KR20050081434A - Damping force variable valve of shock absorber - Google Patents

Abstract

The damping force variable valve, which is installed in the damping force variable shock absorber and includes a variable orifice for controlling the damping force, is connected to a rotating shutter for changing the cross-sectional area of the variable orifice, and connected to one end of the rotating shutter to rotate the rotating shutter. And a rotary actuator.

Description

감쇠 DAMPING FORCE VARIABLE VALVE OF SHOCK ABSORBER}

The present invention relates to a damping force variable valve for controlling the damping force in a damping force variable shock absorber used in automobiles. More particularly, the present invention relates to a rotary shutter for adjusting the flow area of variable orifices for damping force characteristics in a damping force variable valve. By controlling by using, the damping force variable valve which can reduce the size of the entire variable valve and improve the mounting property.

In general, vehicle suspensions must adequately control the damping force in relation to the relative movement of the body and the wheels. For example, the damping force variable shock absorber including a damping force variable valve can reduce the damping force during normal driving of the vehicle, thereby absorbing vibration caused by unevenness of the road surface and improving riding comfort. On the other hand, when turning, accelerating, braking, driving at high speeds, etc., the damping force can be increased, and the attitude change of the vehicle body can be suppressed to improve steering stability.

However, since the wheel movement requires a quick response of 10 Hz or more, the mechanical valve mechanism inside the shock absorber can quickly adjust the damping force according to the relative movement of the vehicle body and the wheel, and the compression and rebound strokes. The development of a valve capable of controlling the damping force characteristics separately at the time has been promoted.

The damping force variable valve of the existing suspension system is divided into a normal type variable valve and a reverse type variable valve according to the damping force control method according to the movement of the vehicle. Reverse type variable valve is characterized by controlling the compression and tension stroke as a separate valve according to the movement of the vehicle. Thus, the reverse type variable valve generates a small damping force in the tension stroke and a large damping force in the compression stroke, or a large damping force in the tension stroke and a small damping force in the compression stroke. However, since the reverse type variable valve uses a separate valve, the production cost is expensive, and the size of the reverse type variable valve is relatively large due to the use of additional valves.

Normally variable valves use a single valve to control both damping forces during compression and tension strokes. Therefore, the normal variable valve generates either a large damping force or a small damping force both in the tension stroke and the compression stroke.

1 is a cross-sectional view showing the structure of a damping force variable shock absorber 1 equipped with a normal damping force variable valve according to the prior art. The inside of the cylinder 10 is partitioned into the tension chamber 2 and the compression chamber 3 by the piston 11 which moves up and down in the cylinder 10. In addition, one end is connected to the piston 11 and the other end is extended to the piston rod 12 and the reservoir 13 to compensate for the volume change in the cylinder 10 according to the vertical movement of the piston rod 12 Is installed in communication with the cylinder (10). A valve 14 for the flow of oil between the tension chamber 2 and the compression chamber 3 is provided in the piston 11, and a valve 15 for the flow of oil between the reservoir 13 and the compression chamber 3. ) Is installed at the bottom of shock absorber (1). One or more of the valves 14 and 15 to be installed may be used as a check valve for allowing oil to flow in one direction without generating damping force and a damping valve for allowing oil to flow in one direction while generating damping force. Can be. The damping force variable valve 20 is provided at one end of the outer diameter portion of the base shell 16, which is the outer portion of the shock absorber 1.

2 is a cross-sectional view showing the structure of a normal type variable valve according to the prior art. The housing 21 of the damping force variable valve 20 is installed at one end of the outer shell portion of the base shell 16 of the shock absorber 1, and the solenoid valve 31 is installed at one end of the housing 21. In the coupling portion of the housing 21 and the shock absorber 1, a first flow path 22 connected to the tension chamber 2 and the compression chamber 3 of the shock absorber 1 and a second connection to the reservoir 13 are provided. The flow path 23 is formed.

Inside the housing 21, a spool 24 is installed to be reciprocated by the solenoid valve 31 in the longitudinal direction. The spool 24 has a plurality of stepped outer diameters in the vertical direction to allow flow of oil. On the outside of the spool 24 is installed a spool rod 25 for guiding the sliding movement of the spool 24, and at the outside of the spool rod 25, a retainer 27 having a connection port 26 is installed. do. The retainer 27 is divided into an upper retainer 27a and a lower retainer 27b, and a disk assembly 28 is installed between the upper retainer 27a and the lower retainer 27b.

An elastic member 29 is installed above the spool 24 to lower the spool 24 raised by the solenoid valve 31 to the initial position, and into the spool rod 25 according to the position of the spool 24. A cutaway groove 24a is formed in a portion of the outer circumference of the spool 24 so as to selectively open the flow path, and correspondingly, a plurality of through holes 25a are formed in the spool rod 25.

