Differential type air cylinder

Abstract

The utility model discloses a differential type air cylinder which comprises a cylinder barrel, a piston and a piston rod, a piston cavity is formed in the cylinder barrel, the piston cavity is divided into a first cavity and a second cavity which are independent from each other by the piston, and the longitudinal section area of the first cavity and the longitudinal section area of the second cavity have a difference value. The cylinder barrel is provided with an air port A communicated with the first cavity and an air port B communicated with the second cavity, the area of the working face A, located in the first cavity, of the piston is different from the area of the working face B, located in the second cavity, of the piston, the cylinder barrel comprises a front cylinder barrel body and a rear cylinder barrel body which are in threaded connection, and a rear cover is integrally arranged at the rear end of the rear cylinder barrel body. The cylinder barrel is composed of the front cylinder barrel and the rear cylinder barrel which are in threaded connection, the rear cover and the rear cylinder barrel are integrally formed, and a front cover is not needed, so that the hydraulic cylinder is simple in structure, few in needed accessories, convenient to assemble and low in production cost. When the air cylinder works, a force difference value is generated through the area difference between the working face A and the working face B, so that the air cylinder is suitable for scenes with different thrust and tension requirements.

Description

Technical Field

[0001] The utility model relates to the technical field of cylinders, and particularly relates to a differential cylinder. Background Art

[0002] Pneumatic transmission and control are one of the most effective means for the automation and mechanization of the production process. Pneumatic devices are widely used in automated production lines due to their simple structure, safe use, environmental friendliness, and easy pressure adjustment. The cylinder is one of the most commonly used pneumatic devices and is often used as an actuator for clamping, positioning, and ejecting in automated equipment. The differential cylinder is one of many cylinders, which provides non-equal thrust and pulling forces through the extension and retraction of the piston rod to be applicable to scenarios with different requirements for thrust and pulling force.

[0003] For example, a differential cylinder with secondary feeding disclosed in a Chinese utility model patent (publication number: CN201582246U) includes a cylinder barrel, a front end cover, a rear end cover, a piston, a piston rod, and a sealing ring. The piston includes piston I and piston II, the cylinder barrel includes cylinder barrel I and cylinder barrel II. Cylinder barrel I and cylinder barrel II are connected to each other, and the inner diameter of the inner wall of cylinder barrel I is smaller than that of the inner wall of cylinder barrel II. Piston I is located inside cylinder barrel I. The left end of piston II matches the inner wall of cylinder barrel II, and the right end matches the inner wall of cylinder barrel I. The front end cover is connected to the left end of cylinder barrel II, and the rear end cover is connected to the right end of cylinder barrel I. The piston rod passes through the front end cover and piston II in sequence and is connected to piston II. It has the characteristics of simple structure, convenient manufacturing, and high reliability.

[0004] However, the deficiencies of the differential cylinder with secondary feeding disclosed in the above prior art are as follows: First, it requires a large number of accessories, including two groups of pistons (piston I and piston II), two groups of cylinder barrels (cylinder barrel I and cylinder barrel II), a front end cover, and a rear end cover, resulting in high production costs and complex assembly. Second, the length of its piston rod is a fixed length, so that the stroke of the piston rod is a fixed stroke and fine adjustment cannot be achieved.

[0005] Therefore, it is necessary to improve the prior art. Content of the Utility Model

[0006] The purpose of the utility model is to provide a differential cylinder with a simple structure, fewer required accessories, convenient assembly, low production cost, and capable of fine-tuning the stroke of the piston rod in view of the defects and deficiencies of the prior art.

[0007] To achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A differential cylinder includes a cylinder barrel, a piston and a piston rod. A piston chamber is formed in the cylinder barrel. The piston divides the piston chamber into an independent first chamber and a second chamber. The longitudinal cross-sectional area of the first chamber and that of the second chamber have a difference. An air port A communicating with the first chamber and an air port B communicating with the second chamber are provided on the cylinder barrel. The area of the working surface A of the piston in the first chamber and the area of the working surface B of the piston in the second chamber have a difference. The rear end of the piston rod is fixedly connected to the piston, and the front end of the piston rod extends out of the cylinder barrel. A fine-tuning structure is provided at the end of the front end of the piston rod. The fine-tuning structure includes a push block that can move back and forth relative to the piston rod. The cylinder barrel includes a front cylinder barrel and a rear cylinder barrel connected by screwing. A rear cover is integrally provided at the rear end of the rear cylinder barrel.

