CN113175460A

CN113175460A - Hydraulic cylinder with variable piston section size

Info

Publication number: CN113175460A
Application number: CN202110445657.9A
Authority: CN
Inventors: 徐海军; 高雪; 徐小军; 张雷; 徐藜洋; 常雨康; 王晓聪
Original assignee: National University of Defense Technology
Current assignee: National University of Defense Technology
Priority date: 2021-04-23
Filing date: 2021-04-23
Publication date: 2021-07-27
Anticipated expiration: 2041-04-23
Also published as: CN113175460B

Abstract

The invention discloses a hydraulic cylinder with a variable piston section size, which comprises a cylinder body, a piston rod and at least more than one valve core, wherein the piston and the valve core are arranged in the cylinder body, the piston is connected with the piston rod, the piston is at least provided with more than one oil flow channel along the axial direction, the piston is at least provided with more than one valve core channel along the radial direction, the valve core channel is perpendicular to and intersected with the oil flow channel, the valve core is arranged in the valve core channel, a cavity is arranged in the valve core, an elastic part is arranged in the cavity, and the position of the valve core relative to the oil flow channel is controlled by adjusting the compression amount of the elastic part to realize the adjustment of the cross section area of the piston. The invention has the advantages of low cost, capability of quickly and accurately meeting the load requirement, less energy consumption, higher working efficiency and the like.

Description

Hydraulic cylinder with variable piston section size

Technical Field

The invention mainly relates to the technical field of hydraulic cylinders, in particular to a hydraulic cylinder with a variable piston section size.

Background

The hydraulic cylinder is a hydraulic actuating element which converts hydraulic energy into mechanical energy and makes linear reciprocating motion (or swinging motion), has simple structure and reliable work, can omit a speed reducer when realizing reciprocating motion, has no transmission clearance and moves stably, and is widely applied to hydraulic systems of various machines.

In the prior art, the speed regulation and the pressure regulation of a hydraulic system are realized by regulating a hydraulic element in a valve control system or a pump control system, when the speed and the pressure required by a load change, a plurality of elements such as a valve, a pump and the like in a hydraulic loop often need to be regulated, and in addition, throttling loss is caused, so that a hydraulic actuating element (hydraulic cylinder) has slow response, untimely regulation and large energy loss, the requirement of the load cannot be met in time, and the working efficiency is greatly reduced. Therefore, designing a hydraulic cylinder which can respond quickly, can change dynamically along with the load demand and improve the working efficiency of a hydraulic system is an urgent problem to be solved by technical personnel in the field.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides the hydraulic cylinder with the variable piston section size, which is lower in cost, can quickly and accurately meet the load requirement, is low in energy consumption and high in working efficiency.

In order to solve the technical problems, the invention adopts the following technical scheme:

a hydraulic cylinder with a variable piston section size comprises a cylinder body, a piston rod and at least more than one valve core, wherein the piston and the valve core are arranged in the cylinder body, the piston is connected with the piston rod, the piston is at least provided with more than one oil flow channel along the axial direction, the piston is at least provided with more than one valve core channel along the radial direction, the valve core channels are perpendicular to and intersected with the oil flow channels, the valve core is arranged in the valve core channels, a cavity is arranged in the valve core, an elastic part is arranged in the cavity, and the cross section area of the piston is adjusted by adjusting the position of the valve core relative to the oil flow channel through the compression amount of the elastic part.

As a further improvement of the invention: the piston is provided with piston control pipelines along the axial direction, and the piston control pipelines are the same in number with the valve core channels, are perpendicular to the valve core channels and are communicated with the valve core channels.

As a further improvement of the invention: and the piston rod is provided with a piston rod control pipeline along the axial direction, and the piston rod control pipeline is communicated with the piston control pipeline.

As a further improvement of the invention: the valve core comprises a first valve core and a second valve core, the radial size of the first valve core is larger than that of the second valve core, and the cavity is formed in the first valve core.

As a further improvement of the invention: the valve core passage comprises a first valve core passage and a second valve core passage, the diameter of the first valve core passage is the same as that of the first valve core, and the diameter of the second valve core passage is the same as that of the second valve core.

As a further improvement of the invention: the axial length of the first spool is less than the axial length of the first spool passage.

As a further improvement of the invention: one end of the elastic piece is connected with the bottom of the cavity of the first valve core, and the other end of the elastic piece is fixed on the piston.

As a further improvement of the invention: the piston divides the inner cavity of the cylinder body into a first cavity and a second cavity, and a first oil inlet and an oil outlet which are communicated with the first cavity and a second oil inlet and an oil outlet which are communicated with the second cavity are formed in the cylinder body.

