阅读说明：本技术 一种阀芯和电机内置式数字流体缸 (Digital fluid cylinder with built-in valve core and built-in motor ) 是由 齐潘国 沈洋洋 赵丽薇 王顶柱 高明泽 刘政奇 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种阀芯和电机内置式采用四边滑阀控制2个压力腔来实现运动控制的数字流体缸包括：缸筒、缸端盖、缸底盖、活塞、活塞杆、外耳环、电机、方形导轨及四边滑阀。依据本发明的数字流体缸,可以避免电机在采煤时受到煤岩的冲击而损坏,在轴向及径向空间尺寸均严格受限的情况,也可以实现对重达几十甚至上百吨的负载的高精度控制。(The invention discloses a digital fluid cylinder with a valve core and a built-in motor, which adopts a four-side slide valve to control 2 pressure cavities to realize motion control, and comprises: the cylinder, cylinder end cover, cylinder bottom cover, piston rod, outer earrings, motor, square guide rail and four sides slide valve. According to the digital fluid cylinder disclosed by the invention, the motor can be prevented from being damaged by the impact of coal rocks during coal mining, and under the condition that the axial and radial space dimensions are strictly limited, the high-precision control on the load of dozens of tons or even hundreds of tons can be realized.)

1. The utility model provides a case and built-in digital fluid cylinder of motor which characterized in that: comprises the following steps: the cylinder comprises a cylinder barrel, a cylinder end cover, a cylinder bottom cover, a piston rod, an outer ear ring, a motor, a square guide rail and a four-side slide valve; one end of the cylinder barrel is fixedly connected with the cylinder end cover through a bolt, the other end of the cylinder barrel is fixedly connected with the cylinder bottom cover through a bolt, the cylinder end cover is in static seal fit with the cylinder barrel, and the cylinder bottom cover is in static seal fit with the cylinder barrel; the piston rod is fixedly connected with the external ear ring through a bolt; the motor is arranged in a cavity at the top of the piston rod, is axially fixed by an external ear ring part, does not axially displace with the piston rod, and is sealed by a motor sealing cover; the cylinder is sleeved on the piston, the piston is sleeved on the piston rod, the cylinder is matched with the piston in a dynamic sealing mode, and the piston is fixedly connected with the piston rod through threads.

2. The digital fluid cylinder of claim 1, wherein: the oil way communicated with the rod cavity of the hydraulic cylinder on the piston is a first oil way, the first oil way on the piston is communicated with a third oil way on the piston rod in a sealing way, and the third oil way is communicated with a four-side slide valve A cavity in the piston rod; the oil way communicated with the rodless cavity of the hydraulic cylinder on the piston is a second oil way, the second oil way on the piston is communicated with a fourth oil way on the piston rod in a sealing manner, and the fourth oil way is communicated with a B cavity of the four-side sliding valve in the piston rod; the four-side slide valve is divided into two parts, namely a four-side slide valve core and a valve sleeve, wherein the valve core and the valve sleeve form 4 variable throttling ports; two throttling ports are formed in the middle of the four-side sliding valve and are oil inlet throttling ports, and two throttling ports are formed in the two end parts of the four-side sliding valve and are oil outlet throttling ports; the oil outlet throttling ports at two ends of the four-side sliding valve sleeve are respectively communicated with an annular groove a and an annular groove c on the piston rod, and the annular groove a and the annular groove c are mutually communicated and are communicated with an oil outlet oil way on the piston rod; and the oil inlet throttling ports of the four-side slide valve are communicated with an annular groove b, and the annular groove b is communicated with an oil inlet oil way on the piston rod.

3. The digital fluid cylinder of claim 1, wherein: the motor can be a stepping motor or a servo motor, and a motor shaft of the motor is fixedly connected with one end of the square guide rail through a coupler; the other end of the square guide rail is sleeved in the square hole connecting piece and penetrates through the inside of the ball screw to be parallel to the ball screw; the square hole connecting sheet is fixedly connected with the ball screw through a bolt; the motor and the square guide rail are placed in a cavity at the top of the piston rod, and are axially fixed by the outer ear ring part of the piston and sealed by the motor sealing cover; and a certain electric signal is given to the motor to enable the motor shaft to rotate by a certain angle, the motor shaft drives the ball screw to rotate through the square guide rail and the square hole connecting sheet, and the rotating angle of the ball screw is the same as the rotating angle of the motor shaft.

