Direct-acting damper and steering device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-02-24
- Publication Date
- 2026-08-11
Smart Images
Figure CN117098932B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a linear damper that attenuates kinetic energy during linear motion and a steering device having the same linear damper. Background Technology
[0002] There have always been linear dampers that attenuate the kinetic energy in linear motion. For example, the inventors of this application have proposed a linear damper as shown in Patent Document 1 below, which reduces the impact load generated between the rack end and the rack housing by limiting the flow of fluid in the steering mechanism of a self-propelled vehicle to the damping force generated by the rack end which is relatively displaced relative to the rack housing.
[0003] Existing technical documents
[0004] Patent documents
[0005] Patent Document 1: Japanese Patent Application No. 2020-096430 Summary of the Invention
[0006] However, the direct-acting damper disclosed in the aforementioned patent document 1 has the following problem: when the rack end suddenly approaches the rack housing and the direct-acting damper collides with the rack housing, a large impact sound is generated, and a large impact is generated on the steering device in an instant.
[0007] The present invention was made to address the above-mentioned problems, and its object is to provide a direct-acting damper and a steering device equipped with the direct-acting damper, which can suppress the generation of large impact noise or impact even under the condition of large load and sudden action.
[0008] To achieve the above objectives, the present invention is characterized by a direct-acting damper comprising: an inner cavity forming body formed in a cylindrical shape, having a fluid-tight inner cavity on the inner side of the cylindrical portion; a relative displacement body slidably fitted into the inner cavity forming body and subject to relative displacement relative to the inner cavity forming body; and a flow control valve disposed in at least one of the inner cavity forming body and the relative displacement body, which restricts the flow of fluid while allowing it to flow. The direct-acting damper is disposed between two mounting objects that are linearly relative to each other, and the external force caused by the relative displacement is attenuated by restricting the flow of fluid. One of the inner cavity forming body and the relative displacement body has a mounting portion mounted on one of the two mounting objects, and the other of the inner cavity forming body and the relative displacement body has a collision portion that is collided with by the other of the two mounting objects. The collision portion is configured to include an elastic body that elastically withstands the collision of the other of the two mounting objects.
[0009] Therefore, since the direct-acting damper is configured such that the impact part includes an elastic body, even in the case where the impact part collides with the object opposite to the impact part of the two objects on which the direct-acting damper is installed, and a large load is applied rapidly, the generation of large impact noise or impact can be suppressed.
[0010] Furthermore, another feature of the present invention is that the direct-acting damper includes a reset elastic body that imparts an elastic force to at least one of the cavity forming body and the relative displacement body, thereby elastically pushing the cavity forming body or the relative displacement body without a collision portion toward a side away from the collision portion.
[0011] Therefore, the resetting elastic body of the direct-acting damper imparts an elastic force to the inner cavity forming body or the relative displacement body without a collision part, causing it to elastically displace away from the collision part. Thus, in the direct-acting damper of the present invention, when no external force causing relative displacement between the inner cavity forming body and the relative displacement body is applied, the inner cavity forming body or the relative displacement body without a collision part can always be located at the end of the relative displacement region away from the collision part, i.e., the starting position for the attenuation function of the flow control valve, thereby maximizing the stroke of the relative displacement body.
[0012] Furthermore, another feature of the present invention is that, in the linear damper, the collision portion is formed in a ring shape.
[0013] Therefore, since the collision part of the direct-acting damper is formed in a ring shape, the components of the direct-acting damper or all or part of the installation object of at least one of the two installation objects on which the direct-acting damper is installed can be arranged inside the collision part, which can expand the variation of the composition, installation object or installation method of the direct-acting damper.
[0014] Furthermore, another feature of the present invention is that, in the linear damper, the impact portion is made of an elastomeric material.
[0015] Therefore, in a direct-acting damper, since the impact part is made of an elastomeric material, it can more effectively suppress the generation of impact noise or impact compared to cases where the impact part is made of a metal material such as a coil spring. The elastomeric material is a rubber or resin material that can elastically withstand the impact when the impact part collides with an object. More specifically, it includes thermosetting elastomers (such as vulcanized rubber, polyurethane rubber, silicone rubber, fluororubber, etc.) and thermoplastic elastomers (such as styrene-based, olefin-based, vinyl chloride-based, urethane-based, or amide-based resins, etc.). Furthermore, the impact part can, of course, be made of materials other than elastomeric materials, such as metal leaf springs or coil springs.
[0016] Furthermore, another feature of the present invention is that, in the linear damper, the impact portion is formed with at least one of a bottom hole and a through hole.
[0017] According to other features of the invention configured in this way, the direct-acting damper, since the impact portion is formed with at least one of a bottom hole and a through hole, can adjust the damping force of the impact caused by the impact portion by the number, size or position of the bottom hole or the through hole.
[0018] Furthermore, another feature of the present invention is that, in the direct-acting damper, the inner cavity forming body and the relative displacement body each have a displacement limit defining portion, which collide with each other through relative displacement, thereby defining the displacement limit on one side and the displacement limit on the other side of the range of relative displacement, and the displacement limit defining portion is configured such that at least one of the displacement limit on one side and the displacement limit on the other side includes an elastic body.
