KR20140116048A - Shock absorber - Google Patents

Abstract

The present invention relates to a shock absorber using hydraulic pressure to reduce vibrations, noise, and shocks associated with operating a mass in various industrial machines. According to an embodiment of the present invention, the shock absorber includes: a body formed with cylindrical space formed with a length groove wherein fluid can flow along a longitudinal direction of the cylindrical space; an inner tube connected to the cylindrical space which can rotate and in which operation space is formed, wherein the fluid is stored in the operation space formed with a plurality of orifices linked with the operation space; a piston capable of being sliding in the operation space by an external force; and a passage groove linked with the orifices, which forms the outer peripheral surface of the inner tube to be recessed along the circumferential direction of the inner tube of which a cross sectional area gradually decreases.

Description

Shock absorber

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber that uses hydraulic pressure to reduce vibrations, noise, shocks, and the like due to the operation of a mass body in various industrial machines.

The shock absorber is used to eliminate vibrations, noise, shocks, etc. of masses such as machinery and workpieces.

A typical shock absorber consists of an oil-filled cylinder and a piston, the cylinder side is fixed to a rigid structure, and the piston forms an input through which impacts are transmitted. At this time, the cylinder has a double structure and forms an orifice through which the oil flows to the inner cylinder or the piston, in order to reduce a larger impact gently.

There is a further improved shock absorber which can control the flow path cross-sectional area of the oil represented by the orifice to control the performance of the shock absorber. This increases the versatility of a product because the degree of attenuation due to the control of the cross-sectional area of the flow path is changed. That is, after a large amount of one kind of buffer is purchased, the buffer can be set and used according to the degree of attenuation required in each place where the amount of the buffer is different. This leads to improved productivity for manufacturers producing small items, and for convenience to the purchaser.

Korean Patent Laid-Open No. 10-2004-0064028 has a disadvantage in that the attenuation variable buffer according to the prior art has a limited configurable range of attenuation due to its structure. In addition, since the buffer is not easily manufactured in a complicated structure, the productivity is not so good.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-described problems and has an object to increase the variable range of attenuation. It also has an object of facilitating the production.

In order to achieve the above object, according to an aspect of the present invention, there is provided an apparatus comprising: a body having a cylindrical space formed with a longitudinal groove through which fluid can move along a longitudinal direction of the cylindrical space; An inner tube in which a fluid is stored in the working space, a plurality of orifices communicating with the working space are formed, and a piston slidable in the working space by an external force, the piston communicating with each of the orifices, And an outer circumferential surface of the inner tube is depressed in accordance with a direction of the outer circumferential surface of the inner tube.

Here, the depth of the bottom surface gradually increases as the flow path is further away from the orifice, so that the cross-sectional area can be reduced.

In another embodiment, both side surfaces of the flow path groove may become closer to each other as they are away from the orifice, so that the cross-sectional area may be reduced.

The flow channel may be formed in a range of 60 to 350 degrees along the circumferential direction of the inner tube at the center of the circular cross section of the working space.

Wherein the one end of the body is opened and the other end is integrally formed with a step portion for reducing an inner diameter of the cylindrical space, and a latching portion formed outside the insertion end of the inner tube is caught by the stepped portion, Can be rotatably supported.

An injection hole may be formed in the protruding portion of the inner tube protruding from the body through the stepped portion along the longitudinal direction of the inner tube, and the injection hole may be communicated with the extension hole formed in the radial direction of the inner tube. have.

The inner tube has a first fluid storage space defined by the piston and a second fluid storage space defined by the piston, the volume of which is changed by the movement of the piston. The inner tube is in contact with the inner circumferential surface of the inner tube. And a body having a longitudinal groove for communicating the first fluid storage space and the second fluid storage space, wherein the fluid groove communicated with the first fluid storage space or the orifice connected to the second fluid storage space And the flow rate of the fluid flowing to the longitudinal groove is adjusted according to the rotation of the inner tube with respect to the body.

In this case, an engagement groove is formed in the inner peripheral surface of the opened one side of the body, and a C-ring coupled to the outer peripheral surface of the structure inserted into the opened body is inserted into the engagement groove, Deviation can be prevented.

