KR101239912B1 - Damping force variable valve for shock absorber - Google Patents

Abstract

According to the present invention, the damping force of the shock absorber which can prevent the oil leak in the vicinity of the outlet hole and reduce the processing cost by preventing the pilot path of the oil passing through the pilot chamber to the low pressure chamber through the outlet hole affected by the disk valve. A valve is provided. The damping force variable valve according to the present invention includes a valve retainer having an inlet hole for introducing oil from the high pressure chamber and an outlet hole for discharging oil of the main path into the low pressure chamber; A disc valve disposed to cover at least the inlet hole; A pilot chamber formed at the rear of the disk valve; And a pilot oil discharge passage for directing the oil in the pilot path flowing into the pilot chamber to the low pressure chamber without passing through the outlet hole.

Description

Damping force variable valve of shock absorber {DAMPING FORCE VARIABLE VALVE FOR SHOCK ABSORBER}

The present invention relates to a damping force variable valve for use in a variable damping force type shock absorber, and more particularly, to a damping force variable valve of a shock absorber comprising an improved flow path arrangement.

In general, the shock absorber is installed between the vehicle body and the wheel, and absorbs vibrations or shocks received from the road surface while driving, converts it into thermal energy and releases it to the outside, thereby improving the riding comfort.

Such a shock absorber includes a cylinder and a piston rod provided in the cylinder so as to be compressible and extensible, and the cylinder and the piston rod are respectively installed on a vehicle body, a wheel or an axle.

The shock absorber having a low damping force among the shock absorbers can absorb the vibration due to the unevenness of the road surface during traveling to improve ride comfort. On the other hand, the shock absorber having a high damping force has a characteristic in which the posture change of the vehicle body is suppressed and the steering stability is improved. Therefore, in the conventional vehicle, a shock absorber having a damping force characteristic different depending on the purpose of use of the vehicle is applied.

On the other hand, in recent years, a damping force variable valve capable of appropriately adjusting damping force characteristics on one side of the shock absorber is installed. Was developed.

1 is a cross-sectional view showing an example of a variable damping force shock absorber according to the prior art, wherein the variable damping force variable shock absorber 10 according to the prior art is provided inside the base shell 12 and the base shell 12. The piston rod 24 includes an inner tube 14 which is installed to be movable in the longitudinal direction. Rod guides 26 and body valves 27 are installed at the upper and lower ends of the inner tube 14 and the base shell 12, respectively. In addition, a piston valve 25 is coupled to one end of the piston rod 24 in the inner tube 14, and the piston valve 25 complies the internal space of the inner tube 14 with the rebound chamber 20. It partitions into the ratio chamber 22. An upper cap 28 and a base cap 29 are provided on the upper and lower portions of the base shell 12, respectively.

A reservoir chamber 30 is formed between the inner tube 14 and the base shell 12 to compensate for the volume change inside the inner tube 14 due to the reciprocating motion of the piston rod 24. Oil flow between the reservoir chamber 30 and the compression chamber 22 is controlled by the body valve 27.

Further, a separator tube 16 is provided inside the base shell 12. The interior of the base shell 12 is divided into the high pressure chamber PH connected to the rebound chamber 20 by the separator tube 16, and the low pressure chamber PL as the reservoir chamber 30.

The high pressure chamber PH is connected to the rebound chamber 20 through the inner hole 14a of the inner tube 14. The low pressure chamber PL is connected to the flow path of the body valve 27 through a lower flow path 32 formed between the body of the body valve 27 and the base shell 12.

The shock absorber 10 according to the prior art includes a damping force variable valve 40 mounted on one side of the base shell 12 to vary the damping force. The damping force variable valve 40 is formed with an oil flow path connected to the base shell 12 and the separator tube 16 and communicating with the high pressure chamber PH and the low pressure chamber PL, respectively.

