Air cylinder with air pressure controlled stroke and method of driving same

Abstract

The present application relates to a kind of pneumatic cylinder of air pressure control stroke and its driving method, belong to pneumatic cylinder technical field, solve the problem of complex structure, large space occupation in prior art.The present application includes: piston assembly, cylinder sleeve, cylinder cover, first quick connector and second quick connector;Piston assembly is slidably installed in the inside of cylinder sleeve, and end extends cylinder sleeve;Piston assembly is in sealing contact with cylinder sleeve, and the inside space of piston assembly and cylinder sleeve is enclosed to form closed first cavity;Cylinder cover is fixedly installed at the port of cylinder sleeve, and cylinder cover, cylinder sleeve and piston assembly form second cavity;First quick connector is installed on cylinder sleeve, and is communicated with first cavity;Second quick connector is installed on cylinder cover, and is communicated with second cavity;First quick connector, second quick connector are used to pass into gas to first cavity, second cavity respectively.The present application realizes the displacement output of multiple strokes.

Description

Technical Field

[0001] This invention relates to the field of cylinder technology, and in particular to a cylinder with pneumatically controlled stroke and its driving method. Background Technology

[0002] A stroke cylinder is a common pneumatic actuator used to convert pneumatic energy into mechanical motion. In the industrial and automation fields, stroke cylinders are often used to control and drive the linear motion of mechanical devices.

[0003] The stroke of a stroke cylinder is generally met by selecting different cylinder specifications and sizes. For cylinders with larger structures that require long strokes, mechanical or pneumatic limit switches are used to control the cylinder stroke. Alternatively, the stroke length can be manually adjusted or the cylinder stroke can be controlled in real time using electronic components, but this method is complex.

[0004] Therefore, there is a need for a multi-stroke cylinder that is simple in structure and easy to control. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a pneumatically controlled cylinder and its driving method to solve the problems of inconvenient operation of existing multi-stroke cylinder control, complex cylinder structure and large space occupation.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] A cylinder with pneumatically controlled stroke includes: a piston assembly, a cylinder liner, a cylinder head, a first quick-connect fitting, and a second quick-connect fitting;

[0008] The piston assembly is slidably mounted inside the cylinder liner, with its end extending out of the cylinder liner; the piston assembly is in sealed contact with the cylinder liner, and the internal space of the piston assembly and the cylinder liner forms a closed first cavity; the cylinder head is fixedly mounted at the port of the cylinder liner, and the cylinder head, cylinder liner, and piston assembly form a second cavity;

[0009] The first quick-connector is mounted on the cylinder liner and communicates with the first cavity; the second quick-connector is mounted on the cylinder head and communicates with the second cavity; the first quick-connector and the second quick-connector are used to introduce gas into the first cavity and the second cavity, respectively.

[0010] Furthermore, the piston assembly includes: a piston rod, a main piston, a secondary piston, and a spring.

[0011] Furthermore, both the piston rod and the auxiliary piston are slidably mounted inside the main piston, and the piston rod and the auxiliary piston are fixedly connected; when the auxiliary piston slides relative to the main piston, it can compress the spring.

[0012] Furthermore, the piston assembly also includes a guide sleeve; the main piston has a threaded hole and a fourth through hole inside; the guide sleeve is screwed into the threaded hole; the auxiliary piston is slidably mounted in the fourth through hole. The spring is disposed in the fourth through hole of the main piston and sleeved on the outside of the piston rod.

[0013] Furthermore, the spring is disposed between the guide sleeve and the auxiliary piston.

[0014] The guide sleeve is provided with a fifth through hole and a third blind hole; one end of the piston rod is slidably installed in the fifth through hole, and the other end is fixedly connected to the auxiliary piston; the side of the auxiliary piston is provided with a second blind hole; the two ends of the spring abut against the end face of the third blind hole and the end face of the second blind hole, respectively.

