阅读说明：本技术 超高压液压缸结构 (Ultrahigh pressure hydraulic cylinder structure ) 是由 陈宇 周宏根 刘金锋 康超 李炳强 蔡秋艳 严张会 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种超高压液压缸结构,包括设有塞体的内筒,内筒的空腔作为超高压液压缸的工作腔；在内筒的外部沿径向向外至少套设有一个外筒,每两筒体的筒壁之间形成环形空腔；环形空腔与内筒之间设有根据内筒的工作压力动态控制环形空腔中液压油压力的调压系统,液压油进入内筒内形成的工作压力作用于调压系统,调压系统将压力传递于环形空腔从而进一步作用于内筒。本发明将至少一组中间形成环形空腔的外筒和内筒作为超高压液压缸的缸筒,利用环形空腔与内筒之间的调压系统,使其根据内筒的工作压力动态控制环形空腔中液压油压力,从而进一步作用于内筒上,可有效提高液压缸缸筒的超高压耐受能力,提高超高压液压缸的安全系数,且降低成本。(The invention discloses an ultrahigh-pressure hydraulic cylinder structure, which comprises an inner cylinder provided with a plug body, wherein a cavity of the inner cylinder is used as a working cavity of the ultrahigh-pressure hydraulic cylinder; at least one outer cylinder is sleeved outside the inner cylinder along the radial direction, and an annular cavity is formed between the cylinder walls of every two cylinders; a pressure regulating system for dynamically controlling the pressure of hydraulic oil in the annular cavity according to the working pressure of the inner cylinder is arranged between the annular cavity and the inner cylinder, the working pressure formed when the hydraulic oil enters the inner cylinder acts on the pressure regulating system, and the pressure regulating system transmits the pressure to the annular cavity so as to further act on the inner cylinder. The invention takes at least one group of the outer cylinder and the inner cylinder which form the annular cavity in the middle as the cylinder barrel of the ultrahigh pressure hydraulic cylinder, and utilizes the pressure regulating system between the annular cavity and the inner cylinder to dynamically control the hydraulic oil pressure in the annular cavity according to the working pressure of the inner cylinder, thereby further acting on the inner cylinder, effectively improving the ultrahigh pressure tolerance capability of the cylinder barrel of the hydraulic cylinder, improving the safety coefficient of the ultrahigh pressure hydraulic cylinder and reducing the cost.)

1. An ultrahigh-pressure hydraulic cylinder structure is characterized by comprising an inner cylinder (2) provided with a plug body (3), wherein an inner cavity of the inner cylinder (2) is used as a working cavity (5) of the ultrahigh-pressure hydraulic cylinder; at least one outer cylinder (1) is sleeved outside the inner cylinder (2) along the radial direction, and an annular cavity (4) is formed between the cylinder walls of every two cylinders; be equipped with between toroidal cavity (4) and inner tube (2) according to the operating pressure dynamic control toroidal cavity (4) of inner tube (2) hydraulic pressure's pressure regulating system (9), the operating pressure that hydraulic oil got into inner tube (2) and formed acts on pressure regulating system (9), thereby pressure regulating system (9) transmit pressure in toroidal cavity (4) further act on inner tube (2).

2. Ultrahigh-pressure hydraulic cylinder arrangement according to claim 1, characterized in that the pressure regulating system (9) is a piston cylinder, one end of which is connected to the rodless chamber of the inner cylinder (2) and the other end of which is connected via a first hydraulic channel (8) to at least one annular cavity (4) formed by the outer cylinder (1).

3. Ultrahigh-pressure hydraulic cylinder structure according to claim 1, characterized in that the high-pressure end of the pressure regulating system (9) is connected with the rodless cavity of the inner cylinder and the low-pressure end of the pressure regulating system is connected with the annular cavity.

4. Ultrahigh-pressure hydraulic cylinder arrangement according to claim 1, characterized in that the inner cylinder (2) is provided with a second hydraulic channel (10) for inlet liquid and a third hydraulic channel (11) for outlet liquid.

