Small-length hydraulic damper

Abstract

The invention relates to the technical field of dampers, and discloses a small-length hydraulic damper which is characterized in that a first damping hole is formed in a piston, and a second damping hole is formed in the cavity wall, right facing the lower end of the piston, of a closed containing cavity, so that the damping force and the damping coefficient of the hydraulic damper of a single-rod structure in the stretching direction and the compression direction are the same; the hydraulic damper has the effect that the performance of the hydraulic damper can be kept stable under the condition that the length of the hydraulic damper is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of dampers, and more specifically, to a small-length hydraulic damper. Background Art

[0002] When many mechanisms perform mechanical movements, due to external forces, vibrations and impacts will occur, resulting in a reduction in the working efficiency of the mechanical system, affecting the service life, and in severe cases, damaging the mechanical structure; when some mechanisms move, due to their low damping, the movement stability of the mechanism is poor or unstable, and even resonance occurs, causing the mechanism to be damaged. In order to reduce the impact of these phenomena on the mechanism, a damping device that can effectively protect the mechanism and improve the system efficiency is usually added to the mechanism. A damper is a device that provides resistance to motion and dissipates motion energy. The working process of the damper is a dissipation process, which realizes the function of vibration reduction or suppression of excessive motion of the mechanical system by converting mechanical energy into heat energy.

[0003] A hydraulic damper is a device in which, during the movement of a mechanical system, the piston in the damper moves to force the liquid in the damper cylinder to flow through the damping element (small holes or slits, or a combination of both), causing the liquid molecules to squeeze and rub against each other, converting mechanical energy into heat energy and dissipating it, thereby generating a damping effect. Hydraulic dampers are commonly used to control impact fluid vibrations, such as rapid closing of main steam valves, safety valve discharges, water hammers, pipe breaks and other impact disturbances, as well as pipe system vibrations caused by seismic disturbances.

[0004] Compared with other dampers, hydraulic dampers are small in size, light in weight, and simple in structure, and are widely used. However, the existing hydraulic dampers have the following problems:

[0005] The installation size of the hydraulic damper with a double-rod structure is large;

[0006] For the hydraulic damper with a single-rod and sleeve-rod structure, due to the mismatch between the piston force areas and flow rates in the tensile and compression directions, the damping forces and damping coefficients in the tensile and compression directions are not equal. Summary of the Invention

[0007] The purpose of the present invention is to provide a small-length hydraulic damper. By setting a first damping hole on the piston and a second damping hole on the cavity wall of the closed cavity opposite to the lower end of the piston, the damping forces and damping coefficients in the tensile direction and the compression direction of the single-rod structure hydraulic damper are made the same, achieving the effect of maintaining the stable performance of the hydraulic damper while reducing the length of the hydraulic damper.

[0008] The present invention is achieved by the following technical solutions:

[0009] The present application provides a hydraulic damper with a small length, which includes a piston rod, a piston, a closed cavity, damping holes, and hydraulic oil disposed inside the damper. The piston rod drives the piston to reciprocate. The piston squeezes the hydraulic oil in the closed cavity to make the oil flow. The oil flowing through the damping holes generates pressure, and the pressure acts on the piston of the piston rod, thereby providing a force opposite to the moving direction for the piston rod. The piston rod is connected to the upper end of the piston. The piston divides the closed cavity into a first damping cavity and a second damping cavity with different piston force-bearing areas. The piston is provided with a first damping hole. The cavity wall of the closed cavity opposite to the lower end of the piston is provided with a second damping hole and a liquid supplement unit. The first damping hole cooperates with the second damping hole so that when the piston reciprocates in the closed cavity to squeeze the hydraulic oil, the first damping force generated by the oil flowing through the first damping hole and the second damping hole in the stretching direction is the same as the second damping force generated in the compression direction.

[0010] In order to better implement the present invention, further, the cavity wall of the closed cavity opposite to the upper end of the piston is provided with an exhaust hole.