4. The digital fluid cylinder of claim 3, wherein: one end of the ball screw is a free end, and the other end of the ball screw is a driving end; the motor and the square guide rail are arranged at the ball screw driving end, and the square guide rail is connected with the ball screw through a square hole connecting sheet; the free end of the ball screw penetrates through the center of the cylinder bottom cover, a screw abdicating hole is formed in the center of the cylinder bottom cover, the free end of the ball screw penetrates through the screw abdicating hole, and the ball screw is parallel to the cylinder barrel; the free end of the ball screw is sleeved with a deep groove ball bearing, a positioning shaft sleeve, a bearing cover and a locking nut, the ball screw is axially fixed at a screw abdicating hole of the cylinder bottom cover, and the ball screw only rotates and does not translate through the matching between a shaft shoulder and the bearing; the motor sealing cover is arranged on the driving end of the ball screw and is connected with the piston rod through a screw; the sealing cover is in dynamic sealing fit with the ball screw driving end.

5. The digital fluid cylinder of claim 4, wherein: the ball nut is sleeved on the free end of the ball screw and can axially move on the ball screw; the ball nut is sleeved with a four-side slide valve core and fixedly connected through screw connection; the four-side sliding valve core is fixedly provided with a guide key at one end close to the cylinder bottom cover, the inner wall of the piston is provided with a guide key groove, and the four-side sliding valve core only has the degree of freedom of linear sliding relative to the piston rod; the four-side sliding valve core is sleeved with a valve sleeve which is sleeved inside the piston rod; the four-side slide valve core is in clearance seal fit with the valve sleeve, the valve sleeve is in clearance seal fit with the inner wall of the piston rod, and the slide valve core can axially move back and forth in the valve sleeve to change the opening amount of the throttling opening, so that the throttling opening is opened or closed.

6. The digital fluid cylinder of claim 5, wherein: the four-side sliding valve core is sleeved with a valve sleeve which is sleeved inside the piston rod; the four-side sliding valve core is in clearance sealing fit with the valve sleeve, the valve sleeve is in clearance sealing fit with the inner wall of the piston rod, and the sliding valve core can axially move back and forth in the valve sleeve to change the opening amount of the throttling opening so as to open or close the throttling opening; the four-side slide valve is characterized in that the 4 variable throttling mouths are divided into two groups, and each group comprises two throttling mouths and respectively controls the inlet and outlet flow of a rodless cavity and a rod cavity of the hydraulic cylinder; if the opening areas of the two groups of variable throttling openings are the same, a symmetrical four-side slide valve is formed; if the opening areas of the two groups of variable throttling openings are similar, the ratio of the opening areas is equal to the ratio of the effective acting areas of the rodless cavity and the rod cavity, and the asymmetric four-side sliding valve is formed.

7. The digital fluid cylinder of claim 6, wherein: the symmetrical four-side sliding valve can be realized by forming two groups of same valve sleeve windows on the valve sleeve, and the valve sleeve windows can be round windows or rectangular windows; the asymmetric four-side sliding valve can be realized in two ways, one way is realized by forming two groups of similar valve sleeve windows on the valve sleeve, and the shape of the valve sleeve window can be a circular window or a rectangular window; another way to realize this is to open two sets of similar grooves on the spool valve core, and the grooves can be circular grooves, rectangular grooves or U-shaped grooves.

Technical Field

The invention relates to a digital fluid cylinder with a built-in valve core and a built-in motor, belonging to the technical field of digital hydraulic pressure.