[0019] According to other features of the invention configured in this way, the direct-acting damper is configured such that at least one displacement limit specification portion of the displacement limit on one side and the displacement limit on the other side of the relative displacement range of the relative displacement body includes an elastic body. Therefore, by pre-setting a displacement limit specification portion including an elastic body at the displacement limit position on one side of the relative displacement range of the relative displacement body, the direct-acting damper can mitigate the impact when the relative displacement body reaches the displacement limit position on said side, and can attenuate this external force even when further external force is applied. Furthermore, by pre-setting a displacement limit specification portion including an elastic body at the displacement limit position on the other side of the relative displacement range of the relative displacement body, the direct-acting damper can mitigate the impact when the relative displacement body reaches the displacement limit position on said other side, and can attenuate this external force even when further external force is applied. That is, the direct-acting damper can attenuate the impact or external force when the relative displacement body reaches the displacement limit position when subjected to an external force and / or when the relative displacement body reaches the displacement limit position of its original position before being subjected to the external force.
[0020] Furthermore, another feature of the present invention is that, in the direct-acting damper, the relative displacement body includes a volume change compensation device that compensates for volume changes of the fluid within the cavity.
[0021] According to other features of the invention configured in this way, the direct-acting damper can be made more compact because the relative displacement body has a volume change compensation device that compensates for the volume change of the fluid in the cavity.
[0022] Furthermore, the present invention can be implemented not only as an invention of a direct-acting damper, but also as an invention of a steering device equipped with such a direct-acting damper.
[0023] Specifically, a steering device includes: a steering shaft extending in a rod shape and rotated by operation of a steering wheel; a rack extending in a rod shape and transmitting the rotational motion of the steering shaft as a reciprocating motion in the axial direction; an intermediate connector connected to both ends of the rack, with the wheels, which are the objects of steering, directly or indirectly connected to the ends; and a rack housing covering the rack. The steering device includes a direct-acting damper disposed between the rack housing and the rack or intermediate connector to attenuate impacts from the wheels and / or impacts from inertial forces on the steering shaft side. Thus, the steering device of the present invention is expected to have the same effect as the aforementioned direct-acting damper.
[0024] In this case, in the steering device, the relative displacement body is connected to the intermediate connecting body, and the inner cavity forming body is formed by contacting or moving away from the rack housing through the reciprocating motion of the rack rod.
[0025] Therefore, the steering device involved in the present invention is provided with a relative displacement body connected to an intermediate connecting body, and the inner cavity forming body is formed in such a way that it contacts or moves away from the rack housing through the reciprocating motion of the rack rod. The damper is provided in the intermediate connecting body such as the tie rod or the end of the rack, so the maintenance or replacement of the direct-acting damper can be easily performed.
[0026] Furthermore, in this case, in the steering device, the inner cavity forming body is connected to the end of the rack housing, and the relative displacement body may have a rack rod or intermediate connecting body passing through it, and the rack rod or intermediate connecting body may be formed by the reciprocating motion of the rack rod, causing the rack rod or intermediate connecting body to contact or move away.
[0027] Therefore, the inner cavity of the steering device according to the present invention is formed at the end of the rack housing, and a rack rod or intermediate connector (tie rod or rack end, etc.) passes through the interior of the relative displacement body, so that the relative displacement body is formed by the reciprocating motion of the rack rod, causing the rack rod or tie rod to contact or move away. Thus, because the direct-acting damper is provided in the rack housing, the rack rod or intermediate connector (tie rod or rack end, etc.) of the steering device according to the present invention can be made lighter. Attached Figure Description
[0028] [ Figure 1 [Illustration] is an explanatory diagram schematically showing the overall structure of the steering device according to an embodiment of the present invention.
[0029] [ Figure 2 ] indicates composition Figure 1 A perspective view showing the outline of the direct-acting damper of the steering device.
[0030] [ Figure 3 ] indicates Figure 2 The front view shows a summary of the external structure of the direct-acting damper.
[0031] [ Figure 4 ] indicates Figure 3 The diagram shows a schematic cross-sectional view of the internal structure of the direct-acting damper, viewed from line 4-4.
[0032] [ Figure 5 ] indicates Figure 4 The cross-sectional view shown is of the instant the inner cavity forming body of the direct-acting damper contacts the rack housing.
[0033] [ Figure 6 ] indicates Figure 4 The cross-sectional view shown shows the state in which the inner cavity forming body of the direct-acting damper is pushed against the rack housing side. Detailed Implementation
[0034] Hereinafter, an embodiment of the steering device with a direct-acting damper according to the present invention will be described with reference to the accompanying drawings. Figure 1 The editor will provide an explanation. Figure 1 This is an explanatory diagram schematically showing the overall structure of the steering device 100 according to an embodiment of the present invention. Furthermore, Figure 2 It indicates composition Figure 1 A perspective view showing the outline of the direct-acting damper 120 of the steering device 100. Also, Figure 3 It means Figure 2 The diagram shows a schematic front view of the external structure of the direct-acting damper 120. Also, Figure 4 It means from Figure 3 The diagram shows a schematic cross-sectional view of the internal structure of the direct-acting damper 120 as observed along line 4-4.
[0035] This steering device 100 is a mechanical device used to steer the two front wheels (or rear wheels) of a four-wheeled self-propelled vehicle (not shown) to the left and right respectively.
[0036] (Composition of steering device 100)
[0037] The steering system 100 includes a steering wheel 101. The steering wheel 101 is an operating element (i.e., a handle) for the driver of a self-propelled vehicle to manually operate the direction of travel, and is formed into a ring shape from resin or metal material. A steering shaft 102 is connected to this steering wheel 101.
