CN102207114B - Two-stage servo hydraulic cylinder - Google Patents

Abstract

The invention relates to a two-stage servo hydraulic cylinder. The technical scheme is: the hydraulic cylinder is composed of a static pressure cylinder and a dynamic pressure cylinder, and the cylinder body (2) of the static pressure cylinder and the dynamic pressure cylinder is integrated. The static pressure piston rod (33) is concentrically installed in the static pressure cavity (27) of the static pressure cylinder, the working end of the static pressure piston rod (33) passes through the left end cover (1), and the static pressure piston (5) is installed on the On the static pressure piston rod (33). The dynamic pressure piston rod (34) is concentrically installed in the dynamic pressure chamber (21) of the dynamic pressure cylinder, and the dynamic pressure piston (9) is installed on the dynamic pressure piston rod (34); the work of the dynamic pressure piston rod (34) The end passes through the hollow part of the cylinder partition wall and the hydrostatic piston rod (33). The width of the first leakage oil annular groove (32) provided on the inner wall of the through hole of the left end cover (1) is 1.3 to 2 times of the stroke of the static pressure piston (5). The invention has the characteristics of small frictional force, high dynamic response, energy saving, and the ability to output high vibration frequency and high excitation force that vary up and down according to a certain rule around a larger constant force.

Description

A two-stage servo hydraulic cylinder

technical field

The invention belongs to the technical field of hydraulic cylinders, and in particular relates to a two-stage servo hydraulic cylinder.

Background technique

In some working conditions, it is necessary to output a high-frequency force that changes up and down according to a certain law around a large constant force, such as 200kN±100sinωtkN, 200kN is a large constant force, and 100sinωtkN is a high-frequency dynamic force that changes according to a certain law. When the cylinder outputs this kind of force, there are the following problems:

1. Due to the large load, the natural frequency of the hydraulic cylinder becomes smaller, the response speed is poor, and it is difficult to meet the requirements of outputting high-frequency changing force;

2. The pressure in the working chamber of the hydraulic cylinder is high, the deformation of the sealing ring between the piston and the cylinder body of the hydraulic cylinder is large, and the friction between the piston and the cylinder body is large, which increases the running resistance of the piston and is difficult to meet the requirements of outputting high-frequency changing force;

3. Due to the high frequency and large force output, the piston area of the hydraulic cylinder is large, the maximum operating speed of the piston is large, and the working flow required by the hydraulic cylinder is large, which is not conducive to energy saving.

Based on the above reasons, due to the large friction force and poor dynamic response, ordinary hydraulic cylinders cannot meet the requirements of high vibration frequency and high excitation force whose output changes up and down according to a certain rule around a large constant force.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art, and the purpose is to provide a two-stage vibrating vibration generator with small friction, high dynamic response, energy saving, and the ability to output high vibration frequency and high excitation force that vary up and down according to a certain rule around a relatively large constant force. Servo hydraulic cylinder.

In order to achieve the above object, the technical solution adopted by the present invention is: the two-stage servo hydraulic cylinder is composed of a static pressure cylinder and a dynamic pressure cylinder. The cylinder body of the static pressure cylinder and the dynamic pressure cylinder is an integral body, the first half of the cylinder body is a static pressure cylinder, the second half is a dynamic pressure cylinder, and a cylinder body partition wall is arranged between the static pressure cylinder and the dynamic pressure cylinder.

The static pressure cylinder includes a left end cover, a static pressure piston and a static pressure piston rod. The static pressure piston rod is a hollow cylinder, and the static pressure piston rod is installed concentrically in the static pressure chamber of the static pressure cylinder. The working end of the static pressure piston rod passes through the left end cover, and the static pressure piston is installed on the static pressure piston rod. One side of the hydrostatic piston rests against the shoulder of the hydrostatic piston rod, and a spring washer and nut are mounted on the hydrostatic piston rod on the other side of the hydrostatic piston. The dynamic pressure cylinder includes a right end cover, a dynamic pressure piston and a dynamic pressure piston rod. The dynamic pressure piston rod is concentrically installed in the dynamic pressure chamber of the dynamic pressure cylinder. One side is close to the shaft shoulder of the dynamic pressure piston rod, and a spring washer and a nut are arranged on the dynamic pressure piston rod on the other side of the dynamic pressure piston. The working end of the dynamic pressure piston rod passes through the through hole in the center of the partition wall of the cylinder body and the central through hole of the static pressure piston rod, and a ninth sealing ring is arranged in the sealing groove of the working end of the dynamic pressure piston rod. The end of the dynamic pressure piston rod passes through the right end cover, and the installation cover is installed at the center position of the right end cover. One end of the displacement sensor is fixed on the installation cover, and the other end of the displacement sensor is placed in the hole at the end of the dynamic pressure piston rod.

