Vehicle dampers

Abstract

To provide a damper for vehicle which can simultaneously achieve reduction of a load on a damper mount upon input of an excess load, an improvement of the behavior stability of the vehicle by highly responsive impact absorption, and an improvement of riding comfort by blocking input of high-frequency low-load.SOLUTION: A damper for a vehicle comprises: a movable member which linearly moves according to a load input from wheel side; a conversion member for converting the linear movement of the movable member to rotational movement; an electric motor having a rotor which rotates in conjunction with the rotational movement converted by the conversion member; a motor housing accommodating the electric motor; and a damper mount housing fixed to a vehicle body and connected with the motor housing via a first elastic member. The damper attenuates the linear movement of the movable member with an electromagnetic force of the electric motor. At least either of the motor housing and the damper mount housing is provided with a second elastic member which abuts on the other side when the motor housing and the damper mount housing approach each other along with by an input of a load.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle damper. [Background technology]

[0002] Conventionally, a vehicle suspension device is known in which vehicle vibrations are converted from linear motion to rotational motion via a ball screw shaft and a ball screw nut arranged in a housing, and transmitted to a rotor of a motor, and the rotational force of the rotor is damped by utilizing torque resulting from electromagnetic force (see, for example, Patent Document 1).

[0003] In this vehicle suspension device, a stopper member with good shock absorption properties is provided on the shaft end member located at the end of the ball screw shaft to mitigate the impact when the shaft end member collides with the bottom surface of the housing due to large linear movement when an overload is input. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-96536 Summary of the Invention [Problem to be solved by the invention]

[0005] In vehicle dampers, the load on the damper mount increases when an overload is applied. Because the impact of an overload applied to the damper mount affects the vehicle's behavioral stability, it is desirable to improve the vehicle's behavioral stability by setting the damper mount to a high rigidity and providing highly responsive shock absorption when an overload is applied. A high rigidity setting is also necessary from the perspective of the durability of the damper mount rubber.

[0006] On the other hand, it is desirable to set the response to high-frequency low-load road inputs low to block the inputs and improve the ride comfort of the vehicle.

[0007] The object of the present invention is to provide a vehicle damper that can reduce the load on the damper mount when an overload is input, improve the vehicle's behavioral stability through highly responsive impact absorption, and improve ride comfort by blocking high-frequency low-load input. [Means for solving the problem]

[0008] (1) A vehicle damper according to the present invention includes a movable member (e.g., a movable member 2 described later) that moves linearly in response to a load input from a wheel side, a conversion member (e.g., a conversion member 7 described later) that converts the linear motion of the movable member into rotational motion, an electric motor (e.g., an electric motor 3 described later) having a rotor (e.g., a rotor 32 described later) that rotates in conjunction with the rotational motion converted by the conversion member, a motor housing (e.g., a motor housing 4 described later) that accommodates the electric motor, and a first elastic member (e.g., a damper mount rubber described later) that is fixed to a vehicle body (e.g., a vehicle body BD described later). and a damper mount housing (e.g., damper mount housing 5 described later) connected to the motor housing via an electromagnetic force of the electric motor, and damping the linear motion of the movable member by the electromagnetic force of the electric motor, wherein at least one of the motor housing and the damper mount housing has a second elastic member (e.g., additional rubber 6, 6A described later) that abuts against the other side when the motor housing and the damper mount housing approach each other due to the input of a load.

[0009] (2) In the vehicle damper described above in (1), the second elastic member has higher rigidity than the first elastic member.

[0010] (3) In the vehicle damper described in (1) or (2) above, the second elastic member has a ring shape.

[0011] (4) In the vehicle damper described in (3) above, the motor housing has an axis portion (e.g., axis portion 452 described below) connected to the damper mount housing via the first elastic member, the motor housing and the damper mount housing each have opposing surfaces (e.g., opposing surfaces 454, 523) arranged opposite to and spaced apart from each other around the axis portion, and the second elastic member is arranged on the opposing surface of at least one of the motor housing and the damper mount housing.

[0012] (5) In the vehicle damper described in any one of (1) to (4) above, at least one of the motor housing and the damper mount housing has a convex portion (e.g., convex portion 524 described below) that protrudes toward the other side and prevents over-compression of the second elastic member.