According to another embodiment of the present invention, there is provided a body having a cylindrical space formed therein and having a longitudinal groove through which the fluid can move along the longitudinal direction of the cylindrical space, a rotatable body rotatable in contact with the cylindrical space, An inner tube having a plurality of orifices formed therein communicating with the working space, and a piston slidable in the working space by an external force, the piston communicating with the orifices, Wherein a flow path groove recessed from the outer circumferential surface of the inner tube is formed and the depth of depression of the flow path groove gradually becomes shallower from the orifice.

According to the embodiment of the present invention, since the flow path groove for controlling the flow rate can be formed long around the outer circumferential surface of the inner tube, it is possible to control the minute flow rate, and accordingly, There is an effect that setting can be made.

In addition, the inner working of the cylindrical body is reduced, and the complicated shape is machined on the outer peripheral surface of the inner tube, thereby improving the productivity of the buffer.

1 is a schematic perspective view of a shock absorber according to an embodiment of the present invention;
2 is a schematic cross-sectional view of the shock absorber shown in Fig.
3 is a partial cross-sectional view of the body employed in the shock absorber shown in Fig.
4 is an exploded perspective view of an inner tube, a piston, and the like employed in the shock absorber shown in FIG.
5 is an enlarged view of a portion A in Fig.
6 is a sectional view taken along line BB in Fig.
7 is a cross-sectional view showing the use state of the shock absorber shown in Fig.
8 is a conceptual view of the state of use of the shock absorber according to Fig. 7;
FIG. 9 is a sectional view showing another use state of the shock absorber shown in FIG. 1. FIG.
FIG. 10 conceptually illustrates another use state of the shock absorber shown in FIG. 9; FIG.
11 is a conceptual view illustrating a state of use of a shock absorber according to another embodiment of the present invention.
12 is a perspective view of an inner tube employed in a shock absorber according to another embodiment of the present invention.

The shock absorber according to the present invention adopts a dual cylinder structure of an inner tube and a body forming a space in which a fluid is stored. Inside the inner tube, a piston member for transmitting impact force or vibration transmitted from the outside to the fluid stored in the inner tube is coupled. A part of the piston member protrudes to the outside of the body.

The piston sliding on the inside of the inner tube, which is a component of the piston member, divides the inner space of the inner tube as it slides inside the inner tube.

In the following description, the spaces defined by the pistons among the inner spaces of the generally cylindrical inner tubes are referred to as a first fluid storage space and a second fluid storage space, respectively. Particularly, a space formed in front of the piston in which the volume gradually decreases as the piston member is pressed is used as a first fluid storage space, and a space formed behind the piston is referred to as a second fluid storage space. Further, an orifice for communicating the first fluid storage space and the second fluid storage space with the outside is formed on the outer circumferential surface of the inner tube. At least one of the orifices is formed at the front end and the rear end of the space in which the piston reciprocates.

The body has an inner space into which the outer peripheral surface of the inner tube is inserted while being in contact therewith. In addition, on the inner circumferential surface of the body, a longitudinal groove communicating the first fluid storage space and the second fluid storage space is formed. Accordingly, the fluid in the first fluid storage space flows into the second fluid storage space via the respective orifices and the longitudinal grooves formed in the inner tube according to the reciprocating movement of the piston, or conversely, the fluid in the second fluid storage space flows into the first fluid storage space .

One of the features of the present invention is that the amount of flow that moves from the first fluid storage space to the second fluid storage space can be finely adjusted by being pushed by the piston according to the pressure of the piston. This is accomplished by adjusting the size of the cross-sectional area of the first fluid storage space, the orifices of the first fluid storage space, the longitudinal grooves, the orifices of the second fluid storage space, and the series of flow passages formed by the second fluid storage space.

Specifically, the present invention enables the flow rate to be changed by physically adjusting the size of the cross-sectional area of the flow path of the connection portion between the orifice and the longitudinal groove of the first fluid storage space. Such a change in flow rate eventually results in a different degree of attenuation of the impact quantity. As a result, the cross-sectional area of the orifice and the longitudinal groove connecting portion of the first fluid storage space is minutely changed, so that the damping performance of the buffer can be finely adjusted.

The adjustment of the cross-sectional area of the orifice and the longitudinal groove connecting portion of the first fluid storage space is made by the rotation angle of the inner tube with respect to the body. The orifice formed in the inner tube is formed as a through hole having a circular cross section, and a channel groove communicated with the orifice is formed along the circumferential direction on the outer circumference of the inner tube. In addition, the cross-sectional area of the flow grooves is varied along the circumferential direction, so that the cross-sectional area of the flow passages varies depending on the position of the flow grooves that are aligned with the longitudinal grooves opened toward the outer peripheral surface of the inner tube.

