A magnetorheological damper with an adjustable damping gap and a double-helix annular channel.

Abstract

This invention proposes a magnetorheological damper with an adjustable damping gap and a double-helix annular channel. The damper mainly consists of a fixed valve core, a movable piston rod, a cylinder, a piston head, and a floating piston. The fixed valve core and piston head form two helical flow channels through a helical connection. Under the influence of a magnetic field, magnetorheological effects occur in both helical channels, increasing the shear yield stress of the magnetorheological fluid and generating damping force. This damping force hinders the movement of the movable piston rod, while the floating piston compensates for volume changes. Compared to traditional dampers using a double-helix annular channel, this invention effectively extends the damping channel length and increases the output damping force. Furthermore, adjusting the position of the fixed valve core by rotating the nut changes the thickness of the damping gap, thus adjusting the damping force. Effective control of the damping force can be achieved by changing the current flowing through the excitation coil.

Description

Technical Field

[0001] This invention relates to a magnetorheological damper, and more particularly to a magnetorheological damper with a double-helical annular channel. Background Technology

[0002] Magnetorheological dampers are a new type of intelligent damping device that uses magnetorheological fluid as the working medium. Based on the magnetorheological effect, magnetorheological dampers have advantages such as simple structure, small size, low energy consumption, and fast response. Due to their adjustable damping characteristics, they are widely used in vibration control fields such as automobiles, shock absorbers, and prosthetics.

[0003] Currently, the excitation coils of most magnetorheological dampers are wound within a circular groove in the piston head, with the fluid flow channel mostly passing through the annular gap formed between the outer surface of the piston and the inner surface of the cylinder. During operation, the magnetorheological fluid flows within this annular gap. When the excitation coil is energized, a magnetic field perpendicular to the flow direction of the magnetorheological fluid is generated within the annular gap, producing a controllable damping force under the influence of this magnetic field. The damping is variable by altering the magnitude of the applied current, thereby changing the magnetic induction intensity. To increase the maximum damping force of such magnetorheological dampers, measures such as increasing the inner diameter of the damper cylinder, changing the thickness of the damping gap, or adjusting the magnetic field distribution are necessary. However, this approach introduces limitations and makes it difficult to meet the practical application requirements under various working conditions.

[0004] Based on this, the present invention proposes a magnetorheological damper with an adjustable damping gap and a double helical annular channel, which increases the output damping force by extending the fluid flow channel while also having the advantage of adjustable damping gap. Summary of the Invention

[0005] To overcome the shortcomings of the magnetorheological dampers described in the background art and meet the requirements of engineering applications, this invention proposes a magnetorheological damper with an adjustable damping gap and a double-helical annular channel. This magnetorheological damper mainly consists of a fixed valve core, a movable piston rod, a cylinder, a piston head, and a floating piston. The fixed valve core and piston head form two helical flow channels through a helical connection. Under the action of a magnetic field, magnetorheological effects occur in both helical flow channels, increasing the shear yield stress of the magnetorheological fluid and generating damping force. This damping force hinders the movement of the movable piston rod, while the floating piston compensates for volume changes. Compared to traditional dampers using a double-helical annular channel, this invention effectively extends the damping channel length and increases the output damping force. Furthermore, adjusting the position of the fixed valve core by rotating the nut changes the thickness of the damping gap, thus adjusting the damping force. Effective control of the damping force can be achieved by changing the current flowing through the excitation coil.

[0006] The technical solution adopted by the present invention to solve its technical problem includes: a movable piston rod (1), an oil injection screw (2), a screw (3), a left end cover (4), air (5), a damper cylinder (6), a magnetorheological fluid (7), a piston head (8), an excitation coil (9), a sleeve (10), a floating piston (11), a right end cover (12), an adjusting nut (13), an end cover (14), and a fixed valve core (15); the movable piston rod (1) is processed into a stepped shape, and its left end outer circumferential surface is processed with external threads; the damper left end cover (4) and the damper cylinder (6) are fixedly connected by screws (3) and sealed by a sealing ring; the damper left end cover (4) is processed with a central through hole, and the left piston rod (1) and the inner surface of the central through hole of the damper left end cover (4) are clearance-fitted and sealed by a sealing ring; the damper cylinder (6) is processed with a positioning and fixing boss (601) for positioning and fixing the piston head (8); the damper cylinder (6) The end cover (14) and the right end cover (12) are fixedly connected by screws (3) and sealed by a sealing ring; a sleeve (10) is interference-fitted between the right end cover (12) and the damper cylinder (6) to clamp the piston head (8); a spiral channel (8) is machined in the inner hole of the piston head (8) and spirally engaged with the spiral channel (1501) machined on the left end of the fixed valve core (15) to form two effective damper channels; a thread is machined on the outer circle of the right end of the fixed valve core (15) and spirally engaged with the adjusting nut (13); the floating piston (11) and the right end cover (12) are both machined with a central through hole, and the fixed valve core (15) is clearance-fitted with the inner surface of the central through hole of the floating piston (11) and the right end cover (12) and sealed by a sealing ring; the excitation coil (9) is evenly wound on the piston head (8); a right lead hole is machined on the left side of the piston head (8) and on the damper cylinder (6), and the lead of the excitation coil (9) is led out through the lead hole;

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] (1) The magnetorheological damper of the present invention forms a double helical channel by processing the inner hole of the piston head into a spiral shape and connecting it with the left end of the fixed valve core. This extends the effective damping channel length and can effectively improve the output damping force and adjustable range of the damper without changing the external dimensions.

