Single ended drive cylinder with symmetrical control characteristics

Abstract

The present application belongs to the technical field of hydraulic cylinder, and particularly relates to a single-end driving cylinder with symmetrical control characteristics. The technical scheme of the single-end driving cylinder with symmetrical control characteristics is composed of a gasket, a spring seat with a gas hole, a sleeve, a cylinder, an inner hexagonal cylindrical head screw, a piston, an outer hexagonal screw, a pressing plate, a rear end cover, a limiting sleeve, a return spring, a spring gasket, a steel wire retainer, a piston rod, an OD type sealing element, a front end cover, a rear limiting pad and a limiting rod. The single-end driving cylinder can realize symmetrical reciprocating motion of a valve core. In addition, a sealing ring groove is arranged at the left inner hole of the front end cover, and an OD type piston rod sealing element is installed to prevent control oil from entering the sleeve, thereby avoiding cross contamination of the controlled element using oil and the control oil.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic cylinder technology, and specifically relates to a single-end drive cylinder with symmetrical control characteristics. Background Technology

[0002] In the field of hydraulic directional valve control, hydraulic control valves generally achieve the reciprocating motion of the valve core by supplying control oil to both ends. Currently, this hydraulic control method has certain limitations in installation, making it difficult to integrate multiple control methods into a single product, thus significantly reducing the product's integration level. If a single-end hydraulic cylinder is required for drive, it is difficult to achieve symmetrical control of the piston movement due to the different areas of the rod-side and rodless sides of the hydraulic cylinder.

[0003] Currently, there is no hydraulic cylinder in the market that can achieve symmetrical reciprocating motion of the valve core with single-end control. Summary of the Invention

[0004] The purpose of this invention is to provide a single-end drive cylinder with symmetrical control characteristics for applications integrating multiple control methods during the development of hydraulic valves.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A single-end drive cylinder with symmetrical control characteristics is composed of a gasket, a spring seat with air holes, a sleeve, a cylinder barrel, an internal hexagonal head screw, a piston, an external hexagonal head screw, a pressure plate, a rear end cover, a limit sleeve, a return spring, a spring gasket, a wire retaining ring, a piston rod, an OD type seal, a front end cover, a rear limit pad, and a limit rod.

[0007] The external hexagonal screw connects the sleeve, front end cover, cylinder, and rear end cover sequentially via a washer and pressure plate. A flat washer is provided between the external hexagonal screw and the pressure plate. The piston rod is installed in the hole in the middle of the front end cover. The left end of the piston rod connects to the semi-circular groove on the right end of the limiting rod. The right end of the piston rod is connected to the piston via an internal hexagonal head screw, forming a rigid connection. The spring seat is installed on the limiting rod, and its inner end face is in contact with the left end face of the limiting rod boss. The inner end face of the perforated spring seat coincides with the end face of the controlled valve core, and its large end face is in close contact with the washer. A spring and a limiting pad are provided between the spring seats with air holes, and the rear limiting pad is provided between the spring seat and the front end cover; the front end cover, cylinder and piston form a rod chamber, and the rear end cover, cylinder and piston form a rodless chamber. The limiting sleeve is provided in the rod chamber, and the return spring and spring washer are installed on the limiting sleeve in sequence. The steel wire retaining ring is installed in the square groove provided on the outer circle of the left end of the limiting sleeve to limit the initial compression of the return spring; the front end cover and the rear end cover are respectively provided with control oil ports; a Glyd ring is provided on the piston, and a sealing ring is provided on the front end cover and the rear end cover.

[0008] In a further preferred embodiment, the spring, the spring seat with air holes, and the spring seat form a reset spring assembly one, and the limiting sleeve, the reset spring, the spring washer, and the wire retaining ring form a reset spring assembly two.

[0009] In a further preferred embodiment, the front end cover is provided with an OD-type seal.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] This invention employs the aforementioned technical solution, setting control oil ports on the front and rear covers respectively, thus forming a single-end drive cylinder. Since the working areas of the rodless and rod-side chambers are different, two spring return assemblies are designed to achieve symmetrical proportional control characteristics. Utilizing the linear relationship between spring force and compression, both spring return assemblies work simultaneously when oil enters the rodless chamber, while only one return spring assembly works when oil enters the rod-side chamber. Therefore, this invention provides a single-end control system for a drive cylinder that enables symmetrical reciprocating motion of the valve core.