At this time, the cross-sectional area of the flow path may be changed by the change of the area of the flow path groove itself or by the change of the area of the flow path that is communicated with the length groove. Furthermore, the area change of the channel groove itself and the area change of the channel groove communicated with the length groove are sequentially performed, thereby changing the cross-sectional area of the channel.

Another feature of the present invention resides in the ease of processing of such a buffer. In general, it is easier to process the outer circumferential surface of the cylindrical member than to form a groove in the inner space of the cylindrical member, due to the ease of access of the tool in cutting or polishing. The longitudinal grooves formed in the inside of the body are processed in a simple linear shape along the longitudinal direction of the body, so that there is no great difficulty in processing. Further, the orifice and the flow path groove are formed by machining the outer peripheral surface of the inner tube. That is, even if the depth and width of the flow channel are gradually changed, positioning of the machining member and the machining tool can be easily performed. Therefore, machining difficulty is reduced compared to machining the inside of the cylinder. As a result, the ease of fabrication leads to an improvement in productivity, a reduction in manufacturing cost, and an increase in machining accuracy, thereby reducing defective products and improving operational reliability of the final shock absorber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration, function and operation of a shock absorber according to an embodiment of the present invention will be described with reference to the accompanying drawings. However, the drawing numbers for similar or identical components are used in unison. Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Referring to FIG. 1, the shock absorber 10 according to the embodiment of the present invention has a body 1, a piston member 3, and a dial 4. The body 1 can be changed into various shapes such as a cylindrical shape and a hexahedron shape. A sealable space such as a cylinder is formed in the inside of the body.

A piston member (3) is coupled to one end of the body (1). In the figure, the piston member 3 is tensioned at one end of the body 1, and this state is in a general use state. As will be described later, the end of the projected piston member 3 becomes an input end through which impact, vibration, and the like are transmitted.

On the other hand, on the other end of the body 1, a dial 4 is rotatably mounted. The outer peripheral surface of the dial 4 is knurled so that it can be easily grasped by the user. Further, on the surfaces of the body 1 and the dial 4, instruction means for indicating the degree of rotation of the dial is provided. This indicating means can be formed through various configurations or methods such as printing, stickers, embossing, and the like.

2 to 4 show the cross section of the shock absorber, each component.

First, a cylindrical space 11 is formed in the body 1. On the inner circumferential surface of the cylindrical space 11, a longitudinal groove 12 is formed in the longitudinal direction of the cylindrical space 11, that is, in accordance with the movement direction of the piston member. In Fig. 3, the body and length groove 12 are schematically shown. The longitudinal grooves 12 are formed to have a predetermined width along the longitudinal direction of the body. However, the longitudinal grooves may be formed eccentrically in the circumferential direction of the cylindrical space, having a longitudinal length along the longitudinal direction of the body from the inner circumferential surface of the cylindrical space, as shown.

In addition, although not shown, a fluid movement groove may be formed in the cylindrical space of the body and connected to the longitudinal groove and formed in a circumferential direction. The fluid moving groove is communicated with a return hole of an inner tube to be described later, and connects the length groove and the return hole regardless of the rotational angle change of the inner tube with respect to the body.

The inner tube 2 and the piston member 3 are mounted in the cylindrical space 11 and the structure 14 further equipped with an accumulator 13 and a sealing member is further inserted and fixed in the cylindrical space 11 . Particularly, a hole through which the piston rod 32 passes is formed in the structure 14, and an o-ring or the like sealing means for preventing leakage of the fluid is provided in the hole.

Further, the structure 14 prevents the inner tube 2 and the accumulator 13 from being separated from the body.

At this time, the body 1 is formed with the latching groove 16 and the structure 14 is coupled to the body 1 while the C-ring 27 coupled to the outer peripheral surface of the structure 14 is inserted into the latching groove . That is, the C-ring 27 caught in the engagement groove 16 prevents the inner tube 2, the accumulator 13, and the structure 14 from escaping from the body 1.

The C-ring 27 replaces the structure in which the structure is screwed to the body in the prior art. The screw connection of the structure and the body according to the conventional art may loosen the screw connection of the structure due to the repeated vibration during the long use period, but the C ring 27 according to the present application solves this problem. Also, the assembly of the structure by the C ring 27 can be carried out very easily and quickly.