[0015] Furthermore, the cylinder liner is provided with a first through hole and a second through hole; the end of the main piston extends out of the cylinder liner from the first through hole; the first quick-connect fitting is installed in the second through hole.

[0016] Furthermore, the main piston includes a cylindrical section and a piston section; the cylindrical section of the main piston is slidably installed in the first through hole, and the piston section of the main piston is slidably installed in the inner cavity of the cylinder liner.

[0017] Furthermore, the cylindrical section is sealed to the first through hole by a first sealing ring; the cylinder head and the cylinder liner are sealed by a second sealing ring.

[0018] Furthermore, a fourth annular groove is provided on the outer side of the auxiliary piston; a third sealing ring is provided in the fourth annular groove; a second annular groove is provided on the outer side of the piston section of the main piston; a fourth sealing ring is installed in the second annular groove.

[0019] A cylinder driving method for driving a cylinder with a pneumatically controlled stroke.

[0020] The technical solution of this invention can achieve at least one of the following effects:

[0021] 1. This invention designs a pneumatically controlled cylinder, which drives the main piston and auxiliary piston to move by pneumatic pressure, and can realize three-level control of the cylinder stroke, thus meeting the needs of cylinder stroke control in automation control.

[0022] 2. The pneumatically controlled cylinder of the present invention realizes the need for a long stroke action of a small-sized cylinder, saves cylinder installation space, and has the characteristics of simple structure and small size.

[0023] 3. The pneumatically controlled cylinder of the present invention has a simple and reliable driving method, can realize multiple stroke controls, and can thus adapt to a variety of application scenarios.

[0024] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0025] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0026] Figure 1 This is a three-dimensional view of the cylinder for the pneumatic control stroke of the present invention;

[0027] Figure 2 This is a cross-sectional view of the cylinder for the pneumatic control stroke of the present invention;

[0028] Figure 3 A three-dimensional view of the piston assembly;

[0029] Figure 4 This is a cross-sectional view of the piston assembly.

[0030] Figure 5 This is a 3D diagram of the piston rod;

[0031] Figure 6 This is a sectional view of the piston rod;

[0032] Figure 7 This is a 3D diagram of the secondary piston;

[0033] Figure 8 This is a cross-sectional view of the auxiliary piston;

[0034] Figure 9 A 3D diagram of the main piston;

[0035] Figure 10 Front view of the main piston;

[0036] Figure 11 A sectional view of the main piston;

[0037] Figure 12 A three-dimensional view of the cover;

[0038] Figure 13 This is the main view of the guide sleeve;

[0039] Figure 14 This is a sectional view of the guide sleeve;

[0040] Figure 15 This is a three-dimensional view of the cylinder liner;

[0041] Figure 16 This is a sectional view of the cylinder liner;

[0042] Figure 17 This is a three-dimensional view of the cylinder head;

[0043] Figure 18 This is a sectional view of the cylinder head.

[0044] Figure label:

[0045] 1. Piston assembly; 2. First sealing ring; 3. Cylinder liner; 4. Second sealing ring; 5. Cylinder head; 6. First quick-connect fitting; 7. First screw; 8. Second quick-connect fitting; 9. Piston rod; 10. Main piston; 11. Third sealing ring; 12. Fourth sealing ring; 13. Guide ring; 14. Second guide ring; 15. Secondary piston; 16. Second screw; 17. Sealing gasket; 18. Retaining cap; 19. Third screw; 20. Spring; 21. Guide sleeve;

[0046] 3-1, First through hole; 3-2, Second through hole; 3-3, First annular groove;

[0047] 5-1, First blind hole; 5-2, Third through hole;

[0048] 10-1, Cylindrical section; 10-2, Piston section; 10-3, Second annular groove; 10-4, Third annular groove; 10-5, Threaded hole; 10-6, Fourth through hole;

[0049] 15-1, Fourth annular groove; 15-2, Fifth annular groove; 15-3, Second blind hole;