5. The structure of the ultrahigh-pressure hydraulic cylinder according to claim 1, wherein a first end cover (6) and a second end cover (7) for forming a closed space for the annular cavity (4) are respectively arranged at two ends of the outer cylinder (1) and the inner cylinder (2).

6. Ultrahigh-pressure hydraulic cylinder structure according to claim 1, characterized in that the pressure regulating system is embedded in the first end cover (6).

7. Ultrahigh-pressure hydraulic cylinder arrangement according to claim 1, characterized in that hydraulic oil with an initial pressure is pre-charged in the annular cavity (4).

8. Ultrahigh-pressure hydraulic cylinder structure according to claim 1, characterized in that the dimensions of the two chambers of the piston cylinder are controlled so as to control the working pressure of the inner cylinder (2) to rise and fall synchronously in proportion to the hydraulic oil pressure in the annular cavity (4).

9. Ultrahigh-pressure hydraulic cylinder arrangement according to claim 1, characterized in that the inner cylinder (2) and the outer cylinder (1) are coaxially arranged.

10. An ultrahigh-pressure hydraulic cylinder structure according to claim 1, wherein the ultrahigh-pressure hydraulic cylinder structure is a double-layer cylinder structure or a multi-layer cylinder structure of 3 layers or more.

Technical Field

The invention relates to an actuating element of an ultrahigh pressure hydraulic system, in particular to an ultrahigh pressure hydraulic cylinder structure.

Background

According to the brief handbook of hydraulic system design (edited by Yangpei Yuan Ministry), in the design process of the hydraulic cylinder, the wall thickness of the hydraulic cylinder can be generally calculated according to a thick-wall cylinder formula in material mechanics. The maximum output pressure of a common hydraulic system is generally lower than 32MPa, and cast iron ([ sigma ] ═ 60MPa), cast steel ([ sigma ] ═ 100-110 MPa) or forged steel ([ sigma ] ═ 110-120 MPa) is generally selected as a cylinder barrel material for a hydraulic cylinder serving as an actuating element, so that the structure is small, and the cost is low.

However, in a special situation where a large output force is partially required, the pressure of the hydraulic system needs to be increased to 70MPa, 140MPa or even higher, which is called as an extra-high pressure hydraulic system. According to the wall thickness calculation formula, the ultrahigh pressure hydraulic cylinder serving as an actuating element obviously cannot select cast iron or even cast steel as a cylinder barrel material. In order to ensure the safety and reliability of the ultrahigh pressure hydraulic cylinder, the wall thickness of the cylinder barrel needs to be greatly increased, and alloy steel with higher allowable stress and higher cost is replaced as a cylinder barrel material, so that the hydraulic cylinder is large in overall dimension, heavy in volume and high in cost.

Patent CN 104595276 a discloses an ultrahigh pressure hydraulic cylinder, which uses the main plunger as the main plunger of the main hydraulic cylinder and uses the inner wall as the rigid body of the return cylinder, and reduces the weight of the hydraulic cylinder by simplifying the parts of the hydraulic cylinder, but the essential requirements of ultrahigh pressure hydraulic cylinder for increasing the wall thickness of the cylinder barrel and high cost alloy materials are still not solved.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide an ultrahigh pressure hydraulic cylinder structure which effectively improves the ultrahigh pressure tolerance of a cylinder barrel of the hydraulic cylinder and reduces the requirement of the cylinder barrel on the material performance.

