KR20050082198A - Shock absorber to vary with piston stroke - Google Patents

Abstract

The present invention relates to a stroke-sensitive shock absorber, and more particularly, to a stroke-sensitive shock absorber that can freely set the damping force at low cost without using a general electronic control suspension because the damping force is adjusted according to the stroke during the vertical movement of the piston rod. will be.

Description

Shock absorber to vary with piston stroke

The present invention relates to a stroke-sensitive shock absorber, and more particularly, to a stroke-sensitive shock absorber whose damping force can be varied according to the stroke during the vertical movement of the piston rod.

In general, the suspension device is connected between the axle and the body frame to absorb vibrations or shocks transmitted from the road surface while driving to improve ride comfort and stability of the vehicle. It consists of a shock absorber that suppresses the up and down vibration of the vehicle to improve ride comfort. Among these, the shock absorber acts to convert the up and down kinetic energy of the piston into thermal energy, and the single-acting shock absorber exerts damping force at the time of stretching according to its operation method, and the damping force at both compression and extension. The double acting shock absorber is classified into a double acting shock absorber. The double acting shock absorber includes a stroke-sensitive shock absorber that allows the damping force of the shock absorber to be varied according to the displacement of the vehicle, which is varied according to the load state and the driving state of the vehicle.

As such a stroke-sensitive shock absorber, it is disclosed in Korean Patent Laid-Open No. 1999-0085869.

1 is a schematic configuration diagram of a conventional stroke-sensitive shock absorber.

As shown in FIG. 1, a cylinder tube 22 forming a working chamber O and having a low damping area (LDA) and a high damping area (HDA), and a cylinder A reservoir tube 21 installed outside the tube 22 to form a storage chamber R, and an actuating piston 23 vertically moving inside the cylinder tube 22 and having an orifice 23 '; In the stroke-sensitive shock absorber, the low damping area LDH includes a plurality of bypass holes 25a to 25d and bypass holes 25a to 25d formed through the inside and the outside of the cylinder tube 22. It is formed by the band tube 26 is installed on the outside of the cylinder tube 22 to close the, the bypass holes 25a to 25d are spaced apart by a height difference by a set value.

However, the stroke-sensitive shock absorber of the above-described configuration has the following problems.

In the conventional shock absorber, the setting of the damping force according to the speed is relatively free, but there is a limit to the setting of the damping force according to the stroke.

In particular, even in the shock absorber type that generates the damping force according to the stroke, the torque setting between the attenuation zones is not free, the damping force changes abruptly when the zone is changed, and it is difficult to set the smooth damping force due to the friction of the hydraulic fluid when the piston rod moves abruptly up and down. This follows.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and since the damping force is adjusted according to the stroke, the damping force can be freely set at low cost without using a general electronic control suspension, thereby providing a stroke-sensitive shock absorber that can reduce the cost. Its purpose is to.

Another feature of the present invention is to provide a stroke-sensitive shock absorber that can afford a tolerance because it does not require high precision when machining a spiral groove on the inner surface of the cylinder.

Another feature of the present invention is to provide a stroke-sensitive shock absorber that can freely set and tune the damping force, and can set the damping force in various ways at low cost, thereby reducing the cost.

In addition, the frictional resistance of the hydraulic fluid during the piston rod vertical movement decreases, and the area of communication between the through hole of the disk and the through hole of the carrier gradually changes, so that the damping force changes smoothly, so that the riding comfort can be improved.

Stroke-sensitive shock absorber according to an aspect of the present invention for achieving the above object is a shock absorber mounted between the vehicle body and the wheel exerts a damping force against the up and down vibration, the cylinder with a spiral groove formed on the inner surface ; A piston rod vertically moving inside the cylinder; A piston valve device disposed at an end of the piston rod and having at least one orifice formed therein; And a disk fixed to the piston rod to be adjacent to the piston valve device and having a through hole formed therein, wherein the piston valve device is rotated along the spiral groove during vertical movement of the piston rod.

According to this configuration, since the damping force is adjusted according to the stroke, the damping force can be freely set at low cost without using a general electronic control suspension, thereby reducing the cost.

In the above configuration, the piston valve device is equipped with a planetary gear device, if the through-hole is formed in the carrier of the planetary gear device, the rotational speed of the spiral groove can be set to three or more rotations, the spiral groove on the cylinder inner surface Even if a slight tolerance occurs during processing, it can be adjusted by the reduction ratio of the planetary gear system, so it does not require high precision, so that the tolerance can be afforded and the working efficiency is improved.