[0009] Further, the longitudinal cross-sectional area of the first chamber is larger than that of the second chamber; the area of the working surface A of the piston in the first chamber is larger than the area of the working surface B of the piston in the second chamber.

[0010] Further, a push block groove adapted to the push block is provided at the end of the front end of the piston rod. The push block is coaxially connected to the piston rod by a screw; the end face of the screw does not protrude from the end face of the push block.

[0011] Further, the piston rod includes a piston rod A and a piston rod B fixedly connected. The diameter of the piston rod A is larger than that of the piston rod B. The push block is provided at the front end of the piston rod A.

[0012] Further, the piston rod A is arranged in the front cylinder barrel. The piston rod B passes through between the front cylinder barrel and the rear cylinder barrel. The front end of the piston rod B is embedded in the end of the piston rod A, and the rear end of the piston rod B is embedded in the end of the piston.

[0013] Further, a special-shaped dust-proof ring is provided between the piston rod B and the front cylinder barrel.

[0014] Further, a bushing is provided between the piston rod A and the front cylinder barrel.

[0015] Further, a guide ring is provided between the piston rod A and the front cylinder barrel.

[0016] Further, a C-ring is provided between the piston and the cylinder barrel.

[0017] Further, a balance port is provided between the air port A and the air port B. The balance port is provided on the side of the first chamber close to the second chamber.

[0018] After adopting the above structure, the beneficial effects of the utility model are as follows:

[0019] (1)A differential cylinder according to the present utility model includes a cylinder barrel, a piston and a piston rod. A piston chamber is formed in the cylinder barrel. The piston divides the piston chamber into an independent first chamber and a second chamber. The longitudinal cross-sectional area of the first chamber and the longitudinal cross-sectional area of the second chamber have a difference. An air port A communicating with the first chamber and an air port B communicating with the second chamber are provided on the cylinder barrel. The area of the working surface A of the piston in the first chamber and the area of the working surface B of the piston in the second chamber have a difference. The cylinder barrel includes a front cylinder barrel and a rear cylinder barrel connected by screwing. A rear cover is integrally provided at the rear end of the rear cylinder barrel. The cylinder barrel is composed of a front cylinder barrel and a rear cylinder barrel connected by screwing, and the rear cover is integrally formed with the rear cylinder barrel, without a front cover, making the structure of this application simple, with fewer required accessories, convenient assembly and lower production costs. When it works, a difference in force is generated by the difference in the areas of the working surface A and the working surface B, so that the cylinder is suitable for scenarios with different thrust and pull requirements.

[0020] (2)In a differential cylinder according to the present utility model, a fine-tuning structure is provided at the front end of the piston rod. The fine-tuning structure includes a push block that can move back and forth relative to the piston rod. The fine-tuning of the piston rod stroke is realized through the setting of the fine-tuning structure, making the cylinder more applicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present utility model, the drawings required for use in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 is the overall structural schematic diagram of the present utility model;

[0023] Figure 2 is the overall structural sectional view of the present utility model;

[0024] Figure 3 is of the present utility model Figure 2 enlarged schematic view of the structure at A;

[0025] Figure 4 is of the present utility model Figure 2 enlarged schematic view of the structure at B.

[0026] Figures 1 to 4 The reference numerals in

[0027] 1. Cylinder barrel; 11. Front cylinder barrel; 12. Rear cylinder barrel; 121. Rear cover; 13. Air port A; 14. Air port B; 15. Balance port; 2. Piston; 21. Working surface A; 22. Working surface B; 3. Piston rod; 31. Piston rod A; 311. Push block groove; 32. Piston rod B; 321. Special-shaped dust-proof ring; 4. Piston cavity; 41. First chamber; 42. Second chamber; 5. Fine-tuning structure; 51. Push block; 52. Screw; 6. Bush; 7. Guide ring; 8. C-ring. Detailed implementation manners

[0028] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will describe the detailed implementation manners of the present utility model with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0029] In the description of the present utility model, it should be understood that if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present utility model.