The technical scheme is as follows: the ultrahigh-pressure hydraulic cylinder structure comprises an inner cylinder provided with a plug body, wherein a cavity of the inner cylinder is used as a working cavity of the ultrahigh-pressure hydraulic cylinder; at least one outer cylinder is sleeved outside the inner cylinder along the radial direction, and an annular cavity is formed between the cylinder walls of every two cylinders; a pressure regulating system for dynamically controlling the pressure of hydraulic oil in the annular cavity according to the working pressure of the inner cylinder is arranged between the annular cavity and the inner cylinder, the working pressure formed when the hydraulic oil enters the inner cylinder acts on the pressure regulating system, and the pressure regulating system transmits the pressure to the annular cavity so as to further act on the inner cylinder.

The pressure regulating system is a piston cylinder, one end of the piston cylinder is connected with a rodless cavity of the inner cylinder, and the other end of the piston cylinder is connected with at least one annular cavity formed by the outer cylinder through a first hydraulic channel; the high-pressure end of the pressure regulating system is connected with the rodless cavity of the inner cylinder, and the low-pressure end of the pressure regulating system is connected with the annular cavity.

The inner cylinder is provided with a second hydraulic channel for liquid inlet and a third hydraulic channel for liquid outlet.

And a first end cover and a second end cover which are used for enabling the annular cavity to form a closed space are respectively arranged at the two ends of the outer cylinder and the inner cylinder. The second hydraulic channel and a third hydraulic channel for discharging liquid respectively penetrate through the first end cover and the second end cover; the pressure regulating system is embedded in the first end cover.

And hydraulic oil with initial pressure is preset in the annular cavity.

The sizes of the two cavities of the piston cylinder are controlled, so that the working pressure of the inner cylinder and the pressure of hydraulic oil in the annular cavity are controlled to synchronously lift in a row-by-row mode.

Wherein, the inner cylinder and the outer cylinder are coaxially arranged.

The ultrahigh pressure hydraulic cylinder structure is a double-layer cylinder structure or a multi-layer cylinder structure with 3 layers or more.

Has the advantages that: compared with the prior art, the invention has the following remarkable effects: 1. the outer cylinder and the inner cylinder which form the annular cavity in the middle of at least one group are used as the cylinder barrel of the ultrahigh-pressure hydraulic cylinder, and the pressure regulating system between the annular cavity and the inner cylinder is utilized to dynamically control the hydraulic oil pressure in the annular cavity according to the working pressure of the inner cylinder, so that the ultrahigh-pressure hydraulic cylinder further acts on the inner cylinder, the ultrahigh-pressure tolerance of the cylinder barrel of the hydraulic cylinder can be effectively improved, and the safety coefficient of the ultrahigh-pressure hydraulic cylinder is improved. 2. The cylinder barrel of the ultrahigh-pressure hydraulic cylinder has low requirement on material performance, and the material cost can be effectively reduced. 3. The inner cylinder and the outer cylinder of the ultrahigh pressure hydraulic cylinder can synchronously lift and descend according to a certain proportion, and when the hydraulic cylinder unloads, the pressure of the annular cavity between the inner cylinder and the outer cylinder is synchronously unloaded, so that the safety is high.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Detailed Description

The present invention is described in further detail below.

As shown in figure 1, the ultrahigh pressure hydraulic cylinder structure of the invention comprises an outer cylinder 1 and an inner cylinder 2, wherein the outer diameter of the inner cylinder 2 is slightly smaller than the inner diameter of the outer cylinder 1, the inner cylinder 2 is coaxially arranged in the outer cylinder 1 to form a cylinder barrel of the hydraulic cylinder, an annular cavity 4 is formed between the inner cylinder 2 and the outer cylinder 1, the inner cavity of the inner cylinder 2 is a working cavity 5 of the hydraulic cylinder, and a plug body 3 is arranged in the working cavity 5 of the inner cylinder 2. The two ends of the outer cylinder 1 and the inner cylinder 2 are respectively connected with the first end cover 6 and the second end cover 7 in a sealing way, so that the annular cavity 4 forms a closed space. The first end cover 6 and the second end cover 7 are respectively provided with a second hydraulic channel 10 and a third hydraulic channel 11 for liquid inlet and outlet.

