A pseudoplastic fluid variable damping shock absorber and its application

Abstract

The present invention discloses a pseudoplastic fluid variable damping shock absorber and its application. The shock absorber includes a shock absorption cavity and a damping head disposed in the shock absorption cavity. The shock absorption cavity is filled with a pseudoplastic fluid, and under the action of an external force, a damping force is generated through the movement of the damping head in the pseudoplastic fluid to achieve shock absorption. This pseudoplastic fluid variable damping shock absorber can achieve a variable damping effect under variable frequency working conditions, improve the shock absorption performance at high frequencies, and at the same time has the advantages of relatively simple structure, low cost, convenient maintenance, inspection and replacement, etc., and is particularly suitable for the shock absorption system of a drum washing machine.

Description

Technical Field

[0001] The present invention relates to the technical field of variable damping shock absorbers, and particularly relates to a pseudoplastic fluid variable damping shock absorber and its application. Background Art

[0002] With the improvement of living standards, people's quality requirements for small and medium-sized household appliances such as washing machines are also constantly increasing. Due to the continuous pursuit of comfort experience, people not only require the washing rate of the washing machine to be improved, but also require it to be safe and stable during operation. However, at present, there are still problems such as severe vibration when the washing machine is washing with a low load. When the laundry volume is small, that is, during the low-load dehydration operation, it is easy to cause load eccentricity, and the high-speed rotation exacerbates the instability of the system. The shock absorption system (spring + damper) fails to effectively block the vibration transmission path, resulting in increased vibration of the washing machine body, thereby affecting the dehydration rate and dehydration effect of the washing machine.

[0003] In the common shock absorption system of drum washing machines, the spring is mainly responsible for balancing the mutual conversion of the kinetic energy of vibration and the potential energy of spring deformation and cannot absorb vibration, while the solid friction damper plays a role in absorbing and attenuating vibration energy. In actual use, the damper simultaneously exhibits the two-phase characteristics of a spring and a viscous pot, and the shock absorption effect of the damper is proportional to the deformation amount. Usually, as the working frequency increases, the rigidity of the damper increases sharply, and the deformation amount decreases. When working at a high frequency, the damper becomes hard, and the shock absorption performance is significantly reduced. Therefore, during high-speed dehydration, the vibration problem of the washing machine will be more prominent. Summary of the Invention

[0004] The purpose of the present invention is to provide a pseudoplastic fluid variable damping shock absorber and its application. It uses a fluid damper to replace the original solid friction damper, and utilizes the shear thinning characteristics of the pseudoplastic fluid and the rheological characteristics of a large viscosity change range to overcome the defect that the existing solid friction damper causes increased system vibration at high frequencies.

[0005] The present invention achieves the above purpose through the following technical solutions:

[0006] A pseudoplastic fluid variable damping shock absorber, the shock absorber includes a shock absorption cavity and a damping head disposed in the shock absorption cavity. The shock absorption cavity is filled with a pseudoplastic fluid, and under the action of an external force, damping force is generated through the movement of the damping head in the pseudoplastic fluid to achieve shock absorption.

[0007] Further improvement lies in that the pseudoplastic fluid is a composite preparation made of multiple solvents and solutes. At room temperature, the viscosity of the pseudoplastic fluid is 6000 - 40000 mcP at a rotational speed of 1 rpm, and 100 - 8000 mcP at a rotational speed of 200 rpm.

[0008] A further improvement is that the pseudoplastic fluid remains in a liquid state when the temperature is higher than -40°C.

[0009] A further improvement is that the composition and volume ratio of the pseudoplastic fluid are as follows: silicone oil: guar gum: citric acid: surfactant: ethylene glycol: water = 0 - 10%: 5 - 15%: 15 - 20%: 5 - 10%: 10 - 30%: 25 - 60%.

[0010] A further improvement is that the volume ratio of the pseudoplastic fluid in the damping cavity is 70 - 85%.

[0011] A further improvement is that the shock absorber further includes a liquid cylinder, a sealing ring, a push rod, and a connector. One end of the liquid cylinder is open and is sealed by the sealing ring, so that a damping cavity is formed inside the liquid cylinder. One end of the push rod extends into the damping cavity through the sealing ring and is connected to the damping head. There are two connectors, which are respectively arranged at the other end of the push rod and the other end of the liquid cylinder.

[0012] A further improvement is that in the pseudoplastic fluid variable damping shock absorber, the damping head can be replaced and can also be made into different shapes, such as conical, flat plate, multi-layered, or sieve plate-shaped, for changing the damping force.

