CN118188637A

CN118188637A - Hydraulic piston

Info

Publication number: CN118188637A
Application number: CN202410329298.4A
Authority: CN
Inventors: 王佳新; 王红磊; 刘萌; 庄凤芝; 顾坚; 唐继响
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2024-03-21
Filing date: 2024-03-21
Publication date: 2024-06-14

Abstract

The invention belongs to the technical field of diesel engine common rail system experiments, and discloses a hydraulic piston. The piston comprises a piston rod, a piston cylinder and a piston head, wherein an inserting cavity is formed in the piston cylinder, the piston rod is inserted in the inserting cavity, the piston head is inserted at the other side of the inserting cavity, and an oil cavity is formed between the piston rod and the piston head in an enclosing mode; one end of the piston head is sleeved with a sealing component which is abutted with the inner wall of the inserting cavity; the first sealing member, the second sealing member and the third sealing member are mutually abutted and sleeved on the piston rod, the first sealing member is provided with an oil pipe along the moving direction of the piston rod, the second sealing member comprises a third sealing ring, one side of the third sealing ring is convexly provided with an inner lip and an outer lip, an annular lip groove is formed between the inner lip and the outer lip in a surrounding manner, and the lip groove is communicated with the oil cavity through the oil pipe; the problem that sealing capacity of a sealing element in a hydraulic piston can be rapidly reduced under the impact of high-pressure oil in the prior art is solved.

Description

Hydraulic piston

Technical Field

The invention relates to the technical field of diesel engine common rail system experiments, in particular to a hydraulic piston.

Background

In order to rapidly test the fatigue life of the common rail system under high-pressure impact, a hydraulic piston is required to provide the common rail system with ultrahigh-frequency hydraulic oil for high-low pressure switching. In fatigue test, the difference between the maximum circulation pressure and the minimum circulation pressure is large, the maximum pressure difference can reach 280MPa, and the working frequency is up to 15Hz, so that the piston rod needs to perform high-speed reciprocating motion to continuously provide hydraulic oil in the form of high frequency and high-low pressure.

In fatigue failure test, the hydraulic piston is required to provide and maintain high-pressure hydraulic oil, the piston rod needs to reciprocate in a piston cavity at a high speed, a sealing element is arranged on the piston rod, during the high-speed reciprocation, a lip groove between the side walls of the sealing element can expand and deform under the impact of the hydraulic oil, the diameter of the sealing element can be increased, irreversible deformation of the sealing element can occur under the high impact of oil, the sealing element can always be in high-pressure contact with the inner wall of the piston cavity, finally, the sealing element can be quickly worn under excessive contact, the sealing capability of the sealing element is reduced, the service life is shorter, and in addition, the sealing element is not easy to replace after the function of the sealing element is invalid; meanwhile, the common sealing element cannot meet the requirements of larger hydraulic oil quantity and higher bearing capacity.

Disclosure of Invention

The invention aims to provide a hydraulic piston, which solves the problem that the sealing capacity of a sealing element in the hydraulic piston can be rapidly reduced under the impact of high-pressure oil in the prior art.

To achieve the purpose, the invention adopts the following technical scheme: the invention provides a hydraulic piston, which comprises a piston rod, a piston cylinder and a piston head, wherein an inserting cavity is formed in the piston cylinder, the piston rod is inserted in the inserting cavity, the piston head is inserted at the other side of the inserting cavity, the piston rod slides back and forth along the axis of the inserting cavity, and an oil cavity is formed between the piston rod and the piston head;

One end of the piston head is sleeved with a sealing component, and the sealing component is abutted with the inner wall of the plug cavity; the sealing assembly comprises a first sealing member, a second sealing member and a third sealing member, wherein the first sealing member, the second sealing member and the third sealing member are mutually abutted and sleeved on the piston rod, the first sealing member is provided with an oil pipe along the moving direction of the piston rod, the second sealing member comprises a third sealing ring, one side of the third sealing ring is convexly provided with an inner lip and an outer lip, an annular lip groove is formed between the inner lip and the outer lip in a surrounding mode, the lip groove is communicated with the oil cavity through the oil pipe, the first sealing member is made of metal, the third sealing member is made of rubber, and the second sealing member is made of metal.