The cylinder body of the static pressure cylinder is respectively provided with the first working oil port and the second working oil port communicating with both sides of the static pressure chamber, and the cylinder body of the dynamic pressure cylinder is respectively provided with a third oil port communicating with both sides of the dynamic pressure chamber. Working oil port and fourth working oil port. A third oil leakage annular groove is formed on the inner wall of the central through hole of the cylinder body partition wall, and an oil leakage port communicated with the third oil leakage annular groove is arranged at the middle position of the cylinder body partition wall. The first working oil port, the second working oil port, the third working oil port, the fourth working oil port and the leakage oil port communicate with the valve port corresponding to the servo valve seat respectively.

The inner wall of the through hole of the left end cover is provided with a first leakage oil annular groove, and the first leakage oil annular groove passes through the first leakage oil passage on the left end cover and the second leakage oil passage and the third leakage oil passage on the cylinder body of the static pressure cylinder. The annular grooves are connected. A second oil leakage annular groove is provided on the inner wall of the static pressure piston rod corresponding to the first oil leakage annular groove, and the second oil leakage annular groove communicates with the first oil leakage annular groove through the third oil leakage channel.

The width of the first leakage oil annular groove is 1.3-2 times of the stroke of the static pressure piston.

A gap seal is adopted between the dynamic pressure piston and the cylinder body, a gap seal is adopted between the dynamic pressure piston rod and the inner wall of the partition wall of the cylinder body, and a gap seal is adopted between the dynamic pressure piston rod and the static pressure piston rod.

The outer wall of the dynamic pressure piston has 3 to 5 first balance grooves, and 4 to 6 second balance grooves are formed on the dynamic pressure piston rod at the contact part of the central through hole of the cylinder partition wall. groove.

Owing to adopting above-mentioned technical scheme, the present invention has following positive effect:

1. The present invention divides the hydraulic cylinder into two parts, the static pressure cylinder and the dynamic pressure cylinder. The static pressure cylinder outputs a relatively large constant force, and the dynamic pressure cylinder outputs a dynamic force that changes up and down, such as outputting a force of 200kN±100sinωtkN. The cylinder outputs a large constant force of 200kN, and the dynamic pressure cylinder outputs a small dynamic force of ±100sinωtkN. Although the static pressure cylinder has a large constant load, since the static pressure cylinder is statically loaded, there is no requirement for the response frequency of the hydraulic cylinder. The load is small, the dynamic response is high, and it is easy to achieve higher frequency output.

2. In the present invention, the dynamic pressure piston rod passes through the hollow part of the static pressure piston rod, and a gap seal is used in between, and the leakage oil passes through the first leakage oil annular groove, the second leakage oil annular groove, the third leakage oil annular groove, the first leakage oil The oil passage, the second leakage oil passage and the third leakage oil passage lead back to the oil tank from the leakage oil port, forming a low-pressure area at the working end of the dynamic pressure piston rod and the static pressure piston rod. Due to the low pressure, the static pressure piston rod and the dynamic pressure piston rod The ninth sealing ring used for low-pressure dynamic sealing between the piston rods has small deformation, and the friction force between the dynamic pressure piston rod and the static pressure piston rod is small; in addition, due to the partition wall between the dynamic pressure piston rod and the cylinder body, and the Gap seals are used between the cylinders, the dynamic pressure cylinder has low friction and high dynamic response.

3. The present invention divides the hydraulic cylinder into two parts, the static pressure cylinder and the dynamic pressure cylinder. The static pressure cylinder is supplied with constant pressure by a constant pressure oil source (accumulator), and the dynamic pressure cylinder is supplied with oil by an oil pump. The dynamic load is small, the area of the dynamic pressure piston is small, and the required working flow is small, which has the effect of saving energy.

Therefore, the present invention has the characteristics of small frictional force, high dynamic response, energy saving, and the ability to output high vibration frequency and high exciting force that vary up and down according to a certain rule around a larger constant force.