As a further improvement of the invention: when the number of the valve cores is even, the valve cores, the valve core channels and the oil liquid flow passages are symmetrically arranged by taking the axial direction of the piston as a center; when the number of the valve cores is odd, the valve cores, the valve core channels and the oil liquid flow passages are uniformly arranged by taking the axial direction of the piston as the center.

As a further improvement of the invention: the cross section of the oil liquid runner is in a closed shape.

Compared with the prior art, the invention has the advantages that:

1. according to the hydraulic cylinder with the variable piston section size, the oil liquid flow channel is formed in the piston in the axial direction, the valve core channel is formed in the radial direction, the valve core channel is perpendicular to and intersected with the oil liquid flow channel, the valve core provided with the elastic piece is arranged in the valve core channel, and the cross section area of the piston can be dynamically changed by controlling the position of the valve core relative to the oil liquid flow channel, so that the output thrust and the output speed are adjusted, a valve control system or a pump control system is not needed, the energy loss can be reduced, and the cost can be reduced.

2. According to the hydraulic cylinder with the variable piston section size, the piston is provided with the piston control pipelines along the axial direction, each valve core corresponds to one piston control pipeline and is not communicated with each other, the piston control pipelines can be combined randomly according to the load requirement, the number of the piston control pipelines is the same as that of the valve core channels and are communicated with the valve core channels, and the valve cores are not easy to malfunction when impact or pressure mutation occurs in the cylinder body as the movement direction of the valve cores is vertical to the piston control pipelines; and the elastic part stretches continuously, namely the change of the cross section area of the piston of the hydraulic cylinder is not sudden, so that the violent impact of high-pressure fluid caused by the obstacle is avoided, the hydraulic element is protected, and the energy loss caused by the sudden change of the cross section area can be reduced.

Drawings

Fig. 1 is an exploded view of the present invention.

Fig. 2 is a cross-sectional view of the present invention.

Fig. 3 is an axial and radial cross-sectional view of the piston of the present invention.

Illustration of the drawings:

1. a cylinder body; 2. a piston; 21. a piston control line; 3. a piston rod; 31. a piston rod control line; 4. a valve core; 41. a cavity; 42. an elastic member; 43. a first valve spool; 44. a second valve core; 5. an oil fluid flow passage; 6. a spool passage; 61. a first spool passage; 62. a second spool passage; 7. a first oil inlet and outlet; 8. and the second oil inlet and outlet.

Detailed Description

The invention will be described in further detail below with reference to the drawings and specific examples.

As shown in fig. 1 to 3, the present invention discloses a hydraulic cylinder with a variable piston cross-section size, which includes a cylinder body 1, a piston 2, a piston rod 3 and at least one valve core 4, wherein the piston 2 and the valve core 4 are arranged in the cylinder body 1, the piston 2 is connected with the piston rod 3, the piston 2 is at least provided with at least one oil flow channel 5 along an axial direction, the piston 2 is at least provided with at least one valve core channel 6 along a radial direction, the valve core channel 6 is perpendicular to and intersects with the oil flow channel 5, the valve core 4 is arranged in the valve core channel 6, the axial lines of the valve core 4 and the valve core channel 6 are overlapped, the valve core 4 is provided with a cavity 41 along the axial direction, an elastic member 42 (such as a spring) is arranged in the cavity 41, and the cross-sectional area of the piston 2 is adjusted by adjusting the position of the valve core 4 relative to the oil flow channel 5 by controlling the compression amount of the elastic member 42.

According to the hydraulic cylinder with the variable piston section size, the oil flow channel 5 and the valve core channel 6 are axially arranged on the piston 2, the valve core channel 6 is perpendicular to and intersected with the oil flow channel 5, the valve core 4 provided with the elastic piece 42 is arranged in the valve core channel 6, and the cross section area of the piston 2 can be dynamically changed by controlling the position of the valve core 4 relative to the oil flow channel 5, so that the output thrust and speed can be adjusted, a valve control system or a pump control system is not needed, energy loss can be reduced, and cost can be reduced.

In this embodiment, the piston 2 is provided with piston control pipelines 21 along the axial direction, each valve core 4 corresponds to one piston control pipeline 21 and is not communicated with each other, the piston control pipelines 21 can be combined at will according to the load requirement, and the number of the piston control pipelines 21 is the same as that of the valve core channels 6 and is perpendicular to and communicated with the valve core channels 6. Because the motion direction of the valve core 4 is vertical to the piston control pipeline 21, when impact or pressure mutation occurs in the cylinder body 1, the valve core 4 is not easy to generate misoperation; and the elastic part 42 is continuous in extension and retraction, namely the change of the cross section area of the piston 2 of the hydraulic cylinder is not abrupt, so that the violent impact of high-pressure fluid caused by the obstacle is avoided, hydraulic elements are protected, and the energy loss caused by the abrupt change of the cross section area can be reduced.

