A VARIABLE DAMPING SHOCK ABSORBER

Abstract

A variable damping shock absorber has a sleeve and a piston rod, one end of the sleeve being an opening and the other end being closed, one end of the piston rod being inserted through the opening and slidable in an axial direction inside the sleeve. Two sets of friction plates are arranged in the axial direction between an inner wall of the sleeve and an outer wall of the piston rod. A friction plate is fixed in the axial direction with the inner wall of the sleeve, and a sliding friction force between each friction plate set and the outer wall of the piston rod gradually decreases from the closed end to the opening end of the sleeve. The structure can ensure that the damping force is variable under different load and rotational speed conditions.

Claims

1. A variable damping shock absorber, comprising a sleeve and a piston rod, one end of the sleeve being an opening and the other end being closed, one end of the piston rod being inserted into through the opening and being slideably provided in an axial direction inside the sleeve, wherein: at least two sets of friction plates are arranged in the axial direction between an inner wall of the sleeve and an outer wall of the piston rod, the friction plates are fixed in the axial direction on the inner wall of the sleeve, and a sliding friction force between each friction plate set and the outer wall of the piston rod is different.

2. The variable damping shock absorber according to claim 1, wherein: the sliding friction force between the friction plates and the outer wall of the piston rod is gradually reduced from a closed end to an open end of the sleeve.

3. The variable damping shock absorber according to claim 1, wherein: each set of the friction plates has a same thickness in a radial direction of the sleeve and has a different friction coefficient of a surface of one side which is in contact with the outer wall of the piston rod, and the friction coefficient decreases from the closed end to the open end of the sleeve.

4. The variable damping shock absorber according to claim 1, wherein: each set of friction plates are of a same material, and thicknesses of the friction plates in a radial direction of the sleeve are different, and the thicknesses of each set of friction plates decrease from the closed end to the open end of the sleeve.

5. The variable damping shock absorber according to claim 1, wherein: the friction plates are cylindrical structure, and a chamfered guide structure for facilitating an insertion of the piston rod is provided at an end corresponding to the opening of the sleeve.

6. The variable damping shock absorber according to claim 1, wherein: a head of the end inserted into the sleeve of the piston rod is provided with a truncated cone shaped guide structure which is easily passed through the friction plates.

7. A variable damping shock absorber, comprising a sleeve and a piston rod, one end of the sleeve being an opening, the other end being closed, one end of the piston rod is inserted into through the opening and is slideably provided in an axial direction inside the sleeve, wherein: one set of friction plates is arranged between an inner wall of the sleeve and an outer wall of the piston rod, the friction plates are fixed in the axial direction on the inner wall of the sleeve, and is in contact with the outer wall of the piston rod and relatively slides to each other, when the piston rod is slid towards the opening, a friction force between the piston rod and the friction plate along an axial direction of the piston rod is gradually reduced.

8. The variable damping shock absorber according to claim 7, wherein: a friction coefficient of an outer surface of the piston rod is gradually increased from one end inserted into the sleeve to the other end.

9. The variable damping shock absorber according to claim 7, wherein: a diameter of the piston rod is gradually increased from one end inserted into the sleeve to the other end, and the piston rod is a truncated cone shaped structure.

10. The variable damping shock absorber according to claim 7, wherein: the piston rod is a cylindrical structure, the friction plate is a cylindrical structure affixed to the inner wall of the sleeve, a thickness of the friction plate is gradually reduced from a closed end to an opening end of the sleeve.

11. The variable damping shock absorber according to claim 2, wherein: each set of the friction plates has a same thickness in a radial direction of the sleeve and has a different friction coefficient of a surface of one side which is in contact with the outer wall of the piston rod, and the friction coefficient decreases from the closed end to the open end of the sleeve.

12. The variable damping shock absorber according to claim 2, wherein: each set of friction plates are of a same material, and thicknesses of the friction plates in a radial direction of the sleeve are different, and the thicknesses of each set of friction plates decrease from the closed end to the open end of the sleeve.

13. The variable damping shock absorber according to claim 5, wherein: a head of the end inserted into the sleeve of the piston rod is provided with a truncated cone shaped guide structure which is easily passed through the friction plates.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 is a front sectional view of a prior art washing machine;

[0033] FIG. 2 is a longitudinal sectional view of a prior art shock absorber;

[0034] FIG. 3 is a schema is diagram of a shock absorber of the present disclosure;

[0035] FIG. 4 and FIG. 5 are longitudinal sectional views of different structures of the sleeve of the shock absorber of the present disclosure, respectively;

[0036] FIG. 6 is a schematic diagram of a structure of the piston rod of the shock absorber of the present disclosure;

[0037] FIG. 7, FIG. 8 and FIG. 9 are longitudinal sectional views of different structures of the shock absorber of the present disclosure;

[0038] FIG. 10 is a schematic diagram of another structure of the piston rod of the shock absorber of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0039] Embodiments of the present disclosure will now be described in further detail with reference to the accompanying drawings.