Description of drawings

Fig. 1 is a kind of structural representation of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the present invention is further described, not limitation to its protection scope:

Example 1

A two-stage servo hydraulic cylinder. The two-stage servo hydraulic cylinder is shown in Figure 1 and consists of a static pressure cylinder and a dynamic pressure cylinder. The cylinder block 2 of the static pressure cylinder and the dynamic pressure cylinder is an integral body, the first half of the cylinder body 2 is a static pressure cylinder, the second half is a dynamic pressure cylinder, and a cylinder partition wall is arranged between the static pressure cylinder and the dynamic pressure cylinder.

The static pressure cylinder includes a left end cover 1 , a static pressure piston 5 and a static pressure piston rod 33 . The static pressure piston rod 33 is a hollow cylinder, and the static pressure piston rod 33 is concentrically installed in the static pressure chamber 27 of the static pressure cylinder. The working end of the static pressure piston rod 33 passes through the left end cover 1, and the static pressure piston 5 is installed on the On the static pressure piston rod 33 , one side of the static pressure piston 5 is close to the shoulder of the static pressure piston rod 33 , and a spring washer 25 and a nut 26 are mounted on the static pressure piston rod 33 on the other side of the static pressure piston 5 . The dynamic pressure cylinder includes a right end cover 12, a dynamic pressure piston 9 and a dynamic pressure piston rod 34. The dynamic pressure piston rod 34 is concentrically installed in the dynamic pressure cavity 20 of the dynamic pressure cylinder, and the dynamic pressure piston 9 is installed on the dynamic pressure piston rod 34. On, one side of the dynamic pressure piston 9 is close to the shoulder of the dynamic pressure piston rod 34, and the dynamic pressure piston rod 34 on the other side of the dynamic pressure piston 9 is equipped with a spring washer 18 and a nut 17. The working end of the dynamic pressure piston rod 34 passes through the through hole in the center of the cylinder partition wall and the central through hole of the static pressure piston rod 33 , and the ninth sealing ring 35 is housed in the sealing groove of the working end of the dynamic pressure piston rod 34 . The end of the dynamic pressure piston rod 34 passes through the right end cover 12, and the installation cover 15 is installed at the center of the right end cover 12; one end of the displacement sensor 16 is fixed on the installation cover 15, and the other end of the displacement sensor 16 is inserted into the dynamic pressure piston rod 34 in the hole at the end.

The cylinder block 2 of the static pressure cylinder is respectively provided with the first working oil port 3 and the second working oil port 6 communicating with the two sides of the static pressure chamber 27, and the cylinder body 2 of the dynamic pressure cylinder is respectively provided with the first working oil port 3 and the second working oil port 6 connected with the dynamic pressure chamber 27. The third working oil port 8 and the fourth working oil port 11 communicated on both sides. A third oil leakage annular groove 21 is formed on the inner wall of the central through hole of the cylinder partition wall, and an oil leakage port 7 communicating with the third oil leakage annular groove 21 is provided at the middle position of the cylinder partition wall. The first working oil port 3 , the second working oil port 6 , the third working oil port 8 , the fourth working oil port 11 and the leakage oil port 7 communicate with corresponding valve ports of the servo valve seat 4 respectively.

The inner wall of the through hole of the left end cover 1 is provided with a first leakage oil annular groove 32, and the first leakage oil annular groove 32 passes through the first leakage oil passage 31 on the left end cover 1 and the second leakage oil on the cylinder block 2 of the static pressure cylinder. Passage 29 communicates with the third leakage oil annular groove 21; A second leakage oil annular groove 36 is provided at the inner wall of the static pressure piston rod 33 corresponding to the first leakage oil annular groove 32, and the second leakage oil annular groove 36 passes through the third leakage oil annular groove The leakage oil passage 38 communicates with the first leakage oil annular groove 32 .

The width of the first leakage oil annular groove 32 is 1.3-1.5 times of the stroke of the static pressure piston 5 .

Four first balance grooves 10 are formed on the outer wall of the dynamic pressure piston 9, and four second balance grooves 22 are formed on the dynamic pressure piston rod 34 at the contact part between the dynamic pressure piston rod 34 and the central through hole of the cylinder partition wall.

In this embodiment: a gap seal is used between the dynamic pressure piston 9 and the cylinder body 2, a gap seal is used between the dynamic pressure piston rod 34 and the inner wall of the cylinder partition wall, and a gap seal is used between the dynamic pressure piston rod 34 and the static pressure piston rod 33. Gap seals are used.