[0038] The steering shaft 102 is a rod-shaped component that rotates around an axis in response to the clockwise or counterclockwise rotation of the steering wheel 101. It is constructed by connecting one or more metal rods via universal joints or the like. The steering shaft 102 is connected to the steering wheel 101 at one end and forms a pinion 102a at the other end, which is connected to the rack 103.
[0039] The rack and pinion 103 is a rod-shaped component that transmits the force and amount of steering input to the steering knuckle arm 111 by reciprocating in the axial direction. It is made of metal. In this case, a rack and pinion 103a is formed on a part of the rack and pinion 102a that meshes with the steering shaft 102. That is, the pinion 102a and the rack and pinion 103a constitute a rack and pinion mechanism (steering gearbox) that converts the rotational motion of the steering shaft 102 into the reciprocating linear motion of the rack and pinion 103.
[0040] Both ends of the rack rod 103 in the axial direction protrude from the rack housing 104 when the gear and rack mechanism is covered by the rack housing 104. Moreover, each of the two ends of the rack rod 103 that protrude from the rack housing 104 is connected to a wheel 112 via a direct-acting damper 120, an intermediate connector 105, and a steering knuckle arm 111, respectively.
[0041] The rack housing 104 is a component used to cover and protect the main parts such as the gear and rack mechanism in the rack rod 103, and is constructed by forming a cylindrical shape from metal material. This rack housing 104 is fixedly mounted to the chassis (not shown) of a self-propelled vehicle.
[0042] The intermediate connector 105 is a component used to transmit the steering force and steering amount transmitted from the rack 103 to the steering knuckle arm 111, and is mainly composed of a rack end 106 and a tie rod 110. The rack end 106 is a component that movably connects the tie rod 110 to the front end of the rack 103 and connects to the direct-acting damper 120, and is mainly composed of a stud body 107 and a bearing body 108.
[0043] The stud 107 is a component used to movably connect the tie rod 110 to the bearing 108, and is constructed by forming a round rod shape from metal material. The stud 107 has a spherical ball portion 107a at one end (left side of the figure) and an external thread portion (not shown) that screws into the end of the tie rod 110 on the other side (right side of the figure).
[0044] The bearing body 108 is a component used to movably connect the stud 107 to the front end of the relative displacement body 140, and is constructed by forming a round rod shape from metal material. More specifically, the bearing body 108 is mainly composed of a bearing body 108a and a connecting portion 108b. The bearing body 108a is the part that holds the ball portion 107a in a slidable state, and is formed into a concave spherical shape covering the ball portion 107a. The connecting portion 108b is a shaft-like part that connects to the relative displacement body 140, and has external threads that screw into the relative displacement body 140.
[0045] The tie rod 110 is a component that movably connects the steering knuckle arm 111 to the front end of the rack end 106, and is configured such that a ball joint is movably mounted on the front end of the tie rod body extending into a rod shape. The steering knuckle arm 111 is a metal component used to hold the wheel 112 relative to the tie rod 110 and to transmit the steering force and steering amount transmitted from the tie rod 110 to the wheel 112, and is formed in the shape of multiple rod-shaped bodies extending from around the cylindrical portion. The wheel 112 is a pair of left and right components that rotate on the road surface to move the self-propelled vehicle forward or backward, and is configured such that rubber tires are mounted on the outer side of the metal wheel.
[0046] The direct-acting damper 120 is a device for absorbing inertial forces from the steering axle 102 side and / or strong thrust (impact) transmitted from the wheel 112, and is disposed between the left and right intermediate connectors 105 and the two ends of the rack 103. This direct-acting damper 120 has an inner cavity forming body 121.
[0047] The inner cavity forming body 121 is a component used to form the first inner cavity 125a and the second inner cavity 125b respectively, while supporting the relative displacement body 140. It is constructed by forming a cylindrical shape from metal material. A valve support portion 123 is formed at the center of the inner peripheral surface 122 in the axial direction. The valve support portion 123 supports the first flow control valve 127, the second flow control valve 128 and the relative displacement body 140 respectively, and is formed by extending in an annular shape from the inner peripheral surface 122 toward the inner side in the diametrical direction.
[0048] In this valve support portion 123, four through holes are formed at equal intervals along the circumferential direction, extending towards the axial direction. The first flow control valve 127 is held in a state where it is engaged with three of these four through holes, and the second flow control valve 128 is held in a state where it is engaged with the remaining through hole. Furthermore, with a sealing ring 124 formed of an elastic body embedded in the inner circumferential surface of the valve support portion 123, a relative displacement body 140 is slidably engaged. Thus, a first inner cavity 125a and a second inner cavity 125b are formed on both sides of the inner cavity forming body 121 in the axial direction of the valve support portion 123, respectively.
[0049] The first inner cavity 125a and the second inner cavity 125b are portions that liquid-tightly contain the fluid 126, and are formed as an annular cylinder extending in the axial direction on the outer periphery of the relative displacement body 140. That is, the first inner cavity 125a and the second inner cavity 125b are formed as a spatial region between the relative displacement body 140 and the inner cavity forming body 121. In this case, the first inner cavity 125a is formed between the first inner cavity forming wall 142 of the relative displacement body 140 and the valve support portion 123.