[0012] In addition, a sealing ring groove is provided at the inner hole on the left side of the front cover, and an OD type piston rod seal is installed to prevent control oil from entering the sleeve, thereby avoiding cross-contamination between the control oil and the control oil used by the controlled components. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0014] The present invention will now be further described with reference to the accompanying drawings.

[0015] like Figure 1As shown, a single-end drive cylinder with symmetrical control characteristics in this embodiment is composed of a gasket 1, a spring 2, a spring seat 3 with air holes, a spring seat 4, a sleeve 5, a sealing ring 6, a cylinder 7, a Glyd ring 8, an internal hexagonal head screw 9, a piston 10, a sealing ring 11, a flat washer 12, an external hexagonal screw 13, a pressure plate 14, a rear end cover 15, a limiting sleeve 16, a return spring 17, a spring washer 18, a wire retaining ring 19, a piston rod 20, an OD type seal 21, a front end cover 22, a rear limiting pad 23, a limiting pad 24, and a limiting rod 25. The external hexagonal screw 13 connects the sleeve 5, the front end cover 22, the cylinder 7, and the rear end cover 15 sequentially through the gasket 1 and the pressure plate 14. A flat washer 12 is provided between the external hexagonal screw 13 and the pressure plate 14 to distribute pressure. The piston rod 20 is installed in the hole in the middle of the front cover 22. The left end of the piston rod 20 is connected to the semi-circular stepped groove on the right end of the limiting rod 25. The right end of the piston rod 20 is connected to the piston 10 by an internal hexagonal head screw 9, forming a rigid connection. The spring seat 4 is installed on the limiting rod 25, and its inner end face is in contact with the left end face of the boss of the limiting rod 25. The inner end face of the perforated spring seat 3 coincides with the end face of the controlled valve core, and its large end face is in close contact with the gasket 1. A spring 2 and a limiting pad 24 are provided between the two spring seats. The rear limiting pad 23 is provided between the spring seat 4 and the front cover 22 to ensure that the limiting rod can move to the right during the stroke. The front cover 22, cylinder 7, and piston 10 form a rod chamber, and the rear cover 15, cylinder 7, and piston 10 form a rodless chamber. A limiting sleeve 16 is located in the rod chamber. A return spring 17 and a spring washer 18 are sequentially installed on the limiting sleeve 16. A wire retaining ring 19 is installed in the square groove on the outer circumference of the left end of the limiting sleeve to limit the initial compression of the return spring 17. Control oil ports are respectively provided on the front cover 22 and the rear cover 15. To separate the rod chamber and the rodless chamber and reduce the friction of the piston movement, a Gladley ring 8 is provided on the piston, and sealing rings 6 and 11 are respectively provided on the front cover and the rear cover to prevent control oil leakage.

[0016] Due to the area difference between the rodless and rod chambers, two return spring assemblies are designed to ensure the symmetrical control characteristics of the drive cylinder. Spring 2, spring seat 3 with air holes, and spring seat 4 form return spring assembly one. Limiting sleeve 16, return spring 17, spring washer 18, and wire retaining ring 19 form return spring assembly two. When the rodless chamber control oil is activated, return spring assembly one and return spring assembly two work simultaneously. The spring washer 18 of return spring assembly two abuts against the inner end face of the hole on the right side of the front cover 22. The piston 10 drives the limiting sleeve 16 forward, thereby further compressing the return spring 17 until the left end face of the spring seat 4 contacts the right end face of the limiting washer, ensuring a linear relationship between the stroke of the piston 10 to the left and the control oil pressure. When the rod chamber is activated, only return spring assembly one works. The return spring 17 maintains its initial compression state under the action of the wire retaining ring 19 and spring washer 18, ensuring a linear relationship between the stroke of the piston 10 to the right and the control oil pressure.

[0017] To prevent cross-contamination between the control oil and the oil used in the controlled product when they are not used at the same time, the front cover 22 is provided with an OD type seal 21.

[0018] The limiting pad 24 restricts the stroke of the drive cylinder, and the stroke of the drive cylinder can be adjusted by adjusting the thickness of the limiting pad.