The sealing groove on the outer wall of the annular boss of the left end cover 1 is equipped with a sixth sealing ring 28; the eighth sealing ring 30 is installed in the sealing hole of the first leakage oil passage 31 on the end surface of the left end cover 1, and the diameter of the sealing hole is larger than or It is equal to the outer diameter of the eighth sealing ring 30, and the inner diameter of the eighth sealing ring 30 is greater than or equal to the diameter of the first leakage oil passage 31; The seventh sealing ring 37 is housed respectively.

A fifth sealing ring 23 is respectively installed in the two sealing grooves on the outer wall of the static pressure piston 5 , and a fourth sealing ring 24 is installed in the sealing groove on the inner hole wall of the static pressure piston 5 .

A third sealing ring 19 is installed in the sealing groove of the inner hole wall of the dynamic pressure piston 9 .

A first sealing ring 13 is installed in the sealing groove of the outer wall of the annular boss of the right end cover 12; a second sealing ring 14 is respectively installed in the two sealing grooves of the inner hole wall of the right end cover 12.

Example 2

A two-stage servo hydraulic cylinder. Except following technical parameter, all the other are with embodiment 1.

The width of the first leakage oil annular groove 32 is 1.5-2 times of the stroke of the static pressure piston 5 .

There are three first balance grooves 10 on the outer wall of the dynamic pressure piston 9, and five second balance grooves 22 are formed on the dynamic pressure piston rod 34 at the contact part of the central through hole of the dynamic pressure piston rod 34 and the cylinder partition wall.

Example 3

A two-stage servo hydraulic cylinder. Except following technical parameter, all the other are with embodiment 1.

The width of the first leakage oil annular groove 32 is 1.4-1.8 times of the stroke of the static pressure piston 5 .

The outer wall of the dynamic pressure piston 9 is provided with 5 first balance grooves 10, and the dynamic pressure piston rod 34 is provided with 6 second balance grooves 22 at the contact part between the dynamic pressure piston rod 34 and the central through hole of the cylinder partition wall.

This embodiment has the following positive effects:

Owing to adopting above-mentioned technical scheme, this specific embodiment has following positive effect:

1. In this specific embodiment, the hydraulic cylinder is divided into two parts, the static pressure cylinder and the dynamic pressure cylinder. The static pressure cylinder outputs a relatively large constant force, and the dynamic pressure cylinder outputs a dynamic force that changes up and down, such as outputting a force of 200kN±100sinωtkN. The static pressure cylinder outputs a large constant force of 200kN, and the dynamic pressure cylinder outputs a small dynamic force of ±100sinωtkN. Although the static pressure cylinder has a large constant load, since the static pressure cylinder is statically loaded, there is no requirement for the response frequency of the hydraulic cylinder. The dynamic pressure cylinder The dynamic load is small, the dynamic response is high, and it is easy to achieve higher frequency output.

2. In this specific embodiment, the dynamic pressure piston rod 34 passes through the hollow part of the static pressure piston rod 33, and a gap seal is used in between, and the leakage oil passes through the first leakage oil annular groove 32, the second leakage oil annular groove 36, and the third leakage oil. The annular groove 21, the first leakage oil passage 31, the second leakage oil passage 29 and the third leakage oil passage 38 lead back to the oil tank from the leakage oil port 7, and are formed at the working ends of the dynamic pressure piston rod 34 and the static pressure piston rod 33 In the low-pressure area, due to the low pressure, the ninth sealing ring 35 used for low-pressure dynamic sealing between the static pressure piston rod 33 and the dynamic pressure piston rod 34 has little deformation, and the friction force between the dynamic pressure piston rod 34 and the static pressure piston rod 33 In addition, since the dynamic pressure piston rod 34 and the partition wall of the cylinder body, the dynamic pressure piston 9 and the cylinder body 2 are all sealed with gaps, the friction force of the dynamic pressure cylinder is small and the dynamic response is high.

3. In this specific embodiment, the hydraulic cylinder is divided into two parts, the static pressure cylinder and the dynamic pressure cylinder. The static pressure cylinder can be given a constant pressure by a constant pressure oil source, such as an accumulator, and the dynamic load of the dynamic cylinder is small. The flow rate is small, so the working flow required by the hydraulic cylinder is small, which has the effect of saving energy.

This specific embodiment has the characteristics of small friction, high dynamic response, energy saving, and can output high vibration frequency and high excitation force that vary up and down according to a certain rule around a large constant force.