In this embodiment, the piston rod 3 is provided with a piston rod control pipeline 31 along the axial direction, and the piston rod control pipeline 31 is communicated with the piston control pipeline 21. I.e. the spool channel 6, the piston control line 21 and the piston rod control line 31, communicate with each other, and the mechanical signals of the external controller and sensor are transmitted to the spool 4 by means of cables, hydraulic oil, air pressure, etc. arranged in the piston rod control line 31.

In the present embodiment, the spool 4 includes a first spool 43 and a second spool 44, the radial dimension of the first spool 43 is larger than the radial dimension of the second spool 44, and the cavity 41 is opened in the first spool 43; the length of the first spool 43 is slightly greater than the radial dimension of the oil flow passage 5 to prevent oil leakage. The spool passage 6 includes a first spool passage 61 and a second spool passage 62, the diameter of the first spool passage 61 is the same as the diameter of the first spool 43, and the diameter of the second spool passage 62 is the same as the diameter of the second spool 44. By designing the valve core 4 into the first valve core 43 with the thick section and the second valve core 44 with the thin section, after the first valve core 43 with the thick section is completely pushed out of the oil flow channel 5, the second valve core 44 with the thin section cannot block the oil flow channel 5 in a large area, so that the effect of the variable cross section of the piston is avoided being influenced; and the valve core 4 and the valve core channel 6 are divided into two sections, the second valve core 4 in the thin section can play a role in fixing the radial displacement of the first valve core 43 and the second valve core 44, the phenomenon that the first valve core 43 in the thick section is dislocated with the first valve core channel 61 after being impacted by fluid and cannot move smoothly is avoided, the cavity 41 is arranged in the first valve core 43, the elastic piece is arranged in the cavity 41, and the thrust output by the piston 2 is more stable through the dynamic adjustment of the elastic piece 42. Further, in the preferred embodiment, the first and

second spools

43 and 44 are integrally cast.

The specific working principle is as follows: the first valve core 43 is arranged in the first valve core channel 61, a cavity 41 is arranged in the first valve core 43, the bottom of the cavity 41 is connected with one end of an elastic part 42, the other end of the elastic part 42 is fixedly connected on the wall of the piston 2 through a rivet, and the axis of the elastic part 42 is overlapped with the axis of the valve core 4 and is vertical to the axis of the oil fluid channel 5; the normal state of the piston 2 is that the oil flow channel 5 is completely blocked by the first valve core 43, namely the function of the complete piston 2 is exerted, and at the moment, the elastic element 42 is in a free extension state; in an external force driving device (such as any mode of an electromagnetic circuit, a hydraulic pipeline, a pneumatic pipeline and the like), a mechanical signal is transmitted to the second valve core 44 through the piston rod control pipeline 31 and the piston control pipeline 21, the second valve core 44 moves in the second valve core channel 62 to drive the first valve core 43 to move and compress the elastic element 42, the blocked part of the oil flow channel 5 is reduced, the oil flowing through the oil flow channel 5 is increased, and the cross section area of the piston 2 is reduced; when the external force is reduced or cancelled, the elastic element 42 pushes the second valve spool 44 back to the original position by means of the self elastic force, the cross-sectional area of the piston 2 is increased, and finally the oil flow passage 5 is completely blocked, so that the cross-sectional area of the piston 2 is dynamically changed.

In the present embodiment, the axial length of the first spool 43 is smaller than the axial length of the first spool passage 61, so that the first spool 43 has a space in which it can move in the first spool passage 61 when the elastic member 42 expands and contracts.

In this embodiment, the piston 2 divides the inner cavity of the cylinder body 1 into a first cavity and a second cavity, the cylinder body 1 is provided with a first oil inlet/outlet 7 communicated with the first cavity and a second oil inlet/outlet 8 communicated with the second cavity, and the oil filling port is used for sucking and discharging hydraulic oil. Piston 2 separates into first chamber and second chamber with the inner chamber of cylinder body 1, and when piston 2 compressed liquid, the fluid that flows into first chamber or second chamber through fluid runner 5 can play the cushioning effect to realize exporting more steady regulation of thrust.