Background

A fluid cylinder is an end effector that performs a linear reciprocating motion by converting pressure energy of a fluid (liquid or gas) into mechanical energy. The traditional fluid cylinder can realize the practical functions of position control, speed control, direction control and the like only by combining with a fluid control valve (a direction valve, a pressure valve, a flow valve, a servo valve and the like), and has the main defects of complex system structure, high price, inconvenient use and maintenance, higher requirement on technical personnel and incapability of directly realizing the control of a digital computer.

The digital fluid cylinder is essentially different from the traditional fluid cylinder, is a linear actuating element integrating an energy conversion function and a control function, and is far better than the traditional fluid cylinder in both practical function and control performance in a middle and low frequency range. Most of digital cylinders on the market adopt a mechanical-hydraulic servo system, and the digital cylinders can be divided into two types, namely a valve core external type digital cylinder and a valve core internal type digital cylinder.

The invention patent ZL 201910445065. X discloses a digital fluid cylinder with a built-in valve core, wherein the valve core of the digital fluid cylinder is built in a piston, and the axial installation space of the cylinder is effectively reduced. However, the motor is fixedly arranged on the outer wall of the cylinder barrel, so that great inconvenience is brought to installation and maintenance due to overlarge radial dimension, and the motor can be damaged by the impact of coal rocks during coal mining, thereby causing shutdown and production halt. The valve core and the motor are both arranged in the piston, so that the problems can be avoided, and the valve core is more suitable for mining equipment with strictly limited installation space and loads of dozens of tons or even hundreds of tons.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a digital fluid cylinder with a built-in valve core and a built-in motor, which can prevent the motor from being damaged by the impact of coal rocks during coal mining, and can realize high-precision control of loads up to tens of tons or even hundreds of tons under the condition that the axial and radial space dimensions are strictly limited. In order to achieve the above object, the present invention adopts the following technical solutions.

A digital fluid cylinder with a built-in valve core and a built-in motor comprises: the cylinder, cylinder end cover, cylinder bottom cover, piston rod, outer earrings, motor, square guide rail and four sides slide valve. One end of the cylinder barrel is fixedly connected with the cylinder end cover through a bolt, the other end of the cylinder barrel is fixedly connected with the cylinder bottom cover through a bolt, the cylinder end cover is in static seal fit with the cylinder barrel, and the cylinder bottom cover is in static seal fit with the cylinder barrel. The piston rod is fixedly connected with the external ear ring through a bolt. The motor is arranged in a cavity at the top of the piston rod, is axially fixed by the external ear ring part, does not axially displace with the piston rod, and is sealed by the motor sealing cover. The cylinder is sleeved on the piston, the piston is sleeved on the piston rod, the cylinder is matched with the piston in a dynamic sealing mode, and the piston is fixedly connected with the piston rod through threads.

The oil way communicated with the rod cavity of the hydraulic cylinder on the piston is a first oil way, the first oil way on the piston is communicated with a third oil way on the piston rod in a sealing way, and the third oil way is communicated with a four-side slide valve A cavity in the piston rod. And the oil path communicated with the rodless cavity of the hydraulic cylinder on the piston is a second oil path, the second oil path on the piston is communicated with a fourth oil path on the piston rod in a sealing manner, and the fourth oil path is communicated with a B cavity of the four-side sliding valve in the piston rod. The four-side slide valve is divided into two parts of a four-side slide valve core and a valve sleeve, and the valve core and the valve sleeve form 4 variable throttling ports. Two throttling ports are formed in the middle of the four-side slide valve and are oil inlet throttling ports, and two throttling ports are formed in the two end portions of the four-side slide valve and are oil outlet throttling ports. And oil outlet throttling ports at two ends of the four-side sliding valve sleeve are respectively communicated with an annular groove a and an annular groove c on the piston rod, and the annular groove a and the annular groove c are mutually communicated and are communicated with an oil outlet oil way on the piston rod. And the oil inlet throttling ports of the four-side slide valve are communicated with an annular groove b, and the annular groove b is communicated with an oil inlet oil way on the piston rod.