Claims (3)

1. A two-stage servo hydraulic cylinder is characterized in that: the two-stage servo hydraulic cylinder is composed of a static pressure cylinder and a dynamic pressure cylinder, and the cylinder body (2) of the static pressure cylinder and the dynamic pressure cylinder is an integral body, and the cylinder body (2 ) is a static pressure cylinder, the second half is a dynamic pressure cylinder, and a cylinder partition wall is set between the static pressure cylinder and the dynamic pressure cylinder; the static pressure cylinder is supplied by a constant pressure oil source with high pressure, and the dynamic pressure The cylinder is supplied with oil by an oil pump, the static pressure cylinder outputs a larger constant force, and the dynamic pressure cylinder outputs a high-frequency dynamic force that changes up and down, and the area of the dynamic pressure piston (9) is smaller than that of the static pressure piston (5); The static pressure cylinder comprises a left end cover (1), a static pressure piston (5) and a static pressure piston rod (33); the static pressure piston rod (33) is a hollow cylinder, and the static pressure piston rod (33) is concentrically installed on the In the static pressure chamber (27) of the pressure cylinder, the working end of the static pressure piston rod (33) passes through the left end cover (1), the static pressure piston (5) is installed on the static pressure piston rod (33), and the static pressure piston ( 5) one side is close to the shoulder of the static pressure piston rod (33), and the static pressure piston rod (33) on the other side of the static pressure piston (5) is equipped with a spring washer (25) and a nut (26); The cylinder includes a right end cover (12), a dynamic pressure piston (9) and a dynamic pressure piston rod (34). The dynamic pressure piston rod (34) is concentrically installed in the dynamic pressure chamber (20) of the dynamic pressure cylinder. (9) Installed on the dynamic pressure piston rod (34), one side of the dynamic pressure piston (9) is close to the shoulder of the dynamic pressure piston rod (34), and the dynamic pressure piston rod on the other side of the dynamic pressure piston (9) (34) is equipped with spring washer (18) and nut (17); A sealing ring (35) is installed in the sealing groove of the working end of the pressure piston rod (34); the end of the dynamic pressure piston rod (34) passes through the right end cover (12), and the installation cover (15) is installed at the center of the right end cover (12) One end of the displacement sensor (16) is fixed on the installation cover (15), and the other end of the displacement sensor (16) is inserted into the hole at the end of the dynamic pressure piston rod (34); The cylinder block (2) of the static pressure cylinder is respectively provided with the first working oil port (3) and the second working oil port (6) communicating with both sides of the static pressure chamber (27), and the cylinder body (2) of the dynamic pressure cylinder ) are respectively provided with the third working oil port (8) and the fourth working oil port (11) communicating with both sides of the dynamic pressure chamber (20); there is a third oil leakage port on the inner wall of the central through hole of the cylinder partition wall. Annular groove (21), the middle position of the cylinder partition wall is provided with a leakage oil port (7) communicating with the third leakage oil annular groove (21); the first working oil port (3), the second working oil port ( 6), the third working oil port (8), the fourth working oil port (11) and the leakage oil port (7) communicate with the corresponding valve port of the servo valve seat (4); The inner wall of the through hole of the left end cover (1) is provided with a first leakage oil annular groove (32), and the first leakage oil annular groove (32) passes through the first leakage oil passage (31) on the left end cover (1) and the static pressure cylinder The second leakage oil passage (29) on the cylinder (2) communicates with the third leakage oil annular groove (21); at the inner wall of the hydrostatic piston rod (33) corresponding to the first leakage oil annular groove (32) A second leakage oil annular groove (36) is provided, and the second leakage oil annular groove (36) communicates with the first leakage oil annular groove (32) through a third leakage oil passage (38); The width of the first leakage oil annular groove (32) is 1.3-2 times of the stroke of the hydrostatic piston (5). 2. The two-stage servo hydraulic cylinder according to claim 1, characterized in that a gap seal is used between the dynamic pressure piston (9) and the cylinder body (2), and the dynamic pressure piston rod (34) is separated from the cylinder body A gap seal is adopted between the wall inner walls, and a gap seal is adopted between the dynamic pressure piston rod (34) and the static pressure piston rod (33). 3. The two-stage servo hydraulic cylinder according to claim 1 or 2, characterized in that the outer wall of the dynamic pressure piston (9) has 3 to 5 first balance grooves (10), and the dynamic pressure piston rod (34) has 4～6 second balance grooves (22) on the dynamic pressure piston rod (34) of the contact part with the central through hole of the cylinder partition wall.

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