JP4820196B2 - Damping force adjustment damper - Google Patents

Description

  The present invention relates to a damping force adjusting damper.

As a damping force adjusting damper, as described in Patent Document 1, a piston attached to a piston rod is slidably inserted into a cylinder and has a damping force adjusting device for suppressing expansion and contraction of the piston rod. is there. Conventional damping force adjusting dampers focus on how to increase the variable range of damping force by the damping force adjusting device in a wide piston speed range from low speed to high speed.
JP-A-11-82601

  However, as a result of research by the present inventor, it is possible to greatly change the driving comfort of the vehicle by adjusting the damping force in the extremely low speed range where the piston speed range is extremely lower than the conventional low speed range with a slight variable width. Admitted that you can.

  An object of the present invention is to improve the driving comfort of a vehicle by varying the damping force in the extremely low speed piston speed range in the damping force adjusting damper.

According to the first aspect of the present invention, the piston attached to the piston rod is slidably inserted into the cylinder, the damping force adjusting device for suppressing expansion and contraction of the piston rod, and the outer peripheral surface of the piston rod fixed to the cylinder An oil seal that scrapes off the oil adhering to the outer peripheral surface of the piston rod, and a reservoir chamber that is provided on the outer periphery of the cylinder and has an oil chamber and a gas chamber inside, and changes the gas pressure in the reservoir chamber. an actuator for, communicates with the reservoir chamber, in the damping force control damper comprising a, a rod guide having a passageway for transmitting the gas pressure in the oil seal, the damping force adjusting apparatus, a front Kio Irushiru The damping force is adjusted by adjusting the friction of the sliding part with the piston rod, and the extremely low speed range where the piston speed is 0.05m / s or less. The oil seal is configured so that the fastening force to the piston rod changes when the damping force adjusting device changes the gas pressure in the reservoir chamber by the actuator. is there.

A second aspect of the present invention provides a damping force adjusting damper having a damping force adjusting device for slidably inserting a piston attached to a piston rod into a cylinder and suppressing the expansion and contraction of the piston rod. The apparatus is provided with a bypass flow path that bypasses the main flow path drilled in the partition wall member so as to have a main valve that opens to the piston speed in the middle and high speed range, and the throttle amount is adjusted by the actuator in the bypass flow path. The variable throttle valve and the pressure side leaf valve that controls the damping force in the extremely low speed range are arranged in series, and the variable throttle valve and the extension side leaf valve that controls the damping force in the extremely low speed range are arranged in series. Thus, the damping force can be adjusted only in the extremely low speed range where the piston speed is 0.05 m / s or less.

(Claim 1)
(a) The damping force adjustment device makes it possible to adjust the damping force only in the extremely low speed range where the piston speed is 0.05 m / s or less. Because the damping force is variable only in the extremely low speed range, there is no need to generate a large damping force, and the variable range of the maximum variable value and the minimum variable value to be changed at the same piston speed is about 2 to 5 kgf. The effect can be demonstrated with a small variable width. Even if it is the maximum variable value, the value is extremely small with respect to the maximum damping force through the entire speed range of the damper, and the minimum variable value does not need to be close to zero. High response is possible.

  (b) The damping force adjusting device is simple and does not require any special components, and it is only necessary to reduce the size of the components of the conventionally known damping force adjusting structure to a very low speed range. .

  (c) It is sufficient to change the damping force by a slight variable width only in the extremely low speed range by the damping force adjusting device, and it does not affect the damping force in the low speed range to the high speed range. For example, with a conventional damper that softens the setting of damping force in the medium and high speed range, the damping force in the very low speed range becomes small and fluffy, but with the damper of the present invention that has increased damping force in the extremely low speed range, the fluffy feeling Can be reliably suppressed and ride comfort can be improved. On the other hand, with a conventional damper with a stiff damping force setting in the high speed range, the damping force in the very low speed range becomes large and feels rugged, but with the damper of the present invention in which the damping force in the extremely low speed range is reduced, it feels rugged. The ride comfort is improved.