[0011] In order to better implement the present invention, the diameter of the exhaust hole is less than or equal to 0.2 mm.

[0012] In order to better implement the present invention, further, for the inner cylinder, the upper support sleeve, and the lower support sleeve that cooperate to form the closed cavity, the second damping hole is provided in the lower support sleeve, and the exhaust hole is provided in the upper support sleeve.

[0013] In order to better implement the present invention, further, the liquid supplement unit includes a liquid supplement hole and a spherical ball that cooperates with the liquid supplement hole.

[0014] In order to better implement the present invention, further, the first damping hole is provided on a damping gasket, and the damping gasket is detachably connected to the piston.

[0015] In order to better implement the present invention, further, it further includes: an outer cylinder and an end cap, and the inner cylinder is disposed inside the outer cylinder through the end cap.

[0016] In order to better implement the present invention, further, the relational expression between the diameter of the first damping hole and the diameter of the second damping hole is where d 1 is the diameter of the first damping hole, d 2 is the diameter of the second damping hole, and k is the ratio of the force-bearing area at the upper end of the piston to the force-bearing area at the lower end of the piston.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] (1) As a hydraulic damper with a single-rod structure, compared with a hydraulic damper with a double-rod structure of the same stroke, the installation size is smaller;

[0019] (2) Through the cooperation of the first damping hole and the second damping hole, the damping force and damping coefficient of the hydraulic damper are the same in both the tensile and compressive directions, and the leakage amount will not be affected when the temperature changes, making the overall damping performance more stable. Description of the Drawings

[0020] The present invention will be further described in conjunction with the following drawings and embodiments. All creative concepts of the present invention should be regarded as the disclosed content and the protection scope of the present invention.

[0021] Figure 1 It is a schematic diagram of the small-length hydraulic damper in this application.

[0022] Wherein: 1. Outer cylinder; 2. Inner cylinder; 3. Piston rod; 4. Upper support sleeve; 5. Lower support sleeve; 6. Damping hole; 7. End cover; 8. Closed cavity; 9. Piston; 10. Exhaust hole. Detailed Embodiment

[0023] Embodiment 1:

[0024] A small-length hydraulic damper in this embodiment, as Figure 1 shown, includes a piston rod 3, a piston, a closed cavity 8, a damping hole 6, and the hydraulic oil disposed inside the damper. The piston rod 3 drives the piston to reciprocate. The piston squeezes the hydraulic oil in the closed cavity 8 to make the hydraulic oil flow. The hydraulic oil flowing through the damping hole 6 generates pressure, and the pressure acts on the piston of the piston rod 3, thereby providing a force opposite to the movement direction for the piston rod 3. The piston rod 3 is connected to the upper end of the piston. The piston divides the closed cavity 8 into a first damping cavity and a second damping cavity with different piston force areas. The piston is provided with a first damping hole. The cavity wall of the closed cavity 8 opposite to the lower end of the piston is provided with a second damping hole and a liquid supplement unit. The first damping hole cooperates with the second damping hole so that when the piston reciprocates in the closed cavity 8 to squeeze the hydraulic oil, the first damping force generated by the hydraulic oil flowing through the first damping hole and the second damping hole in the tensile direction is the same as the second damping force generated in the compressive direction.

[0025] With this embodiment, by means of a single-rod piston structure, the closed cavity 8 is divided into a first damping cavity and a second damping cavity with different piston force-bearing areas, which can effectively reduce the installation length of the entire damper; due to the different piston force-bearing areas of the first damping cavity and the second damping cavity, in order to ensure that the damping forces and damping coefficients of the damper in the tensile direction and the compression direction are the same, by simultaneously providing a first damping hole on the piston and a second damping hole on the second damping cavity, the flow rate and internal leakage during stretching / compression can be controlled to achieve the same damping forces and damping coefficients of the damper in the tensile direction and the compression direction, and to achieve the stable damping performance of the damper in the face of temperature changes; the oil in the damper is unidirectionally replenished through the liquid replenishing unit to further keep the damper with stable damping performance; among them, the damping forces generated by the first damping hole and the second damping hole are determined according to the piston force-bearing areas corresponding to the first damping cavity and the second damping cavity.