[0009] (2) The magnetorheological damper of the present invention adjusts the position of the valve core by adjusting the nut, thereby changing the thickness of the two spiral channels, thus realizing the adjustable damping gap and further improving the damping force adjustment range of the damper.

[0010] (3) The present invention has a compact structure and occupies little space. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the structure of the present invention.

[0013] Figure 2 This is a cross-sectional view of the piston head of the present invention.

[0014] Figure 3 This is a three-dimensional schematic diagram of the fixed valve core of the present invention.

[0015] Figure 4 This is a cross-sectional view of the damper cylinder of the present invention.

[0016] Figure 5 This is a magnetic field line distribution diagram of the present invention.

[0017] Explanation of reference numerals in the attached figures:

[0018] 1-Moving piston rod, 2-Oil injection screw, 3-Screw, 4-Left end cover, 5-Air, 6-Damper cylinder body, 7-Magnetorheological fluid, 8-Piston head, 9-Excitation coil, 10-Sleeve, 11-Floating piston, 12-Right end cover, 13-Adjusting nut, 14-End cover, 15-Fixed valve core. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 The diagram shown is a schematic of the structure of the present invention. The components are: movable piston rod (1), oil injection screw (2), screw (3), left end cover (4), air (5), damper cylinder (6), magnetorheological fluid (7), piston head (8), excitation coil (9), sleeve (10), floating piston (11), right end cover (12), adjusting nut (13), end cover (14), and fixed valve core (15).

[0021] Figure 2 This is a cross-sectional view of the piston head. The center hole inside the piston head (8) is machined into a spiral boss (801).

[0022] Figure 3 This is a three-dimensional schematic diagram of the fixed valve core of the present invention. The fixed valve core (15) is machined to form a spiral boss (1501).

[0023] Figure 4 This is a cross-sectional view of the damper cylinder body of the present invention. The damper cylinder body (6) has a fixed positioning boss (601) machined inside.

[0024] Figure 5 This is a magnetic field distribution diagram of the present invention. The magnetic field lines generated by the excitation coil (9) start from the damper cylinder (6), pass through the piston head (8), pass through two spiral annular channels, reach the damper cylinder (6), and form a closed loop at the damper cylinder (6).

[0025] The working principle of this invention is as follows:

[0026] A spiral annular fluid flow channel is formed at both ends between the outer spiral surface of the left end of the fixed valve core and the inner spiral annular surface of the piston head's inner hole. The piston head, damper cylinder, and damping gap constitute a closed magnetic field circuit. When current is passed through the excitation coil, a magnetic field perpendicular to the fluid flow direction is formed in the fluid flow channel. After the magnetorheological fluid flows through the fluid flow channel, it generates a magnetorheological effect, increasing the shear stress. At this time, under external excitation, the movable piston rod 1 moves, pushing the magnetorheological fluid 7 to flow through the damper channel; due to the increased shear stress, a large damping is generated, hindering the left piston rod 1 from achieving the damping and vibration reduction effect. Changing the magnitude of the current flowing through the excitation coil 9 changes the output damping force. The damping gap can be controlled by changing the position of the fixed valve core and the thickness of the damping gap by changing the adjusting nut.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions will not cause the substance of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A magnetorheological damper with an adjustable damping gap in a double-helical annular channel, characterized in that: Includes a movable piston rod (1), an oil filler screw (2), a screw (3), a left end cap (4), air (5), a damper cylinder (6), a magnetorheological fluid (7), a piston head (8), an excitation coil (9), a sleeve (10), a floating piston (11), a right end cap (12), an adjusting nut (13), an end cover (14), and a fixed valve core (15); the movable piston rod (1) is machined into a stepped shape, and its left end outer circumferential surface is machined with external threads; the damper left end cap (4) and the damper cylinder (6) are fixedly connected by screws (3) and sealed by a sealing ring; the damper left end cap (4) is machined with a central through hole, and the movable piston rod (1) and the inner surface of the central through hole of the damper left end cap (4) are clearance-fitted and sealed by a sealing ring; the damper cylinder (6) is machined with a positioning and fixing boss (601) for positioning and fixing the piston head (8); the damper cylinder (6), the end cover (12), the adjusting nut (13), the end cover (14), and the fixed valve core (15) are all connected. 4) The right end cover (12) and the other two parts are fixedly connected by screws (3) and sealed by a sealing ring; a sleeve (10) is interference-fitted between the right end cover (12) and the damper cylinder (6) to clamp the piston head (8); a spiral channel is machined in the inner hole of the piston head (8) and spirally engaged with the spiral channel (1501) machined on the left end of the fixed valve core (15) to form two effective damper channels; a thread is machined on the outer circle of the right end of the fixed valve core (15) and spirally engaged with the adjusting nut (13); the floating piston (11) and the right end cover (12) are both machined with a central through hole, and the fixed valve core (15) is clearance-fitted with the inner surface of the central through hole of the floating piston (11) and the right end cover (12) and sealed by a sealing ring; the excitation coil (9) is evenly wound on the piston head (8); a right lead hole is machined on the left side of the piston head (8) and on the damper cylinder (6), and the lead of the excitation coil (9) is led out through the lead hole; The piston head (8) and the fixed valve core (15) form a double helical fluid flow channel; By adjusting the position of the valve core by fixing the nut, the thickness of the two spiral channels changes, thereby making the damping gap adjustable.

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