[0050] Furthermore, a second inner cavity 125b is formed between the second inner cavity forming wall 145 of the relative displacement body 140 and the valve support portion 123. Moreover, the volumes of these first inner cavities 125a and second inner cavities 125b vary depending on the position of the relative displacement body 140, which reciprocates within the inner cavity forming body 121. These first inner cavities 125a and second inner cavities 125b correspond to the inner cavities involved in this invention.
[0051] Fluid 126 is a substance used to enable the direct-acting damper 120 to function as a damper by overcoming the resistance encountered when flowing through the three first flow control valves 127 disposed between the first inner cavity 125a and the second inner cavity 125b, and is filled within the space formed by the first inner cavity 125a and the second inner cavity 125b. This fluid 126 is composed of a viscous, fluid, liquid, gel, or semi-solid substance having a viscosity corresponding to the specifications of the direct-acting damper 120. In this case, the viscosity of fluid 126 is appropriately selected according to the specifications of the direct-acting damper 120. In this embodiment, fluid 126 is composed of oil, such as mineral oil or silicone oil. Furthermore, fluid 126 in… Figures 4-6 The dashed circle inside the dashed circle represents the area.
[0052] The three first flow control valves 127 are configured to restrict the flow of fluid 126 between the first inner cavity 125a and the second inner cavity 125b while allowing bidirectional flow. In this case, restricting the flow of fluid 126 in the first flow control valve 127 means that, relative to the ease of flow of fluid 126 in the second flow control valve 128 in the flow direction, fluid 126 is difficult to flow under the same conditions (e.g., pressure and viscosity of the working fluid).
[0053] The second flow control valve 128 is configured to allow fluid 126 to flow from the second inner cavity 125b side toward the first inner cavity 125a side, and to prevent fluid 126 from flowing from the first inner cavity 125a side toward the second inner cavity 125b side.
[0054] At one end (left side of the figure) of the inner cavity forming body 121, a collision portion 131 is provided by a support base 130. The support base 130 is a component for supporting the collision portion 131 and is formed of metal material in a ring shape. The outer periphery of the support base 130 on the end of the inner cavity forming body 121 side has an external thread for threaded engagement with the end thread of the inner peripheral surface 122 of the inner cavity forming body 121, and a fitting portion 130a is formed on the end face of the end opposite to this end. The fitting portion 130a is the part that fits into the collision portion 131, and the concave groove is formed in a ring shape.
[0055] The impact portion 131 is a component used to mitigate the impact when the direct-acting damper 120 collides with the rack housing 104. It is constructed by forming an elastically deformable elastomer into a ring shape. In this embodiment, the impact portion 131 is made of rubber material. This impact portion 131 has a through hole 131a formed in a state of penetrating in the axial direction. The through hole 131a is a hole for a bolt 132 to pass through, the bolt 132 being used to mount the impact portion 131 on the support base 130. Three through holes 131a are formed at equal intervals along the circumferential direction of the impact portion 131.
[0056] Furthermore, a fitting portion 131b is formed at one end (right side of the figure) in the axial direction of the collision portion 131, and a bottom hole 131c is formed at the other end (left side of the figure). The fitting portion 131b is a portion used to fit into the concave fitting portion 130a of the support base 130 to define the mounting position of the collision portion 131, and the protrusion that fits into the fitting portion 130a is formed in an annular shape.
[0057] The bottomed holes 131c are bottomed holes used to adjust the elastic force of the impact portion 131, and three of them are formed between each of the three through holes 131a along the circumferential direction of the impact portion 131. These bottomed holes 131c are formed to a depth of approximately half the length of the impact portion 131 along its axial direction. Furthermore, the three through holes 131a, like the bottomed holes 131c, also function to adjust the elastic force of the impact portion 131.
[0058] The relative displacement body 140 is a component used to connect the rack rod 103 and the rack end 106 to each other, and together with the inner cavity forming body 121, it forms the first inner cavity 125a and the second inner cavity 125b, respectively. It is constructed by forming a round rod shape from metal material. This relative displacement body 140 is mainly composed of an inner cavity opposing portion 141, a first inner cavity forming wall 142, a second inner cavity forming wall 145, a rack end connecting portion 148, a rack rod connecting portion 149, and a compensation device receiving portion 150.
[0059] The opposing inner cavity portion 141 is formed by the first inner cavity 125a and the second inner cavity 125b, and is the portion through which the valve support portion 123 slides. It is constructed with a smooth curved surface that is shaped like a circle. This opposing inner cavity portion 141 is formed at the center of the relative displacement body 140 along its axial direction.
[0060] The first inner cavity forming wall 142 is the portion that forms the first inner cavity 125a and slides on the inner peripheral surface 122 of the inner cavity forming body 121 to push the fluid 126. It extends out in a flange-like shape from one end of the inner cavity opposing portion 141 (right side of the figure). In this case, the first inner cavity forming wall 142 is integrally formed of the same material as the relative displacement body 140. With a sealing ring 143 formed of an elastic body inserted into the outer peripheral portion of this first inner cavity forming wall 142, the inner peripheral surface 122 of the inner cavity forming body 121 slides freely into it. Furthermore, a first displacement limit defining portion 144 is provided on the end face of the first inner cavity forming wall 142 on the first inner cavity 125a side.