[0019] The working process of this invention is as follows:

[0020] In actual operation, the oil flowing through the control port increases linearly. When pressure oil flows through control port 1, the pressure oil acts on the right end face of the piston. The piston drives the piston rod and the limit rod, thereby pushing the controlled part to the left. At this time, reset spring assembly one and assembly two work simultaneously. The spring washer of reset spring assembly two abuts against the inner end face of the hole on the right side of the front cover. The piston drives the limit sleeve to move forward, thereby driving the reset spring to be further compressed until the left end face of the spring seat 4 contacts the right end face of the limit pad. During this process, the force of the two spring assemblies increases with the increase of compression, and the ratio to the control oil pressure is a constant value. When resetting, the force of the two spring assemblies decreases with the decrease of compression, and the ratio to the control oil pressure is still a constant value. When oil is supplied to control port 2, the effective area is the annular area formed by the cylinder and piston rod. Under the action of control oil pressure, the piston drives the piston rod and limit rod to pull the controlled part to the right until the right end face of the limit pad contacts the left end face of the spring seat 4. At this time, the second return spring assembly does not participate in the work. The return spring maintains its initial compressed state under the action of the wire retaining ring. The spring force of the first return spring assembly increases with the increase of compression, and the ratio to the control oil pressure is constant. During reset, the force of the first return spring assembly decreases with the decrease of compression, and the ratio to the control oil pressure remains constant. This achieves the symmetrical proportional control characteristics of the single-end driven cylinder.

Claims

1. A single-end driven cylinder with symmetrical control characteristics, characterized in that, It consists of a gasket (1), a spring seat with air holes (3), a spring seat (4), a sleeve (5), a cylinder (7), an internal hexagonal head screw (9), a piston (10), an external hexagonal head screw (13), a pressure plate (14), a rear end cover (15), a limit sleeve (16), a return spring (17), a spring washer (18), a steel wire retaining ring (19), a piston rod (20), an OD type seal (21), a front end cover (22), a rear limit pad (23), and a limit rod (25); The external hexagonal screw (13) connects the sleeve (5), front end cover (22), cylinder (7), and rear end cover (15) in sequence through the washer (1) and pressure plate (14). A flat washer (12) is provided between the external hexagonal screw (13) and pressure plate (14). The piston rod (20) is installed in the hole in the middle of the front end cover (22). The left end of the piston rod (20) is connected to the semi-circular groove on the right end of the limiting rod (25). The right end of the piston rod (20) is connected to the piston (10) through the internal hexagonal head screw (9). The three form a rigid connection. The spring seat (4) is installed on the limiting rod (25), and its inner end face is in contact with the left end face of the boss of the limiting rod (25). The inner end face of the spring seat (3) with air hole coincides with the end face of the valve core being controlled, and its large end face is in close contact with the washer (1). A spring (2) and a limiting pad (24) are provided between the spring seat (4) and the spring seat (4). The rear limiting pad (23) is provided between the spring seat (4) and the front cover (22). The front cover (22), the cylinder (7) and the piston (10) form a rod cavity. The rear cover (15), the cylinder (7) and the piston (10) form a rodless cavity. The limiting sleeve (16) is provided in the rod cavity. The return spring (17) and the spring washer (18) are installed on the limiting sleeve (16) in sequence. The wire retaining ring (19) is installed in the square groove provided on the outer circle of the left end of the limiting sleeve to limit the initial compression of the return spring (17). The front cover (22) and the rear cover (15) are respectively provided with control oil ports. A glyph (8) is provided on the piston (10). Sealing rings (6, 11) are respectively provided on the front cover (22) and the rear cover (15). Due to the area difference between the rodless chamber and the rod chamber, two return spring assemblies were designed to ensure the symmetrical control characteristics of the drive cylinder. The spring (2), the spring seat (3) with air holes, and the spring seat (4) form the first return spring assembly. The limiting sleeve (16), the return spring (17), the spring washer (18), and the wire retaining ring (19) constitute the second return spring assembly. When the control oil in the rodless chamber is in action, the first return spring assembly and the second return spring assembly work simultaneously. The spring washer (18) of the second return spring assembly rests against the right side of the front end cover (22). On the inner end face of the hole on the side, the piston (10) drives the limiting sleeve (16) to move forward, thereby driving the return spring (17) to be further compressed until the left end face of the spring seat (4) contacts the right end face of the limiting pad, ensuring that the stroke of the piston (10) when it moves to the left is linearly related to the control oil pressure; when the rod cavity is in action, only the return spring assembly participates in the work, and the return spring (17) is kept in the initial compressed state under the action of the wire retaining ring (19) and the spring washer (18), ensuring that the stroke of the piston (10) when it moves to the right is linearly related to the control oil pressure.

2. The single-end drive cylinder with symmetrical control characteristics according to claim 1, characterized in that, The front cover (22) is provided with an OD type seal (21).

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