Embodiment 1

[0040] As shown in from FIG. 3 to FIG. 5, a variable damping shock absorber 1 of the present disclosure comprises a sleeve 2 and a piston rod 3, one end of the sleeve 2 is an opening and the other end is closed. One end of the piston rod 3 is inserted into through the opening and is slideable in an axial direction inside the sleeve 2. At least two sets of friction plates 4 are arranged in an axial direction of the sleeve 2 between an inner wall and an outer wall of the piston rod 3, the friction plates 4 is fixed in the axial direction of the sleeve 2 with the inner wall of the sleeve 2, and the sliding friction force between each set of the friction plates 4 and the outer wall of the piston rod 3 is gradually reduced from a closed end to an open end of the sleeve 2.

Embodiment 2

[0041] As shown in FIG. 4, the sleeve 2 of the present embodiment is provided with three sets of friction plates 4 which are respectively a first friction plate 41 provided at an inner wall of the opening end of the sleeve, a second friction plate 42 provided at a middle part of the sleeve and a third friction plate 43 provided near the closed end of the sleeve. The three sets of friction plates 41, 42, 43 have the same thickness in the radial direction of the sleeve 2 and have different friction coefficients of the surfaces in contact with the outer wall of the piston rod 3, and the friction coefficients decrease from the closed end to the opening end of the sleeve 2. That is, the friction coefficients of the surfaces of the third friction plate 43, the second friction plate 42, and the first friction plate 41 in contact with the outer wall of the piston rod 3 get smaller in turn. The friction plates are arranged like this so that the sliding friction force between the piston rod and the friction plate gradually increases from the opening end to the closed end of the sleeve.

[0042] Since the length of the piston rod 3 in the sleeve 2 is larger during washing, the third friction plate 43 having a larger friction coefficient comes into contact with the piston rod 3, and the pressure between the third friction plate 43 and the piston rod 3 is larger, so the damping force is larger. When the drainage process is completed, the water in the washing bucket is drained away and the washing bucket assembly continually moves up. The third friction rod 43 is no longer in contact with the piston rod 3, the sliding friction force between the second friction plate 42 and the piston rod 3 is the damping force of the shock absorber at this time. As the progress of the dewatering, the water contained in the laundry in the washing bucket gradually decrease and the second friction plate 42 is no longer in contact with the piston rod 3, only the first friction plate 41 at the opening end of the sleeve is in contact with the piston rod, and the pressure between the friction plate and the piston rod is smaller and the damping force reduces. Of course, due to the impact of factors such as amount of clothing, clothing water absorption, clothing eccentric distribution and rotation speed, in the low-speed dewatering process, the stroke of the piston rod in the sleeve changes greatly. Therefore, there is also possible that the sliding friction force between the third friction plate 43 and the piston rod 3, the sliding friction force between the second friction plate 42 and the piston rod 3, the sliding friction force between the first friction plate 41 and the piston rod 3 act respectively as the damping force, that is the damping force changing frequently.

Embodiment 3

[0043] As shown in FIG. 5, the different between the present embodiment and the embodiment 2 is: the three sets of friction plates 41, 42, 43 are of a same material, and the thicknesses of the friction plates in the radial direction of the sleeve 2 are different, and the thicknesses of three sets of friction plates decrease from the closed end to the open end of the sleeve 2. That is, the thicknesses of the third friction plate 43, the second friction plate 42 and the first friction plate 41 in the radial direction of the sleeve 2 decrease in turn. The arrangement of the friction plates can also cause the sliding friction force between the piston rod and the friction plate to gradually increase from the opening end to the closed end of the sleeve.

Embodiment 4

[0044] As shown in FIG. 5, the present embodiment is a further improvement on the basis of the embodiment 3. Because several sets of friction plates are provided and when every time the piston rod needs to pass the friction plate 4, such as the second friction plate 42 and the third friction plate 43, a chamfered guide structure 5 for facilitating an insertion of the piston rod 3 is provided at an end corresponding to the opening of the sleeve 2 in order to prevent the piston rod from properly inserting. The inner diameter of the friction plate 4 is expanded from the inside to the outside to guide the insertion of the piston rod 3. Alternately, a head of the end inserted into the sleeve 2 of the piston rod 3 is provided with a truncated cone shaped guide structure 6 which is easily passed through the friction plate 4 (see FIG. 6). The above two structures can be used alone or in combination.