Preferably, the first sealing member includes a first sealing ring, a groove is formed at the front end of the piston rod, a protruding portion is formed at an inner ring of the first sealing ring, the protruding portion is embedded in the groove, a first oil hole is circumferentially formed in the first sealing ring, and the first oil hole communicates the lip groove with the oil cavity.

Preferably, the first sealing member further comprises a second sealing ring, the second sealing ring is installed between the first sealing ring and the third sealing ring, a second oil hole is formed in the second sealing ring, one end of the second oil hole is communicated with the first oil hole, and the other end of the second oil hole is communicated with the lip groove.

Preferably, the second oil holes comprise six groups, the second oil holes are distributed in the circumferential direction along the axis of the second sealing ring at equal intervals, and the first oil holes are in one-to-one correspondence with the second oil holes.

Preferably, the second sealing member further includes a fourth sealing ring, the fourth sealing ring abuts against the third sealing ring, and the fourth sealing ring has elasticity greater than that of the third sealing ring.

Preferably, the third sealing member includes a fifth sealing ring and a sixth sealing ring, the fifth sealing ring is mounted between the fourth sealing ring and the sixth sealing ring, and the sixth sealing ring abuts against the piston rod.

Preferably, the contact surface between the fifth sealing ring and the sixth sealing ring is an annular conical surface.

Preferably, the sixth sealing ring is contacted with the piston rod through an annular conical surface.

Preferably, the first sealing ring comprises two groups of splicing parts, the splicing parts are semicircular, and the splicing parts enclose the first sealing ring.

Preferably, the hardness of the first sealing member, the second sealing member and the third sealing member is lower than the hardness of the piston rod.

The beneficial effects are that: the first sealing member, the second sealing member and the third sealing member can reciprocate along with the piston rod, oil enters the lip groove through the oil pipe when in pressurization, the third sealing ring can not be directly impacted by high-pressure oil in the oil cavity, after the oil pipe throttles, the third sealing member enters the lip groove, the impact on the lip groove is reduced, the inner lip of the third sealing ring is contracted inwards to seal with the piston rod, the outer lip is expanded outwards, the radial gap of the position of the third sealing member is eliminated, the sealing capability of the sealing assembly is improved, meanwhile, oil flows to one side of the oil cavity along the oil pipe when in pressure relief, the inner lip and the outer lip are restored to be original shapes, the abrasion of the third sealing ring is reduced, and the service life of the sealing assembly is prolonged.

Drawings

FIG. 1 is an enlarged cross-sectional view of a seal assembly of the present invention;

FIG. 2 is a cross-sectional view of a hydraulic piston body of the present invention;

FIG. 3 is a main view of a splice of the present invention;

FIG. 4 is a main view of a second seal ring of the present invention;

FIG. 5 is a main view of a third seal ring of the present invention;

FIG. 6 is a main view of a fourth seal ring according to the present invention;

FIG. 7 is a main view of a fifth seal ring of the present invention;

fig. 8 is a main view of a sixth seal ring according to the present invention.

In the figure: 1. a first seal ring; 11. a first oil hole; 12. a splice; 13. a boss; 2. a second seal ring; 21. a second oil hole; 3. a third seal ring; 31. an inner lip; 32. an outer lip; 33. a lip groove; 4. a fourth seal ring; 5. a fifth seal ring; 6. a sixth seal ring; 7. an oil cavity; 8. a piston rod; 9. a piston head; 10. a piston cylinder; 20. and (5) a conical surface.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

Under the prior art, cup joint the sealing member on the piston rod generally, when piston rod removes extrusion fluid, fluid will get into the lip inslot, fluid will make outer lip and interior lip take place to warp, lead to the edge of sealing member to contact with the inner wall in fluid chamber all the time, and because the impact strength of fluid is great, so will make the sealing member take place great deformation, and then will make the sealing member take place irreversible deformation, because the piston rod need be constantly carry out reciprocating motion, so can make the sealing member take place violent wearing and tearing, and then lead to the sealing member of wherein to lose efficacy gradually, the working life of sealing member has been shortened.