[0026] Embodiment 2:

[0027] This embodiment is further optimized on the basis of Embodiment 1. In this embodiment, the relationship between the diameter of the first damping hole and the diameter of the second damping hole is where d 1 is the diameter of the first damping hole, d 2 is the diameter of the second damping hole, and k is the ratio of the force-bearing area at the upper end of the piston to the force-bearing area at the lower end of the piston.

[0028] With this embodiment, it is possible to control the flow rate and internal leakage during stretching / compression to achieve the same damping forces and damping coefficients of the damper in the tensile direction and the compression direction, and to achieve the stable damping performance of the damper in the face of temperature changes.

[0029] In this embodiment, an exhaust hole 10 is provided on the cavity wall of the closed cavity 8 facing the upper end of the piston.

[0030] With this embodiment, after gas enters the closed cavity 8 of the hydraulic damper, the gas can be discharged, thereby avoiding the situation that there is no damping force at the initial stage of piston movement due to the formation of a cavity in the closed cavity 8, and further keeping the damper with stable damping performance.

[0031] In this embodiment, the diameter of the exhaust hole 10 is less than or equal to 0.2 mm.

[0032] With this embodiment, a good exhaust effect on the closed cavity 8 can be achieved while ensuring the overall sealing performance and damping effect of the hydraulic damper.

[0033] In this embodiment, the inner cylinder 2, the upper support sleeve 4, and the lower support sleeve 5 that cooperate to form the closed cavity 8 are provided. The second damping hole is provided in the lower support sleeve 5, and the exhaust hole 10 is provided in the upper support sleeve 4.

[0034] By adopting this embodiment, a detachable closed cavity 8 can be formed. By replacing the lower support sleeve 5 with different second damping holes or replacing the piston with different first damping holes, the adjustment of the damping coefficient of the hydraulic damper can be realized.

[0035] In this embodiment, the liquid replenishing unit includes a liquid replenishing hole and a spherical ball that cooperates with the liquid replenishing hole.

[0036] By adopting this embodiment, the one-way liquid replenishment of the hydraulic damper is realized through a simple and effective structure. The liquid replenishing hole is divided into two parts. The diameter of the first part is larger than that of the spherical ball and narrows at the outer outlet, so that the spherical ball is enclosed in the first part. The diameter of the second part is smaller than that of the spherical ball. When the piston moves towards the lower support sleeve 5, a pressure in the same direction as the piston movement is generated on the oil in the second damping cavity. The spherical ball is pressed to move and cover the liquid replenishing hole with a smaller diameter to complete the sealing. When the piston moves towards the upper support sleeve 4, the pressure on the oil in the second damping cavity changes, and the spherical ball is pushed away from the liquid replenishing hole with a smaller diameter, so that the oil can enter the second damping cavity through the liquid replenishing hole to complete the one-way liquid replenishment and supplement the volume difference between the first damping cavity and the second damping cavity.

[0037] In this embodiment, it further includes: an outer cylinder 1 and an end cover 7. The inner cylinder 2 is arranged in the outer cylinder 1 through the end cover 7.

[0038] By adopting this embodiment, the overall detachable of the small-length hydraulic damper can be realized.

[0039] Other parts of this embodiment are the same as those of Embodiment 1, so they will not be elaborated here.

[0040] Embodiment 3:

[0041] On the basis of the above Embodiment 1 or 2, this embodiment is further optimized. In this embodiment, the first damping hole is provided on a damping gasket, and the damping gasket is detachably connected to the piston.

[0042] By adopting this embodiment, the adjustment of the damping coefficient of the hydraulic damper can be realized by replacing the piston and the damping gasket on the piston.