[0013] (6) In the vehicle damper described in any one of (1) to (5) above, the contact surface (e.g., contact surface 6a described later) with the other side of the second elastic member (additional rubber 6A described later) is arranged obliquely with respect to the opposing surface on the other side, and is formed approximately parallel to a plane (e.g., plane PL described later) perpendicular to the linear motion direction of the movable member. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a vehicle damper that can reduce the load on the damper mount when an overload is input, improve the vehicle's behavioral stability through highly responsive shock absorption, and improve ride comfort by blocking high-frequency low-load input. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a cross-sectional view showing the vehicle damper in a normal state. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a portion of the vehicle damper in a normal state. [Figure 3] FIG. 3 is an enlarged cross-sectional view of a portion of the vehicle damper when an overload is input. [Figure 4A] FIG. 2 is a schematic diagram illustrating a function of the vehicle damper in a normal state. [Figure 4B] 5A and 5B are schematic diagrams illustrating a function of the vehicle damper when an overload is input. [Figure 5] FIG. 10 is an enlarged cross-sectional view of a portion of the vehicle damper when an overload is applied. [Figure 6] FIG. 10 is a plan view of a second elastic member. [Figure 7] FIG. 10 is a perspective view of a second elastic member. [Figure 8] 7 is a cross-sectional view taken along line AA in FIG. 6 illustrating a second elastic member and a load input direction. [Figure 9] 9 is an enlarged cross-sectional view showing a part of the vehicle damper having the second elastic member shown in FIGS. 6 to 8. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of a vehicle damper according to the present invention will be described in detail with reference to the drawings. As shown in Fig. 1, the vehicle damper 1 is suspended between a vehicle body BD of a four-wheeled vehicle or the like and a lower arm (not shown) or the like constituting an unsprung member on the wheel (not shown) side. The vehicle damper 1 includes a movable member 2, an electric motor 3, a motor housing 4, and a damper mount housing 5.

[0017] The movable member 2 includes a cylindrical outer tube 21. One axial end (the right end in FIG. 1) of the outer tube 21 is closed by a closing member 22. A connecting portion 23 that is connected to a lower arm or the like is attached to the closing member 22. Note that "movable" in the movable member 2 means that it moves relative to a component member connected to the vehicle body BD of the vehicle damper 1 when a load is input from the wheel side.

[0018] A first inner cylinder 24 extending from the closing member 22 in the axial direction of the outer cylinder 21 is housed inside the outer cylinder 21. A protruding shaft portion 241 is integrally formed at one axial end (the right end in FIG. 1) of the first inner cylinder 24. The protruding shaft portion 241 is fixed to the center of the closing member 22. This fixes the first inner cylinder 24 to the outer cylinder 21 via the closing member 22 so that it cannot rotate around its axis. Inside the outer cylinder 21, a buffer member 25 made of an elastic material such as rubber with shock-absorbing properties is housed on the outer periphery of one end side of the first inner cylinder 24.

[0019] An expanded diameter portion 242 with an expanded inner diameter is integrally formed at the other axial end (the left end in FIG. 1 ) of the first inner cylinder 24. The outer diameter of the expanded diameter portion 242 is smaller than the inner diameter of the outer cylinder 21. A ball screw nut 26 that screws into a ball screw 43 (described later) is attached to the expanded diameter portion 242 inside the expanded diameter portion 242 so as to be unable to rotate around its axis.

[0020] The electric motor 3 has a stator 31 to which a coil 311 is attached, and a rotor 32 to which a permanent magnet (not shown) is attached. The rotor 32 has a rotor shaft 321, and is rotatably supported at the center of the stator 31. The electric motor 3 generates an electromagnetic force corresponding to a current supplied to the coil 311 from a drive unit (not shown) mounted on a vehicle (not shown), and uses torque corresponding to the electromagnetic force to rotate the rotor 32 or to attenuate the rotational force of the rotor 32.

[0021] The motor housing 4 is formed in a substantially cylindrical shape and accommodates the electric motor 3 therein. One axial end of the motor housing 4 (the right end in FIG. 1 ) is formed with a smaller diameter and protrudes further than the electric motor 3. A cylindrical second inner cylinder 41 is connected to the inside of one end of the motor housing 4 and is arranged concentrically with the motor housing 4. The second inner cylinder 41 has a smaller diameter than the outer cylinder 21 of the movable member 2 and a larger diameter than the expanded diameter portion 242 of the first inner cylinder 24. An annular bumper rubber 42 made of an elastic material such as rubber with shock absorbing properties is attached to the edge of one end of the motor housing 4 so as to surround the outer periphery of the second inner cylinder 41.