[0030] In addition, if these terms "first" and "second" appear, these terms are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0031] In the present utility model, unless otherwise clearly defined and limited, if terms such as "installed", "connected", "joined", "fixed", etc. appear, these terms shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly defined and limited, if there is a description such as the first feature being "on" or "under" the second feature, its meaning may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0033] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. If an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. If any, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present utility model are only for the purpose of illustration and do not represent the only implementation manner.

[0034] It should be noted that, without conflict, the embodiments and the features in the embodiments of the present utility model may be combined with each other. The present utility model will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0035] Such as Figures 1 to 4As shown in the figure, a differential cylinder includes a cylinder barrel 1, a piston 2 and a piston rod 3. A piston chamber 4 is formed inside the cylinder barrel 1. The piston 2 divides the piston chamber 4 into two independent first chamber 41 and second chamber 42. There is a difference in the longitudinal cross-sectional area between the first chamber 41 and the second chamber 42. An air port A13 communicating with the first chamber 41 and an air port B14 communicating with the second chamber 42 are provided on the cylinder barrel 1. There is a difference in the area between the working surface A21 of the piston 2 inside the first chamber 41 and the working surface B22 of the piston 2 inside the second chamber 42. The rear end of the piston rod 3 is fixedly connected to the piston 2, and the front end of the piston rod 3 extends out of the cylinder barrel 1. A fine-tuning structure 5 is provided at the front end of the piston rod 3. The fine-tuning structure 5 includes a push block 51 that can move back and forth relative to the piston rod 3. The cylinder barrel 1 includes a front cylinder barrel 11 and a rear cylinder barrel 12 connected by screwing. A rear cover 121 is integrally provided at the rear end of the rear cylinder barrel 12. A push block groove 311 adapted to the push block 51 is provided at the front end of the piston rod 3. The push block 51 is coaxially connected to the piston rod 3 through a screw rod 52. The end face of the screw rod 52 does not protrude from the end face of the push block 51. The longitudinal cross-sectional area of the first chamber 41 is larger than that of the second chamber 42. The area of the working surface A21 of the piston 2 inside the first chamber 41 is larger than the area of the working surface B22 of the piston 2 inside the second chamber 42.

[0036] Based on the above embodiments, the utility model aims to provide a differential cylinder, which includes a cylinder barrel 1, a piston 2 and a piston rod 3. A piston chamber 4 is formed in the cylinder barrel 1. The piston 2 divides the piston chamber 4 into an independent first chamber 41 and a second chamber 42. The longitudinal cross-sectional area of the first chamber 41 and the longitudinal cross-sectional area of the second chamber 42 have a difference. An air port A13 communicating with the first chamber 41 and an air port B14 communicating with the second chamber 42 are provided on the cylinder barrel 1. The area of the working surface A21 of the piston 2 in the first chamber 41 and the area of the working surface B22 of the piston 2 in the second chamber 42 have a difference. The cylinder barrel 1 includes a front cylinder barrel 11 and a rear cylinder barrel 12 connected by screwing. A rear cover 121 is integrally provided at the rear end of the rear cylinder barrel 12. The cylinder barrel 1 is composed of the front cylinder barrel 11 and the rear cylinder barrel 12 connected by screwing, and the rear cover 121 is integrally formed with the rear cylinder barrel 12 without a front cover, making the structure of the present application simple, with fewer required accessories, convenient assembly and lower production costs. In this embodiment, the first chamber 41 is a rod chamber, and the second chamber 42 is a rodless chamber. When it works, a force difference is generated by the area difference between the working surface A21 and the working surface B22, making the cylinder applicable to scenarios with different thrust and pull force requirements. Specifically, when the longitudinal cross-sectional area of the first chamber 41 is larger than that of the second chamber 42 and the area of the working surface A21 is larger than that of the working surface B22, the thrust generated when the piston rod 3 extends is smaller than the pull force generated when the piston rod 3 retracts; when the longitudinal cross-sectional area of the first chamber 41 is smaller than that of the second chamber 42 and the area of the working surface A21 is smaller than that of the working surface B22, the thrust generated when the piston rod 3 extends is larger than the pull force generated when the piston rod 3 retracts. In this way, the cylinder is applicable to scenarios with different thrust and pull force requirements. In this embodiment, the longitudinal cross-sectional area of the first chamber 41 is larger than that of the second chamber 42, and the area of the working surface A21 is larger than that of the working surface B22, that is, the thrust generated when the piston rod 3 extends is smaller than the pull force generated when the piston rod 3 retracts.