[0061] The first displacement limit defining part 144 is a component used to define the displacement limit on one side of the two ends of the displacement range of the relative displacement body 140 by displacement and collision with the valve support part 123 via the first inner cavity forming wall 142, and to mitigate the impact during collision. It is constructed by forming an elastically deformable elastomer into a ring shape. In this embodiment, the first displacement limit defining part 144 is made of rubber material. Furthermore, the first displacement limit defining part 144 is formed as a cone-shaped section with a larger outer diameter on the side of the first inner cavity forming wall 142 than on the side of the valve support part 123.
[0062] The second inner cavity forming wall 145 is the portion that forms the second inner cavity 125b and slides on the inner peripheral surface 122 of the inner cavity forming body 121 to push the fluid 126. It is provided as a flange extending from the other end (left side of the figure) in the opposing portion 141 of the inner cavity. This second inner cavity forming wall 145 is constructed by forming a ring-shaped metal material that is separate from the relative displacement body 140, and is integrated with the relative displacement body 140 by screwing it into the outer peripheral portion of the relative displacement body 140.
[0063] Furthermore, with the sealing ring 146 formed of an elastic body embedded in the outer periphery of the second inner cavity forming wall 145, the inner peripheral surface 122 of the sliding inner cavity forming body 121 can slide freely into it. Further, a second displacement limit defining portion 147 is provided on the end face of the second inner cavity forming wall 145 on the second inner cavity 125b side.
[0064] The second displacement limit defining part 147 is a component used to define the displacement limit on the other side of the two ends of the displacement range of the relative displacement body 140 by displacement and collision with the valve support part 123 through the second inner cavity forming wall 145, and to mitigate the impact during collision. It is constructed by forming an elastically deformable elastomer into a ring shape. In this embodiment, the second displacement limit defining part 147 is constructed of rubber material.
[0065] The rack end connecting portion 148 is the part that connects to the bearing body 108 of the rack end 106, and is formed in a bottomed hole that extends in the axial direction of the relative displacement body 140 and opens at the end on the right side of the figure. In this case, the rack end connecting portion 148 has an internal thread formed on the inner circumferential surface of the bottomed hole, and the internal thread is threaded into the external thread of the connecting portion 108b of the bearing body 108.
[0066] The rack rod connecting portion 149 is the part that connects to the rack rod 103. It is configured to extend in the axial direction relative to the displacement body 140 and to form an internal thread on the inner circumferential surface of a bottomed hole at the end opening on the left side of the drawing. The internal thread is threadedly engaged with the external thread formed at the end of the rack rod 103. These rack end connecting portions 148 and rack rod connecting portions 149 correspond to the mounting portions involved in this invention.
[0067] The compensation device receiving portion 150 is a part for liquid-tightly accommodating the volume change compensation device 153, and is formed as a bottomed hole integrally formed with the rack end connection portion 148. This compensation device receiving portion 150 is connected to the second inner cavity 125b through the inner cavity connecting passage 151, and is connected to the atmosphere outside the direct-acting damper 120 through the atmospheric connecting passage 152.
[0068] The volume change compensation device 153 is an apparatus for compensating for volume changes caused by expansion or contraction of the fluid 126 within the first inner cavity 125a and the second inner cavity 125b due to temperature variations. This volume change compensation device 153 is configured such that a piston, which reciprocates within the compensation device housing 150, is elastically pushed towards the inner cavity communication passage 151 by a helical spring. In this configuration, the space housing the helical spring is connected to the atmosphere outside the direct-acting damper 120 via the atmospheric communication passage 152.
[0069] An elastomer bracket 154 is mounted on the cylindrical portion outside the rack end connection portion 148 of the relative displacement body 140. The elastomer bracket 154 is a component for holding the reset elastomer 155 and is constructed by forming a cylindrical shape from metal material. The elastomer bracket 154 holds the reset elastomer 155 at its outer periphery. In this case, a bearing portion 154a is formed by a flange extending from one end in the axial direction at the outer periphery of the elastomer bracket 154, and this bearing portion 154a bears one end of the reset elastomer 155.
[0070] The reset elastomer 155 is a component used to elastically push the first inner cavity forming wall 142 and the second inner cavity forming wall 145 in the relative displacement body 140 toward the right end shown in the figure, respectively, into the first inner cavity 125a and the second inner cavity 125b. It is constructed by overlapping multiple metal wave washers in the axial direction of the elastomer support 154. The end of this reset elastomer 155 on one side (right side shown in the figure) elastically pushes the receiving portion 154a of the elastomer support 154, and the end on the other side (left side shown in the figure) elastically pushes the right end shown in the figure of the inner cavity forming body 121.
[0071] (Operation of steering device 100)
[0072] Next, the operation of the steering device 100 configured as described herein will be explained. This steering device 100 is assembled inside a four-wheeled self-propelled vehicle (not shown) as a mechanism for steering the wheels (e.g., the two front wheels) in a left-right steering operation. Then, this steering device 100 changes the direction of the two wheels 112 in response to the operation of the steering wheel 101 by the driver of the self-propelled vehicle, thereby determining the direction of travel of the self-propelled vehicle.
[0073] In driving such a self-propelled vehicle, the direct-acting damper 120 in the steering device 100 functions when the rack 103, in its relationship with the pinion 102a, is displaced to near its left and right displacement limits. In this case, the displacement limits of the rack 103 refer to the left and right steering control limits of the wheel 112. These limits occur not only when the driver of the self-propelled vehicle turns the steering wheel 101 clockwise or counterclockwise to near its rotational limits, but also when the wheel 112 collides with an obstacle such as a curb, resulting in a significant input to the rack 103 from the wheel 112 side.