The other end of the body 1, which is opened at one end to insert the inner tube 2 and the structure 14, is integrally formed with a step portion 15 for reducing the inner diameter of the cylindrical space. As the step portion 15 is formed integrally with the other portion of the body as described above, a separate cap member for narrowing the hole at the other end is not required. Accordingly, it is possible to reduce the labor and cost of separately forming the cap member, and it is possible to omit the process of assembling the cap member and the body.

The inner tube 2 is a cylindrical member having a cylindrical space 11 and an outer peripheral surface in contact with each other. One end of the inner tube 2 is opened for insertion of the piston 31 and the other end thereof is closed. The inner tube 2 has an outer circumferential surface at the other end which is formed with a stopper 25 in a stepped manner and the inner tube 2 is rotatable with respect to the body 1 Lt; / RTI >

The inner tube 2 is formed with a protruding portion 21 protruding to the outside through the body 1 narrowed by the step portion 15. That is, when the inner tube 2 is inserted into the cylindrical space, the protruding portion 21 protrudes from the other end of the body 1, and the dial 4 is engaged with the protruded portion. The dial (4) is firmly fixed to the projection (21) by a tongue screw.

On the other hand, an injection hole 211 is formed in the projecting portion 21 along the longitudinal direction of the inner tube 2. The injection hole 211 is in communication with the extension hole 212 formed in the inner tube 2. At this time, the elongated hole 212 is formed in the radial direction of the inner tube 2. Further, the extension hole 212 communicates with the cylindrical space of the body 1. The injection hole 211 and the extension hole 212 are used as a flow path for injecting fluid for operation. After the injection of the fluid is completed, the injection hole 211 is sealed by generally known means.

In the prior art, the injection hole formed in the longitudinal direction of the inner tube communicates with the inner space of the inner tube. This causes the fluid pressurized by the piston to be pushed to the injection hole in using the shock absorber after the fluid for operation is injected. Therefore, the fluid in the injection hole having a high pressure may leak to the outside.

However, in the present invention, even if the fluid is pressurized by the piston 31 by the extension hole 212 formed in the radial direction of the inner tube 2, the pressing force of the piston 31 bypasses the extension hole 212, ). The flow path bypassed in this way does not affect the injection hole 211 directly by the pressing force of the piston 31, so that leakage of the fluid in the injection hole 211 can be minimized.

On the other hand, as the cylindrical space 11 and the inner tube 2 have a circular cross-section, the inner tube 2 can rotate with respect to the body 1 when the dial is rotated. At this time, the outer circumferential surface of the inner tube 2 is in contact with the inner circumferential surface of the body 1 except for the open portion of the longitudinal groove 12.

On the other hand, in the inner tube 2, an operation space 24 filled with a fluid is formed. Although not necessarily, the working space 24 is circular in cross section. The piston 31 is slidably coupled to the working space and the working space 24 is divided by the piston 31 into the first fluid storage space 241 and the second fluid storage space 242 described above.

The inner tube 2 is provided with a plurality of orifices 22 communicating with the working space 24. In the drawing, four orifices 22 and return holes 28 are formed. The number of the orifices 22 and the number of the return holes 28 are set such that at least one orifice communicating with the first fluid storage space 241 and one return hole communicating with the second fluid storage space 242 But is not limited to that number.

If the inner tube 2 is rotated (see FIG. 2) so that the orifice 22 meets the longitudinal groove 12, the first fluid storage space 241, the longitudinal groove 12, (242) communicate with each other. When the piston member 3 is moved into the inner tube 2 and the piston 31 presses the first fluid storage space 241, the fluid is moved to the longitudinal groove 12 via the orifice 22 , The fluid in the longitudinal groove 12 is moved to the second fluid storage space 242 via the return hole 28. [ At this time, regardless of the rotation angle of the inner tube, the space of the longitudinal groove 12 and the accumulator 13 are communicated with each other.

4 to 6, a flow channel 23 communicating with the orifice 22 and recessed along the circumferential direction of the inner tube 2 is formed on the outer peripheral surface of the inner tube 2 .

In the embodiment of the present invention, the flow path groove 23 starts at the orifice 22. One side of the outer circumferential surface of the orifice (22) is cut off and communicated with the orifice (22). Thus, the fluid that has passed through the orifice (22) can flow into the flow path groove (23). Although not shown, the connection between the orifice and the channel groove may be the middle portion of the channel groove.