When the damping force variable valve 20 of the shock absorber 1 configured as described above is traveling on a flat road at a constant speed, the flow path formed in the spool 24 and the spool rod 25 is blocked to have a single damping characteristic. When passing through the road surface, the prevention jaw, etc., by changing the position of the spool 24 to open the flow path formed in the spool 24 and the spool rod 25 to have a variable damping characteristics. That is, the damping characteristic of the damping force variable valve 20 changes according to the extent to which the flow path is opened by the movement of the spool 24.

Meanwhile, as described above, the translational movement of the spool 24 is performed by the solenoid valve 31, which includes the solenoid coil (not shown) and the solenoid member 32. When acceleration occurs in the vertical direction of suspension devices such as wheels and control arms (not shown) due to vibration and driving conditions, the acceleration sensor (not shown) detects this acceleration and detects the acceleration. The ECU transmits the signal to the ECU (not shown), and the ECU, which receives the acceleration signal, compares the signal and judges that the current flows through the solenoid coil to generate a magnetic field, which is the solenoid installed at the center of the solenoid coil. Control the position of the member 32.

The solenoid valve 31 occupies a considerable volume in the damping force variable valve 20, as shown in FIG. 2, which makes it possible to mount the shock absorber 1 having the damping force variable valve 20 and the damping force variable valve. There is a disadvantage of deterioration.

Accordingly, an object of the present invention is to provide a damping force variable valve that can improve the mounting by reducing the size of the damping force variable valve as a whole by using a rotary actuator and a rotary shutter.

According to an embodiment of the present invention for achieving the above object, in the damping force variable valve installed in the variable damping force shock absorber, a rotary shutter for changing the cross-sectional area of the variable orifice, and connected to the rotary shutter A damping force variable valve is provided that includes a rotary actuator for rotating a typical shutter.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, about the same part as a prior art, the same code | symbol is attached | subjected and unnecessary description is abbreviate | omitted.

3 is a cross-sectional view showing the structure of a damping force variable valve according to the present invention. Hereinafter, the structure of the damping force variable valve according to the present invention will be described.

A guide member 43 for guiding the rotational movement of the rotary shutter 41 is coupled to the rotary actuator 42 for rotating the rotary shutter 41. In this case, a step motor may be used as the rotary actuator. An actuating rod 44 of the rotary actuator 42 is coupled with the rotary shutter 41. The rotatable shutter 41 inserted into the guide member 43 includes an upper slit 41a and a lower slit 41b.

The guide member 43 includes a plurality of radially connecting ports 43a, 43b, 43c for connecting the inside and the outside of the hollow and the guide member 43 for inserting the rotatable shutter 41 at the center thereof. A ring disk 45 having a central hole for inserting the guide member 43 and a slit of the circumferential portion and serving as a fixed orifice is fitted to the guide member 43 and connected with the guide member 43. A lower retainer 46 having a central hole for inserting the guide member 43 and serving to fix the position of the guide member 43 is mounted on the ring disk 45 while being fitted to the guide member 43. . The lower retainer 46 includes connecting ports 46a and 46b to allow the flow of oil.

A ring disk 47, which has a central hole and slit for inserting the guide member 43, partitions the high pressure side Ph and the control chamber 62, and serves as a main valve, on the lower retainer 46. Is installed. An upper retainer 48 having a central hole for inserting the guide member 43 and serving to fix the position of the guide member 43 is mounted on the ring disk 47 while being fitted to the guide member 43. . The upper retainer 48 includes connecting ports 48a and 48b to allow the flow of oil.

By the nut 49, the above-described guide member 43, the lower retainer 46, the upper retainer 48 and the like are connected in one unit. The rotary shutter 41 which rotates by the rotary actuator 42 in the hollow inside of the guide member 43 is inserted, and the plug 50 is engaged with one end of the guide member 43. An upper retainer guide 51 is mounted to cover the upper retainer 48, with a gap between them sealed by an O ring 52.

Hereinafter, the flow of oil according to the structure of the damping force variable valve 40 described will be described.

The oil moves from the high pressure side Ph to the hydraulic chamber 60 formed by the upper retainer 48 and the ring disk 47 through the connection ports 48a and 48b of the upper retainer 48 by the movement of the piston. . The oil which has moved to the hydraulic chamber 60 enters into the guide member 43 through the second variable orifice consisting of the connecting port 43a of the guide member 43 and the upper slit 41a of the rotatable shutter 41. It moves and moves to the low pressure side Pl through the connection port 53 with the low pressure side Pl.

The oil moved to the hydraulic chamber 60 in the same manner is the first variable consisting of a slit of the ring disk 47, a connecting port 43b of the guide member 43 and a lower slit 43b of the rotatable shutter 41. It passes through the connection port 43c of the orifice and the guide member 43 in order to move to the hydraulic chamber 61. Some of the moved oil exits to the low pressure side Pl through the circumferential slit (not shown) of the ring disk 45 constituting the fixed orifice. The oil that has not escaped to the fixed orifice travels to the control chamber 62 formed of the lower retainer 46 and the ring disk 47.