[0022] A ball screw 43 is housed inside the second inner cylinder 41. The ball screw 43 extends axially from the motor housing 4 over substantially the entire length of the second inner cylinder 41. A base end 43a (the left end in FIG. 1 ) of the ball screw 43 is coaxially coupled to the rotor shaft 321 of the electric motor 3 via a connecting member 431. The connecting member 431 is supported inside the motor housing 4 via a bearing 44 so as to be rotatable about the axis. Therefore, when the ball screw 43 rotates about the axis, the rotor 32 of the electric motor 3 rotates via the connecting member 431 and the rotor shaft 321.

[0023] The movable member 2 is concentrically fitted into the second inner cylinder 41. More specifically, the second inner cylinder 41 is inserted into and accommodated inside the outer cylinder 21 of the movable member 2, and the first inner cylinder 24 of the movable member 2 is inserted into and accommodated inside the second inner cylinder 41. The ball screw nut 26 provided on the first inner cylinder 24 is threadedly engaged with the ball screw 43 in the second inner cylinder 41. The gap between the outer peripheral surface of the second inner cylinder 41 and the inner peripheral surface of the outer cylinder 21, and the gap between the inner peripheral surface of the second inner cylinder 41 and the outer peripheral surface of the first inner cylinder 24 are sealed by sealing members 211, 411, respectively. The other end (the left end in FIG. 1 ) of the outer cylinder 21 is disposed so as to face the bump rubber 42 of the motor housing 4. One end of the second inner cylinder 41, where the sealing member 411 is disposed, is disposed so as to face the buffer member 25 in the outer cylinder 21.

[0024] The other end (the left end in FIG. 1) of the motor housing 4 is closed by a terminal member 45. The terminal member 45 has a large diameter portion 451 that closes the other end of the motor housing 4, and a shaft portion 452 that protrudes from the center of the large diameter portion 451 toward the vehicle body BD. An annular flange 453 is fixed to the outer periphery of the middle portion of the shaft portion 452. The flange 453 extends in a circular shape in the outer radial direction from the shaft portion 452.

[0025] The damper mount housing 5 is fixed to a predetermined position on the vehicle body BD with bolts BT. The damper mount housing 5 integrally comprises an annular mounting portion 51 that is attached to the vehicle body BD, and an annular support base portion 52 that protrudes from the inner diameter side of the mounting portion 51 toward the motor housing 4.

[0026] 2, support base 52 has opening 521 opening at its center and rubber housing groove 522 opening toward the vehicle body BD with a larger diameter than opening 521. Rubber housing groove 522 is circular and communicates with opening 521, and is concentric with opening 521. An annular damper mount rubber 53 made of an elastic material such as rubber is housed inside. Damper mount rubber 53 is held in rubber housing groove 522 by an annular closing ring 54 that is attached from the vehicle body BD side to close rubber housing groove 522. This damper mount rubber 53 corresponds to the first elastic member.

[0027] The shaft portion 452 of the terminal member 45 of the motor housing 4 is connected to the damper mount housing 5 attached to the vehicle body BD via the damper mount rubber 53. More specifically, the shaft portion 452 is inserted into the opening 521 of the support base portion 52 of the damper mount housing 5 from the side opposite the vehicle body BD. The shaft portion 452 passes through the damper mount rubber 53 and the inside of the closing ring 54, which are held in the rubber accommodating groove 522. The damper mount rubber 53 supports the shaft portion 452 within the rubber accommodating groove 522 by clamping flanges 453 provided on the shaft portion 452 from both sides. In this way, the damper mount housing 5 is connected to the motor housing 4 via the damper mount rubber 53.

[0028] 2, the motor housing 4 and the damper mount housing 5 are arranged opposite each other with a predetermined distance between them under normal conditions when no overload is applied to the vehicle damper 1. In other words, the motor housing 4 and the damper mount housing 5 do not come into contact with each other except when the flange 453 is sandwiched between the damper mount rubber 53.