In order to solve the above problems, as shown in fig. 1 to 8, the present invention provides a hydraulic piston, which comprises a piston rod 8, a piston cylinder 10 and a piston head 9, wherein an insertion cavity is formed in the piston cylinder 10, the piston rod 8 is inserted into the insertion cavity, the piston head 9 is inserted into the other side of the insertion cavity, the piston rod 8 slides reciprocally along the axis of the insertion cavity, and an oil cavity 7 is enclosed between the piston rod 8 and the piston head 9; one end of the piston head 9 is sleeved with a sealing component which is abutted with the inner wall of the inserting cavity; the sealing assembly comprises a first sealing member, a second sealing member and a third sealing member, the first sealing member, the second sealing member and the third sealing member are mutually abutted and sleeved on the piston rod 8, the first sealing member is provided with an oil pipe along the moving direction of the piston rod 8, the second sealing member comprises a third sealing ring 3, an inner lip 31 and an outer lip 32 are formed on one side of the third sealing ring 3 in a protruding mode, an annular lip groove 33 is formed between the inner lip 31 and the outer lip 32 in a surrounding mode, the lip groove 33 is communicated with the oil cavity 7 through the oil pipe, the first sealing member and the third sealing member are made of metal, and the second sealing member is made of rubber.

The piston rod 8 of the invention is provided with three groups of sealing members, wherein the second sealing member is made of rubber material and mainly plays a role in sealing to provide a closed condition for the oil cavity 7, and the first sealing member and the third sealing member are made of metal material and are mainly used for reinforcing the second sealing member, so that the second sealing member can maintain the original shape under the impact of high-pressure oil.

When the pressure is applied, the piston rod 8 moves towards the inside of the inserting cavity, the volume of the oil cavity 7 is reduced, meanwhile, oil enters the lip groove 33 along the oil pipe, and due to the fact that the oil pipe, namely the passage formed by the first oil hole 11 and the second oil hole 21 is arranged, high-pressure oil slowly moves under the throttling of the oil pipe, after the oil enters the lip groove 33, the impact force of the oil received by the third sealing ring 3 is reduced, irreversible deformation of the third sealing ring 3 under the impact of the oil is avoided, the inner lip 31 in the third sealing ring 3 still contracts towards the axis side, and meanwhile, the outer lip 32 radially expands outwards, so that the sealing capacity of the third sealing ring 3 is improved.

When the pressure is relieved, the piston rod 8 moves reversely, the volume of the oil cavity 7 is increased, the air pressure of the oil cavity 7 is reduced, oil in the lip groove 33 is sucked into the oil cavity 7 along the oil pipe, the inner lip 31 and the outer lip 32 are restored to the normal shape, the compression degree of the third sealing ring 3 and the inner wall of the oil pipe is reduced, and further the loss of the third sealing ring 3 after friction with the oil cavity 7 is reduced, and the service life of the third sealing ring 3 is prolonged.

The first sealing component comprises a first sealing ring 1, a groove is formed at the front end of a piston rod 8, a protruding portion 13 is formed on the inner ring of the first sealing ring 1, the protruding portion 13 is embedded in the groove, a first oil hole 11 is formed in the circumferential direction of the first sealing ring 1, and the lip groove 33 is communicated with the oil cavity 7 through the first oil hole 11.

The first sealing ring 1 is directly contacted with the oil in the oil cavity 7, so that in order to ensure the strength of the sealing assembly, the first sealing ring 1 is made of metal with highest strength and can bear the impact of hydraulic oil, the first sealing ring 1 is fixed on the piston rod 8 through the bulge 13 of the inner ring, the other sealing rings are prevented from moving back and forth under the impact of the oil, the sealing capability of the sealing assembly is improved, the first sealing ring 1 is provided with the first oil hole 11, the oil can move back and forth along the first oil hole 11, and the oil pressure balance between the lip groove 33 and the oil cavity 7 is realized.