When the flow rate increases during the tension or compression stroke and the pressure difference between the high pressure side Ph and the control chamber 62 becomes large, the ring disk 47 is bent toward the control chamber by the force generated by the pressure difference. . That is, a gap may occur between the upper retainer 48 and the ring disk 47 according to the pressure on the high pressure side Ph, the pressure in the control chamber 62, and the preload of the initial ring disk 47. That is, the main valve is opened so that oil flows directly from the high pressure side Ph to the low pressure side Pl.

The main valve opens at a different pressure depending on the pressure of the control chamber 62, which is formed by the action of a first variable orifice installed upstream and a fixed orifice installed downstream. By controlling the area of the first variable orifice, the pressure in the control chamber 62 is increased to switch to hard mode. In addition, a second variable orifice is installed to allow a flow rate from the high pressure side Ph to the low pressure side Pl, and as the area of the first variable orifice increases, the area of the second variable orifice decreases, As the area decreases, the area of the second variable orifice increases. Through this, proper damping force characteristics can be obtained.

To realize this, as shown in FIG. 3, the upper and lower slits 41a and 41b of the rotatable shutter 41 have a relative position with respect to the connecting ports 43a and 43b with respect to the circumferential direction of the rotatable shutter 41. It is arranged in reverse. Therefore, when the rotary shutter 41 rotates due to the rotary actuator 42, when the flow area of the first variable orifice consisting of the connecting port 43b and the lower slit 41b increases, the connecting port 43a ) And the flow area of the second variable orifice consisting of the upper slit 41b is reduced. Conversely, when the flow area of the first variable orifice decreases, the flow area of the second variable orifice increases.

More preferably, by varying the shape of the upper slit 41a and the lower slit 41b or the shape of the connection ports 43a and 43b, the rate of change of the cross-sectional area of the second variable orifice is the cross-sectional area of the first variable orifice. It can be set to be larger than the rate of change.

In addition, in this embodiment, the case where the upper and lower slits 41a and 41b of the rectangular-shaped rotary shutter 41 were formed by being alternated in the circumferential direction is shown. However, it is also possible that the rotatable shutters are formed identically in the circumferential direction, and the connecting ports of the guide members are staggered, or rotatable shutters of shapes other than rectangular may be formed.

By using the rotary actuator and rotary shutter described above, the volume occupied by the solenoid valve can be greatly reduced. Therefore, the mountability of the shock absorber equipped with the damping force variable valve and the damping force variable valve can be greatly improved.

Meanwhile, in the above description of the present invention, specific embodiments have been described, but the present invention is not limited to the above-described embodiments, and those skilled in the art to which the present invention pertains will have the present invention described in the following claims. Various changes may be made without departing from the gist of the matter. Therefore, the scope of the invention should not be defined by the described embodiments, but should be defined by the claims.

As described above, the size of the damping force variable valve can be reduced by using the rotary actuator and the rotary shutter. As a result, it is possible to maintain appropriate damping force characteristics and greatly improve the mountability of the shock absorber equipped with the damping force variable valve and the damping force variable valve.

1 is a cross-sectional view showing a shock absorber equipped with a damping force variable valve according to the prior art.

Figure 2 is a cross-sectional view showing the structure of a damping force variable valve according to the prior art.

3 is a cross-sectional view showing a structure of a damping force variable valve according to the present invention.

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

40: damping force variable valve 41: rotary shutter

41a, 41b: Slit 42: Rotary Actuator

43: guide member 43a, 43b, 43c: connection port

45, 47: ring disc 46: lower retainer

46a, 46b: connection port 48: upper retainer

48a, 48b: connection port 49: nut

60, 61: hydraulic chamber 62: control chamber

Claims (4)

In the damping force variable valve installed in the variable damping force shock absorber, A rotatable shutter for changing the cross-sectional area of the variable orifice; And a rotatable actuator connected to the rotatable shutter to rotate the rotatable shutter. The method of claim 1, It is installed between the high pressure side and the low pressure side, and can be opened and closed according to the pressure of the high pressure side, the initial preload and the pressure of the control chamber, and when opened, the main valve to allow the flow of oil from the high pressure side to the low pressure side Wow, A first variable orifice formed between the high pressure side and the control chamber to control the pressure of the control chamber; A fixed orifice installed between the control chamber and the low pressure side, And a second variable orifice provided between said high pressure side and said low pressure side. The method of claim 2, The cross-sectional area of the first variable orifice and the second variable orifice are simultaneously varied due to the rotation of the rotatable shutter, and when the cross-sectional area of the first variable orifice increases, the cross-sectional area of the second variable orifice decreases, And when the cross-sectional area of the first variable orifice decreases, the cross-sectional area of the second variable orifice increases. The method of claim 3, wherein And a change rate of the cross-sectional area of the second variable orifice is greater than a change rate of the cross-sectional area of the first variable orifice.