On the other hand, the stroke-sensitive shock absorber according to another aspect of the present invention is a shock absorber mounted between the vehicle body and the wheel to exert a damping force against the up and down vibrations, the cylinder having a spiral groove formed on the inner surface; A piston rod vertically moving inside the cylinder; A piston valve device disposed at an end of the piston rod and having at least one orifice formed therein; And a disk fixed to the piston rod and having a through hole formed therein, wherein a planetary gear device is mounted on the piston rod so as to be adjacent to the disk, and the ring gear of the planetary gear device spirals when the piston rod moves up and down. It rotates along the groove, and a through hole is formed in the carrier of the planetary gear device.

According to this configuration, the damping force can be adjusted by varying the rotational speed of the helical groove, the reduction ratio of the planetary gear device, the size of the through hole formed in the carrier and the disk, and the communicating area, so that the damping force can be freely set and tuned. In addition, it is possible to set various damping forces at low cost, thereby reducing costs.

In addition, the spiral groove on the inner surface of the cylinder is set to 3 rotations or more, so even if a slight tolerance occurs when machining the spiral groove on the inner surface of the cylinder, it can be adjusted by the reduction ratio of the planetary gear device, so that high tolerance is required because the precision is not required. It is possible to improve the work efficiency, the area of communication between the through-hole of the disk and the through-hole of the carrier is gradually changed, and accordingly, the damping force is changed gently, so that the riding comfort is improved.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

For reference, among the configurations of the present invention to be described below, the same configuration as the prior art will be referred to the above-described prior art, and a detailed description thereof will be omitted.

3 is a cross-sectional view showing a stroke-sensitive shock absorber according to a preferred embodiment of the present invention, Figure 4 is an enlarged perspective view of the main part of Figure 3, Figure 5 (a), (b) is Figure 3 Is a state diagram showing a state where the disk and the carrier of the planetary gear device are operated.

As shown in Figs. 3 and 4, the stroke-sensitive shock absorber of the present embodiment is a cylinder in which a hydraulic fluid is filled in a shock absorber mounted between a vehicle body and a wheel and exerting damping force against up and down vibrations. 100, the piston rod 200 which moves up and down according to the impact or vibration of the vehicle body in the cylinder 100, the piston valve device 300 disposed at the end of the piston rod 200, and the piston rod 200 It comprises a disk 400 fixed to.

A spiral groove 110 is formed on an inner surface of the cylinder 100, and the spiral groove 110 rotates three times in the cylinder 100. The rotation speed of the helical groove 110 is not a predetermined value, but a value that can be varied when setting the damping force according to the stroke.

The upper end of the piston rod 200 is connected to the vehicle body side and moves up and down inside the cylinder 100 according to the movement of the vehicle body.

The piston valve device 300 is composed of various parts such as an orifice-formed piston body, washer, spring and retainer.

Such a piston valve device is shown as 300 in FIG. 2, but is disclosed in detail in Korean Laid-Open Patent Publication No. 2003-0054718, which is assumed to belong to the present specification. However, in FIG. 3 of the present specification, note that 300 is simply illustrated.

The piston rod 200 is inserted into the center of the piston valve device 300, and at least one orifice is formed.

A piston rod inserting portion 410 into which the piston rod 200 is inserted is formed at the center of the disk 400, and an arc-shaped through hole 430 is formed to allow the hydraulic oil to pass therethrough.

The length of the arc of the through hole 430 is sufficient to be about one third of the circumference of the disk 400, and the length of the arc is not a predetermined value and can be varied according to the damping force setting according to the stroke.

The planetary gear device 500 is mounted to the piston rod 200 to be adjacent to the disk 400.

The planetary gear device 500 includes a sun gear 510, a plurality of planetary pinions 550 engaged with the sun gear 510, ring gears 530 engaged with the planetary pinions 550, and respective centers of the planetary pinions 550. It is composed of connected carriers 570.

A piston rod fixing part 511 is formed at the center of the sun gear 510 to be inserted into and fixed to the piston rod 200.

At least one protrusion 531 is formed on an outer circumferential surface of the ring gear 530 so as to be inserted into the spiral groove 110 formed in the inner surface of the cylinder 100 and rotate along the spiral groove 110.

