JP2007321824A - Damping force adjustable damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping force adjustable damper for improving the steering stability and ride comfort of a vehicle by stably adjusting the friction of a sliding portion of a piston rod and a sliding portion of a piston in the extremely low speed region of the piston to generate a damping force variable to suppress the expansion of the piston rod. <P>SOLUTION: The damping force adjustable damper 10 comprises a lateral force imparting device 60 for imparting a lateral force to at least one of the piston rod 13 and a cylinder 12. The lateral force imparting device 60 adjusts the lateral force only in the extremely low speed region of the piston rod being 0.05 m/s or lower to adjust the friction of the sliding portion of the piston rod 13 and the sliding portion of the piston 33, thus making the damping force adjustable to suppress the expansion of the piston rod 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a damping force adjusting damper.

As a damping force adjusting damper, as described in Patent Document 1, when a piston attached to a piston rod is slidably inserted into a cylinder, the guide is divided into a plurality of circumferential directions arranged around the piston rod. A member, an elastic body that is attached to the opening of the cylinder so as to surround the guide member and forms a fluid chamber, and a means for adjusting the pressure in the fluid chamber according to the traveling state of the vehicle There is. When the vehicle travels and minute vibrations are applied to the piston rod, the pressure in the fluid chamber is kept small, and the guide member deforms the elastic body and displaces following the movement of the piston rod. Thus, the ride comfort is improved. Further, when the running vehicle turns, suddenly brakes, or suddenly starts, the adjusting means increases the pressure in the fluid chamber, and as a result, the binding force that the guide member grabs the piston rod increases, The frictional force with respect to the movement of the piston rod is increased, and a change in the posture of the vehicle such as rolling is reduced, whereby the steering stability is improved.
62-97335

  In the damping force adjusting damper of Patent Document 1, friction is generated in the piston rod by the structure in which the guide member grips the piston rod, and it is difficult to stably generate the friction.

  Further, the damping force adjusting damper disclosed in Patent Document 1 does not consider adjusting the damping force for adjusting the friction exerted on the piston rod when the piston speed is in the extremely low speed range and suppressing the expansion and contraction of the piston rod. As a result of the research by the present inventors, the damping force for adjusting the friction generated in the piston rod and the sliding portion of the piston and suppressing the expansion and contraction of the piston rod in a very low speed range where the piston speed range is extremely lower than the conventional low speed range. It was confirmed that the ride comfort of the vehicle can be greatly changed by adjusting the vehicle with a slight variable width. However, in the damping force adjusting damper of Patent Document 1, the guide member disposed around the piston rod in order to give friction to the piston rod is structurally accompanied by bending of the elastic body between the piston rod and the damper. . When the piston rod is in the extremely low speed range, the presence of this deflection prevents stable friction from being applied to the piston rod.

  An object of the present invention is to provide a damping force adjusting damper with a simple structure that stably generates friction between the sliding portion of the piston rod and the sliding portion of the piston, and the damping force for suppressing expansion and contraction of the piston rod is variable. This is to improve the riding comfort of the vehicle.

  Another object of the present invention is to suppress the expansion and contraction of the piston rod by stably adjusting the friction between the sliding portion of the piston rod and the sliding portion of the piston in the extremely low speed piston speed range in the damping force adjusting damper. By changing the damping force for the vehicle, the ride comfort of the vehicle is improved.

  According to a first aspect of the present invention, in a damping force adjusting damper, wherein a piston rod is slidably supported on a rod guide fixed to a cylinder, and a piston attached to the piston rod is slidably inserted into the cylinder. A lateral force applying device that applies a lateral force by inclining relative to the cylinder, and the lateral force applying device adjusts the friction between the sliding portion of the piston rod and the sliding portion of the piston, The damping force for suppressing expansion and contraction is made adjustable.

  According to a second aspect of the present invention, in the first aspect of the present invention, the lateral force imparting device is installed on the rod guide side to impart a lateral force to the piston rod.