[0043] Other parts of this embodiment are the same as those of the above Embodiment 1 or 2, so they will not be elaborated here.

[0044] It should be noted that in the above embodiments, the specific installation positions of the first damping hole and the second damping hole are not specifically limited. The first damping hole only needs to be installed on the piston, and the second damping hole only needs to be installed at relevant positions in the second damping cavity, such as on the lower support sleeve 5, to achieve the relevant functions. Of course, in the above embodiments, only the case where the number of both the first damping hole and the second damping hole is one is exemplified. When the numbers of the first damping hole and the second damping hole change, the relational expression of the ratio of the diameter to the force-bearing area may change slightly. For example, when the number of the first damping holes is n and the number of the second damping holes is m, the relational expression is

[0045] Embodiment 4:

[0046] In this embodiment, an embodiment of a preferred implementation manner of a small-length hydraulic damper includes an outer cylinder 1 and an inner cylinder 2 fixed in the outer cylinder 1 through an end cap 7. The inner cylinder 2, the upper support sleeve 4, and the lower support sleeve 5 cooperate to form a closed cavity 8. The piston is fitted in the inner cylinder 2 and can move in the closed cavity 8;

[0047] Adopting this implementation manner, the small-length hydraulic damper as a whole is easy to install and disassemble, facilitating the adjustment of the damping coefficient of the small-length hydraulic damper.

[0048] One end of the piston rod 3 is connected to the upper end of the piston, so that the piston divides the closed cavity 8 into a first damping cavity with a smaller force-bearing area of the piston and a second damping cavity with a larger force-bearing area of the piston. The other end of the piston rod 3 is used to connect a load;

[0049] Adopting this implementation manner, through the single-rod piston structure, the closed cavity 8 is divided into a first damping cavity and a second damping cavity with different force-bearing areas of the piston, which can effectively reduce the installation length of the entire damper. The overall installation length of the small-length hydraulic damper is reduced, and the saved space can also be used to increase the stroke of the piston. Subsequently, while reducing the overall length of the small-length hydraulic damper, the overall stroke of the small-length hydraulic damper is increased.

[0050] An exhaust hole 10 is provided on the upper support sleeve 4. A damping hole 6 or a damping gasket is provided on the piston as the first damping hole. A damping hole 6 is provided on the lower support sleeve 5 as the second damping hole. A liquid replenishing hole and a spherical ball cooperating with the liquid replenishing hole are also provided on the lower support sleeve 5 as a liquid replenishing unit. Among them, the diameter of the exhaust hole 10 is less than or equal to 0.2 mm. The relational expression between the diameter of the first damping hole and the diameter of the second damping hole is where d 1 is the diameter of the first damping hole, d 2 is the diameter of the second damping hole, and k is the ratio of the force-bearing area at the upper end of the piston to the force-bearing area at the lower end of the piston;

[0051] By adopting this embodiment, through the provision of the exhaust hole 10, it is possible to discharge the gas after the gas enters the closed cavity 8 of the damper, thereby avoiding the formation of a cavity in the closed cavity 8 and resulting in no damping force at the initial stage of the piston movement, and further enabling the damper to maintain a stable damping performance;

[0052] By replacing the lower support sleeve 5 provided with different damping holes 6, replacing the piston provided with different damping holes 6, and / or replacing the damping gasket on the piston, it is possible to adjust the damping coefficient of the hydraulic damper;

[0053] Through the cooperation of the first damping hole and the second damping hole, it is possible to control the flow rate and internal leakage during stretching / compression, so as to achieve the same damping force and damping coefficient in the stretching direction and the compression direction of the damper, and to achieve the damper maintaining a stable damping performance in the face of temperature changes;

[0054] Through the liquid supplement unit, the oil in the damper is supplemented unidirectionally, further enabling the damper to maintain a stable damping performance. When the piston moves towards the lower support sleeve 5, a pressure in the same direction as the piston movement is generated on the oil in the second damping cavity, and the ball will be pressed into the liquid supplement hole to complete the seal. When the piston moves towards the upper support sleeve 4, the pressure on the oil in the second damping cavity changes, and the ball is pushed away from the liquid supplement hole, enabling the oil to enter the second damping cavity through the liquid supplement hole to complete the unidirectional liquid supplement and compensate for the volume difference between the first damping cavity and the second damping cavity.