[0074] First, an explanation will be given regarding the scenario where no external force is applied to the direct-acting damper 120, and the direct-acting damper 120 does not operate. For example... Figure 4 As shown, this direct-acting damper 120 will not operate when the wheels 112 of the self-propelled vehicle are not steered to near the steering limit, or when the rack rod 103 has not reached the displacement limit, because the inner cavity forming body 121 will not collide with the rack housing 104. In this case, the direct-acting damper 120... Figure 4 As shown, the inner cavity forming body 121 is elastically pushed to the left of the displacement range of the inner cavity forming body 121 by the reset elastic body 155, thereby the second inner cavity forming wall 145, which defines the displacement limit, is elastically pushed towards the valve support portion 123 via the second displacement limit defining portion 147.
[0075] Next, the operation of the direct-acting damper 120 when an external force is applied will be explained. For example... Figure 5 As shown, this direct-acting damper 120 begins to operate when the rack rod 103 reaches its displacement limit, such as when the wheel 112 of the self-propelled vehicle is steered to near the steering limit. The end of the inner cavity forming 121 contacts the rack housing 104 to initiate operation. That is, the rack housing 104 is equivalent to the other of the two mounting objects involved in this invention. Furthermore, the intermediate connector 105 is equivalent to one of the two mounting objects involved in this invention.
[0076] In this scenario, firstly, the direct-acting damper 120 undergoes elastic deformation due to compression upon impact with the rack housing 104 via the collision part 131, thereby attenuating the impact during the collision. Then, as... Figure 6 As shown, when the impact portion 131 reaches the limit of elastic deformation, the relative displacement body 140 moves within the inner cavity forming body 121 towards the rack housing 104 while resisting the elastic force of the reset elastic body 155. That is, the relative displacement body 140 moves towards the valve support portion 123 while pushing the fluid 126.
[0077] Therefore, the direct-acting damper 120 generates a damping force as the fluid 126 in the first inner cavity 125a flows toward the second inner cavity 125b through the three first flow control valves 127 while accompanied by flow resistance. Then, when the direct-acting damper 120 collides with the valve support portion 123 in the case of the first inner cavity forming wall 142 colliding with the valve support portion 123, the elastic deformation of the direct-acting damper 120 due to the collision of the first displacement limit setting portion 144 with the valve support portion 123 attenuates the impact of the collision and the external force that displaces the relative displacement body 140.
[0078] Next, after the self-propelled vehicle's wheel 112 is steered to near its steering limit and the rack 103 reaches near its displacement limit, as the wheel 112 returns to its original position, the relative displacement body 140 in the direct-acting damper 120 displaces within the inner cavity forming body 121 in a direction away from the rack housing 104. That is, the relative displacement body 140 displaces towards the valve support portion 123 while pushing fluid 126 through the reset elastic body 155 and the second inner cavity forming wall 145.
[0079] Therefore, the fluid 126 in the second inner cavity 125b of the direct-acting damper 120 flows towards the first inner cavity 125a side with minimal flow resistance via a second flow control valve 128. That is, the direct-acting damper 120 generates almost no damping force on the external force when the relative displacement body 140 resets. Then, in the case where the second inner cavity forming wall 145 of the direct-acting damper 120 collides with the valve support portion 123, the impact during the collision is damped by the elastic deformation caused by the second displacement limit setting portion 147 colliding with the valve support portion 123 (see reference). Figure 4 ).
[0080] Next, after the direct-acting damper 120 collides with the valve support portion 123 at the second displacement limit setting portion 147, it moves away from the rack housing 104 via the inner cavity forming body 121, thereby releasing the compression deformation of the collision portion 131 and moving away from the rack housing 104 (see reference). Figure 4 Therefore, the wheels 112 of the self-propelled vehicle will return to their original positions.
[0081] As can be understood from the above description of the operating method, according to the first embodiment described above, the direct-acting damper 120 is configured such that the impact portion 131 includes an elastic body. Therefore, even if the impact portion 131 impacts the rack housing 104 facing the impact portion 131 in the two rack housings 104 of the direct-acting damper 120 and the intermediate connecting body 105, and a large load is applied rapidly, the generation of large impact noise or impact can be suppressed.
[0082] Furthermore, in the implementation of this invention, it is not limited to the above-described embodiments; various modifications can be made as long as they do not depart from the purpose of this invention. In addition, in the description of each modification, the same reference numerals are used for the same parts as in the above embodiments, and repeated descriptions are omitted.
[0083] For example, in the above embodiment, the collision part 131, the first displacement limit defining part 144, and the second displacement limit defining part 147 are each made of rubber material. However, the collision part 131, the first displacement limit defining part 144, and the second displacement limit defining part 147 can be made of an elastic body that can elastically withstand external forces. In this case, as the elastic body, a viscoelastic body that slowly deforms under external forces to absorb impact or vibration is preferred. Furthermore, as the viscoelastic body, a viscoelastic body with a low resilience modulus is preferred; specifically, a viscoelastic body with a resilience modulus of 50% or less is preferred.