  According to a third aspect of the present invention, in the first aspect of the present invention, the lateral force applying device is installed on a damper tube side having a built-in cylinder so as to apply a lateral force to the cylinder.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the lateral force applying device adjusts the lateral force only in a very low speed region where the piston speed is 0.05 m / s or less. The friction between the sliding portion of the rod and the sliding portion of the piston is adjusted so that the damping force for suppressing expansion and contraction of the piston rod can be adjusted.

(Claim 1)
(a) The lateral force imparting device stably generates friction between the sliding portion of the piston rod and the sliding portion of the piston with a simple structure in which the piston rod is inclined relative to the cylinder. By changing the damping force for suppressing the expansion and contraction of the rod, the riding comfort of the vehicle can be improved.

(Claim 2)
(b) A lateral force applying device is installed on the rod guide side and applies a lateral force to the piston rod. The pressing portion of the lateral force applying device causes the piston rod to bend and deform, so that in addition to the sliding portion between the piston rod guide and the piston cylinder, the pressing portion of the lateral force applying device and the piston rod By changing the friction of the three sliding portions of the sliding portion, it is possible to reliably generate the stable friction described above (a).

(Claim 3)
(c) A lateral force imparting device is installed on the side of the damper tube containing the cylinder, and imparts lateral force to the cylinder. The pressing part of the lateral force imparting device bends and deforms the cylinder, thereby changing the friction of the two sliding parts of the sliding part of the piston rod guide and the sliding part of the piston cylinder. The generated friction can be reliably generated.

(Claim 4)
(d) By adjusting the lateral force only in the extremely low speed range where the piston speed is 0.05 m / s or less by the lateral force applying device, the friction between the sliding part of the piston rod and the sliding part of the piston is adjusted, and the piston Made it possible to adjust the damping force to suppress the expansion and contraction of the rod. The lateral force imparting device imparts lateral force to at least one of the piston rod and the cylinder, and presses a part of the circumferential direction of the piston rod and cylinder from the lateral direction. When the piston rod moves by a small stroke in the extremely low speed range by bending the rod and cylinder to change the friction of at least two sliding parts of the sliding part of the piston rod rod guide and the sliding part of the piston cylinder In addition, stable friction can be given to the piston rod and piston.

  (e) Since the damping force is made variable by adjusting the lateral force only in the extremely low speed range with the lateral force applying device, it is not necessary to generate a large damping force, and the damping is changed at the same piston speed. The variable range of the maximum variable value and minimum variable value of the force can be effective with a small variable width of about 2 to 5 kgf. 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.

  (f) The lateral force imparting device imparts lateral force to at least one of the piston rod and the cylinder, and does not require any special component and is simple.

  (g) By adjusting the lateral force only in the extremely low speed range with the lateral force applying device, it is sufficient to change the damping force with a slight variable width, and 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 damping force setting in the medium and high speed range, the damping force in the very low speed range becomes smaller and feels fluffy, but the lateral force in the extremely low speed range is adjusted to increase the damping force. With the damper according to the present invention, it is possible to reliably suppress the fluffy feeling and improve the riding comfort. On the other hand, with the conventional damper that hardened the damping force setting in the high speed range, the damping force in the very low speed range also increased and became rugged, but the lateral force in the extremely low speed range was adjusted and lowered to reduce the damping force. With the damper according to the present invention, the harsh feeling is eliminated and the riding comfort can be improved.

  1 is a cross-sectional view showing a damping force adjusting damper, FIG. 2 is a cross-sectional view showing a lateral force applying device, FIG. 3 is a cross-sectional view showing another example of a lateral force applying device, and FIG. 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 large diameter outer peripheral portion fitted to the damper tube 11 and a lower end small diameter outer peripheral portion fitted to the cylinder 12, and a bush 22 that slidably supports the piston rod 13 is provided on the inner periphery. Prepare for. 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 and a dust lip 23C made of The oil lip 23B is annularly arranged below the inner circumference of the core bar 23A and faces the large step surface on the upper end side of the rod guide 21. The outer circumference of the piston rod 13 is generated by its own elasticity and the clamping force of the clamping spring 23D. The oil adhered to the outer periphery of the piston rod 13 is scraped off. The dust lip 23C is annularly arranged above the inner periphery of the core metal 23A and faces the outside world. The dust lip 23C is in sliding contact with the outer peripheral surface of the piston rod 13 by its own elastic force, and external foreign matter attached to the outer periphery of the piston rod 13 12 is prevented from entering.