( d) The damping force adjusting device can easily and reliably adjust the damping force in the extremely low speed range by adjusting the friction of the sliding portion between the oil seal and the piston rod.

(Claim 2 )
(e) The damping force adjusting device is provided with a bypass flow path that bypasses the main flow path protruding from the partition member so as to have a main valve that opens with respect to the piston speed in the middle and high speed range, and the bypass flow path is provided with an actuator. A variable throttle valve for adjusting the throttle amount and a leaf valve for controlling the damping force in the extremely low speed range are arranged in series. By arranging the variable throttle valve in series with the leaf valve that operates reliably even with a small oil flow rate in the extremely low speed range, the damping force in the very low speed range can be stably adjusted by adjusting the throttle amount of the variable throttle valve.

  1 is a cross-sectional view showing a damping force adjusting damper, FIG. 2 is a schematic diagram showing a damping force adjusting device, FIG. 3 is a schematic diagram showing another example of the damping force adjusting device, and FIG. 4 is a low speed to high speed damping. FIG. 5 is a diagram showing damping force characteristics in a very low speed region.

  As shown in FIG. 1, the damper 10 constitutes a double pipe in which a cylinder 12 is built in a damper tube 11, a piston rod 13 is inserted into the cylinder 12, and an axle-side mounting portion including an eye joint is formed below the damper tube 11. 14, and a vehicle body side mounting portion 15 is provided above the piston rod 13 to constitute a vehicle suspension device.

  The damper 10 has a suspension spring 17 interposed between a lower spring seat 16 on the outer periphery of the damper tube 11 and an upper spring seat (not shown) provided on the vehicle body side mounting portion 15 at the upper end portion of the piston rod 13.

  The damper 10 clamps and fixes a rod guide 21, a bush 22, and an oil seal 23 for the piston rod 13 inserted into the cylinder 12 between the upper end crimping portion 24 of the damper tube 11 and the upper end portion of the cylinder 12. ing.

  The rod guide 21 has an upper end side large-diameter outer peripheral portion fitted to the damper tube 11 and a lower end side small-diameter outer peripheral portion fitted to the cylinder 12, and includes a bush 22 for the piston rod 13 on the inner periphery. The rod guide 21 returns to the reservoir chamber 41 (to be described later) the oil that is attached to the outer periphery of the piston rod 13 and is scraped from the oil chamber 37B (to be described later) through the bushing 22 to the upper end surface side. Are provided with passages 25A and 25B for oil return and gas sealing for sealing the pressurized gas into the reservoir chamber 41.

  The oil seal 23 has a cored bar 23A that is mounted on the upper end surface of the rod guide 21 and is held by the crimping portion 24 of the damper tube 11 and is formed of a perforated disk-shaped flat plate. An oil lip 23B, a check lip 23C, a dust lip 23D and a tube seal portion 23E are provided by baking or the like. The oil lip 23B is annularly arranged below the inner periphery of the core 23A and faces the large stepped surface on the upper end side of the rod guide 21. The outer peripheral surface of the piston rod 13 by its own elastic force and the tightening force of the tightening spring 23F. The oil adhered to the outer periphery of the piston rod 13 is scraped off. The check lip 23C is annularly arranged around the oil lip 23B on the inner peripheral side of the lower surface of the cored bar 23A. The check lip 23C comes into contact with the small step surface on the upper end side of the rod guide 21 by its own elasticity and is scraped off by the oil lip 23B. The oil thus allowed is allowed to flow to the passage 25A side of the rod guide 21, and the pressurized gas in the reservoir chamber 41 is prevented from flowing from the passage 25A side to the oil lip 23B side. The dust lip 23D is annularly arranged above the inner periphery of the metal core 23A and faces the outside world. The dust lip 23D comes into sliding contact with the outer peripheral surface of the piston rod 13 by its own elastic force, and external foreign matters attached to the outer periphery of the piston rod 13 are cylinders. 12 is prevented from entering. The tube seal portion 25E is provided integrally with the dust lip 23D on the upper surface of the core metal 23A on the outer peripheral side of the dust bar 23D and closer to the inner periphery than the outer periphery of the core metal 23A. Stick out.

