Variable speed valve stem control structure and method

Abstract

The application discloses a variable-speed valve rod control structure and a control method, which comprises an end cover, a valve body and a spring cover; the end cover, the valve body and the spring cover are sequentially connected to form a shell with an internal connection; a piston, a valve rod and a reset spring part are sequentially arranged in the shell and are connected; a pilot port a is arranged on the end cover, the pilot port a has a left pilot cavity; a closed cavity is arranged in the end cover, and a hole matched with the piston is arranged at the front end of the closed cavity; the piston is provided with continuous upper and lower throttle grooves, the opening directions of the upper and lower throttle grooves are opposite, and the longitudinal area of the throttle grooves is variable; a pilot port b is arranged on the spring cover, and the pilot port b has a right pilot cavity. The application customizes the segmented control in the movement process of the valve rod according to different user requirements, so that the special requirements of the host machine on the flow gain in the initial, intermediate and final stages or multi-stage intervals are met, and the whole machine mechanism is stable, responds quickly and has soft acceleration.

Description

Technical Field

[0001] This invention relates to the field of hydraulic multi-way valve technology, and more specifically to a variable speed valve stem control structure. Background Technology

[0002] Hydraulic multi-way valves are widely used hydraulic control components, playing a role in flow distribution on hydraulic equipment. Pilot-operated hydraulic multi-way valves control the valve stem movement through the pressure output of a hydraulic handle. To prevent excessive flow gain due to rapid manual operation, which could lead to equipment instability and shaking, damping or one-way damping is typically installed at both ends of the valve stem. This damping is achieved through small throttling orifices, and different orifice sizes can be configured according to actual needs. However, this fixed or one-way damping has the drawback of not being adjustable; the damping effect is exactly the same throughout the entire valve stem stroke, failing to meet customers' needs for differentiated valve stem movement speeds at different positions. With the widespread application of hydraulic equipment, customer demands are increasing, and the industry urgently needs to address the differentiated requirements and refined control of hydraulic equipment.

[0003] Existing patents disclose a bidirectional damping valve for use in hydraulic pilot control systems, but this technology has the following shortcomings:

[0004] 1. The patent mentions that a bidirectional damping valve is configured at the pilot port to solve the problem of pressure shock during reversal. The bidirectional damping is set according to the different requirements of the valve stem reciprocating motion. However, the bidirectional damping is a fixed structure and remains unchanged throughout the valve stem movement. It is impossible to identify the special requirements of the damping effect at different stages of the valve stem movement.

[0005] 2. The damping channels in the two directions in the patent have overlapping parts, that is, the throttling plug 3 is a channel shared by both directions. The theoretically independent bidirectional structure is related in practice, and the damping channel from B to A can only be less than or equal to the channel from A to B, which has limitations in use.

[0006] 3. The patent requires damping joints to be installed at both ends of the valve stem, which increases the cost of the two components and the risk of failure. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention discloses a variable speed valve stem control structure. This structure addresses the problem of constant speed throughout the entire process in existing multi-way valves by customizing segmented control of the valve stem movement to meet the specific flow gain requirements of the host machine in three or more stages (initial, intermediate, and final stages), ensuring smooth operation, rapid response, and gentle acceleration of the entire mechanism.

[0008] This invention is implemented according to the following technical solution:

[0009] The first aspect of this invention discloses a variable speed valve stem control structure, including an end cap, a valve body, and a spring cover; the end cap, valve body, and spring cover are sequentially connected to form an internally interconnected housing; a piston, a valve stem, and a return spring component are sequentially arranged in the housing; the end cap has a pilot port a, which has a left pilot cavity; a sealed cavity is provided in the end cap, and the front end of the sealed cavity has a hole that mates with the piston; the piston has a continuous upper throttling groove and a lower throttling groove, and the opening directions of the upper and lower throttling grooves are opposite, and the longitudinal area of ​​the throttling grooves is variable; the spring cover has a pilot port b, which has a right pilot cavity.

[0010] In some embodiments, the piston and the valve stem are movably connected.

[0011] In some embodiments, the piston head is provided with a ball, and the axial end face of the valve stem is provided with a groove, the ball being installed in the groove to form a spherical hinge.

[0012] In some embodiments, the reset spring component includes a spring rod, a spring, and a spring seat; the front protrusion of the spring rod is threadedly fixedly connected to the axial end face of the valve body; two spring seats are fitted on the spring rod, and the spring seats are clearance-fitted with the spring rod; the spring is fitted on the spring rod and located between the two spring seats; the two spring seats are axially limited by the step at the connection between the spring rod and the valve body and the tail flange of the spring seat.

[0013] In some embodiments, an O-ring is installed at the connection between the end cap and the valve body.

[0014] In some embodiments, an O-ring is installed at the connection between the valve body and the spring cover.