The motor can select a stepping motor or a servo motor, and a motor shaft of the motor is fixedly connected with one end of the square guide rail through a coupler. The other end of the square guide rail is sleeved in the square hole connecting piece and penetrates through the inside of the ball screw to be parallel to the ball screw. And the square hole connecting piece is fixedly connected with the ball screw through a bolt. The motor and the square guide rail are placed in a cavity at the top of the piston rod, and are axially fixed by the outer ear ring part of the piston and sealed by the motor sealing cover. And a certain electric signal is given to the motor to enable the motor shaft to rotate by a certain angle, the motor shaft drives the ball screw to rotate through the square guide rail and the square hole connecting sheet, and the rotating angle of the ball screw is the same as the rotating angle of the motor shaft.

One end of the ball screw is a free end, and the other end of the ball screw is a driving end. The motor and the square guide rail are arranged at the ball screw driving end, and the square guide rail is sleeved in the square hole connecting piece and penetrates through the inside of the ball screw to be parallel to the ball screw. The free end of the ball screw penetrates through the center of the cylinder bottom cover, a screw abdicating hole is formed in the center of the cylinder bottom cover, and the free end of the ball screw penetrates through the screw abdicating hole and is parallel to the cylinder barrel. The free end of the ball screw is sleeved with a deep groove ball bearing, a positioning shaft sleeve, a bearing cover and a locking nut, the ball screw is axially fixed at a yielding hole of the cylinder bottom cover screw, and the ball screw only rotates and does not translate through the matching between a shaft shoulder and the bearing. The motor sealing cover is sleeved on the ball screw driving end and fixedly connected with the piston rod through a bolt. The motor sealing cover is in dynamic sealing fit with the ball screw driving end and is in static sealing fit with the piston rod.

The ball nut is sleeved on the free end of the ball screw and can axially move on the ball screw. The ball nut is sleeved with a four-side slide valve core and fixedly connected through screw connection. The four-side sliding valve core is fixedly provided with a guide key at one end close to the cylinder bottom cover, the inner wall of the piston is provided with a guide key groove, and the four-side sliding valve core only has the degree of freedom of linear sliding relative to the piston rod. The four-side sliding valve core is sleeved with a valve sleeve, and the valve sleeve is sleeved inside the piston rod. The four-side slide valve core is in clearance seal fit with the valve sleeve, the valve sleeve is in clearance seal fit with the inner wall of the piston rod, and the slide valve core can axially move back and forth in the valve sleeve to change the opening amount of the throttling opening, so that the throttling opening is opened or closed.

The four-side slide valve is characterized in that the 4 variable throttling mouths are divided into two groups, and each group comprises two throttling mouths and respectively controls the inlet and outlet flow of a rodless cavity and a rod cavity of the hydraulic cylinder. If the opening areas of the two groups of variable chokes are the same, a symmetrical four-side slide valve is formed. If the opening areas of the two groups of variable throttling openings are similar, the ratio of the opening areas is equal to the ratio of the effective acting areas of the rodless cavity and the rod cavity, and the asymmetric four-side sliding valve is formed.

The symmetrical four-side sliding valve can be realized by forming two groups of identical valve sleeve windows on the valve sleeve, and the valve sleeve windows can be circular windows or rectangular windows. The asymmetric four-side sliding valve can be realized in two ways, one way is realized by forming two groups of similar valve sleeve windows on the valve sleeve, and the shape of the valve sleeve window can be a circular window or a rectangular window. Another way to realize this is to open two sets of similar grooves on the spool valve core, and the grooves can be circular grooves, rectangular grooves or U-shaped grooves.

The invention has the beneficial effects that: the digital fluid cylinder with the built-in valve core, which realizes motion control by controlling 2 pressure cavities through the four-side sliding valve, can realize high-precision control on loads of dozens of tons or even hundreds of tons under the condition that the axial and radial space sizes are strictly limited.