[0055] In summary, the beneficial effects of this embodiment are as follows:

[0056] (1) As a hydraulic damper with a single-rod structure, compared with a hydraulic damper with a double-rod structure of the same stroke, the installation size is smaller;

[0057] (2) Through the cooperation of the first damping hole and the second damping hole, the damping force and damping coefficient of the hydraulic damper are the same in the stretching and compression directions, and the leakage amount will not be affected when the temperature changes, and the overall damping performance is more stable;

[0058] (3) The damping coefficient of the small-length hydraulic damper can be flexibly adjusted by adjusting the first damping hole and the second damping hole;

[0059] (4) By providing the exhaust hole, it is possible to avoid the formation of a cavity in the closed cavity and resulting in no damping force at the initial stage of the piston movement, and further enabling the damper to maintain a stable damping performance;

[0060] (5) It is more conducive to being applied to various types of moving mechanisms that require small-size hydraulic dampers in the fields of aviation, aerospace, etc.

[0061] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A short-length hydraulic damper, comprising a piston rod (3), a piston, a closed cavity (8), a damping hole (6) and oil arranged inside the damper, wherein the piston rod (3) drives the piston to reciprocate, the piston squeezes the oil in the closed cavity (8) to make the oil flow, the oil flows through the damping hole (6) to generate pressure, the pressure acts on the piston of the piston rod (3), thereby providing the piston rod (3) with a force opposite to the direction of movement, characterized in that: The piston rod (3) is connected to the upper end of the piston, and the piston divides the closed cavity (8) into a first damping cavity and a second damping cavity with different piston force areas. The piston is provided with a first damping hole, and the cavity wall of the closed cavity (8) facing the lower end of the piston is provided with a second damping hole and a liquid replenishing unit. The first damping hole cooperates with the second damping hole so that when the piston reciprocates in the closed cavity (8) to squeeze the oil, the first damping force generated in the tensile direction by the oil flowing through the first damping hole and the second damping hole is the same as the second damping force generated in the compressive direction.

2. A short-length hydraulic damper according to claim 1, characterized in that: The cavity wall of the closed cavity (8) facing the upper end of the piston is provided with an exhaust hole (10).

3. A short-length hydraulic damper according to claim 2, characterized in that: The diameter of the exhaust hole (10) is less than or equal to 0.2 mm.

4. A short-length hydraulic damper according to claim 2, characterized in that: The inner cylinder (2), the upper support sleeve (4) and the lower support sleeve (5) cooperate to form the closed cavity (8), the second damping hole is arranged on the lower support sleeve (5), and the exhaust hole is arranged on the upper support sleeve (4).

5. A short-length hydraulic damper according to claim 1, characterized in that: The fluid replenishment unit includes a fluid replenishment hole and a round ball matched with the fluid replenishment hole.

6. A short-length hydraulic damper according to claim 1, characterized in that: The first damping hole is arranged on the damping gasket, and the damping gasket is detachably connected to the piston.

7. A short-length hydraulic damper according to claim 2, characterized in that: Also includes: An outer cylinder (1) and an end cover (7), wherein the inner cylinder (2) is arranged in the outer cylinder (1) via the end cover (7).

8. A short-length hydraulic damper according to any one of claims 1 to 7, characterized in that: The relationship between the diameter of the first damping hole and the diameter of the second damping hole is: Wherein, d1 is the diameter of the first damping hole, d2 is the diameter of the second damping hole, and k is the ratio of the force-bearing area of ​​the upper end of the piston to the force-bearing area of ​​the lower end of the piston.

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