[0015] A second aspect of this invention discloses a control method based on the above-described variable speed valve stem control structure:

[0016] When the valve stem moves to the right, the pilot port a is input with pressure, filling the left pilot chamber. The pilot pressure enters the sealed cavity through the upper throttling groove J1 on the piston. The pressure acts on the valve stem area. When the pressure in the left pilot chamber exceeds the spring preload, the valve stem drives the piston to move to the right. Since the oil passage area on the upper throttling groove J1 is small at the beginning, the valve stem moves slowly due to damping. As the displacement increases, the passage area on the upper throttling groove J1 increases, and the valve stem moves faster, forming a slow speed in the first section and a fast speed in the second section. This makes the flow output in the first section stable and the flow output in the second section rapidly increase.

[0017] When the valve stem moves to the left, pressure is input into the pilot port b, filling the right pilot chamber. The oil in the sealed container is discharged from the sealed chamber through the lower throttling groove J2 on the piston. The pressure acts on the valve stem area. When the pressure in the right pilot chamber exceeds the spring preload, the valve stem drives the piston to move to the left. Due to the small initial oil passage area on the lower throttling groove J2, the valve stem moves slowly due to damping. As the displacement increases, the passage area on the lower throttling groove J2 increases, and the valve stem moves faster, forming a slow speed in the first section and a fast speed in the second section, resulting in a stable flow output in the first section and a rapid increase in flow in the second section.

[0018] Beneficial effects of this invention:

[0019] This invention employs throttling control related to valve stem displacement, enabling relatively precise control of valve stem displacement speed based on actual operating conditions, thereby achieving stable flow output and comfortable operation. The universal joint connection structure compensates for misalignment between the end cap and valve hole, ensuring that the piston does not jam when linked with the valve stem. The biggest difference from traditional damping or unidirectional damping is that it allows for segmented control, achieving "free" flow control. Attached Figure Description

[0020] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0021] In the attached diagram:

[0022] Figure 1 This is a schematic diagram of the variable speed valve stem control structure of the present invention.

[0023] The attached diagrams are labeled as follows: End cap 1, Piston 2, O-ring 3, Valve body 4, Valve stem 5, O-ring 6, Spring seat 7, Spring 8, Spring cover 9, Upper throttling groove J1, Lower throttling groove J2, Pilot port a, Pilot port b, Sealed cavity c, Left pilot cavity d, Right pilot cavity e.

[0024] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0026] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] like Figure 1 As shown, a variable speed valve stem control structure includes an end cap 1, a valve body 4, and a spring cover 9. The end cap 1, valve body 4, and spring cover 9 are sequentially connected to form an internally interconnected housing. A piston 2, a valve stem 5, and a return spring component are sequentially arranged in the housing. The end cap 1 has a pilot port a, which has a left pilot cavity d. The end cap 1 has a sealed cavity c, and the front end of the sealed cavity c has a hole that mates with the piston 2. The piston 2 has a continuous upper throttling groove J1 and a lower throttling groove J2, and the opening directions of the upper throttling groove J1 and the lower throttling groove J2 are opposite, and the longitudinal area of ​​the throttling groove is variable. The spring cover 9 has a pilot port b, which has a right pilot cavity e.

[0029] A further option: the piston 2 and the valve stem 5 are connected in a movable manner.

[0030] Preferred solution: The piston 2 head is provided with a ball, and the axial end face of the valve stem 5 is provided with a groove, and the ball is installed in the groove to form a spherical hinge.

[0031] A further solution: The reset spring assembly includes a spring rod, a spring 8, and a spring seat 7; the front protrusion of the spring rod is threadedly fixed to the axial end face of the valve body 4, and two spring seats 7 are fitted on the spring rod with clearance fit; the spring 8 is fitted on the spring rod and located between the two spring seats 7; the two spring seats 7 are axially limited by the step at the connection between the spring rod and the valve body 4 and the tail flange of the spring seat 7.

[0032] Preferred configuration: An O-ring 3 is installed at the connection between the end cap 1 and the valve body 4. An O-ring 6 is installed at the connection between the valve body 4 and the spring cover 9.

[0033] As can be seen from the above, segmented control is achieved through the change of oil in the sealed cavity. The oil in the sealed cavity enters or exits through the throttling groove on the piston, and the throttling groove on the piston changes with the movement position of the piston. The piston and valve stem are rigidly connected. To compensate for the concentricity deviation of the two inner holes, a universal joint is designed on the piston. The valve stem and piston are associated structures. Different positions of the valve stem correspond to different throttling grooves on the piston, so as to achieve the requirement that the valve stem moves at different speeds at different positions. The valve stem movement speed determines the flow gain of the multi-way valve.