  The damper 10 includes a piston valve device 30 and a bottom valve device 40, and the damping force generated by the damper 10 controls the expansion and contraction vibration of the piston rod 13 accompanying the absorption of the impact force by the suspension spring 17.

(Piston valve device 30)
In the piston valve device 30, a valve stopper 31, a check valve 32, a piston 33, a disk valve 34, and a valve stopper 35 are attached to the piston rod 13, and these are fixed by a piston fixing nut 36, and the piston 33 slides on the cylinder 12. Insert freely.

  At the time of compression, the oil in the piston-side oil chamber 37A passes through the pressure-side flow path 38A of the piston 33, bends and deforms the check valve 32, and is led to the rod-side oil chamber 37B. Further, at the time of extension, the oil in the rod side oil chamber 37B passes through the extension side flow path 38B (not shown) of the piston 33, bends and opens the disk valve 34, and is guided to the piston side oil chamber 37A. Generate a damping force.

(Bottom valve device 40)
In the damper 10, the gap between the damper tube 11 and the cylinder 12 serves as a reservoir chamber 41, and the interior of the reservoir chamber 41 is partitioned into an oil chamber and a gas chamber. The bottom valve device 40 closes the bottom 11A of the damper tube 11 by spinning molding, and arranges a bottom piece 43 that partitions the piston-side oil chamber 37A and the reservoir chamber 41 inside the cylinder 12 at the lower end of the cylinder 12, The piston-side oil chamber 37 </ b> A and the reservoir chamber 41 can be communicated with each other through a flow path (not shown) provided in the bottom piece 43. Bolts 44 and nuts 45 are fastened to the bottom piece 43, and a disc valve 46, a bottom piece 43, a check valve 47 and a valve stopper 48 are interposed between the bolts 44 and the nut 45.

  At the time of compression, the oil corresponding to the volume of the piston rod 13 entering the cylinder 12 opens from the piston-side oil chamber 37A through the pressure-side flow path 49A of the bottom piece 43 by bending the disk valve 46, thereby opening the reservoir chamber. 41 to obtain a compression side damping force. At the time of extension, the oil corresponding to the retraction volume of the piston rod 13 retreating from the cylinder 12 pushes the check valve 47 open, and from the reservoir chamber 41 via the expansion side flow path 49B (not shown) of the bottom piece 43, the piston side oil chamber 37A. Will be replenished.

  In the damper 10, the first collar 51 on the rebound seat 50 fixed to the piston 33 side (lower side) around the piston rod 13 located in the rod side oil chamber 37B of the cylinder 12, Between the second collar 52 loosely inserted on the rod guide 21 side (upper side), a rebound spring 53 that is compressed and deformed when the piston rod 13 is extended (the damper 10 is in the most extended state) is interposed. .

  However, the damper 10 has a damping force adjusting device 60 for suppressing expansion and contraction of the piston rod 13 as shown in FIG. The damping force adjusting device 60 is configured by connecting a pressurizing chamber 62 </ b> A of the pressurizing pump 62 controlled by the control means 61 to the gas chamber of the reservoir chamber 41. The damping force adjusting device 60 adjusts the gas pressure in the pressurizing chamber 62A by operating an electric (or manual) actuator 62B such as a solenoid of the pressurizing pump 62 by the control means 61, and eventually the pressurizing chamber 62A. The gas pressure in the reservoir chamber 41 is changed, and the gas pressure in the reservoir chamber 41 is applied to the check lip 23C of the oil seal 23 via the passages 25A and 25B of the rod guide 21, so that the oil lip 23B of the oil seal 23 The fastening force exerted on the outer peripheral surface of the piston rod 13 is changed. As a result, the damping force adjusting device 60 adjusts the friction of the sliding portion between the oil seal 23 and the piston rod 13, and as a result, the piston speed is extremely small at 0.05 m / s or less with the compression stroke and the extension stroke of the piston rod 13. Only in the low speed range, the damping force on the compression side and the extension side applied to the piston rod 13 by the oil seal 23 is adjusted.