[0050] 21-1, Threaded section; 21-2, Clamping section; 21-3, Fifth through hole; 21-4, Third blind hole. Detailed Implementation

[0051] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0052] Example 1

[0053] One specific embodiment of the present invention discloses a cylinder with pneumatically controlled stroke, such as... Figure 1 , Figure 2As shown, the assembly includes: a piston assembly 1, a cylinder liner 3, a cylinder head 5, a first quick-connect fitting 6, and a second quick-connect fitting 8; the piston assembly 1 is slidably mounted inside the cylinder liner 3, with its end extending out of the cylinder liner 3; the piston assembly 1 and the cylinder liner 3 are in sealed contact, and the internal spaces of the piston assembly 1 and the cylinder liner 3 form a closed first cavity; the cylinder head 5 is fixedly mounted at the port of the cylinder liner 3, and the cylinder head 5, the cylinder liner 3, and the piston assembly 1 form a second cavity; the first quick-connect fitting 6 is mounted on the cylinder liner 3 and communicates with the first cavity; the second quick-connect fitting 8 is mounted on the cylinder head 5 and communicates with the second cavity; the first quick-connect fitting 6 and the second quick-connect fitting 8 are respectively used to introduce gas into the first cavity and the second cavity.

[0054] During implementation, gas is injected into the first cavity and / or the second cavity through the first quick-connect connector 6 and the second quick-connect connector 8 to adjust the gas pressure in the first cavity and the second cavity. Then, the gas pressure pushes the piston assembly 1 to move to the left (away from the cylinder head 5) or to the right (closer to the cylinder head 5) relative to the cylinder liner 3, and then outputs linear displacement through the piston assembly 1.

[0055] Specifically, the cylinder liner 3 and the cylinder head 5 are fixedly connected by the first screw 7.

[0056] Furthermore, a convex frustum is provided on the side of the cylinder head 5, which extends into the interior of the cylinder liner 3 and contacts and engages with the inner cavity of the cylinder liner 3; a groove is provided on the side of the convex frustum, and a second sealing ring 4 is installed in the groove, and the cylinder head 5 and the cylinder liner 3 are sealed by the second sealing ring 4.

[0057] like Figure 17 , Figure 18 As shown, the cylinder head 5 is composed of a rectangular plate-shaped body and a convex frustum. The outer circle of the convex frustum has an annular groove, in which a second sealing ring 4 is installed. Specifically, a third through hole 5-2 is provided in the center of the rectangular plate-shaped body, and four through holes are provided at the four corners of the end face of the flat rectangular plate-shaped body for installing the first screw 7.

[0058] Specifically, such as Figure 15 , Figure 16 As shown, the cylinder liner 3 is provided with a first through hole 3-1 and a second through hole 3-2. Figure 1 , Figure 2 As shown, the end of the piston assembly 1 extends out from the first through hole 3-1; and the first quick connector 6 is installed in the second through hole 3-2.

[0059] Specifically, such as Figure 17 , Figure 18As shown, a first blind hole 5-1 is provided on the convex platform on the side of the cylinder head 5, and a third through hole 5-2 is provided on the cylinder head 5. Further, after the cylinder head 5 is connected to the cylinder liner 3, a second cavity is formed between the first blind hole 5-1 and the piston assembly 1; and the third through hole 5-2 is used to install a second quick-connect fitting 8, such as... Figure 2 As shown.

[0060] Furthermore, in order to achieve multi-stage cylinder driving, the present invention provides that the piston assembly 1 is a telescopic structure.

[0061] like Figure 3 , Figure 4 As shown, in one specific embodiment of the present invention, the piston assembly 1 includes: a piston rod 9, a main piston 10, a secondary piston 15, a spring 20, and a guide sleeve 21.