[0029] More specifically, in the large-diameter portion 451 of the terminal member 45, a facing surface 454 that faces the damper mount housing 5 is disposed around the shaft portion 452. The facing surface 454 is a flat surface that extends annularly toward the outer diameter side of the shaft portion 452. Meanwhile, in the support base portion 52 of the damper mount housing 5, a facing surface 523 that faces the motor housing 4 is disposed around the opening 521. The facing surface 523 is a flat surface that extends annularly and is disposed around the opening 521. A convex portion 524 that projects annularly toward the facing surface 454 of the motor housing 4 is integrally formed on the outer periphery of the facing surface 523. Under normal conditions when no overload is applied to the vehicle damper 1, the two facing surfaces 454, 523 are disposed opposite and spaced apart from each other. The facing surface 454 on the motor housing 4 side and the convex portion 524 on the damper mount housing 5 side are spaced apart and do not come into contact with each other.

[0030] Of the two opposing surfaces 454, 523, an additional rubber 6 made of an elastic material such as rubber is attached to the opposing surface 454 on the motor housing 4 side. The additional rubber 6 is formed in an annular shape and protrudes from the opposing surface 454 toward the opposing surface 523 on the damper mount housing 5 side. However, as shown in FIG. 2 , during normal operation when no overload is applied to the vehicle damper 1, the additional rubber 6 does not contact the opposing surface 523 on the damper mount housing 5 side, but faces the opposing surface 523 on the inside of the convex portion 524 via a predetermined gap S. The maximum protruding height of the additional rubber 6 from the opposing surface 454 is set slightly larger than the protruding height of the convex portion 524 from the opposing surface 523. The distance from the convex portion 524 to the opposing surface 454 is also set larger than the distance from the additional rubber 6 to the opposing surface 523. As a result, as will be described in detail later, even if an overload is applied to the additional rubber 6, the convex portion 524 of the damper mount housing 5 abuts against the opposing surface 454 of the motor housing 4, thereby protecting the additional rubber 6 from over-compression. This additional rubber 6 corresponds to the second elastic member.

[0031] The additional rubber 6 may be formed using the same elastic material as the damper mount rubber 53, or may be formed using an elastic material different from that of the damper mount rubber 53. Furthermore, it is preferable that the additional rubber 6 has higher rigidity than the damper mount rubber 53. The rigidity of the additional rubber 6 can be adjusted as appropriate by selecting the shape of the additional rubber 6, the type of elastic material used, adjusting the amount of filler or the like mixed into the elastic material, adjusting the manufacturing conditions, etc.

[0032] Next, the operation of the vehicle damper 1 when a load is input will be described.

[0033] In the vehicle damper 1, the movable member 2 moves linearly relative to the second inner cylinder 41 in the extension side X1 and the compression side X2 indicated by double-ended arrows in FIGS. 1 and 2 in response to a load input from the wheel side. This linear movement of the movable member 2 causes the ball screw nut 26 to move along the ball screw 43, causing the ball screw 43 to rotate about its axis. This causes the rotor 32 of the electric motor 3, which is connected to the ball screw 43, to rotate. That is, in the vehicle damper 1, the ball screw nut 26 of the movable member 2 and the ball screw 43 in the second inner cylinder 41 of the motor housing 4 constitute a conversion member 7 that converts the linear movement of the movable member 2 into rotational movement. When a load is input, a predetermined current is supplied to the coil 311 of the electric motor 3 to attenuate the rotational force of the rotor 32, and the linear movement of the movable member 2 is damped by the electromagnetic force of the electric motor 3.

[0034] Under normal conditions without an overload input, as shown by the arrows in Figure 2, a load (vibration) F1 from the wheel side is transmitted from the movable member 2 to the ball screw 43, and then from the ball screw 43 through the connecting member 431 and bearing 44 to the motor housing 4. The load F1 transmitted to the motor housing 4 is transmitted to the damper mount rubber 53 through the shaft portion 452 and flange 453, attenuated by the damper mount rubber 53, and transmitted to the vehicle body BD. At this time, the movable member 2 moves linearly relative to the second inner cylinder 41 in the extension side X1 and compression side X2, to an extent that it does not come into contact with the bump rubber 42 of the motor housing 4. Therefore, the additional rubber 6 attached to the motor housing 4 does not come into contact with the opposing surface 523 of the damper mount housing 5, and remains separated from it via the gap S.