[0034] Working principle: When the valve stem 5 moves to the right, the pilot port a receives pressure, filling the left pilot chamber d. The pilot pressure enters the sealed cavity c through the upper throttling groove J1 on the piston 2. The pressure acts on the area of ​​the valve stem 5. When the pressure in the left pilot chamber d exceeds the preload of the spring 8, the valve stem 5 drives the piston 2 to move to the right. Due to the small initial oil passage area on the upper throttling groove J1, the valve stem 5 moves slowly due to damping. As the displacement increases, the passage area on the upper throttling groove J1 increases, and the valve stem 5 moves faster, forming a slow speed in the first section and a fast speed in the second section, resulting in a stable flow output in the first section and a rapid increase in flow in the second section. When valve stem 5 moves to the left, pressure is input into pilot port b, filling the right pilot chamber e. Oil in the sealed chamber c is discharged from the sealed chamber c through the lower throttling groove J2 on piston 2. Pressure acts on the area of ​​valve stem 5. When the pressure in the right pilot chamber e exceeds the preload of spring 8, valve stem 5 drives piston 2 to move to the left. Due to the small initial oil passage area on the lower throttling groove J2, valve stem 5 moves slowly due to damping. As the displacement increases, the passage area on the lower throttling groove J2 increases, and valve stem 5 moves faster, creating a slow speed in the first stage and a fast speed in the second stage, resulting in a stable flow output in the first stage and a rapid increase in flow in the second stage. The difference in the area of ​​the upper throttling groove J1 and the lower throttling groove J2 allows for speed control throughout the valve stem stroke.

[0035] As can be seen from the above, this invention employs throttling control related to valve stem displacement, which can achieve relatively precise control of valve stem displacement speed according to actual operating conditions, thereby achieving stable flow output and comfortable operation. The universal joint connection structure can compensate for the misalignment problem between the end cap and the valve hole, ensuring that the piston does not jam when linked with the valve stem. The biggest difference from traditional damping or unidirectional damping is that it can achieve segmented control, achieving "free and easy" flow control.

[0036] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0037] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A variable speed valve stem control structure, characterized in that: Includes end caps, valve body, and spring cover; The end cap, valve body, and spring cover are connected in sequence to form an internally interconnected housing. A piston, a valve stem, and a return spring assembly are sequentially connected within the housing. The end cap is provided with a pilot port a, and the pilot port a has a left pilot cavity; The end cap is provided with a sealed cavity, and the front end of the sealed cavity is provided with a hole that cooperates with the piston. The piston has a continuous upper throttling groove and a lower throttling groove, and the opening directions of the upper throttling groove and the lower throttling groove are opposite, and the longitudinal area of ​​the throttling groove is variable; The spring cover is provided with a pilot port b, and the pilot port b has a right pilot cavity; The reset spring component includes a spring rod, a spring, and a spring seat; The front protrusion of the spring rod is threadedly fixed to the axial end face of the valve body. Two spring seats are fitted on the spring rod, and the spring seats are clearance-fitted with the spring rod. The spring is fitted on the spring rod and located between the two spring seats. The two spring seats are axially limited by the step at the connection between the spring rod and the valve body and the tail flange of the spring seat. When the valve stem moves to the right, the pilot port a is input with pressure, filling the left pilot chamber. The pilot pressure enters the sealed cavity through the upper throttling groove J1 on the piston. The pressure acts on the valve stem area. When the pressure in the left pilot chamber exceeds the spring preload, the valve stem drives the piston to move to the right. Since the oil passage area on the upper throttling groove J1 is small at the beginning, the valve stem moves slowly due to damping. As the displacement increases, the passage area on the upper throttling groove J1 increases, and the valve stem moves faster, forming a slow speed in the first section and a fast speed in the second section. This makes the flow output in the first section stable and the flow output in the second section rapidly increase. When the valve stem moves to the left, the pilot port b is input with pressure, filling the right pilot chamber. The oil in the sealed chamber is discharged from the sealed chamber through the lower throttling groove J2 on the piston. The pressure acts on the valve stem area. When the pressure in the right pilot chamber exceeds the spring preload, the valve stem drives the piston to move to the left. Due to the small initial oil passage area on the lower throttling groove J2, the valve stem moves slowly due to damping. As the displacement increases, the passage area on the lower throttling groove J2 increases, and the valve stem moves faster, forming a slow speed in the first section and a fast speed in the second section, resulting in a stable flow output in the first section and a rapid increase in flow in the second section.

2. The variable speed valve stem control structure according to claim 1, characterized in that: The piston and valve stem are connected in a movable manner.

3. The variable speed valve stem control structure according to claim 2, characterized in that: The piston head is provided with a ball, and the axial end face of the valve stem is provided with a groove. The ball is installed in the groove to form a spherical hinge.

4. The variable speed valve stem control structure according to claim 1, characterized in that: An O-ring is installed at the connection between the end cap and the valve body.

5. The variable speed valve stem control structure according to claim 1, characterized in that: An O-ring is installed at the connection between the valve body and the spring cover.

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