[0062] like Figure 5 , Figure 6 As shown, the piston rod 9 is composed of a long cylinder and a short cylinder coaxially, with the diameter of the long cylinder being smaller than that of the short cylinder. Furthermore, the outer circles on both sides of the short cylinder are designed as symmetrical platforms. Furthermore, both ends of the piston rod 9 are provided with central threaded holes, such as... Figure 6 As shown.

[0063] Specifically, the central threaded hole at the end face of the long cylinder is used to install the second screw 16.

[0064] Furthermore, the secondary piston 15 is fixedly connected to the piston rod 9 by a second screw, as shown below. Figure 4 As shown. Furthermore, a sealing gasket 17 is provided between the auxiliary piston 15 and the piston rod 9, as... Figure 4 As shown.

[0065] like Figure 9 , Figure 10 , Figure 11 As shown, the main piston 10 consists of two coaxial cylindrical sections; the main piston 10 includes a cylindrical section 10-1 and a piston section 10-2. Specifically, the cylindrical section 10-1 of the main piston 10 is slidably installed in the first through hole 3-1; the first quick-connect fitting 6 is inserted into the second through hole 3-2, and the piston section 10-2 of the main piston 10 is slidably installed in the inner cavity of the cylinder liner 3. When the piston section 10-2 slides left and right in the inner cavity of the cylinder liner 3, it can change the length of the cylindrical section 10-14 extending out of the first through hole 3-1, thereby realizing the displacement output of the cylinder.

[0066] Both the piston rod 9 and the auxiliary piston 15 are slidably mounted inside the main piston 10, and the piston rod 9 and the auxiliary piston 15 are fixedly connected; when the auxiliary piston 15 slides relative to the main piston 10, it can compress the spring 20.

[0067] Furthermore, the main piston 10 has a two-stage stepped through hole inside; specifically, the main piston 10 has a threaded hole 10-5 and a fourth through hole 10-6 inside.

[0068] Specifically, such as Figure 4 As shown, the guide sleeve 21 is threaded into the threaded hole 10-5; the auxiliary piston 15 is slidably installed in the fourth through hole 10-6. The spring 20 is disposed in the fourth through hole 10-6 of the main piston 10 and is sleeved on the outside of the piston rod 9. The spring 20 is also disposed between the guide sleeve 21 and the auxiliary piston 15.

[0069] like Figure 13 , Figure 14 As shown, the guide sleeve 21 includes a holding part 21-1 and a threaded section 21-2; wherein the holding part 21-1 is a short hexagonal prism, which facilitates the rotation of the guide sleeve 21, and thus facilitates the screwing of the threaded section 21-2 into the threaded hole 10-5 inside the cylindrical section 10-1 of the main piston 10.

[0070] Furthermore, the guide sleeve 21 is internally provided with a fifth through hole 21-3 and a third blind hole 21-4; as shown Figure 13 , Figure 14 As shown.

[0071] Specifically, one end of the piston rod 9 is slidably installed in the fifth through hole 21-3, and the other end is fixedly connected to the auxiliary piston 15.

[0072] Specifically, the diameter of the fifth through hole 21-3 is smaller than the diameter of the third blind hole 21-4. Correspondingly, a second blind hole 15-3 is provided on the side of the auxiliary piston 15, and both ends of the spring 20 are disposed in the second blind hole 15-3 of the auxiliary piston 15 and the third blind hole 21-4 of the guide sleeve 21; the two ends of the spring 20 respectively abut against the end face of the third blind hole 21-4 of the guide sleeve 21 and the end face of the second blind hole 15-3 of the auxiliary piston 15.

[0073] The present invention provides a spring 20 between the guide sleeve 21 and the auxiliary piston 15, which enables the auxiliary piston 15 and the main piston 10 to remain relatively stationary during the first stroke of the cylinder. During the second stroke, the air pressure drives the auxiliary piston 15 to move while compressing the spring 20. The present invention achieves the second-stage drive of the cylinder by setting the spring 20.