  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 lateral force applying device 60 for applying a lateral force to the piston rod 13 and suppressing expansion and contraction of the piston rod 13 as shown in FIG. The lateral force imparting device 60 incorporates a pressing plunger 62 in a pressurizing chamber 61 provided at one place in the circumferential direction of the rod guide 21, and the tip pressing surface of the pressing plunger 62 is arranged in the circumferential direction from one side of the piston rod 13. And a lateral force is applied by inclining the central axis of the piston rod 13 relative to the central axis of the cylinder 12. A hydraulic pressure or gas pressure fluid pressure supply circuit 63 is connected to the pressurizing chamber 61.

  The lateral force applying device 60 controls the fluid pressure supply circuit 63 by the control means 64 so that the pressing plunger 62 can be pushed, and the piston speed of the piston rod 13 is in a very low speed range of 0.05 m / s or less. Only the lateral force applied by the pressing plunger 62 to the intermediate portion in the axial direction of the piston rod 13 is adjusted, and accordingly, an appropriate bending deformation is given to the piston rod 13. That is, the lateral force imparting device 60 adjusts the degree of bending deformation of the piston rod 13 to thereby adjust the sliding portion between the piston rod 13 and the rod guide 21, the sliding portion between the piston 33 and the cylinder 12, and the pressing plunger 62. The friction of the three sliding portions of the sliding portion between the piston rod 13 and the piston rod 13 is adjusted so that the damping force for suppressing expansion and contraction of the piston rod 13 can be adjusted. The control means 64 is a lateral force that the pressing plunger 62 applies to the piston rod 13 in accordance with each detection signal such as the driving state of the vehicle, in other words, the vehicle speed, the steering angle, and the stroke of the damper 10, or a combination thereof. To control.

  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 lateral force applying 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 lateral force is adjusted to raise the maximum variable value of the damping force that gives a hard riding comfort, and the lateral force is adjusted and lowered to change the minimum variable value of the damping force that gives a soft riding comfort. The widths A and B can be effective with a small variable width of about 2 to 5 kgf.

According to the present embodiment, the following operational effects can be obtained.
(a) The lateral force imparting device 60 adjusts the friction between the sliding portion of the piston rod 13 and the sliding portion of the piston 33 by adjusting the lateral force only in the extremely low speed range where the piston speed is 0.05 m / s or less. In addition, the damping force for suppressing expansion and contraction of the piston rod 13 can be adjusted. The lateral force imparting device 60 imparts lateral force to the piston rod 13 and presses a part of the circumferential direction of the piston rod 13 from the lateral direction. When the piston rod 13 moves by a small stroke in the extremely low speed region by changing the friction of at least two sliding portions of the sliding portion of the piston rod 13 with the rod guide 21 and the sliding portion of the piston 33 with the cylinder 12 In addition, stable friction can be applied to the piston rod 13 and the piston 33.

  (b) Since the damping force is made variable by adjusting the lateral force only in the extremely low speed range by the lateral force applying device 60, it is not necessary to generate a large damping force, and it is changed at the same piston speed. The variable width of the maximum variable value and the minimum variable value of the damping force can be effective with a small variable width of about 2 to 5 kgf. 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.

  (c) The lateral force imparting device 60 simply imparts lateral force to the piston rod 13 and only tilts the piston rod 13 relative to the cylinder 12, and does not require any special components, and is simple. It is.

  (d) By adjusting the lateral force only in the extremely low speed range with the lateral force applying device 60, it is sufficient to change the damping force with a slight variable width, and does not affect the damping force in the low speed range to the high speed range. . For example, with the conventional damper 10 in which the damping force setting in the medium / high speed range is softened, the damping force in the very low speed range becomes small and fluffy, but the lateral force in the extremely low speed range is adjusted to increase the damping force. In the damper 10 of the present invention, the fluffy feeling can be reliably suppressed and the ride comfort can be improved. On the contrary, in the conventional damper 10 in which the damping force setting in the high speed region is hard, the damping force in the very low speed region becomes large and feels rugged, but the lateral force in the extremely low speed region is adjusted and lowered to reduce the damping force. In the damper 10 of the present invention, the jerky feeling is eliminated and the riding comfort can be improved.