[0035] 4A, under normal conditions when no overload is applied, the motor housing 4 and damper mount housing 5 of the vehicle damper 1 are connected only via the damper mount rubber 53, and the damper mount rubber 53 attenuates the load F1. Because the motor housing 4 and the damper mount housing 5 are spaced apart and there is no metal-to-metal contact, a good ride comfort is ensured for the vehicle in the normal operating range.

[0036] On the other hand, as shown in FIG. 3 , when an overload is applied from the wheel side toward the retraction side X2 of the movable member 2, the movable member 2 makes a large linear movement toward the motor housing 4. Contact between the tip edge 21a of the outer cylinder 21 and the bump rubber 42 moves the motor housing 4 toward the damper mount housing 5. The motor housing 4 approaches the damper mount housing 5 while compressing the damper mount rubber 53 with the flange 453 of the shaft portion 452. Eventually, the additional rubber 6 of the motor housing 4 abuts against the opposing surface 523 of the damper mount housing 5. At this time, the convex portion 524 of the damper mount housing 5 has not yet contacted the opposing surface 454 of the motor housing 4. Therefore, as shown by the arrow in FIG. 3 , the load (impact) F2 from the wheel side is transmitted from the outer cylinder 21 of the movable member 2 to the motor housing 4 via the bump rubber 42 without passing through the ball screw 43. The load F2 transmitted to the motor housing 4 is then transmitted to the damper mount rubber 53 via the additional rubber 6.

[0037] That is, as shown in Figure 4B, when an overload is input, the motor housing 4 and damper mount housing 5 of the vehicle damper 1 are connected via the damper mount rubber 53 and the additional rubber 6, and the damper mount rubber 53 and the additional rubber 6 share the load F2 and absorb the impact. This reduces the load on the damper mount rubber 53, ensuring the durability of the damper mount rubber 53. The additional rubber 6 absorbs the load F2 simply by the motor housing 4 moving through the gap S between the additional rubber 6 and the opposing surface 523, so it is highly responsive to an overload input.

[0038] Furthermore, because the additional rubber 6 has higher rigidity than the damper mount rubber 53, vibration-damping performance can be improved under normal conditions by the low-rigidity (soft) damper mount rubber 53, while impact resistance can be improved by the high-rigidity additional rubber 6 when an overload is input. Therefore, the vehicle damper 1 can achieve a high level of balance between vibration-damping performance and impact resistance.

[0039] Because the additional rubber 6 has a ring shape, it can respond to bending and torsional stresses on the entire circumference when an overload is input. Moreover, because the additional rubber 6 is arranged on the opposing surface 454 that is located on the periphery of the shaft portion 452 of the motor housing 4, when stresses when an overload is input are transmitted from the shaft portion 452 to the opposing surface 454 on its periphery, the stresses can be borne by the opposing surface 454. Therefore, in the vehicle damper 1, the additional rubber 6 can effectively alleviate bending and torsional stresses on the shaft portion 452 when an overload is input.

[0040] Furthermore, when the load F2 toward the retraction side X2 of the movable member 2 becomes even larger, the additional rubber 6 is compressed and crushed between the opposing surfaces 454, 523, as shown in Figure 5. This brings the motor housing 4 and the damper mount housing 5 even closer together, and eventually the convex portion 524 of the damper mount housing 5 comes into contact with the opposing surface 454 of the motor housing 4. At this time, because the motor housing 4 and the damper mount housing 5 are in metal-to-metal contact, the additional rubber 6 is no longer compressed further and is protected from over-compression.

[0041] The direction of the load input to the movable member 2 of the vehicle damper 1 is not always parallel to the axial direction of the movable member 2. Depending on the camber angle and caster angle set for the wheel, the direction of the load input to the movable member 2 may be at an angle to the axial direction of the movable member 2. In this case, the ring-shaped additional rubber does not need to be formed to have the same thickness around the entire circumference. That is, as in the additional rubber 6A shown in Figures 6 to 8, the contact surface 6a with the mating member may be formed so as to be inclined obliquely with respect to the axial direction D of the additional rubber 6A.