[0074] like Figure 7 , Figure 8 As shown, the auxiliary piston 15 is a cylinder; the outer side of the auxiliary piston is provided with a third annular groove 15-1 and a fourth annular groove 15-2, and a third sealing ring 11 and a second guide ring 14 are provided in the third annular groove 15-1, as shown. Figure 4 As shown.

[0075] In practice, when the auxiliary piston 15 slides along the fourth through hole 10-6 of the main piston 10, it can compress the spring 20, and then the piston rod 9 can extend out of the guide sleeve 21, and the cylinder can achieve a second-stage displacement.

[0076] Furthermore, the cylindrical section 10-1 of the main piston 10 is sealed to the first through hole 3-1 of the cylinder liner 3 by the first sealing ring 2;

[0077] Furthermore, the piston section 10-2 has a second annular groove 10-3 and a third annular groove 10-4 on its outer side, with the outer side being a shallow annular groove and the inner side being a deep annular groove. Specifically, a fourth sealing ring 12 is installed in the second annular groove 10-3. Specifically, a first guide ring 13 is installed in the third annular groove 10-4.

[0078] Furthermore, a fourth annular groove 15-1 is provided on the outer side of the auxiliary piston 15; a third sealing ring 11 is provided in the fourth annular groove 15-1.

[0079] Specifically, the end face of piston section 10-2 is provided with 4 threaded holes for installing the third screw 19; the cover 18 is fixedly installed on piston section 10-2 of main piston 2 by the third screw 19.

[0080] Furthermore, such as Figure 2 , Figure 4 As shown, a retaining cover 18 is fixedly installed at the port of the fourth through hole 10-6 of the main piston 10 by a third screw 19 to block the auxiliary piston 15 and prevent the auxiliary piston 15 from disengaging from the main piston 10.

[0081] like Figure 12 As shown, the cover 18 is annular, and the diameter of the inner ring is smaller than the outer diameter of the auxiliary piston 15. Specifically, the end face of the cover 18 has four mounting holes evenly distributed around the center for mounting the third screw 19.

[0082] Furthermore, the outer truncated cone diameter of the piston rod 9 is larger than the fifth through hole 21-3 inside the guide sleeve 21, thus enabling it to be locked onto the end face of the guide sleeve 21. The end face of the auxiliary piston 15 is pressed down by the cover 18, allowing the piston rod 9 and the auxiliary piston 15 to slide inside the guide sleeve 21 and cylinder liner 3, but without detaching from them.

[0083] like Figure 2 , Figure 4 As shown, the threaded section 21-2 of the guide sleeve 21 is screwed into the threaded hole of the main piston 10, and the axial position of the guide sleeve 21 in the main piston 10 can be adjusted by rotating the threaded section 21-2.

[0084] Specifically, by rotating the guide sleeve 21 and adjusting its axial position in the threaded hole 10-5 of the main piston 10, the initial length of the spring 20 can be changed, the magnitude of the pressure required for the spring 20 to deform can be changed, and thus the air pressure of the drive piston rod 9 sliding relative to the main piston 10 can be adjusted.

[0085] After the pneumatically driven cylinder of the present invention is assembled:

[0086] like Figure 2 As shown, the second quick-connector 8 is used to supply return air pressure for the drive piston assembly 1 to move axially to the left.

[0087] like Figure 2 As shown, the first quick-connect fitting 6 is used to introduce lower pressure gas when the piston assembly 1 moves axially to the right, and higher pressure gas when the piston assembly 1's auxiliary piston compression spring moves axially to the left, extending out of the piston rod.

[0088] Under the action of air pressure, the auxiliary piston 15 can slide relative to the main piston 10, and the compression spring 20 can move axially.

[0089] When the pneumatically driven auxiliary piston 15 moves, the extension and retraction of the spring 20 is related to the position of the guide sleeve 21. By adjusting the axial position of the guide sleeve 21 in the main piston 10, the initial length of the spring 20 can be changed, and thus, under the same pneumatic pressure, the movement distance of the piston rod 9 fixedly connected to the auxiliary piston 15 can be changed.