In each planetary pinion 550, an insertion hole 551 is formed at the center thereof.

A piston rod inserting portion 571 is formed at the center of the carrier 570 to insert the piston rod 200. The area communicating with the through hole 430 of the disk 400 is rotated as the carrier 570 rotates. An arc-shaped through hole 573 is formed to be variable.

Similarly, the length of the arc of the through hole can be varied according to the setting of the damping force according to the stroke, similarly to the through hole 430 of the disk 400.

In addition, the carrier 570 is formed with a pin 575 is inserted into the insertion hole 551 of the planetary pinion 550 to connect the center of each planetary pinion 550.

In this way, the operation of the formed planetary gear device 500, the input is a ring gear 530 fitted into the spiral groove 110, the sun gear 510 is fixed to the piston rod 200, the output is a carrier By 570, the speed of the output carrier 570 is reduced to serve as a reduction gear.

The operation of this embodiment having the above-described configuration will be described below.

When the piston rod 200 moves up and down inside the cylinder 100 when the vehicle body vibrates, the ring gear 530 rotates along the helical groove 110. At this time, the ring gear 530 is rotated three times along the helical groove 110, but the carrier 570 is decelerated and output due to the characteristics of the planetary gear device 500, the carrier 570 is rotated within one rotation.

When the carrier 570 is rotated, the through hole 430 of the disk 400 adjacent to the carrier 570 has a variable area communicating with the through hole 573 of the carrier 570.

For example, the piston rod 200 moves up and down in the low damping area LDA when the vehicle body runs smoothly, that is, when a relatively low stroke occurs, so that the ring gear 530 moves the helical groove 110 of the cylinder 100. When rotated along the carrier 570, a portion where the through hole 573 of the carrier 570 and the through hole 430 of the disk 400 communicate with each other is relatively wide, as shown in FIG. Is rotated within.

Therefore, since a range in which the hydraulic oil penetrates inside the cylinder 100 is widened, the damping force is lowered and the riding comfort is improved.

On the other hand, the piston rod 200 is moved up and down in the high damping area (HDA) when the road body is subjected to excessive load or the vehicle protrudes, that is, when the high stroke occurs, the ring gear 530 is a spiral groove ( When rotated along 110, the carrier 570 has a portion where the through hole 573 of the carrier 570 and the through hole 430 of the disk 400 communicate with each other, as shown in FIG. 5B. , Rotates within a narrow range.

In this way, the portion through which the hydraulic fluid passes is narrowed, thereby generating a large damping force and improving steering stability.

In other words, when the piston rod 200 moves up and down, the ring gear 530 is rotated along the helical groove 110 of the cylinder 100 so that the carrier 570 is decelerated and the penetration of the carrier 570 is performed. The attenuation force is adjusted by varying the area in communication between the hole 573 and the through hole 430 of the disk 400.

Such a damping force adjustment according to the stroke is the rotational speed of the spiral groove 110 formed on the inner surface of the cylinder 100, the reduction ratio of the planetary gear device 500, and the through hole formed in the carrier 570 and the disk 400 ( By varying the size and the area of communication 430,573 in various ways, the damping force can be freely adjusted.

As such, when the damping force is adjusted according to the stroke of the piston rod 200, the damping force can be freely set at low cost without using the electronic control suspension, thereby reducing the cost and freeing the damping force setting and tuning.

In addition, the spiral groove 110 of the inner surface of the cylinder 100 is set to three or more rotations, so that the high precision of groove processing is not required when machining the spiral groove 110 on the inner surface of the cylinder 100. This is because, even if a slight tolerance occurs, it is possible to adjust the reduction ratio of the planetary gear device 500. Therefore, since the precision is not required to set the rotational speed of the helical groove 110 within 1 rotation, the tolerance can be afforded and the working efficiency is improved.

The area communicating between the through hole 430 of the disk 400 and the through hole 573 of the carrier 570 is gradually changed. Accordingly, the damping force is gradually changed, so that the riding comfort is improved.

Meanwhile, in the above detailed description, the disk 400 and the planetary gear device 500 are mounted to be spaced apart from the piston valve device 300, but the disk 400 is mounted adjacent to the piston valve device 300, and the piston valve The planetary gear device 500 may be mounted between the device 300 and the disk 400.

At this time, the piston valve device 300 is integrally connected to the ring gear 530 of the planetary gear device 500, so that when the piston valve device 300 is rotated along the spiral groove 110, the ring gear 530 Is rotated as shown.