[0042] More specifically, when the load input direction is at an angle to the axial direction of the movable member 2, the linear motion direction of the retraction side X2 of the movable member 2 is inclined with respect to the axial direction D of the additional rubber 6A, as shown in FIG. 8. The contact surface 6a of the additional rubber 6A is formed approximately parallel to a plane PL that is perpendicular to the linear motion direction of the retraction side X2. The attachment surface 6b, which is located on the opposite side of the contact surface 6a of the additional rubber 6A, is formed perpendicular to the axial direction D of the additional rubber 6A. This attachment surface 6b is attached to the opposing surface 454 or 523 and is a surface parallel to the opposing surface 454 or 523.

[0043] When the mounting surface 6b of this additional rubber 6A is attached to the opposing surface 454 of the motor housing 4, the contact surface 6a is positioned at an angle relative to the opposing surfaces 454 and 523, as shown in FIG. 9. When an overload is applied to the movable member 2 along the retraction side X2, which is inclined relative to the axial direction of the additional rubber 6A, a bending moment is generated in the motor housing 4, as indicated by the white arrows in FIG. 9. This causes the second inner cylinder 41 side to move downward and the terminal member 45 side of the motor housing 4 to move upward, causing the motor housing 4 to rotate clockwise in FIG. 9. As a result, the entire motor housing 4 approaches the damper mount housing 5 in a bent state. However, at this time, the inclined contact surface 6a of the additional rubber 6A is positioned approximately parallel to the opposing surface 523 of the damper mount housing 5, allowing the entire contact surface 6a of the additional rubber 6A to absorb the load and relieve stress.

[0044] In the above embodiment, the additional rubber 6, 6A is attached to the opposing surface 454 of the motor housing 4, but the additional rubber 6, 6A may also be attached to the opposing surface 523 of the damper mount housing 5.

[0045] The number of additional rubbers 6, 6A is not limited to one, and for example, a plurality of additional rubbers 6, 6A may be arranged concentrically on the opposing surface 454 or 523. The plurality of concentric additional rubbers 6, 6A may be arranged separately on each of the opposing surfaces 454 and 523. Furthermore, when the additional rubbers 6, 6A are arranged on each of the opposing surfaces 454 and 523, the additional rubbers 6, 6A on the respective opposing surfaces 454, 523 may come into contact with each other when an overload is input.

[0046] The additional rubber 6, 6A may have a portion that comes into contact with the mating member without the gap S, to the extent that the vibration-damping performance during normal times when no overload is applied is not impaired.

[0047] In the above embodiment, the opposing surface 523 of the damper mount housing 5 is provided with a protrusion 524 that protrudes toward the opposing surface 454 of the motor housing 4. However, such a protrusion may also be provided on the opposing surface 454 of the motor housing 4 so as to protrude toward the opposing surface 523 of the damper mount housing 5. The protrusions may be provided on each of the opposing surfaces 454, 523 so that they come into contact with each other in the event of an overload input. Furthermore, the protrusions are not limited to being arranged on the outer diameter side of the additional rubber 6, 6A, but may also be arranged on the inner diameter side of the additional rubber 6, 6A, or may be arranged on both the outer diameter side and the inner diameter side of the additional rubber 6, 6A.

[0048] The vehicle damper 1 according to the above embodiment has the following advantages.

[0049] The vehicle damper 1 of this embodiment comprises a movable member 2 that moves linearly in response to the input of a load from the wheel side, a conversion member 7 (ball screw nut 26 and ball screw 43) that converts the linear motion of the movable member 2 into rotational motion, an electric motor 3 having a rotor 32 that rotates in conjunction with the rotational motion converted by the conversion member 7, a motor housing 4 that accommodates the electric motor 3, and a damper mount housing 5 that is fixed to the vehicle body BD and connected to the motor housing 4 via a damper mount rubber 53 (first elastic member), and is a vehicle damper 1 that damps the linear motion of the movable member 2 by the electromagnetic force of the electric motor 3, and at least one of the motor housing 4 and the damper mount housing 5 has an additional rubber 6, 6A (second elastic member) that abuts against the other side when the motor housing 4 and the damper mount housing 5 approach each other due to the input of a load.