Drawings

FIG. 1 is a cross-sectional view of a front view of an embodiment of a four-sided slide valve controlled asymmetric cylinder type digital fluid cylinder with a built-in valve core and motor of the present invention;

FIG. 2 is a cross-sectional view of a top view of an embodiment of a four-sided slide valve controlled asymmetric cylinder type digital fluid cylinder with a built-in spool and motor of the present invention;

FIG. 3 is an enlarged view of portion A1 of FIG. 1;

FIG. 4 is a schematic diagram of a second asymmetric four-sided spool valve of an embodiment of a four-sided spool valve-controlled asymmetric cylinder type digital fluid cylinder with a built-in valve core and a built-in motor of the invention;

FIG. 5 is a schematic diagram of a three asymmetric four sided spool valve of an embodiment of a four sided spool valve controlled asymmetric cylinder type digital fluid cylinder with a built-in spool and motor of the present invention;

FIG. 6 is a schematic diagram of a four asymmetric four sided spool valve of an embodiment of a four sided spool valve controlled asymmetric cylinder digital fluid cylinder with a built-in four sided spool valve and motor of the present invention;

FIG. 7 is a top view of an embodiment of a four asymmetric four sided spool valve spool of a four sided spool valve controlled asymmetric cylinder digital fluid cylinder with a built in valve spool and motor of the present invention;

FIG. 8 is a schematic diagram of a five asymmetric four sided spool valve of an embodiment of a four sided spool valve controlled asymmetric cylinder digital fluid cylinder with a built in valve cartridge and motor of the present invention;

FIG. 9 is a top view of an embodiment five asymmetric four-sided spool valve spool of an asymmetric cylinder digital fluid cylinder controlled by a spool and motor built-in four-sided spool valve of the present invention;

in the figure, 1-external ear ring, 2-motor, 3-cylinder end cover, 4-cylinder, 5-piston rod, 6-motor sealing cover, 7-ball screw, 8-valve core, 9-valve sleeve, 10-annular groove a, 11-oil inlet pipeline, 12-cavity A, 13-annular groove B, 14-cavity B, 15-annular groove c, 16-ball nut, 17-piston, 18-screw, 19-bearing cover, 20-locating shaft sleeve, 21-deep groove ball bearing, 22-cylinder bottom cover, 23-oil outlet pipeline, 24-square hole connecting sheet, 25-square guide rail, 26-coupling 2, 27-coupling 1, 28-motor supporting seat, 29-motor base, 30-second oil channel, 31-fourth oil channel, 32-third oil channel, 33-first oil channel, 34-oil outlet throttling port, 35-oil inlet port, 36-guide key, 37-screw abdicating hole, 38-locking nut, and 39-guide key groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The present invention will be described in further detail with reference to the accompanying drawings.

Example one

As shown in fig. 1 to 3, an internal direct feedback asymmetric four-side sliding valve control asymmetric cylinder type digital fluid cylinder comprises: the device comprises a cylinder barrel 4, a cylinder end cover 3, a cylinder bottom cover 22, a piston 17, a piston rod 5, an external ear ring 1, a motor 2, a square guide rail 25 and a four-side slide valve. One end of the cylinder barrel 4 is fixedly connected with the cylinder end cover 3 through a bolt, the other end of the cylinder barrel is fixedly connected with the cylinder bottom cover 22 through a bolt, the cylinder end cover 3 is in static seal fit with the cylinder barrel 4, and the cylinder bottom cover 22 is in static seal fit with the cylinder barrel 4. The piston rod 5 is fixedly connected with the outer earring 1 through a bolt. The motor 2 is arranged in a cavity at the top of the piston rod 5, is axially fixed by the outer ear ring 1 part, does not axially displace with the piston rod 5, and is sealed by a motor sealing cover 6. The cylinder 4 is sleeved on the piston 17, the piston 17 is sleeved on the piston rod 5, the cylinder 4 is in dynamic seal fit with the piston 17, and the piston 17 is fixedly connected with the piston rod 5 through threads. The cylinder end cover 3 is in dynamic sealing fit with the piston rod 5.