[0090] Example 2

[0091] In one specific embodiment of the present invention, a cylinder driving method is provided to drive the cylinder with pneumatic control stroke described in Embodiment 1.

[0092] Specifically, the driving method includes the following steps:

[0093] Step S1: First-stage drive: The first quick connector 6 is connected to the atmosphere, and low-pressure air is injected into the second cavity of the cylinder through the second quick connector 8; the piston assembly 1 is axially displaced under the drive of air pressure to perform the first-stage stroke output;

[0094] Step S2: Secondary drive: Continue to inject high-pressure air into the cylinder through the second quick connector 8; the auxiliary piston 15 slides inside the main piston 10 under the drive of air pressure, thereby driving the piston rod 9 to move relative to the guide sleeve 21 to perform the secondary stroke output.

[0095] Step S3: Return drive: The second quick connector 8 is connected to the atmosphere, and high-pressure air is injected into the first cavity of the cylinder through the first quick connector 6; the main piston 10 returns to its original position under the drive of air pressure; at the same time, the piston rod 9 returns to its original position under the elastic force of the spring 20.

[0096] In step S1, during the first-stage drive process, the piston assembly 1 slides to the left as a whole along the axis of the cylinder liner 3 in the inner cavity of the cylinder liner 3; before the main piston 10 of the piston assembly 1 contacts the end face of the cylinder liner 3, the auxiliary piston 15 remains stationary relative to the main piston 10 under the action of the spring 20; the auxiliary piston 15 and the piston rod 9 do not move relative to the main piston 10, and the piston assembly 1 moves as a whole.

[0097] In step S1, the pneumatic pressure drives the auxiliary piston 15 to move to the left, while the spring 20 drives the auxiliary piston 15 and the piston rod 9 to move to the right in the fourth through hole 10-6 of the main piston 10, locking the outer truncated cone of the piston rod 9 on the end face of the guide sleeve 21, keeping the piston rod 9 and the main piston 10 relatively stationary.

[0098] Specifically, the low air pressure at this time is insufficient to overcome the elastic force of the spring 20 inside the piston assembly 1 to push the auxiliary piston 15 to move, so that the piston rod 9, which is fixedly connected to the auxiliary piston 15, remains stationary inside the piston assembly 1, and the piston assembly 1 drives the piston rod 9 to perform a first-stage stroke movement in the cylinder liner 3.

[0099] In step S1, after the first stage of stroke is completed, the left end face of the piston section 10-2 of the main piston 10 presses against the inner end face of the cylinder liner 3, keeping the main piston 10 of the piston assembly 1 relatively stationary inside the cylinder liner 3. At this time, the cylindrical section 10-1 extends out of the cylinder liner 3.

[0100] Specifically, the maximum distance of the first-stage stroke depends on the length S1 of the cylindrical section 10-1.

[0101] Specifically, in step S2, high-pressure gas is introduced into the second cavity through the second quick-connect connector 8, and the main piston 10 of the piston assembly 1 is pressed into contact with the inner end face of the cylinder liner 3 under the action of gas pressure.

[0102] Specifically, in step S2, since the main piston 10 is restricted by the cylinder liner 3 and cannot continue to move, when the pressure of the high-pressure gas on the auxiliary piston 15 is greater than the elastic force of the spring 20 on the auxiliary piston 15, the high-pressure gas drives the auxiliary piston 15 to slide to the left relative to the main piston 10. As a result, the auxiliary piston 15 overcomes the elastic force of the spring 20 and compresses the spring 20. At the same time, the auxiliary piston 15 drives the piston rod 9 to slide to the left relative to the guide sleeve 21 to perform the second-stage stroke output.