[0050] As a result, when an overload is input, the vehicle damper 1 can receive the overload in parallel from the damper mount rubber 53 and the additional rubbers 6, 6A. This allows for highly responsive shock absorption without applying an overload to the damper mount rubber 53. As a result, the vehicle damper 1 can improve the behavioral stability of the vehicle.

[0051] In this embodiment, the additional rubber 6, 6A has higher rigidity than the damper mount rubber 53.

[0052] This allows the low-rigidity (soft) damper mount rubber 53 to improve vibration-damping performance during normal times when no overload is applied, while the high-rigidity additional rubber 6 can improve impact resistance during overload application. Therefore, the vehicle damper 1 can achieve a high level of balance between vibration-damping performance and impact resistance.

[0053] In this embodiment, the additional rubber 6, 6A has a ring shape.

[0054] This allows the additional rubber 6, 6A to cope with bending and twisting stresses on the entire circumference when an overload is input.

[0055] In this embodiment, the motor housing 4 has a shaft portion 452 connected to the damper mount housing 5 via a damper mount rubber 53, and the motor housing 4 and the damper mount housing 5 each have opposing surfaces 454, 523 arranged opposite each other and spaced apart around the shaft portion 452, and the additional rubber 6, 6A is arranged on the opposing surface of at least one of the motor housing 4 and the damper mount housing 5.

[0056] With this, when stress during an overload input is transmitted from the shaft portion 452 to the opposing surface 454 at its periphery, the stress can be borne by the opposing surface 454. Therefore, in the vehicle damper 1, the additional rubbers 6, 6A can effectively mitigate bending and twisting stress on the shaft portion 452 during an overload input.

[0057] In this embodiment, at least one of the motor housing 4 and the damper mount housing 5 has a convex portion 524 that protrudes toward the other side and prevents excessive compression of the additional rubber 6, 6A.

[0058] With this, when an overload is input, the motor housing 4 and the damper mount housing 5 come into metal-to-metal contact, so the additional rubber 6 is protected from over-compression.

[0059] In this embodiment, the contact surface 6a of the additional rubber 6A with the other side is disposed obliquely with respect to the opposing surface 523 on the other side, and is formed substantially parallel to a plane PL perpendicular to the linear motion direction of the movable member 2.

[0060] With this, even if the motor housing 4 approaches the damper mount housing 5 in a bent state due to the bending moment generated in response to the linear movement of the movable member 2, the entire contact surface 6a of the additional rubber 6A can absorb the load and relieve the stress. [Explanation of symbols]

[0061] 1 Vehicle damper 2. Movable parts 3 Electric motor 32 rotor 4 Motor housing 452 Shaft 454,523 Opposite faces 5 Damper mount housing 53 Damper mount rubber (first elastic member) 524 convex part 6,6A Additional rubber (second elastic member) 7 Conversion member BD body PL surface

Claims

1. a movable member that moves linearly in response to a load input from the wheel side; a conversion member that converts the linear motion of the movable member into a rotational motion; an electric motor having a rotor that rotates in conjunction with the rotational motion converted by the conversion member; a motor housing that accommodates the electric motor; a damper mount housing fixed to a vehicle body and connected to the motor housing via a first elastic member, A vehicle damper that damps the linear motion of the movable member by an electromagnetic force of the electric motor, A vehicle damper having a second elastic member on at least one of the motor housing and the damper mount housing that abuts against the other side when the motor housing and the damper mount housing approach each other due to the input of a load.

2. 2. The vehicle damper according to claim 1, wherein the second elastic member has a higher rigidity than the first elastic member.

3. The vehicle damper according to claim 1 or 2, wherein the second elastic member has a ring shape.

4. the motor housing has a shaft portion connected to the damper mount housing via the first elastic member, the motor housing and the damper mount housing each have opposing surfaces that are spaced apart from each other and opposed to each other around the shaft portion, The vehicle damper according to claim 3 , wherein the second elastic member is disposed on the opposing surface of at least one of the motor housing and the damper mount housing.

5. 3. The vehicle damper according to claim 1, wherein at least one of the motor housing and the damper mount housing has a protrusion that protrudes toward the other side and prevents excessive compression of the second elastic member.

6. 5. The vehicle damper according to claim 4, wherein the contact surface of the second elastic member with the other side is disposed obliquely with respect to the opposing surface on the other side and is formed approximately parallel to a plane perpendicular to the linear motion direction of the movable member.

Images