The oil path communicated with the rod cavity of the hydraulic cylinder on the piston 17 is a first oil path 33, the first oil path 33 on the piston 17 is communicated with a third oil path 32 on the piston rod 5 in a sealing way, and the third oil path 32 is communicated with the cavity 12 of the four-side slide valve A in the piston rod 5. The oil path communicated with the rodless cavity of the hydraulic cylinder on the piston 17 is a second oil path 30, the second oil path 30 on the piston 17 is communicated with a fourth oil path 31 on the piston rod 5 in a sealing mode, and the fourth oil path 31 is communicated with the B cavity 14 of the four-side sliding valve in the piston rod 5. The four-side slide valve is divided into two parts of a four-side slide valve core 8 and a valve sleeve 9, and the valve core 8 and the valve sleeve 9 form 4 variable throttling ports. Two throttling ports are arranged in the middle of the four-side slide valve and are oil inlet throttling ports 35, and two throttling ports are arranged at two end parts of the four-side slide valve and are oil outlet throttling ports 34. The oil outlet throttle ports 34 at two ends of the four-side slide valve sleeve 9 are respectively communicated with the annular groove a10 and the annular groove c15 of the valve sleeve 9, and the annular groove a10 and the annular groove c15 are communicated with each other and are communicated with the oil outlet oil path 23 on the piston rod 5. The oil inlet throttling port 35 of the four-side slide valve is communicated with the annular groove b13, and the annular groove b13 is communicated with the oil inlet oil path 11 on the piston rod 5.

The motor 2 is arranged in the cavity at the top of the piston rod 5 through a motor base 29 and a motor supporting seat 28, and is axially fixed by the outer ear ring 1 and sealed by a motor sealing cover 6. The outer earrings 1 are fixedly connected with the piston rod 5 through bolts, and the motor 2 does not axially displace with the piston rod 5. The motor shaft of the motor 2 is connected with the square guide rail 25 through a coupling 26 and a coupling 27. The other end of the square guide rail 25 is sleeved in the square hole connecting piece 24 and penetrates through the inside of the ball screw 7 to be parallel to the ball screw 7. The square hole connecting piece 24 is fixedly connected with the ball screw 7 through a bolt and does not axially displace with the ball screw 7. The motor sealing cover 6 is sleeved on the ball screw 7 and fixedly connected with the piston rod 5 through a bolt. The motor sealing cover 6 is in dynamic sealing fit with the ball screw 7 and is in static sealing fit with the piston rod 5. The motor shaft of the motor 2 rotates by a certain angle, the motor shaft drives the ball screw 7 to rotate through the square guide rail 25 and the square hole connecting sheet 24, and the rotating angle of the ball screw 7 is the same as that of the motor shaft of the motor 2.

One end of the ball screw 7 is a free end, and the other end of the ball screw is a driving end. The motor 2 and the square guide rail 25 are arranged at the driving end of the ball screw 7, and the square guide rail 25 is sleeved in the square hole connecting piece 24 and penetrates through the inside of the ball screw 7 to be parallel to the ball screw 7. The free end of the ball screw 7 penetrates through the center of the piston rod 5, a screw rod abdicating hole 37 is formed in the center of the cylinder bottom cover 22, the free end of the ball screw 7 penetrates through the screw rod abdicating hole 37, and the ball screw 7 is parallel to the cylinder barrel 4. The free end of the ball screw 7 is sleeved with a deep groove ball bearing 21, a positioning shaft sleeve 20, a bearing cover 19 and a locking nut 38, so that the ball screw 7 does not translate and only rotates. The motor sealing cover 6 is sleeved on the driving end of the ball screw 7 and fixedly connected with the piston rod 5 through a bolt. And the motor sealing cover 6 is in dynamic sealing fit with the driving end of the ball screw 7 and is in static sealing fit with the piston rod 5.