1 and 2, the conventional damping force variable valve 40 is provided with a spool 44 moving by driving the actuator 42, the high pressure chamber (PH) by the movement of the spool 44 ) And the internal flow path communicating with the low pressure chamber (PL) is variable while the damping force of the shock absorber is varied. The damping force variable valve 40 includes a disk valve 50 and a pilot chamber 60 used therein for variable damping force of the shock absorber. The pilot chamber 60 is provided to have a back pressure that pressurizes the disk valve 50 behind the disk valve. In FIG. 2, two paths of oil flowing from the high pressure chamber PH to the low pressure chamber PL, that is, the main path and the pilot path, are respectively indicated by solid and dotted lines. Referring to this, the oil along the main path enters the damping force variable valve 40 from the high pressure chamber PH and passes through the vertical inlet hole 51a formed in the inner portion of the valve retainer 51. The low pressure chamber (PL) outside the damping force variable valve (40) through the outlet hole (51b) formed in the outer portion of the valve retainer (51) after generating a damping force by working with the disk valve (50) in the disk bending space of the Flows into. The oil along the pilot path, like the oil along the main path, passes through the inlet hole 51a described above, but bypasses between the spool 44 and the spool rod 45 through the ports of the spool rod 45. After flowing to the chamber 60, it flows to the low pressure chamber PL through the above-mentioned outlet hole 51b.

The conventional damping force variable valve 40 has the following problems due to passing through the outlet hole 51b in both the main path and the pilot path. The disc valve 50 includes an outlet disc 50a to block the pilot chamber 60 and the outlet hole 51b, which outlet disc 50a is the seat around the outlet hole 51 of the valve retainer 51. Although grounded with the surface, even a slight flaw in the peripheral seat surface of the valve retainer 51, which is a sintered body, may cause unwanted oil leakage. In addition, in order to maintain the back pressure of the pilot chamber 60, a complex shape must be placed on the peripheral seat surface, which also has a disadvantage of high processing cost.

Therefore, the problem to be solved by the present invention is that the pilot path of the oil through the pilot chamber to the low pressure chamber does not pass through the outlet hole affected by the disk valve, it is possible to prevent the oil leak in the vicinity of the outlet hole and reduce the processing cost It is to provide a damping force variable valve of the absorber.

A damping force variable valve of a shock absorber according to an aspect of the present invention includes a valve retainer having an inlet hole for introducing oil from a high pressure chamber and an outlet hole for discharging oil of a main path to a low pressure chamber; A disc valve disposed to cover at least the inlet hole; A pilot chamber formed at the rear of the disk valve; And a pilot oil discharge passage for directing the oil in the pilot path flowing into the pilot chamber to the low pressure chamber without passing through the outlet hole.

Preferably, the valve retainer includes a hole forming portion in which the inlet hole and the outlet hole are formed, and a chamber forming portion providing a space in which the pilot chamber is formed behind the inlet hole.

Preferably, the outlet hole is located outward of the inlet hole, and the disc valve includes a sealing disc extending further beyond the inlet hole to cover up to the outlet hole, wherein the boundary between the chamber forming portion and the hole forming portion is defined. The seat surface of the sealing contact with the sealing disk is installed to completely block the pilot chamber and the outlet hole.

Preferably, the pilot oil discharge flow path includes a guide hole formed in a guide block disposed to define a rear of the pilot chamber, and an external discharge path formed on an outer circumferential surface of the valve retainer.

More preferably, the valve retainer includes an elongated hollow in the center, and the spool which is movable back and forth by a solenoid-type actuator and a spool rod surrounding the spool are inserted and installed, and the inlet in front of the disc valve. The rear end of the hole is formed into a wider space than the inlet hole by the inclined shape, the space behind the inlet hole is connected to the spool flow path between the spool rod and the spool through a first one of the ports of the spool rod, The spool flow path is led to a pilot chamber through a pilot disk slit connected to a second port of the ports of the spool rod and the second port, wherein the pilot chamber comprises: the inner and outer walls of the disk valve and the chamber forming portion and the The pilot oil defined by the guide block fitted to the inner and outer walls. The discharge passage includes a guide hole formed in the guide block to connect the pilot chamber to the rear space outside thereof, and an external discharge passage formed on the outer circumferential surface of the retainer and connected to the rear space.

 The damping force variable valve of the shock absorber according to the present invention prevents the oil leak in the vicinity of the outlet hole by not passing the pilot hole of the oil through the pilot chamber into the low pressure chamber through the outlet hole affected by the disk valve. This has the advantage of greatly reducing the processing cost near the outlet hole. In addition, by allowing the gas to be discharged through the pilot path through the pilot chamber, it is possible to prevent the occurrence of noise caused by the gas, and to eliminate the side holes required to prevent the generation of noise by the existing gas, so that This can reduce the cost and effort required.