In the embodiment, 4 valve cores 4 are arranged, the number of the valve cores 4, the valve core channels 6 and the oil flow channels 5 is matched, and the valve cores 4, the valve core channels 6 and the oil flow channels 5 are symmetrically arranged by taking the axial direction of the piston 2 as a center; in order to ensure the rigidity of the piston 2, the number of the oil flow passages 5 is not too large, but in order to ensure that the hydraulic cylinder can adapt to more working conditions, the combination of the opening degrees of the oil flow passages 5 is more, and at least one oil flow passage 5 is arranged on the piston 2. In other embodiments, the number of spools 4 may be odd or otherwise even; when the number of the valve cores 4 is even, the valve cores 4 can act simultaneously or two valve cores 4 which are symmetrical to each other act simultaneously, namely at least one group of valve cores 4 work simultaneously; when the number of the valve cores 4 is odd, the valve cores 4, the valve core channels 6 and the oil liquid flow channels 5 are uniformly arranged by taking the axial direction of the piston as the center, and all the valve cores 4 act simultaneously; the oil flowing through the oil flow passage 5 is ensured to be symmetrically distributed, so that the pressure and the flow in the cylinder are symmetrically distributed, the piston 2 is ensured not to generate an overturning angle due to the distribution change of the pressure and the flow in the cylinder body 1, and the situations of motion blocking and the like are avoided.

In this example. The section of the oil fluid flow passage 5 is circular; in other embodiments, the oil flow passage 5 may have other closed shapes such as a rectangle, a diamond, and the like.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.

Claims

1. The hydraulic cylinder with the variable piston section size is characterized by comprising a cylinder body (1), a piston (2), a piston rod (3) and at least one valve core (4), the piston (2) and the valve core (4) are arranged in the cylinder body (1), the piston (2) is connected with the piston rod (3), the piston (2) is provided with at least more than one oil fluid flow passage (5) along the axial direction, the piston (2) is provided with at least more than one valve core channel (6) along the radial direction, the valve core channel (6) is vertical to and intersected with the oil fluid channel (5), the valve core (4) is arranged in the valve core channel (6), a cavity (41) is arranged in the valve core (4), an elastic piece (42) is arranged in the cavity (41), the cross-sectional area of the piston (2) is adjusted by adjusting the position of the compression quantity control valve core (4) of the elastic piece (42) relative to the oil flow passage (5).

2. The hydraulic cylinder with variable piston cross-sectional size according to claim 1, characterized in that the piston (2) is provided with piston control lines (21) in the axial direction, and the piston control lines (21) are the same in number as the spool passages (6) and are perpendicular to and communicate with the spool passages (6).

3. Variable piston cross-section hydraulic cylinder according to claim 2, characterized in that the piston rod (3) is provided with a piston rod control line (31) in the axial direction, the piston rod control line (31) being in communication with the piston control line (21).

4. The variable piston cross-sectional size hydraulic cylinder according to claim 1, wherein the spool (4) includes a first spool (43) and a second spool (44), the first spool (43) having a radial dimension greater than a radial dimension of the second spool (44), and the cavity (41) opens in the first spool (43).

5. The variable piston cross-sectional size hydraulic cylinder according to claim 4, wherein the spool passage (6) includes a first spool passage (61) and a second spool passage (62), the first spool passage (61) having a diameter of the same size as the diameter of the first spool (43), and the second spool passage (62) having a diameter of the same size as the diameter of the second spool (44).

6. The variable piston cross-sectional size hydraulic cylinder of claim 5, wherein the axial length of the first spool (43) is less than the axial length of the first spool passage (61).

7. The hydraulic cylinder with variable piston cross-sectional size according to claim 4, characterized in that one end of the elastic member (42) is connected with the bottom of the cavity (41) of the first spool (43), and the other end of the elastic member (42) is fixed on the piston (2).

8. The hydraulic cylinder with the variable piston section size according to any one of claims 1 to 7, wherein the piston (2) divides an inner cavity of the cylinder body (1) into a first cavity and a second cavity, and a first oil inlet and outlet (7) communicated with the first cavity and a second oil inlet and outlet (8) communicated with the second cavity are formed in the cylinder body (1).

9. The hydraulic cylinder with the variable piston section size according to any one of claims 1 to 7, wherein when the number of the valve cores (4) is even, the valve cores (4), the valve core passages (6) and the oil flow passages (5) are symmetrically arranged by taking the axial direction of the piston (2) as a center; when the number of the valve cores (4) is odd, the valve cores (4), the valve core channels (6) and the oil liquid flow channels (5) are uniformly arranged by taking the axial direction of the piston (2) as the center.

10. The variable piston cross-sectional size hydraulic cylinder according to any one of claims 1 to 7, wherein the cross-sectional shape of the oil flow passage (5) is a closed shape.