In the meantime, although the channel grooves 23 have a rectangular cross section including a bottom surface 231 and both side surfaces 232 in the figure, the cross-section may be variously changed in the shape of an alphabet letter U, a semicircle, or the like.

The flow path groove 23 has a constant width and increases as the bottom surface 231 moves away from the orifice 22, that is, along the outer peripheral surface of the inner tube 2, 23 gradually decreases gradually.

The flow grooves 23 are formed in the range of 60 to 350 degrees along the circumferential direction of the inner tube 2 at the center of the circular cross section of the working space 24. [

If the angle formed between the beginning and the end of the flow path groove 23 is less than 60 degrees, the change in the cross-sectional area of the flow path controlled by the flow path groove 23 is too rapid.

When the angle exceeds 350 degrees, the end of the flow path groove 23 becomes too close to the orifice 22 so that the end of the flow path groove 23 and a part of the orifice 22 can be simultaneously So that it is difficult to accurately set the flow rate. As the angle becomes 60 degrees or more, it is possible to smoothly expand the cross-section of the flow path, thereby finely controlling the flow rate effectively.

In the present invention, the flow path groove 23 is not formed as a hole, so that the outer circumferential surface of the inner tube 2 can be almost used as described above. If the channel groove is formed into a gradually narrowed hole, the hole cut along the circumferential direction directly affects the structural rigidity of the inner tube, so that the angle of the hole formed along the circumferential direction of the inner tube from the center of the working space is considerably large It is bound to be limited. However, according to the present invention, there is no fear of deterioration of the structural rigidity of the inner tube by forming the groove, and the length of the flow channel can be made sufficiently long along the outer peripheral surface of the inner tube.

The piston member 3 includes a piston 31 slidably mounted in the inner tube 2, a piston rod 32 having one end connected to the piston, and a bumper head 33 mounted on the other end of the piston rod . The bumper head 33 may be surrounded by an elastic rubber or the like.

Referring to FIG. 2, when the impact applied to the piston 31 is released and the piston member 3 returns to the position protruding from the original body 1, the fluid staying in the second fluid storage space 242 is quickly To the first fluid storage space (241). The valve means 34 may comprise a sphere 342 which opens or closes the passage 341 formed in the interior of the piston according to the direction of movement of the fluid. Such valve means 34 can be replaced with various other known configurations.

In addition, a coil spring 5 is further provided at the front end of the piston 31. The coil spring 5 is interposed between the inner wall of the inner tube 2 and the piston 31 to push the piston 31 at all times. That is, when the piston member is contracted to the inside of the inner tube by the external force, and then the external force is released, the coil spring returns the piston member to the original protruded position.

2 and 4, a plurality of orifices 22 are formed so as to be gradually closed by a piston 31 moving by an external force. That is, at the beginning of operation of the shock absorber, the fluid staying in the first fluid storage space 241 is discharged into the longitudinal grooves 12 through the orifices 22 as the piston 31 moves. That is, since the cross-sectional area of the fluid that escapes from the first fluid storage space 241 is increased by the number of the orifices 22, a weak damper performance is exhibited at the initial stage of the impact. This is important in that when the buffer is used to reduce the speed of the mass, the shrinkage of the buffer rapidly in response to the initial velocity of the mass.

As the piston 31 further advances into the interior of the inner tube 2, that is, into the working space 24, some orifices are obscured by the outer peripheral surface of the piston 31. As a result, the area of the passage through which the fluid exits from the first fluid storage space 241 into the longitudinal groove 12 is reduced by the obturated orifice. This reduction in flow rate increases the damping performance of the buffer.

At the initial stage of the impact transmitted by the orifices 22 formed so as to be spaced apart from each other, a weak attenuation is achieved, and further, the attenuating performance as the piston member moves further can be obtained. The increase in attenuation performance over such a multistage system is a major factor in speed reduction of a mass having brittleness.

On the other hand, the cross-sectional area of the orifices 22 is made smaller as the distance from the second fluid storage space 242 increases, so that the damping performance of the buffer can be increased. It disperses or absorbs the energy of a moving object at a constant rate while reducing the reaction force transmitted to the mass by the buffer when the speed of a mass object is reduced.