[0084] Therefore, the collision section 131, the first displacement limit defining section 144, and the second displacement limit defining section 147, besides being made of rubber, can be made of thermosetting elastomer materials (such as vulcanized rubber, polyurethane rubber, silicone rubber, fluororubber, etc.) or thermoplastic elastomer materials (such as styrene-based, olefin-based, vinyl chloride-based, polyurethane-based, or amide-based resins, etc.). Furthermore, the collision section 131, the first displacement limit defining section 144, and the second displacement limit defining section 147, besides being made of materials other than elastomer materials, such as metal leaf springs or coil springs, can also be constructed by encapsulating a damper containing a viscous fluid. Additionally, the collision section 131, the first displacement limit defining section 144, and the second displacement limit defining section 147 can also be constructed by attaching a rigid resin plate or metal plate to the surface of the elastomer. Thus, the collision section 131, the first displacement limit defining section 144, and the second displacement limit defining section 147 can improve wear resistance to impact objects such as the rack housing 104 and can prevent damage.
[0085] Furthermore, in the above embodiment, the collision portion 131, the first displacement limit defining portion 144, and the second displacement limit defining portion 147 are formed in annular shape. However, the collision portion 131, the first displacement limit defining portion 144, and the second displacement limit defining portion 147 can be formed into annular shapes other than circular (including elliptical) shapes, such as polygons like triangles, quadrilaterals, pentagons, or hexagons. In this case, the collision portion 131 and the second displacement limit defining portion 147 can also be formed into a conical shape like the first displacement limit defining portion 144. Additionally, the collision portion 131, the first displacement limit defining portion 144, and the second displacement limit defining portion 147 can also be configured by arranging small pieces in annular shape.
[0086] Furthermore, in the above embodiment, the collision part 131 is configured to have a through hole 131a and a bottom hole 131c. Therefore, the elasticity of the collision part 131 can be adjusted. Thus, the number, position, or size of the through holes 131a and the bottom holes 131c can be freely set according to the required elasticity. However, the elasticity of the collision part 131 can be adjusted by configuring it to have at least one of the bottom holes and the through holes. Furthermore, in cases where the collision part 131 has the required elasticity even without using the through holes 131a and the bottom holes 131c, or where the through holes 131a and the bottom holes 131c are unnecessary, the through holes 131a and the bottom holes 131c can be omitted respectively.
[0087] Furthermore, in the above embodiment, the collision part 131 is mounted on the support base 130 by causing the bolt 132 to pass through the through hole 131a. However, the collision part 131 can be mounted on the support base 130 using methods other than the bolt 132, such as adhesive or welding.
[0088] Furthermore, in the above embodiment, the collision part 131 is mounted on the support base 130 via the fitting part 131b. Therefore, the collision part 131 can be mounted in the correct position relative to the support base 130, and post-installation displacement or damage can be prevented. However, the collision part 131 may also be configured without the fitting part 131b. In this case, the support base 130 does not require the fitting part 130a.
[0089] Furthermore, in the above embodiment, the direct-acting damper 120 is configured to include a first displacement limit defining portion 144 and a second displacement limit defining portion 147. Thus, the direct-acting damper 120 can attenuate the impact or external force when the relative displacement body 140 reaches its displacement limit position due to external force and when the relative displacement body 140 reaches its original displacement limit position before being subjected to external force. That is, the first displacement limit defining portion 144 and the second displacement limit defining portion 147 are respectively equivalent to the displacement limit defining portion according to the present invention. However, the direct-acting damper 120 may also be configured to omit at least one of the first displacement limit defining portion 144 and the second displacement limit defining portion 147.
[0090] Furthermore, in the above embodiment, the direct-acting damper 120 is configured to include a volume change compensation device 153. However, the direct-acting damper 120 can be configured without the volume change compensation device 153 as long as the volume change of the fluid 126 can be ignored. Alternatively, the direct-acting damper 120 may have the volume change compensation device 153 located on the outside of the relative displacement body 140 or the inner cavity forming body 121.
[0091] Furthermore, in the above embodiment, the direct-acting damper 120 is configured such that the relative displacement body 140 is connected to the rack 103 and the intermediate connecting body 105 respectively, and the inner cavity forming body 121 is in contact with or away from the rack housing 104. However, the direct-acting damper 120 may also be configured such that the inner cavity forming body 121 is connected to the rack housing 104, and the rack 103 or the intermediate connecting body 105 is close to or away from the relative displacement body 140. In this case, the relative displacement body 140 is formed in a cylindrical shape with the rack 103 passing through it, and a collision part 131 is provided in advance at the part where the rack 103 or a part of the intermediate connecting body 105 directly connected to the rack 103 will approach and contact due to the reciprocating displacement of the rack 103.
[0092] Furthermore, in the above embodiment, the direct-acting damper 120 is configured to have four flow control valves, which are formed by three first flow control valves 127 and one second flow control valve 128. However, the number and specifications of the flow control valves can of course be appropriately set according to the specifications of the direct-acting damper 120. Also, the flow control valves may be provided in place of the inner cavity forming body 121 or additionally in the relative displacement body 140.
[0093] Furthermore, in the above embodiment, the direct-acting damper 120 is configured to include a reset elastic body 155 formed of a wave-shaped washer. However, the reset elastic body 155 may also be configured using an elastic body other than a wave-shaped washer, such as a coil spring. Also, if it is not necessary to continuously push the relative displacement body 140, the reset elastic body 155 may be omitted from the direct-acting damper 120.