The first sealing component of the invention further comprises a second sealing ring 2, the second sealing ring 2 is arranged between the first sealing ring 1 and the third sealing ring 3, a second oil hole 21 is formed in the second sealing ring 2, one end of the second oil hole 21 is communicated with the first oil hole 11, and the other end of the second oil hole 21 is communicated with the lip groove 33.

The second oil hole 21 and the first oil hole 11 that set up on the second sealing washer 2 communicate, realize the oil pressure balance between lip groove 33 and the fluid chamber 7, simultaneously through first oil hole 11 and second oil hole 21 also be the fluid pipe, throttle the hydraulic oil that flows at a high speed, because first sealing washer 1 can directly receive the striking of hydraulic oil, first sealing washer 1 can carry out violent vibration, in order to avoid the direct first sealing washer 1 direct contact of the third sealing washer 3 of rubber material and high-speed vibration to take place great deformation, set up second sealing washer 2 as the buffering, avoid third sealing washer 3 to take place extrusion or wearing and tearing, the life of extension third sealing washer 3.

The second oil holes 21 of the invention comprise six groups, the second oil holes 21 are distributed in the circumferential direction along the axis of the second sealing ring 2 at equal intervals, and the first oil holes 11 are in one-to-one correspondence with the second oil holes 21. Therefore, oil can uniformly enter the lip groove 33 along the oil pipe, the oil entering the lip groove 33 is uniformly distributed, and meanwhile, the oil in the lip groove 33 can be completely sucked away in the process of pressure relief, so that the third sealing ring 3 can be quickly restored to an initial state, excessive contact between the third sealing ring 3 and the oil cavity 7 is avoided, and abrasion of the third sealing ring 3 is reduced.

The second sealing component further comprises a fourth sealing ring 4, the fourth sealing ring 4 is abutted against the third sealing ring 3, the elasticity of the fourth sealing ring 4 is larger than that of the third sealing ring 3, the piston rod 8 can cause relative displacement between six groups of sealing rings when in axial high-speed reciprocating motion, and an axial gap exists in the sealing component during operation. In order to avoid leakage, six groups of sealing rings are tightly combined together, and at the moment, an elastic piece is required to be subjected to controllable elastic deformation to eliminate axial gaps, so that the fourth sealing ring 4 is additionally arranged on one side of the third sealing ring 3, the lip groove 33 of the third sealing ring 3 can be continuously deformed, the gap caused by deformation of the third sealing ring 3 can be eliminated by the fourth sealing ring 4 which is made of soft materials, and the extrusion resistance and sealing capacity of the sealing assembly are improved.

The third sealing member comprises a fifth sealing ring 5 and a sixth sealing ring 6, the fifth sealing ring 5 is arranged between the fourth sealing ring 4 and the sixth sealing ring 6, and the sixth sealing ring 6 is abutted with the piston rod 8. The third sealing member can bind deformation of the fourth sealing ring 4, so that uncontrollable deformation of the fourth sealing ring 4 is avoided, and the probability of clamping stagnation of the piston rod 8 is reduced.

The contact surface between the fifth sealing ring 5 and the sixth sealing ring 6 is the annular conical surface 20, the coaxiality of the fifth sealing ring 5 and the sixth sealing ring 6 after being matched can be better through the annular conical surface 20, the axes of the fifth sealing ring 5 and the sixth sealing ring 6 are kept in a superposition state, the shaking degree of the sealing assembly is reduced, the sixth sealing ring 6 and the piston rod 8 are contacted through the annular conical surface 20, the axes of the sixth sealing ring 6 and the piston rod 8 are also enabled to be in a coaxial state, and meanwhile the contact area between the fifth sealing ring 5 and the sixth sealing ring 6 and the contact area between the sixth sealing ring 6 and the piston rod 8 are enabled to be larger, the pressure intensity is reduced, the compression resistance of the sealing assembly is enhanced, and the service life is prolonged.

The first sealing ring 1 comprises two groups of splicing parts 12, the splicing parts 12 are semicircular, the splicing parts 12 enclose the first sealing ring 1, six groups of sealing rings are mutually extruded after the first sealing ring 1 is assembled, the sealing capacity of a sealing assembly is improved, and meanwhile, the splicing parts 12 are convenient to detach after the third sealing ring 3 is worn, so that the maintenance difficulty is reduced.