The ball screw 7 is sleeved with a ball nut 16 at the free end, and the ball nut 16 can axially move on the ball screw 7. The four-side slide valve spool 8 is sleeved on the ball nut 16 and fixedly connected through a screw 18. The four-side slide valve core 8 is fixedly provided with a guide key 36 at one end close to the cylinder bottom cover 22, and the inner wall of the piston 17 is provided with a guide key groove 39. The four-sided spool valve 8 has only a degree of freedom of linear sliding with respect to the piston rod 5. The four-side slide valve core 8 is sleeved with a valve sleeve 9, and the valve sleeve 9 is sleeved inside the piston rod 5. The four-side sliding valve core 8 is in clearance sealing fit with the valve sleeve 9, the valve sleeve 9 is in clearance sealing fit with the inner wall of the piston rod 5, the valve sleeve 9 does not move in the axial direction, the four-side sliding valve core 8 can move in the valve sleeve 9 in the axial direction back and forth, the opening amount of the throttling opening is changed, and then the throttling opening is opened or closed.

The four-side slide valve is characterized in that the 4 variable throttling mouths are divided into two groups, and each group comprises two throttling mouths and respectively controls the inlet and outlet flow of a rodless cavity and a rod cavity of the hydraulic cylinder. If the opening areas of the two groups of variable chokes are the same, a symmetrical four-side slide valve is formed. If the opening areas of the two groups of variable throttling openings are similar, the ratio of the opening areas is equal to the ratio of the effective acting areas of the rodless cavity and the rod cavity, and the asymmetric four-side sliding valve is formed.

The symmetrical four-side slide valve can be realized by forming two groups of identical valve sleeve 9 windows on the valve sleeve 9, and the shape of the valve sleeve 9 window can be a circular window or a rectangular window. The asymmetric four-side sliding valve can be realized in two ways, one way is realized by opening two groups of similar valve sleeve 9 windows on the valve sleeve 9, and the shape of the valve sleeve 9 window can be a circular window or a rectangular window. Another way to achieve this is to make two sets of similar grooves on the spool valve 8, which can be circular, rectangular or U-shaped. In this first embodiment, a four-sided spool valve is used.

The operation of the present invention is described below with reference to the accompanying drawings:

the invention relates to an asymmetric cylinder type digital fluid cylinder with an internal direct feedback asymmetric four-side sliding valve, wherein when a four-side sliding valve core 8 is positioned at a middle position, a piston 17 and a piston rod 5 are in a static state. An electric signal is input to the motor 2, a motor shaft of the motor 2 rotates for a certain angle, the square guide rail 25 is driven to rotate for a certain angle through the couplers 26 and 27, the square guide rail 25 drives the ball screw 7 to rotate for a certain angle through the square hole connecting piece 24, and the rotation angle of the ball screw 7 is the same as that of the motor shaft. The four-side sliding valve is sleeved on the ball nut 16 and fixedly connected through the screw 18, the ball nut 16 does not rotate under the action of the screw thread pair of the ball screw 7 and the guide key 36, only certain axial displacement is generated, and when the ball screw 7 rotates to drive the ball nut 16 to generate axial displacement, the four-side sliding valve also moves axially. Assuming that the four-sided spool valve element 8 moves leftward, an axial displacement is generated between the four-sided spool valve element 8 and the valve sleeve 9, the throttle ports are opened, and oil flows into the spool valve oil inlet throttle port 35 from the oil inlet passage 11 and enters the four-sided spool valve B chamber 14. After entering the B chamber 14 of the four-sided spool, the oil flows along the fourth oil path 31 of the piston rod 5 into the second oil path 30 of the piston 17. The oil then flows from the second oil passage 30 of the piston 17 into the rodless chamber of the cylinder, and drives the cylinder piston 17 to move to the left. The oil in the rod chamber of the hydraulic cylinder flows into the third oil path 32 on the piston rod 5 along the first oil path 33 on the piston 17, and the oil flowing into the third oil path 32 enters the chamber 12 of the four-side spool a and then is discharged into the oil outlet path 23 through the oil outlet throttle 34. The displacement of the hydraulic cylinder piston 17 is equal to the displacement of the four-side slide valve core 8, the displacement of the piston 17 is used as a feedback signal to carry out direct negative feedback, so that the slide valve opening is closed, the hydraulic cylinder piston 17 stops moving, and one action process is finished. When the electric signal is continuously input to the motor, the continuous left movement of the piston rod 5 of the hydraulic cylinder can be realized, and the displacement of the piston rod 5 can be ensured.