[0103] Furthermore, in step S2, by pre-adjusting the axial position of the guide sleeve 21 in the main piston 10, the magnitude of the gas pressure required to drive the displacement of the auxiliary piston 15 can be adjusted.

[0104] In step S3, the second quick-connect connector 8 is connected to the atmosphere, and the first quick-connect connector 6 is connected to air pressure. Under the action of the spring force of the spring 20, the auxiliary piston 15 slides to the right relative to the main piston 10, and at the same time drives the piston rod 9 to slide to the right. The piston rod 9 returns to its original position in the main piston 10. Under the action of air pressure, the main piston 10 slides to the right in the inner cavity of the cylinder liner 3 until the right end face of the main piston 10 is stuck on the end face of the cylinder head 5, and the piston assembly 1 returns to its original position.

[0105] Specifically, during the return process, the pressure in the first cavity is greater than the pressure in the second cavity.

[0106] Specifically, the diameter of the fourth through hole 10-6 inside the main piston 10 is larger than the diameter of the threaded hole 10-5. Consequently, the maximum displacement of the auxiliary piston 15 is limited by the length S2 of the fourth through hole 10-6; therefore, the maximum distance of the second-stage stroke is the sum of the length S2 of the fourth through hole 10-6 and the length S1 of the cylindrical section 10-1. In other words, the maximum output displacement of the cylinder is the sum of the first-stage and second-stage strokes, S1 + S2.

[0107] Furthermore, by simultaneously filling the first quick-connector 6 and the second quick-connector 8 with high-pressure gas, the main piston 10 can remain relatively stationary with respect to the cylinder liner 3, while the auxiliary piston 15 compresses the spring 20. The auxiliary piston 15 and the piston rod 9 are displaced relative to the main piston 10, thus achieving the third type of displacement output S2.

[0108] It is worth noting that the terms "high-pressure air" and "low-pressure air" used in this invention are comparative concepts and do not refer to specific pressure values; the pressure relationship is: high-pressure air > low-pressure air > atmospheric air (natural air).

[0109] Compared with the prior art, the technical solution provided by the present invention has at least one of the following beneficial effects:

[0110] 1. This invention provides a cylinder with pneumatically controlled stroke. By inputting a relatively low-pressure gas into the cylinder, the piston assembly 1 inside the cylinder is driven to move axially, realizing one displacement stroke of the cylinder piston. Then, a higher-pressure gas is input into the cylinder, which drives the auxiliary piston 15 to move axially against the elastic force of the spring 20. The piston rod 9 connected to the auxiliary piston 15 moves, realizing a second displacement stroke of the cylinder stroke. When a higher-pressure gas is directly input into the cylinder, the piston assembly 1 and the auxiliary piston 15 inside the piston assembly 1 move axially under the action of the gas pressure, realizing a long-distance displacement of the piston rod 9.

[0111] 2. The present invention provides a pneumatically controlled cylinder. Adjusting the axial position of the guide sleeve 21 in the main piston 10 can adjust and change the moving distance of the auxiliary piston 15, thereby changing the moving stroke of the piston rod 9, which meets the needs of multi-stage stroke and stroke accuracy adjustment in the automatic control of the cylinder.

[0112] 3. This invention provides a cylinder with pneumatically controlled stroke, which overcomes the complex structure of existing cylinder stroke control and can meet the needs of multiple stroke control.