The annular cavity 4 is filled with hydraulic oil with certain initial pressure, so that the inner cylinder 2 is simultaneously acted by the internal pressure and the external pressure when the hydraulic cylinder works. A first hydraulic channel 8 is arranged between the annular cavity 4 and the working cavity 5 of the inner barrel 2, and pressure regulating systems are further arranged at the rodless cavity ends of the first hydraulic channel 8 and the working cavity 5 and can dynamically control the hydraulic oil pressure in the annular cavity 4 according to the working pressure of the inner barrel 2. The pressure regulating system of the embodiment comprises a piston cylinder 9, a high-pressure end of the piston cylinder 9 is connected with a rodless cavity end of a hydraulic cylinder working cavity 5, a low-pressure end of the piston cylinder 9 is connected with a first hydraulic channel 8, and synchronous lifting of the working pressure of the inner cylinder 2 and the pressure of hydraulic oil in the annular cavity 4 according to a certain ratio can be guaranteed by adjusting the sizes of two cavities of the piston cylinder 9. And, the piston pressure cylinder 9 is embedded in the first end cover 6, so that the structural size of the pressure cylinder 9 can be effectively reduced, and the whole structure of the hydraulic cylinder can be more compact.

The cylinder barrel of the hydraulic cylinder in the embodiment has a double-layer barrel structure of an outer barrel 1 and an inner barrel 2, and can also have a multi-layer barrel structure of 3 layers or more. It is only necessary to communicate the first hydraulic passage 8 to each of the formed annular cavities and to provide a pressure regulating system between the first hydraulic passage 8 and the annular cavities other than the innermost annular cavity.

When the plunger type hydraulic cylinder is used, high-pressure oil enters a rodless cavity of the working cavity 5 from the second hydraulic channel 10 to form high pressure, the plunger body 3 is pushed to move, and the oil in a rod cavity of the working cavity 5 flows out of the hydraulic cylinder through the third hydraulic channel 11. Meanwhile, high-pressure oil in a rodless cavity of the working cavity 5 generates pressure at a high-pressure end of the pressure cylinder 9, and a low-pressure end of the pressure cylinder 9 generates pressure in equal proportion, so that pressure in equal proportion to the rodless cavity of the working cavity 5 is generated in the annular cavity 4 between the inner cylinder 2 and the outer cylinder 1, the inner cylinder 2 is further enabled to simultaneously receive internal pressure and external pressure, and the ultrahigh pressure tolerance of the hydraulic cylinder barrel is effectively improved.

Assuming that the maximum output pressure of a certain hydraulic cylinder is 70MPa, the test pressure P is 1.4 multiplied by 70MPa and 98MPa when the hydraulic cylinder is designed.

(1) According to the design of the single-layer cylinder barrel structure of the conventional hydraulic cylinder, the cylinder barrel material of the hydraulic cylinder can not select cast steel with lower cost according to a wall thickness calculation formula, and alloy steel materials with higher allowable stress and higher price are required to be used; wherein, the wall thickness calculation formula is as follows:

wherein δ is a cylinder wall thickness (m); d is the inner diameter (m) of the hydraulic cylinder; p is the test pressure, and is generally 1.25 to 1.5 times (MPa) of the maximum working pressure; [ sigma ] is the allowable stress of the cylinder material.

(2) According to the cylinder barrel structure design of the hollow multilayer cylinder body structure provided by the invention, the effective working area ratio of two cavity pistons of the pressure cylinder is 1: 2. the inner cylinder is subjected to internal and external pressures of 98MPa and 49MPa, and the outer cylinder is subjected to an internal pressure of 49 MPa. Therefore, the inner cylinder and the outer cylinder of the hydraulic cylinder barrel can be made of cast steel with lower cost.

Obviously, the cylinder barrel of the ultrahigh-pressure hydraulic cylinder structure disclosed by the invention has lower requirements on material performance, and the material cost can be effectively reduced.