The hardness of the first, second and third sealing members is lower than the hardness of the piston rod 8, avoiding scoring the piston rod 8 during assembly.

The abrasion of the third sealing ring 3 can be reduced and the service life can be prolonged through the matching of six groups of sealing rings.

It is to be understood that the above examples of the present invention are provided for clarity of illustration only and are not limiting of the embodiments of the present invention. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the invention. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.

Claims

1. The hydraulic piston is characterized by comprising a piston rod (8), a piston cylinder (10) and a piston head (9), wherein an inserting cavity is formed in the piston cylinder (10), the piston rod (8) is inserted in the inserting cavity, the piston head (9) is inserted at the other side of the inserting cavity, the piston rod (8) slides back and forth along the axis of the inserting cavity, and an oil cavity (7) is formed between the piston rod (8) and the piston head (9);

One end of the piston head (9) is sleeved with a sealing component, and the sealing component is abutted with the inner wall of the plug-in cavity; the sealing assembly comprises a first sealing member, a second sealing member and a third sealing member, wherein the first sealing member, the second sealing member and the third sealing member are mutually abutted and sleeved on a piston rod (8), the first sealing member is provided with an oil pipe along the moving direction of the piston rod (8), the second sealing member comprises a third sealing ring (3), an inner lip (31) and an outer lip (32) are formed on one side of the third sealing ring (3) in a protruding mode, an annular lip groove (33) is formed between the inner lip (31) and the outer lip (32) in a surrounding mode, the lip groove (33) is communicated with the oil cavity (7) through the oil pipe, the first sealing member is made of metal, the third sealing member is made of rubber material, and the second sealing member is made of rubber material.

2. The hydraulic piston according to claim 1, characterized in that the first sealing member comprises a first sealing ring (1), a groove is formed at the front end of the piston rod (8), a protruding portion (13) is formed at the inner ring of the first sealing ring (1), the protruding portion (13) is embedded in the groove, a first oil hole (11) is formed in the circumferential direction of the first sealing ring (1), and the first oil hole (11) communicates the lip groove (33) with the oil cavity (7).

3. The hydraulic piston according to claim 2, wherein the first sealing member further comprises a second sealing ring (2), the second sealing ring (2) is installed between the first sealing ring (1) and the third sealing ring (3), a second oil hole (21) is formed in the second sealing ring (2), one end of the second oil hole (21) is communicated with the first oil hole (11), and the other end of the second oil hole (21) is communicated with the lip groove (33).

4. A hydraulic piston according to claim 3, wherein the second oil holes (21) comprise six groups, the second oil holes (21) are distributed in the circumferential direction along the axis of the second sealing ring (2) at equal intervals, and the first oil holes (11) are in one-to-one correspondence with the second oil holes (21).

5. The hydraulic piston according to claim 1, characterized in that the second sealing member further comprises a fourth sealing ring (4), the fourth sealing ring (4) being in abutment with the third sealing ring (3), the fourth sealing ring (4) being more elastic than the third sealing ring (3).

6. Hydraulic piston according to claim 5, characterized in that the third sealing member comprises a fifth sealing ring (5) and a sixth sealing ring (6), the fifth sealing ring (5) being mounted between the fourth sealing ring (4) and the sixth sealing ring (6), the sixth sealing ring (6) being in abutment with the piston rod (8).

7. Hydraulic piston according to claim 6, characterized in that the contact surface between the fifth sealing ring (5) and the sixth sealing ring (6) is an annular conical surface (20).

8. Hydraulic piston according to claim 7, characterized in that the sixth sealing ring (6) is in contact with the piston rod (8) via an annular conical surface (20).

9. The hydraulic piston according to claim 2, characterized in that the first sealing ring (1) comprises two sets of joints (12), the joints (12) being semi-circular, the joints (12) enclosing the first sealing ring (1).

10. Hydraulic piston according to claim 1, characterized in that the hardness of the first, second and third sealing members is lower than the hardness of the piston rod (8).