Assuming that the four-sided spool valve element 8 moves rightward, an axial displacement is generated between the four-sided spool valve element 8 and the valve sleeve 9, the throttle ports are opened, and oil flows into the spool valve oil inlet throttle port 35 from the oil inlet oil path 11 and enters the four-sided spool valve a chamber 12. After entering the chamber 12 of the four-sided spool a, the oil flows along the third oil passage 32 of the piston rod 5 into the first oil passage 33 of the piston 17. The oil then flows from the first passage 33 in the piston 17 into the rod chamber of the cylinder, thereby driving the cylinder piston 26 to the right. The oil in the rodless chamber of the hydraulic cylinder flows into the fourth oil passage 31 on the piston rod 5 along the second oil passage 30 on the piston 17, and the oil flowing into the fourth oil passage 31 enters the four-side spool B chamber 14 and then is discharged through the oil outlet throttle 34 into the oil outlet passage 23. The displacement of the hydraulic cylinder piston 17 is equal to the displacement of the four-side slide valve core 8, the displacement of the piston 17 is used as a feedback signal to carry out direct negative feedback, so that the slide valve opening is closed, the hydraulic cylinder piston 17 stops moving, and one action process is finished. When the electric signal is continuously input to the motor 2, the continuous left movement of the piston rod 5 of the hydraulic cylinder can be realized, and the displacement of the piston rod 5 can be ensured.

Example two

In connection with fig. 4, the four-sided symmetrical slide valve of the first embodiment is replaced by an asymmetrical four-sided slide valve, i.e. two large rectangular windows and two small rectangular windows are opened in the valve housing 9. The large rectangular window is communicated with the rodless cavity of the hydraulic cylinder, and the small rectangular window is communicated with the rod cavity of the hydraulic cylinder.

EXAMPLE III

In connection with fig. 5, the four-sided symmetrical slide valve of the first embodiment is replaced by an asymmetrical four-sided slide valve, i.e. two large circular windows and two small circular windows are opened in the valve housing 9. The big round window is communicated with the rodless cavity of the hydraulic cylinder, and the small round window is communicated with the rod cavity of the hydraulic cylinder.

Example four

With reference to fig. 6 to 7, the four-sided symmetrical spool valve in the first embodiment is replaced with an four-sided asymmetrical spool valve, that is, the openings of the valve sleeves 9 are the same, and rectangular grooves or U-shaped grooves with different sizes are formed on the shoulder of the valve core 8. When the four-sided spool valve spool 8 is in the neutral position, the land of the spool 8 is sealed from the opening in the valve sleeve 9. When the valve core 8 moves, the edge of the rectangular groove or the U-shaped groove on the shoulder of the valve core 8 is communicated with the opening of the valve sleeve 9 to form a throttling port. The large rectangular groove or the U-shaped groove is communicated with the rodless cavity of the hydraulic cylinder, and the small rectangular groove or the U-shaped groove is communicated with the rod cavity of the hydraulic cylinder.

EXAMPLE five

With reference to fig. 8 to 9, the four-sided symmetrical slide valve in the first embodiment is replaced with an asymmetrical four-sided slide valve, that is, the openings of the valve sleeve 9 are the same, and circular grooves with different sizes are formed on the shoulder of the valve core 8. When the four-sided spool valve spool 8 is in the neutral position, the land of the spool 8 is sealed from the opening in the valve sleeve 9. When the valve core 8 moves, the edge of the rectangular groove or the U-shaped groove on the shoulder of the valve core 8 is communicated with the opening of the valve sleeve 9 to form a throttling port. The big circular groove is communicated with the rodless cavity of the hydraulic cylinder, and the small circular groove is communicated with the rod cavity of the hydraulic cylinder.

Under the condition that the axial and radial space dimensions are strictly limited, the digital fluid cylinder with the built-in valve core realizes motion control by controlling 2 pressure cavities through the four-side sliding valve, and can also realize high-precision control on loads of dozens of tons or even hundreds of tons.

The embodiments are not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention are intended to be included in the scope of the present invention.