  The damping force adjusting device 60 uses a control means 61 and a pressure pump 62, and the like, and a C-shaped bush provided around the piston rod 13 (one portion in the circumferential direction forming an annular shape) and the piston rod It may have a structure for adjusting the friction of the 13 sliding portions, or may have a structure for adjusting the friction of the sliding portions of the piston 33 and the cylinder 12.

  FIG. 4 shows the damping force characteristics of the compression side and the extension side applied to the piston rod 13 when the piston valve device 30 and the bottom valve device 40 are the compression stroke and the extension stroke of the piston rod 13 and the piston speed is low to high. Show. It was recognized that there was no need to vary the damping force at high speeds in terms of driving comfort of the vehicle.

  FIG. 5 shows the damping force characteristics of the compression side and the extension side applied to the piston rod 13 when the damping force adjusting device 60 is the compression stroke and the extension stroke of the piston rod 13 and the piston speed is extremely low. It was recognized that even if the damping force only in the extremely low speed range was changed slightly, the riding comfort would change greatly. On both the compression side and the extension side, the maximum variable value of damping force that gives a hard riding comfort and the variable width A and B of the minimum variable value of damping force that gives a soft riding comfort are effective with a small variable width of about 2 to 5 kgf. Can be demonstrated.

According to the present invention provided with the damping force adjusting device 60, the following effects are obtained.
(a) The damping force adjusting device 60 makes it possible to adjust the damping force only in the extremely low speed range where the piston speed is 0.05 m / s or less. Because the damping force is variable only in the extremely low speed range, there is no need to generate a large damping force, and the variable range of the maximum variable value and the minimum variable value to be changed at the same piston speed is about 2 to 5 kgf. The effect can be demonstrated with a small variable width. Even if it is the maximum variable value, the value is extremely small with respect to the maximum damping force through the entire speed range of the damper 10, and the minimum variable value does not need to be close to zero. And high response.

  (b) The damping force adjusting device 60 can be simply reduced in size and the like of the components of the conventionally known damping force adjusting structure for a very low speed range, and does not require any special components. is there.

  (c) The damping force adjusting device 60 only needs to change the damping force with a slight variable width only in the extremely low speed range, and does not affect the damping force in the low speed range to the high speed range. For example, in the conventional damper 10 in which the setting of the damping force in the medium / high speed range is soft, the damping force in the very low speed region is reduced and fluffy, but in the damper 10 of the present invention in which the damping force in the extremely low speed region is increased, Suppresses the fluffy feeling and can improve the ride comfort. On the contrary, in the conventional damper 10 in which the damping force in the high speed region is hardened, the damping force in the very low speed region becomes large and feels rugged, but in the damper 10 of the present invention in which the damping force in the extremely low speed region is reduced, It eliminates the rugged feeling and can improve riding comfort.

(d) The damping force adjusting device 60 can easily and reliably adjust the damping force in the extremely low speed range by adjusting the friction of the sliding portion between the oil seal and the piston rod .

  FIG. 3 shows a damping force adjusting device 70 that replaces the damping force adjusting device 60 described above. The damping force adjusting device 70 is added to the bottom piece 43 constituting the bottom valve device 40 of the damper 10, and the disc valve 46 as a main valve that opens with respect to the piston speed in the middle and high speed range of the piston rod 13, check A bypass channel 71 is provided to bypass the pressure side channel 49A and the extension side channel 49B as main channels provided in the bottom piece 43 (partition wall member) so as to include the valve 47. The bypass channel 71 is electrically connected to the bypass channel 71. (Also possible with manual operation) A variable throttle valve 72 composed of a variable needle valve or the like driven by an actuator, and a compression side valve and an extension side leaf valve 73, 74 for controlling the damping force in a very low speed range are arranged in series (variable throttle valve). 72 and the leaf valve 73 are arranged in series, and the variable throttle valve 72 and the leaf valve 74 are arranged in series).