[0094] Furthermore, in the above embodiments, the direct-acting damper 120 is applied to the steering device 100. However, the direct-acting damper 120 can be installed in devices or appliances other than the steering device 100. Specifically, it can be installed in door opening and closing mechanisms, mechanical devices, motor devices, appliances, or furniture other than self-propelled vehicles.
[0095] Explanation of reference numerals in the attached figures
[0096] 100: Steering mechanism
[0097] 101: Steering Wheel
[0098] 102: Steering shaft
[0099] 102a: pinion gear
[0100] 103: Rack and pinion
[0101] 103a: Rack and pinion gear
[0102] 104: Rack and pinion housing
[0103] 105: Intermediate Connector
[0104] 106: Rack end
[0105] 107: Stud body
[0106] 107a: Ball part
[0107] 108: Bearing body
[0108] 108a: Support body
[0109] 108b: Connecting part
[0110] 110: Tie rod
[0111] 111: Steering knuckle arm
[0112] 112: Wheel
[0113] 120: Direct-acting damper
[0114] 121: Cavity Formation
[0115] 122: Inner circumferential surface
[0116] 123: Valve support section
[0117] 124: Sealing ring
[0118] 125a: First inner cavity
[0119] 125b: Second inner cavity
[0120] 126: Fluid
[0121] 127: First flow control valve
[0122] 128: Second flow control valve
[0123] 130: Support base
[0124] 130a: Chimeric part
[0125] 131: Collision Section
[0126] 131a: Through hole
[0127] 131b: Fitting part
[0128] 131c: Has a bottom hole
[0129] 132: Bolt
[0130] 140: Relative displacement body
[0131] 141: Opposite part of the inner cavity
[0132] 142: First inner cavity forming wall
[0133] 143: Sealing ring
[0134] 144: First Displacement Limit Specification Section
[0135] 145: Second inner cavity forming wall
[0136] 146: Sealing ring
[0137] 147: Second Displacement Limit Specification Section
[0138] 148: Rack end connection part
[0139] 149: Rack and pinion connection part
[0140] 150: Compensation device housing
[0141] 151: Internal cavity communication path
[0142] 152: Atmospheric Connectivity
[0143] 153: Volume Change Compensation Device
[0144] 154: Elastomer scaffold
[0145] 154a: Bearing section
[0146] 155: Reset elastomer
Claims
1. A direct-acting damper, comprising: The cavity forming body is formed in a cylindrical shape and has a fluid-tight cavity on the inside of the cylindrical portion; A relative displacement body, which slides freely within the inner cavity forming body and is relatively displaced relative to the inner cavity forming body; and A flow control valve is disposed in at least one of the cavity forming body and the relative displacement body, and restricts the flow of the fluid while allowing it to flow. The direct-acting damper is disposed between two mounted objects that are linearly displaced relative to each other, and attenuates the external force caused by the relative displacement by restricting the flow of the fluid; and is characterized in that... One of the cavity forming body and the relative displacement body has: The mounting part is installed in one of the two mounting objects. The other of the cavity forming body and the relative displacement body has: The collision point is struck by another of the two mounted objects. The collision portion is configured to include: An elastomer that elastically withstands the impact of the other of the two mounted objects. The inner cavity forming body and the relative displacement body each have a displacement limit defining portion, and they collide with each other through the relative displacement, thereby defining the displacement limit on one side and the displacement limit on the other side of the range of relative displacement. The displacement limit specification is configured as follows: At least one of the displacement limit on one side and the displacement limit on the other side, the displacement limit specification part includes an elastic body.
2. The direct-acting damper according to claim 1, characterized in that, have: A resetting elastomer applies an elastic force to at least one of the cavity forming body and the relative displacement body, thereby elastically pushing the cavity forming body or the relative displacement body that does not have the collision portion toward a side away from the collision portion.
3. The direct-acting damper according to claim 1 or claim 2, characterized in that, The collision portion is formed in a ring shape.
4. The direct-acting damper according to claim 1 or claim 2, characterized in that, The collision part is made of an elastomer material.
5. The direct-acting damper according to claim 4, characterized in that, The collision portion has at least one of a bottom hole and a through hole.
6. The direct-acting damper according to claim 1 or claim 2, characterized in that, The relative displacement body has: A volume change compensation device that compensates for volume changes of the fluid within the inner cavity.
7. A steering device, characterized in that, have: The steering shaft extends into a rod shape and rotates through the operation of the steering wheel; A rack and pinion rod extends into a rod shape and converts the rotational motion of the steering shaft into reciprocating motion in the axial direction for transmission; An intermediate connecting body, which is connected to both ends of the rack and pinion respectively, and the wheels that will be the objects of steering are directly or indirectly connected to each of the two ends; and rack housing, which covers the rack bar, The steering device includes the direct-acting damper as described in claim 1 or claim 2. The direct-acting damper is disposed between the rack housing and the rack rod or the intermediate connector to attenuate the impact from the wheel and / or the impact from the inertial force from the steering shaft side.
8. The steering device according to claim 7, characterized in that, The relative displacement body is connected to the intermediate connecting body. The inner cavity is formed in such a way that it comes into contact with or moves away from the rack housing by the reciprocating motion of the rack bar.
9. The steering device according to claim 7, characterized in that, The inner cavity forming body is connected to the end of the rack housing. The relative displacement body is formed such that the rack or the intermediate connector passes through it internally, and the rack or the intermediate connector comes into contact or moves away from each other due to the reciprocating motion of the rack.
Citation Information
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