Accordingly, since the carrier 570 of the planetary gear device 500 which is decelerated and output is installed adjacent to the disk 400, the through hole 573 of the carrier 570 and the disk 400 are rotated according to the rotation of the carrier 570. The area through which the through hole 430 communicates is changed, so that the damping force is adjusted.

At this time, the various components of the piston valve device 300 must be rotated together.

In addition, in addition to the above method, without forming the planetary gear device 500, it is also possible to form a projection directly on the piston valve device 300 to rotate along the spiral groove 110.

At this time, it is preferable that the rotation speed of the helical groove 110 shall be within 1 rotation.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art various modifications of the present invention without departing from the spirit and scope of the invention described in the claims below. Or it may be modified.

According to the stroke-sensitive shock absorber of the present invention as described above, the following effects are obtained.

First, the piston valve device is rotated along the helical groove during the vertical movement of the piston rod, so that the damping force is adjusted according to the stroke, so that the damping force can be freely set at low cost without using a general electronic control suspension, thereby reducing the cost.

Second, since the planetary gear device is mounted on the piston valve device, the rotational speed of the helical groove can be set to 3 or more rotations, so that the tolerance is less required than the rotational speed within 1 rotation when machining the spiral groove on the inner surface of the cylinder. It can be spared, which improves work efficiency.

Third, the piston rod is equipped with a disk, and the planetary gear device is mounted adjacent to the disk, thereby varying the number of rotations of the helical groove, the reduction ratio of the planetary gear device, the size of the through hole formed in the carrier and the disk, and the communicating area. The damping force can be adjusted by adjusting the damping force, and the damping force can be freely set and tuned.

In addition, the spiral groove on the inner surface of the cylinder is set to 3 rotations or more, so even if a slight tolerance occurs when machining the spiral groove on the inner surface of the cylinder, it can be adjusted by the reduction ratio of the planetary gear device, so that high tolerance is required because the precision is not required. It is possible to improve the work efficiency, the area of communication between the through-hole of the disk and the through-hole of the carrier is gradually changed, and accordingly, the damping force is changed gently, so that the riding comfort is improved.

1 is a schematic configuration diagram of a conventional stroke-sensitive shock absorber.

Figure 2 is a cross-sectional view showing a piston valve of another conventional shock absorber.

3 is a cross-sectional view showing a stroke-sensitive shock absorber according to a preferred embodiment of the present invention.

4 is an enlarged perspective view of the main part of FIG. 3;

5 (a) and (b) is a state diagram showing a state in which the carrier of the disk and the planetary gear device of FIG.

<Explanation of symbols for the main parts of the drawings>

100: cylinder 110: spiral groove

200: piston rod 300: piston valve device

400: disc 410: piston rod insert

430: through hole 500: planetary gear device

510: sun gear 511: piston rod fixing portion

530: ring gear 531: protrusion

550: planetary pinion 551: insertion hole

570: carrier 571: piston rod insert

573: through hole 575: pin

HDA: High Attenuation Zone LDH: Low Attenuation Zone

Claims (3)

In the shock absorber mounted between the vehicle body and the wheel to exert damping force against up and down vibration, A cylinder having a spiral groove formed on an inner surface thereof; A piston rod vertically moving inside the cylinder; A piston valve device disposed at an end of the piston rod and having at least one orifice formed therein; It comprises a disk fixed to the piston rod to be adjacent to the piston valve device, the through-hole is formed, The piston valve device is a stroke-sensitive shock absorber, characterized in that rotated along the spiral groove during the vertical movement of the piston rod. The method of claim 1, The piston valve device is equipped with a planetary gear device, Stroke-sensitive shock absorber characterized in that the through-hole is formed in the carrier of the planetary gear device. In the shock absorber mounted between the vehicle body and the wheel to exert damping force against up and down vibration, A cylinder having a spiral groove formed on an inner surface thereof; A piston rod vertically moving inside the cylinder; A piston valve device disposed at an end of the piston rod and having at least one orifice formed therein; It includes a disk fixed to the piston rod and the through-hole is formed, The planetary gear device is mounted to the piston rod to be adjacent to the disk, The ring gear of the planetary gear device rotates along the spiral groove during vertical movement of the piston rod. Stroke-sensitive shock absorber characterized in that the through-hole is formed in the carrier of the planetary gear device.