[0113] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A cylinder driving method, characterized in that, The specific steps for driving a cylinder with pneumatically controlled stroke include: Step S1: First-stage drive: The first quick connector (6) is connected to the atmosphere, and low-pressure air is injected into the second cavity of the cylinder through the second quick connector (8); the piston assembly (1) is axially displaced under air pressure to perform the first-stage stroke output; Step S2: Secondary drive: Continue to inject high-pressure air into the cylinder through the second quick connector (8); the auxiliary piston (15) slides inside the main piston (10) under the pneumatic drive, thereby driving the piston rod (9) to move relative to the guide sleeve (21) to output the secondary stroke; Step S3: Return drive: The second quick connector (8) is connected to the atmosphere, and high-pressure air is injected into the first cavity of the cylinder through the first quick connector (6); the main piston (10) returns to its original position under the drive of air pressure; at the same time, the piston rod (9) returns to its original position under the elastic force of the spring (20); By simultaneously filling the first quick-connect connector (6) and the second quick-connect connector (8) with high-pressure gas, the main piston (10) can remain relatively stationary with respect to the cylinder liner (3), while the auxiliary piston (15) compresses the spring (20), and the auxiliary piston (15) and piston rod (9) are displaced relative to the main piston (10), thus achieving a third type of displacement output. The cylinder includes: piston assembly (1), cylinder liner (3), cylinder head (5), first quick connector (6), and second quick connector (8); The piston assembly (1) is slidably mounted inside the cylinder liner (3), with its end extending out of the cylinder liner (3); the piston assembly (1) is in sealed contact with the cylinder liner (3), and the internal space of the piston assembly (1) and the cylinder liner (3) forms a closed first cavity; the cylinder head (5) is fixedly mounted at the port of the cylinder liner (3), and the cylinder head (5), the cylinder liner (3), and the piston assembly (1) form a second cavity; the piston assembly (1) includes: a piston rod (9), a main piston (10), a secondary piston (15), a spring (20), and a guide sleeve (21); the piston rod (9) and the secondary piston (15) are both slidably mounted inside the main piston (10), and The piston rod (9) and the auxiliary piston (15) are fixedly connected; the two ends of the spring (20) abut against the guide sleeve (21) and the auxiliary piston (15) respectively; when the auxiliary piston (15) slides relative to the main piston (10), it can compress the spring (20); the guide sleeve (21) includes a holding part (21-1) and a threaded section (21-2). The threaded section (21-2) is screwed into the threaded hole of the main piston (10). By rotating the threaded section (21-2), the axial position of the guide sleeve (21) in the main piston (10) is adjusted to change the pressure required for the deformation of the spring (20), thereby realizing the air pressure adjustment for the sliding of the driving piston rod (9) relative to the main piston (10).

2. The cylinder driving method according to claim 1, characterized in that, The first quick-connector (6) is installed on the cylinder liner (3) and communicates with the first cavity; the second quick-connector (8) is installed on the cylinder head (5) and communicates with the second cavity; the first quick-connector (6) and the second quick-connector (8) are respectively used to introduce gas into the first cavity and the second cavity.

3. The cylinder driving method according to claim 1, characterized in that, The cylinder liner (3) is provided with a first through hole (3-1) and a second through hole (3-2).

4. The cylinder driving method according to claim 3, characterized in that, The end of the main piston (10) extends out of the cylinder liner (3) from the first through hole (3-1); the first quick connector (6) is installed in the second through hole (3-2).

5. The cylinder driving method according to claim 3, characterized in that, The main piston (10) includes a cylindrical section (10-1) and a piston section (10-2).

6. The cylinder driving method according to claim 5, characterized in that, The cylindrical section (10-1) of the main piston (10) is slidably installed in the first through hole (3-1), and the piston section (10-2) of the main piston (10) is slidably installed in the inner cavity of the cylinder liner (3).

7. The cylinder driving method according to claim 5 or 6, characterized in that, The cylindrical section (10-1) is sealed to the first through hole (3-1) by a first sealing ring (2); the cylinder head (5) is sealed to the cylinder liner (3) by a second sealing ring (4).

8. The cylinder driving method according to claim 7, characterized in that, The auxiliary piston (15) has a fourth annular groove (15-1) on its outer side; a third sealing ring (11) is provided in the fourth annular groove (15-1); the piston section (10-2) of the main piston (10) has a second annular groove (10-3) on its outer side; a fourth sealing ring (12) is installed in the second annular groove (10-3).

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