Embodiment 5

[0045] As shown in from FIG. 7 to FIG. 9, the variable damping shock absorber 1 of the present disclosure comprising a sleeve 2 and a piston rod 3, one end of the sleeve 2 is an opening, the other end is closed. One end of the piston rod 3 is inserted into through the opening and is slideable in an axial direction inside the sleeve 2. One set of friction plates 4 is arranged at the opening end between an inner wall of the sleeve 2 and an outer wall of the piston rod 3. The friction plates 4 is fixed in the axial direction with the inner wall of the sleeve 2, and contacts with the outer wall of the piston rod 3 and relatively slides to each other. When the piston rod 3 is slid, a friction force between the piston rod 3 and the friction plate 4 along the axial direction of the piston rod is gradually reduced.

Embodiment 6

[0046] As shown in FIG. 7, the friction coefficient of the outer surface of the piston rod 3 is gradually increased from one end inserted into the sleeve 2 to the other end.

[0047] The scheme described above is to change the friction coefficient of the surface of the piston rod 3, and the position of the friction plate 4 is the same which is installed at the opening end of the sleeve 2 as the prior art. During the washing, the length of the piston rod 3 in the sleeve 2 is larger. One end of the piston rod 3 which has the larger friction coefficient of the surface is in contact with the friction plate 4 at the opening end of the sleeve 2, the pressure between the friction plate and the piston rod is larger and the damping force is larger. During the dewatering process, as the amount of water in the washing bucket decrease, the washing bucket assembly continually moves up, a length of the part of the piston rod 3 which is inside the sleeve 2 is getting shorter. The part of the piston rod with smaller surface friction coefficient is in contact with the friction plate 4, the pressure between the friction plate and the piston rod is smaller and the damping force is smaller. The scheme ensures that the damping force is variable regardless of the load and speed conditions, and the damping force changes more frequently especially during the low-speed dewatering process.

Embodiment 7

[0048] As shown in FIG. 8 and 10, the different between the present embodiment and the embodiment 6 is: a diameter of the piston rod 3 is gradually increased from one end inserted into the sleeve 2 to the other end, and the piston rod is a truncated cone shaped structure (see FIG. 10).

[0049] The scheme mentioned above is to change the shape of the structure of the piston rod 3. During the washing process, the length of the part of the piston rod 3 inside the sleeve 2 is larger and the part of the piston rod 3 with larger diameter size is in contact with the friction plate 4 at the opening end of the sleeve 2, the pressure between the two is larger and the damping force is larger. During the dewatering process, the washing bucket assembly continually moves up as the water amount in the washing bucket decrease. The part of the piston rod 3 inside the sleeve decreases and the part of the piston rod 3 with smaller diameter is in contact with the friction plate 4, the pressure between the two is smaller and the damping force is smaller, it gets along with the frequently changing damping force during the low-speed dewatering process as well.

Embodiment 8

[0050] As shown in FIG. 9, the present embodiment is different from embodiment 6 or embodiment 7 mentioned above. Although only one set of friction plate 4 is adopted in the present embodiment, the shape of the structure of the friction plate 4 is changed. The principle is the same as that of the embodiment 7 in which the shape of the structure of the piston rod 3 is changed. Specifically, the piston rod 3 is a cylindrical structure, the friction plate 4 is a cylindrical structure affixed to the inner wall of the sleeve 2, and a thickness of the friction plate 4 is gradually reduced from the closed end to the opening end of the sleeve 2. During the washing, a length of the piston rod 3 in the sleeve 2 is larger, the piston rod 3 squeezed by the thicker part of the friction plate 4 and the damping force is larger. During the dewatering process, as the amount of water in the washing bucket decreased, the washing bucket assembly continually moves up, and the piston rod 3 slides outwardly which moves out of the squeezing of the thicker part of the friction plate 4 and gradually contacts with the thinner part of the friction plate 4, the pressure between the friction plate and the piston rod is smaller and the damping three is smaller.

[0051] The embodiments of the above description are merely illustrative of the preferred embodiments of the present disclosure and are not intended to limit the scope and scope of the disclosure. It will be understood by those skilled in the art that various changes and modifications in the technical solutions of the present disclosure are within the scope of the present disclosure without departing from the design idea of the present disclosure.