[0037] In this embodiment, the rear cover 121 is integrally formed with the rear cylinder barrel 12 without a front cover, effectively reducing the accessories, lowering the cost and improving the installation efficiency; and there is no need to consider the concentricity between the rear cover 121 and the rear cylinder barrel 12, making the processing simpler, effectively improving the installation efficiency and production qualification rate; at the same time, the rear cover 121 is integrally formed with the rear cylinder barrel 12, not only making the airtightness of the cylinder stronger, but also making the anti-pressure effect of the rear cover 121 better, thereby extending the service life of the cylinder.

[0038] In this embodiment, a fine-tuning structure 5 is provided at the front end of the piston rod 3. The fine-tuning structure 5 includes a push block 51 that can move back and forth relative to the piston rod 3. The fine-tuning of the stroke of the piston rod 3 is achieved through the setting of the fine-tuning structure 5, making the applicability of the cylinder stronger. A push block groove 311 adapted to the push block 51 is provided at the front end of the piston rod 3. The push block 51 is coaxially connected to the piston rod 3 through a screw 52; the end face of the screw 52 does not protrude from the end face of the push block 51. As Figure 2 and Figure 4 shown, when it is not necessary to use the push block 51 to achieve fine-tuning, the push block 51 is retracted into the push block groove 311. At this time, the end face of the push block 51 is flush with the end face of the piston rod 3; when it is necessary to use the push block 51 to achieve fine-tuning, the protruding distance of the push block 51 relative to the piston rod 3 is adjusted through the screw 52. In a further embodiment, the screw 52 is an internal hexagonal concave end set screw, and the end face of the screw 52 does not protrude from the end face of the push block 51, avoiding damaging the surface of the ejected product.

[0039] As another preferred solution of the present utility model, the piston rod 3 includes a piston rod A 31 and a piston rod B 32 that are fixedly connected. The diameter of the piston rod A 31 is larger than the diameter of the piston rod B 32, and the push block 51 is provided at the front end of the piston rod A 31. A guide ring 7 is provided between the piston rod A 31 and the front cylinder barrel 11. The piston rod A 31 is disposed in the front cylinder barrel 11. The piston rod B 32 passes through between the front cylinder barrel 11 and the rear cylinder barrel 12. The front end of the piston rod B 32 is embedded in the end of the piston rod A 31, and the rear end of the piston rod B 32 is embedded in the end of the piston 2. A special-shaped dust-proof ring 321 is provided between the piston rod B 32 and the front cylinder barrel 11. A bushing 6 is provided between the piston rod A 31 and the front cylinder barrel 11. In this embodiment, as Figure 2 shown, the diameter of the piston rod A 31 is larger than the diameter of the piston rod B 32, increasing the force-bearing area of the piston rod 3, which can eject products with a larger volume and will not cause the ejected products to deform due to too small a force-bearing area. In this embodiment, as Figure 2 shown, a guide ring 7 is provided between the piston rod A 31 and the front cylinder barrel 11. The guide ring 7 plays a guiding role in the sliding of the piston rod A 31, making the sliding of the piston rod A 31 smoother. In this embodiment, as Figure 4 shown, the bushing 6 plays a supporting and guiding role in the sliding of the piston rod A 31, making the sliding of the piston rod A 31 smoother. In this embodiment, as Figure 3As shown, a special-shaped dust-proof ring 321 is provided between the piston rod B32 and the front cylinder barrel 11. The special-shaped dust-proof ring 321 is made of fluororubber material for sealing. The fluororubber material has the characteristics of wear resistance and high temperature resistance, which can extend the service life of the special-shaped dust-proof ring 321. At the same time, the setting of the special-shaped dust-proof ring 321 can prevent dust and other impurities from entering the piston chamber 4 and affecting the sliding of the piston 2.

[0040] As another preferred solution of the present utility model, a C-ring 8 is provided between the piston 2 and the cylinder barrel 1. In this embodiment, as Figure 2 and Figure 3 shown, the C-ring 8 is made of fluororubber material for sealing. The fluororubber material has the characteristics of wear resistance and high temperature resistance, which can extend the service life of the C-ring 8.