1 is a cross-sectional view showing a conventional damping force variable shock absorber.
FIG. 2 is an enlarged cross-sectional view of a portion of a damping force variable valve applied to the shock absorber shown in FIG. 1. FIG.
Figure 3 is a cross-sectional view showing a damping force variable valve of the shock absorber according to an embodiment of the present invention.
4 is a cross-sectional view showing a main part of the damping force variable valve shown in FIG. 3, showing the main path and the pilot path of the oil together;

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

3 is a cross-sectional view for explaining a damping force variable valve of the shock absorber according to an embodiment of the present invention, Figure 4 is an enlarged cross-sectional view showing the main part of the damping force variable valve shown in FIG.

3 and 4, the damping force variable valve 400 is connected to the base shell 12 and the separator tube 16 of the shock absorber, respectively, and the high pressure chamber PH and the low pressure chamber PL, respectively. A communicating oil flow path is formed. In addition, the damping force variable valve 400 includes a housing 401, a spool 404, a spool rod 405, a valve retainer 410, a disk valve 450, and the like embedded in the housing 401. . The spool 404 is configured to move back and forth by a solenoid actuator drive. The spool rod 405 includes a hollow for guiding the forward and backward linear motion of the spool 404 with a plurality of connection ports.

The valve retainer 410 includes an elongated hollow in which the spool 404 and the spool rod 405 surrounding it are inserted. In addition, the valve retainer 410 includes a front hole forming portion 410a and a rear chamber forming portion 410b. The hole forming portion 410a and the chamber forming portion 410b are preferably integrated, but may be separated. The hole forming portion 410a includes an inlet hole 412 vertically inward relatively close to the spool rod 405 and an outlet hole 414 relatively far from the spool rod 405. do. In addition, the chamber forming part 410b extends vertically to the rear in the vicinity of the edge of the hole forming part 410b to form a substantially annular structure, and forms a space in which the pilot chamber 460 is formed.

The disk valve 450 is composed of a plurality of stacked disks and is disposed to cover the rear of the disk valve 450 to generate a damping force against oil flowing through the inlet hole 412. One end of the disc valve 450 is supported near the hollow of the valve retainer 410, and the other end of the disc valve 450 is formed at a free end to be bent in oil passing through the inlet hole 412. . In particular, the disk valve 450 includes a sealing disk 452 extending to a position that completely covers the outlet hole 414, which sealing disk 452 extends the outlet hole 414 to the pile chamber. 460). In order to reliably completely block the flow of oil from the pilot chamber 460 to the outlet hole 414, the valve retainer 410 is provided with a sealing 413 in close contact with the sealing disk 452. The position of the sealing 413 is determined by the boundary between the hole forming portion 410a and the chamber forming portion 410b of the inner circumferential surface of the chamber forming portion 410b.

The rear end of the inlet hole 412 in front of the disk valve 450 is formed into a relatively wide space by an inclined shape, the first port 405a in the middle of the ports of the spool rod 405 Through the spool flow passage 404a between the spool rod 405 and the spool 404, which is the second port 405b at the rear of the ports of the spool rod 405 and Connected to the pilot chamber 460 through a pilot disk slit 417 (shown only in FIG. 4).

The pilot chamber 460 is positioned behind the disk valve 450 and is fitted to the inner and outer walls of the chamber forming portion 410b of the disk valve 450 and the valve retainer 410 and the inner and outer walls. Defined by the guide block 470. In this embodiment, the disk valve 450 is located in front of the pilot chamber 460 and the guide block 470 is located behind the pilot chamber 460. The chamber forming portion 410b of the valve retainer 410 includes a narrow and long external discharge passage 419 which is connected to the low pressure chamber PL of the shock absorber on the outer circumferential surface facing the housing 401, and the external discharge is performed. The furnace 419 is connected to the rear space of the guide block 470. At this time, the guide block 470 is formed with a guide hole 472 extending from the pilot chamber 460 to the rear space, by the guide hole 472 the external discharge path 419 of the outer peripheral side of the valve retainer 410 ) And the pilot chamber 460 are connected.