  According to the present embodiment provided with the damping force adjusting device 70, the variable throttle valve 72 is arranged in series with the leaf valves 73 and 74 that reliably operate even with a small oil flow rate in a very low speed range. The damping force in the extremely low speed range can be stably adjusted by adjusting the aperture amount.

  As another damping force adjusting device that replaces the above-described damping force adjusting device 60, in the damper 10 using MR fluid (magnetic viscous fluid) or ER fluid (electroviscous fluid), the compression stroke and extension stroke of the piston rod 13 are used. In this case, a magnetic field control device or an electric field control device may be used to adjust the strength of the magnetic field or electric field exerted on the orifice channel through which the viscous fluid passes. The viscosity of the viscous fluid passing through the orifice channel is changed, and as a result, the damping force generated due to the flow resistance of the viscous fluid in the orifice channel can be adjusted in the same manner as in the damping force adjusting device 60.

  Further, as another damping force adjusting device in place of the above-described damping force adjusting device 60, a device that controls the flow of oil in a hydraulic circuit constituting the variable stiffness stabilizer or adjusts the bush friction of the stabilizer can be adopted. .

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

FIG. 1 is a cross-sectional view showing a damping force adjusting damper. FIG. 2 is a schematic diagram showing a damping force adjusting device. FIG. 3 is a schematic view showing another example of the damping force adjusting device. FIG. 4 is a diagram showing damping force characteristics in a low speed region to a high speed region. FIG. 5 is a diagram showing the damping force characteristics in the extremely low speed range.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Damper 12 Cylinder 13 Piston rod 33 Piston 60 Damping force adjustment apparatus 61 Control means 62 Pressurization pump 70 Damping force adjustment apparatus 71 Bypass flow path 72 Variable throttle valve 73, 74 Leaf valve

Claims (2)

A damping force adjusting device for slidably inserting a piston attached to the piston rod into the cylinder and suppressing expansion and contraction of the piston rod ;
An oil seal that is fixed to the cylinder and slidably contacts the outer peripheral surface of the piston rod and scrapes off oil adhering to the outer peripheral surface of the piston rod;
A reservoir chamber provided on an outer periphery of the cylinder, and having an oil chamber and a gas chamber inside;
An actuator for changing the gas pressure in the reservoir chamber;
In a damping force adjustment damper comprising: a rod guide having a passage communicating with the reservoir chamber and transmitting the gas pressure to the oil seal ;
Damping force adjusting device has a front Kio Irushiru, and the piston rod, the adjusting the friction of the sliding portion by adjusting the damping force, the piston speed is only damping force in trace low speed range below 0.05 m / s Adjustable ,
The oil seal, the damping force control damper fastening force to the piston rod, characterized that you change when the damping force adjusting device varying gas pressure in the reservoir chamber by the actuator. In a damping force adjusting damper having a damping force adjusting device for slidably inserting a piston attached to a piston rod into a cylinder and suppressing expansion and contraction of the piston rod,
The damping force adjusting device is provided with a bypass flow path that bypasses the main flow path drilled in the partition wall member so as to have a main valve that opens with respect to the piston speed in the middle and high speed range, and the throttle amount is reduced by an actuator in the bypass flow path The variable throttle valve to be adjusted and the compression-side leaf valve for controlling the damping force in the extremely low speed range are arranged in series, and the variable throttle valve and the expansion-side leaf valve for controlling the damping force in the extremely low speed range are provided. A damping force adjusting damper that is arranged in series so that the damping force can be adjusted only in a very low speed range where the piston speed is 0.05 m / s or less.

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