  (e) A lateral force applying device 60 is installed on the rod guide 21 side and applies a lateral force to the piston rod 13. When the pressing plunger 72 of the lateral force applying device 60 bends and deforms the piston rod 13, the lateral force applying device 60 is added to the sliding portion of the piston 33 with the rod guide 21 and the sliding portion of the piston 33 with the cylinder 12. The friction of the three sliding portions of the sliding portion between the pressing plunger 72 and the piston rod 13 can be changed to reliably generate the stable friction described in (a) above.

  FIG. 3 shows a lateral force applying device 70 for applying a lateral force to the cylinder 12 and suppressing expansion and contraction of the piston rod 13 in the damper 10. The lateral force imparting device 70 incorporates a pressing plunger 72 in a pressurizing chamber 71 provided at one place in the circumferential direction of the inner periphery of the damper tube 11, and the tip pressing surface of the pressing plunger 72 is used as one side of the outer periphery of the cylinder 12. From one place in the circumferential direction. A hydraulic pressure or gas pressure fluid pressure supply circuit 73 is connected to the pressurizing chamber 71.

  The lateral force applying device 70 controls the fluid pressure supply circuit 73 by the control means 74 so that the pressing plunger 72 can be pushed, and the piston speed of the piston rod 13 is in a very low speed region where the piston speed is 0.05 m / s or less. Therefore, the lateral force applied by the pressing plunger 72 to the intermediate portion in the axial direction of the cylinder 12 is adjusted, and accordingly, the cylinder 12 is appropriately bent and deformed. That is, the lateral force imparting device 70 adjusts the degree of bending deformation of the cylinder 12 to adjust the sliding portion between the piston rod 13 and the rod guide 21 and the sliding portion between the piston 33 and the cylinder 12. The frictional force of the piston rod 13 can be adjusted to adjust the damping force. The control means 74 applies the lateral force that the pressing plunger 72 applies to the cylinder 12 in accordance with the detection state signals of the vehicle, in other words, the vehicle speed, the rudder angle, the stroke of the damper 10, or the combination thereof. Control.

  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. For example, the lateral force applying devices 60 and 70 may use fluid pressure bladders instead of the pressure plungers 62 and 72 that are fluid pressure controlled. Further, the lateral force applying devices 60 and 70 may use a piezoelectric actuator such as a piezoelectric element that is electrically controlled, and apply a lateral force to the piston rod 13 and the cylinder 12 by the piezoelectric actuator.

FIG. 1 is a cross-sectional view showing a damping force adjusting damper. FIG. 2 is a cross-sectional view showing the lateral force applying device. FIG. 3 is a cross-sectional view showing another example of the lateral force applying 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

10 damper 11 damper tube 12 cylinder 13 piston rod 21 rod guide 33 piston 60, 70 lateral force applying device

Claims (4)

In a damping force adjusting damper, in which a piston rod is slidably supported by a rod guide fixed to the cylinder, and a piston attached to the piston rod is slidably inserted into the cylinder.
A lateral force applying device that applies a lateral force by inclining the piston rod relative to the cylinder;
The lateral force applying device adjusts the friction between the sliding portion of the piston rod and the sliding portion of the piston so that the damping force for suppressing expansion and contraction of the piston rod can be adjusted.   The damping force adjusting damper according to claim 1, wherein the lateral force applying device is installed on a rod guide side and applies a lateral force to the piston rod.   The damping force adjusting damper according to claim 1, wherein the lateral force applying device is installed on a side of a damper tube having a built-in cylinder and applies a lateral force to the cylinder.   The lateral force applying device adjusts the friction between the piston rod sliding portion and the piston sliding portion by adjusting the lateral force only in the extremely low speed range where the piston speed is 0.05 m / s or less, and the piston rod The damping force adjusting damper according to any one of claims 1 to 3, wherein a damping force for suppressing expansion and contraction is adjustable.

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