In FIG. 4, the main and pilot paths of the oil are indicated by solid and dashed lines. According to the main path of FIG. 4, the oil introduced into the damping force variable valve from the high pressure chamber of the shock absorber bends the disc valve 450 through the inlet hole 412 formed in the hole forming portion 410a of the valve retainer 410. After the outlet hole 414 outside the inlet hole 412 to the low pressure chamber. On the other hand, according to the pilot path of Figure 4, the oil introduced into the damping force variable valve from the high pressure chamber of the shock absorber passes through the inlet hole 412 described above, the spool rod through the first port 405a of the spool rod 405 The spool flow path 404a between the 405 and the spool 404 flows through the second port 405b and the pilot disk slit 417 connected thereto to the pilot chamber 460. The oil flowing into the pilot chamber 460 forms a back pressure therein, and flows out of the pilot chamber 460 through the guide hole 472 formed in the guide block 470 to the outer circumferential side of the valve retainer 410. (419) flows into the low pressure chamber. The pilot oil discharge passage PO including the guide hole 472 and the external discharge passage 419 flows oil from the pilot chamber 472 toward the low pressure chamber of the shock absorber from the pilot chamber 472. As the size of the pilot oil discharge passage PO may be appropriately designed according to the vehicle, the back pressure of the pilot chamber 460 and the damping force characteristics of the damping force variable valve may be appropriately determined.

At this time, the pilot chamber 460 is outlet hole 414 is reliably isolated by the sealing 413 in contact with the sealing disk 452 of the disk valve 450, and therefore, the outlet hole (460) from the pilot chamber 460 Oil flow to 414 is essentially blocked.

400: damping force variable valve 401: housing
404: Spool 405: Spool Load
405: spool rod 410: valve retainer
410a: hole forming portion 410b: chamber forming portion
412: inlet hole 414: outlet hole
450: disk valve 452: sealing disk
460: pilot chamber 413: sealing
470: guide block 472: guide hole
419: External exhaust path 417: Pilot slit disc
PO: pilot oil discharge channel

Claims (5)

A valve retainer 410 having an inlet hole 412 for introducing oil from the high pressure chamber and an outlet hole 414 for discharging oil of the main path into the low pressure chamber;
A disc valve 450 disposed to cover at least the inlet hole 412;
A pilot chamber 460 formed behind the disc valve 450; and
Pilot oil discharge passage including a guide hole 472 formed in the guide block 470 disposed to define the rear of the pilot chamber 460, and an external discharge passage 419 formed on the outer circumferential surface of the valve retainer 410 Including (PO),
The pilot oil discharge flow passage (PO) is a damping force variable valve of the shock absorber, characterized in that for directing the oil of the pilot path flowing into the pilot chamber (460) to the low pressure chamber without passing through the outlet hole (412). 2. The valve retainer 410 of claim 1, wherein the valve retainer 410 includes a hole forming unit 410 a in which the inlet hole 412 and the outlet hole 414 are formed, and the pilot chamber 460 behind the inlet hole 412. A damping force variable valve of the shock absorber, characterized in that it comprises a chamber forming portion (410b) for providing a space in which is formed. The outlet hole 414 is positioned outwardly from the inlet hole 412, and the disc valve 450 extends further beyond the inlet hole 412 to cover the outlet hole 414. A sealing disk 452 is included, and the boundary between the chamber forming portion 410b and the hole forming portion 410a is in contact with the sealing disk 452 to completely fill the pilot chamber 460 and the outlet hole 414. Damping force variable valve of the shock absorber, characterized in that the sealing to block 413 is installed. delete 4. The valve retainer 410 of claim 3, wherein the valve retainer 410 includes an elongated hollow in the center, and the hollow includes a spool 404 that is movable back and forth by a solenoid actuator and a spool rod 405 that surrounds the spool 404. Is inserted and installed, the rear end of the inlet hole 412 in front of the disk valve 450 is formed in a wider space than the inlet hole 412 by the inclined shape, the space behind the inlet hole 412 A spool flow passage 404a between the spool rod 405 and the spool 404 passes through a first one of the ports of the spool rod 405, and the spool flow passage 404a is connected to the spool rod 405. The pilot chamber 460 is connected to the pilot chamber 460 through a pilot disk slit 417 connected to the second port 405b and the second port 405b of the ports of the pilot valve 460. ) And inner and outer walls of the chamber forming part 410a and the It is defined by the guide block 470 fitted to the inner and outer walls, the pilot oil discharge flow path (PO) is formed in the guide block 470 to connect the pilot chamber 460 to the rear space outside thereof The damper force variable valve of the shock absorber, characterized in that it comprises a guide hole (472) and an outer discharge passage (419) formed on the outer peripheral surface of the retainer and connected to the rear space.

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