment, the oil chamber filled with the magnetic fluid and the oil chamber filled with the working oil are separated by the oil seal. However, the present invention is not limited to this, and the oil filled with the magnetic fluid is used. You may comprise so that oil chambers may be partitioned by arrange | positioning separately the cylindrical member which has a chamber inside, and the cylindrical member which has an oil chamber filled with hydraulic fluid inside.

DESCRIPTION OF SYMBOLS 1 Motorcycle 2 Head pipe 2a Hollow part 2b Inner peripheral surface 4 Handle 5 Steering shaft 11, 111, 211 Inner cylinder member (inner cylinder part)
11a, 111a, 211a Flange part (support part)
12, 112 Outer cylinder member (outer cylinder part)
12a, 112a Outer peripheral surface 12b, 112b Coil storage part
12c, 112c Inner peripheral surface 12d, 12e, 112d, 112e Seal holding part (holding part)
14, 114, 214 Oil chamber (first liquid chamber)
15, 16 Oil seal (first seal member)
17, 117, 217 Coil part (magnetic field application part)
111c vane (first vane member)
211c vane (second vane member)
230 Oil seal (second seal member)
250 Oil chamber (second liquid chamber)

Claims (14)

A handle,
A cylindrical head pipe having a hollow inside;
A steering shaft that rotates with the rotation of the handle and is rotatably supported by the hollow portion of the head pipe;
A first liquid chamber formed between the head pipe and the steering shaft so as to surround the periphery of the steering shaft and filled with a magnetic fluid whose viscosity is increased by the action of a magnetic field;
A steering buffer mechanism for a motorcycle, comprising: a magnetic field applying unit that is disposed so as to surround the first liquid chamber and applies a magnetic field to the magnetic fluid in the first liquid chamber.   The steering buffer for a motorcycle according to claim 1, wherein the first liquid chamber filled with the magnetic fluid extends along an axial direction of the steering shaft and surrounds the periphery of the steering shaft. mechanism. An inner cylinder fixed to the outer peripheral surface of the steering shaft;
An outer cylinder portion fixed to the inner peripheral surface of the hollow portion of the head pipe,
The steering buffer mechanism for a motorcycle according to claim 1, wherein the first liquid chamber is formed between the inner cylinder portion and the outer cylinder portion. The magnetic field application unit is a coil arranged to surround the first liquid chamber,
The steering buffer mechanism for a motorcycle according to claim 3, wherein the outer cylinder portion includes a coil housing portion that houses the coil. The coil housing part of the outer cylinder part is formed on the outer peripheral surface of the outer cylinder part,
The outer cylinder portion is configured to hold the magnetic fluid in the first liquid chamber on an inner peripheral surface of the outer cylinder portion and hold the coil on an outer peripheral surface of the outer cylinder portion. 5. A steering buffer mechanism for a motorcycle according to 4.   The steering buffer mechanism for a motorcycle according to claim 4, further comprising a current application unit that applies a current for generating a magnetic field to the coil.   The steering buffer mechanism for a motorcycle according to claim 3, wherein the inner cylinder portion includes a support portion that is provided at a lower portion of the inner cylinder portion and supports the outer cylinder portion from below.   The steering buffer mechanism for a motorcycle according to claim 1, further comprising a first seal member for sealing an upper portion and a lower portion of the first liquid chamber. An outer cylinder portion fixed to the inner wall surface of the hollow portion of the head pipe,
The steering buffer mechanism for a motorcycle according to claim 8, wherein the outer cylinder portion includes a holding portion that holds the first seal member.   2. The steering buffer mechanism for a motorcycle according to claim 1, wherein the magnetic field applying unit is disposed so as to surround a substantially entire area in an axial direction of the steering shaft of the first liquid chamber filled with the magnetic fluid. .   A first vane member configured to rotate in a first liquid chamber filled with a magnetic fluid together with the steering shaft, extending in an axial direction of the steering shaft, and having a longitudinal direction in the axial direction of the steering shaft; A steering buffer mechanism for a motorcycle according to claim 1.   The steering buffer mechanism for a motorcycle according to claim 11, wherein the first vane member is disposed below the magnetic field application unit and below the first liquid chamber filled with the magnetic fluid. A second liquid chamber that is formed between the head pipe and the steering shaft and that is partitioned from the first liquid chamber and filled with a nonmagnetic fluid having Newtonian fluid properties;
The steering buffer mechanism for a motorcycle according to claim 1, further comprising a second vane member that rotates in the second liquid chamber filled with the nonmagnetic fluid together with the steering shaft.   The steering buffer mechanism for a motorcycle according to claim 13, further comprising a second seal member for partitioning and sealing the first liquid chamber and the second liquid chamber.

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