Hereinafter, the operation according to the embodiment of the present invention will be described with reference to FIGS. 7 to 10. FIG. However, in Figs. 7 and 9, the thicknesses of the inner tube 2 and the body 1 are exaggerated. 8 and 9, only the longitudinal grooves 12 are shown in which the inner tube 22 is opened and the flow grooves 23 and the flow grooves 23 meet.

7 and 8 show the same usage state of the present invention.

7, the inner tube 2 is rotated with respect to the body 1 by rotating the dial. The orifice 22 of the inner tube 2 is blocked by the inner circumferential surface of the body 1. However, the flow path groove 23 is formed by the inner circumferential surface of the body 1. The fluid staying in the first fluid storage space 241 passes through the orifice 22 and the flow path groove 23 in turn and flows into the longitudinal groove 12 as the piston is pressed. The fluid which has entered the longitudinal grooves (12) then flows into the second fluid storage space (242). At this time, some of the fluid in the longitudinal grooves 12 may be received in the accumulator 13.

8 shows a flow path. The longitudinal grooves 12 are perpendicular to the longitudinal direction of the flow grooves 23. The flow path groove 23 is moved in the longitudinal direction of the flow path groove 23 in accordance with the rotation of the inner tube 2 in a state where the position of the long groove 12 is fixed. Referring to the drawing, the fluid introduced through the orifice 22 passes through the vertical section V formed at the point of the flow path groove 23 which meets the longitudinal groove 12. If the width of the horizontal section H formed by the width of the longitudinal grooves 12 and the width of the channel grooves 23 is greater than the width of the vertical section V, Sectional area between the first fluid storage space and the second fluid storage space. Therefore, the vertical cross section (V) is a bottleneck of the fluid flow, which limits the total flow rate.

9 and 10 are diagrams for different use states.

The inner tube 2 further rotates counterclockwise with respect to the body 1 and communicates with the longitudinal groove 12 near the end of the flow path groove 23 as shown in Fig. The fluid in the first fluid storage space 241 flows through the orifices 22 and the flow grooves 23 and flows into the longitudinal grooves 12 by the pressure of the piston.

Fig. 10 shows the relationship between the longitudinal grooves 12 and the flow grooves 23 in this case. And is moved in the direction perpendicular to the longitudinal grooves 12 in accordance with the further rotation of the inner tube. The area of the vertical section V formed vertically at the point of the flow path groove 23 that meets the longitudinal groove 12 is greatly reduced because the bottom surface 231 is elevated as compared with FIG. Therefore, the flow rate passing through the reduced vertical section (V) is reduced, and the damping performance of the buffer is increased.

11 is a view showing a shock absorber according to another embodiment of the present invention. FIG. 11 schematically shows the orifices, the flow grooves and the longitudinal grooves. For ease of understanding, the inner grooves are virtually unfolded by the inner grooves.

The shock absorber according to another embodiment of the present invention includes a body, an inner tube, and a piston member, and the structure and operation thereof are the same as those in the above-described embodiment to the extent that they do not conflict with the contents described below, And includes the technical features shown in Figs. 1 to 10.

According to another embodiment of the present invention, both side surfaces 232 of the flow path groove 23 formed in the inner tube are closer to each other as the distance from the orifice 22 increases, so that the cross-sectional area of the flow path groove 23 gradually decreases. When the length groove 12 is positioned close to the orifice 22 in the drawing, the flow path is formed through the orifice through the area of the cross section vertically formed at one point P1 of the flow path groove 23, The flow rate of the fluid is limited.

In the case where the orifice 22 and the long groove 12 shown in the same drawing are positioned together, the area of the cross section perpendicularly formed at two points P2 of the flow grooves 23, which meet with the longitudinal groove 12, The flow rate is limited.

As described above, according to another embodiment of the present invention, the cross-sectional area gradually decreases as the side surfaces forming the flow path are moved closer to each other and further away from the orifice. This is similar to the above-described embodiment in that the attenuation performance is gradually increased.

In another embodiment of the present invention, the degree of processing differs from the above-described embodiment. In the above-described embodiment, since the bottom surface is to be gradually raised, the bottom surface must be eccentric in forming the channel groove in the cylindrical inner tube. However, in another embodiment, the depth of the bottom surface is constant, and instead, both sides need to be machined into an inclined surface so as to be closer to each other.

In addition, the shape of the channel groove, which gradually becomes smaller as the width of the vertical cross section of the channel groove is away from the orifice, can be achieved by simultaneously raising the bottom surface and proximity of both sides.