[0041] As another preferred solution of the present utility model, a balance port 15 is provided between the air port A13 and the air port B14. The balance port 15 is arranged on the side of the first chamber 41 close to the second chamber 42. In this embodiment, as Figure 2 and Figure 3 shown, when the piston rod 3 retracts, that is, the piston 2 moves from the first chamber 41 to the second chamber 42, the gas on the side of the first chamber 41 close to the second chamber 42 is discharged through the balance port 15, and the gas in the second chamber 42 is discharged through the air port B14 and the balance port 15, which improves the exhaust speed, that is, reduces the air resistance of the piston 2 moving, and further improves the moving speed of the piston 2; when the piston rod 3 extends, that is, the piston 2 moves from the second chamber 42 to the first chamber 41, the side of the first chamber 41 close to the second chamber 42 inhales gas through the balance port 15 to prevent negative pressure from being generated here and affecting the movement of the piston 2.

[0042] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present utility model.

Claims

1. A differential cylinder, comprising a cylinder barrel (1), a piston (2) and a piston rod (3), characterized in that: A piston chamber (4) is formed in the cylinder (1), and the piston (2) divides the piston chamber (4) into a first chamber (41) and a second chamber (42) that are independent of each other. The longitudinal cross-sectional area of ​​the first chamber (41) and the longitudinal cross-sectional area of ​​the second chamber (42) are different. The cylinder (1) is provided with an air port A (13) communicating with the first chamber (41) and an air port B (14) communicating with the second chamber (42). The area of ​​the working surface A (21) of the piston (2) in the first chamber (41) is the same as that in the second chamber (42). The area of ​​the working surface B (22) in the second chamber (42) has a difference, the rear end of the piston rod (3) is fixedly connected to the piston (2), the front end of the piston rod (3) protrudes from the cylinder barrel (1), and the end of the front end of the piston rod (3) is provided with a fine-tuning structure (5), and the fine-tuning structure (5) includes a push block (51) that can move forward and backward relative to the piston rod (3); the cylinder barrel (1) includes a front cylinder barrel (11) and a rear cylinder barrel (12) that are screwed together, and the rear end of the rear cylinder barrel (12) is integrally provided with a rear cover (121).

2. A differential cylinder according to claim 1, characterized in that: The longitudinal cross-sectional area of ​​the first chamber (41) is greater than the longitudinal cross-sectional area of ​​the second chamber (42); the area of ​​the working surface A (21) of the piston (2) in the first chamber (41) is greater than the area of ​​the working surface B (22) in the second chamber (42).

3. A differential cylinder according to claim 1, characterized in that: The front end of the piston rod (3) is provided with a push block groove (311) adapted to the push block (51); the push block (51) is coaxially connected to the piston rod (3) via a screw rod (52); and the end surface of the screw rod (52) does not protrude from the end surface of the push block (51).

4. A differential cylinder according to claim 1, characterized in that: The piston rod (3) comprises a piston rod A (31) and a piston rod B (32) which are fixedly connected, the diameter of the piston rod A (31) is larger than the diameter of the piston rod B (32), and the push block (51) is arranged at the front end of the piston rod A (31).

5. A differential cylinder according to claim 4, characterized in that: The piston rod A (31) is arranged in the front cylinder barrel (11), the piston rod B (32) is inserted between the front cylinder barrel (11) and the rear cylinder barrel (12), the front end of the piston rod B (32) is embedded in the end of the piston rod A (31), and the rear end of the piston rod B (32) is embedded in the end of the piston (2).

6. A differential cylinder according to claim 5, characterized in that: A special-shaped dustproof ring (321) is provided between the piston rod B (32) and the front cylinder barrel (11).

7. A differential cylinder according to claim 5, characterized in that: A shaft sleeve (6) is provided between the piston rod A (31) and the front cylinder barrel (11).

8. A differential cylinder according to claim 5, characterized in that: A guide ring (7) is provided between the piston rod A (31) and the front cylinder barrel (11).

9. A differential cylinder according to claim 1, characterized in that: A C-shaped ring (8) is provided between the piston (2) and the cylinder (1).

10. A differential cylinder according to claim 1, characterized in that: A balancing port (15) is provided between the air port A (13) and the air port B (14); the balancing port (15) is provided on a side of the first chamber (41) close to the second chamber (42).

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