12 shows an inner tube employed in a shock absorber according to another embodiment of the present invention.

A shock absorber according to another embodiment of the present invention includes a body, an inner tube, and a piston. Since the structure and operation of the body and the piston are the same as those of the above-described embodiment, a duplicate description will be omitted. Further, the inner tube has the technical characteristics of the inner tube of the above-described embodiments as it is, as long as it does not conflict with the following description.

A plurality of orifices 22 communicating with an internal working space are formed in the inner tube 2 according to another embodiment and a flow path groove 23 communicating with a plurality of orifices 22 is formed in the inner tube 2. [ As shown in Fig.

Concretely, one end of the bottom surface 231 of the flow path groove 23 communicates with the orifices 22. At this time, the flow path groove 23 is formed to have a width including all of the orifices. So that the orifices 22 communicate with the bottom surface 231 of the single flow path groove 23. Alternatively, some of the orifices 22 may be configured to communicate with the bottom of the single flow path groove 23.

Further, the flow path groove 23 is recessed along the circumferential direction of the inner tube 2. The flow grooves can be formed in the range of 60 to 350 degrees along the circumferential direction of the inner tube at the center of the circular cross section of the working space as in the above-described embodiment.

The recess depth of the flow path groove 23 gradually becomes shallower along the circumferential direction of the inner tube 2 at the one end of the bottom surface 231 communicating with the orifices 22 from the orifices 22.

As a result, the fluid introduced into the orifice in the state where the inner tube is rotated with respect to the body is moved to the longitudinal groove of the body after passing through the narrow channel formed by the bottom surface of the flow path groove and the inner circumferential surface of the body. By adjusting the rotation angle of the inner tube, the size of the cross-sectional area of the channel is adjusted, and the length from the orifice to the length groove is changed to adjust the flow rate of the fluid, thereby controlling the attenuation performance of the buffer.

The inner tube according to another embodiment of the present invention can form a single flow path groove, which has an advantage that the processing convenience of the inner tube is increased.

Although not shown, a part of the orifices of each of the plurality of orifices may have an individual channel groove for each orifice, and a channel groove may be formed for the remaining orifices. These flow grooves can be designed so that the flow rate of the fluid can be controlled through the gradual rise of the bottom surface or the adjustment of the sidewall distance as in the above-described embodiments.

10: Shock absorber
1: Body
11: cylindrical space 12: longitudinal groove 13: accumulator
14: structure 15: step portion 16:
2: Inner tube
21: protrusion 211: injection hole 212: extension hole
22: Orifice 23: Euro groove
231: bottom surface 232: side surface 24: working space
241: first fluid storage space 242: second fluid storage space
25: engaging portion 27: C-ring 28: return hole
3: piston member
31: piston 32: piston rod 33: bumper head
34: valve means 341: passage 342: sphere
4: dial 5: coil spring
V: Vertical section H: Horizontal section

Claims (4)

piston,
An inner tube having a first fluid storage space and a second fluid storage space defined by the piston at the front and rear of the piston, the volume of which is changed by the movement of the piston,
Wherein the inner tube is in contact with the inner circumferential surface and has a longitudinal groove connecting the first fluid storage space and the second fluid storage space,
Lt; / RTI >
A plurality of flow grooves respectively connected to the first fluid storage space or the plurality of orifices connected to the second fluid storage space are formed on the outer circumferential surface of the inner tube and the plurality of flow grooves are arranged with a gap therebetween Sectional area along the circumferential direction of the inner tube, and a specific portion of the flow path groove can face the longitudinal groove according to the rotation of the inner tube with respect to the body, As the specific part of the groove is changed, the buffering force is adjusted
buffer. The method of claim 1,
The flow path groove is formed such that the depth of the bottom surface gradually increases along the circumferential surface of the inner tube so that the sectional area becomes gradually smaller or both sides forming the flow path groove become closer to each other as the distance from the orifice becomes smaller, buffer. The method of claim 1,
Wherein the inner tube is provided with an injection hole along the longitudinal direction of the inner tube and the injection hole is in communication with an extension hole formed in the radial direction of the inner tube. The method of claim 1,
A C-ring coupled to an outer circumferential surface of a structure to be inserted into the opened body is inserted into the engaging groove, and the detachment of the inner tube inserted into the body Buffer prevented.

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