[0013] A further improvement is that the damping head has no contact with the inner wall of the liquid cylinder and only interacts through the pseudoplastic fluid damping liquid, and the ratio of the inner diameter of the liquid cylinder to the outer diameter of the damping head is 3 - 1.1:1.

[0014] A further improvement is that the liquid cylinder, the sealing ring, the push rod, and the connector are made of plastic material by injection molding or made of metal material by machining. Among them, the connector and the push rod and the liquid cylinder are of a separable structure or an integrated structure.

[0015] The present invention also provides an application of the pseudoplastic fluid variable damping shock absorber, and the application is to apply the pseudoplastic fluid variable damping shock absorber to the damping system of a drum washing machine.

[0016] The beneficial effects of the present invention are as follows: The pseudoplastic fluid variable damping shock absorber can achieve a variable damping effect under variable frequency conditions, improve the damping performance at high frequencies, and at the same time has the advantages of relatively simple structure, low cost, convenient maintenance, inspection, and replacement, and is especially suitable for the damping system of a drum washing machine. Description of the Drawings

[0017] Figure 1 It is a schematic cross-sectional structure diagram of a pseudoplastic fluid variable damping shock absorber;

[0018] In the figure: 1. Damping cavity; 2. Damping head; 3. Liquid cylinder; 4. Sealing ring; 5. Push rod; 6. Connector. Detailed Embodiments

[0019] The present application will be further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0020] As Figure 1 shown, a pseudoplastic fluid variable damping shock absorber includes a shock absorption cavity 1 and a damping head 2 disposed in the shock absorption cavity 1. The shock absorber further includes a liquid cylinder 3, a sealing ring 4, a push rod 5, and a connecting head 6. One end of the liquid cylinder 3 is open and is encapsulated through the sealing ring 4, so that a shock absorption cavity 1 is formed inside the liquid cylinder 3. One end of the push rod 5 extends into the shock absorption cavity 1 through the sealing ring 4 and is connected to the damping head 2. A rubber ring is built in the sealing ring 4 and tightly combined with the push rod 5 to prevent the leakage of the pseudoplastic fluid damping liquid. There are two connecting heads 6, which are respectively disposed at the other end of the push rod 5 and the other end of the liquid cylinder 3. The two connecting heads 6 are located at both ends of the shock absorber and are used to fix the shock absorber to a washing machine or other equipment that requires vibration isolation. The shock absorption cavity 1 is filled with a pseudoplastic fluid, and the pseudoplastic fluid remains liquid when the temperature is higher than -40°C. When the push rod 5 reciprocates in the liquid cylinder 3 under the drive of an external force, the pseudoplastic fluid flows in the liquid cylinder 3 under the pushing action of the damping head 2, generating a damping force, thereby achieving shock absorption. At the same time, the characteristics of shear thinning of the pseudoplastic fluid and the rheological characteristics of a large viscosity change range are utilized to overcome the defect that the existing solid friction dampers cause the system vibration to intensify at high frequencies.

[0021] The following provides two specific applications of the above shock absorber in the shock absorption system of a drum washing machine:

[0022] Embodiment 1:

[0023] In this embodiment, the connecting head 6 and the push rod 5, and the connecting head 6 and the liquid cylinder 3 are both integrally constructed injection molded parts. The damping head 2 is a sieve plate-shaped multi-layer structure with a diameter of 20 mm and a thickness of 2 mm. The inner diameter of the liquid cylinder 3 is 25 mm and is fixed to the free end of the push rod 5 by hot melting. The sealing ring 4 is made of polytetrafluoroethylene, and the rubber ring is a silicone rubber ring.

[0024] In this embodiment, the pseudoplastic fluid is a composite preparation made of a variety of solvents and solutes, and the specific components and volume ratios are silicone oil: guar gum: citric acid: surfactant: ethylene glycol: water = 2%: 5%: 15%: 6%: 14%: 58%. At 20°C, the viscosity at a rotation speed of 1 rpm is 18000 m cP, and the viscosity at a rotation speed of 200 rpm is 2000 m cP. As the measured rotation speed increases, the viscosity decreases significantly. The volume ratio of the pseudoplastic fluid in the liquid cylinder 3 is approximately 75%.

[0025] Install the shock absorber on the four support feet inside the drum washing machine, and perform high-speed dehydration with a 300g eccentric mass block. The vibration isolation transfer ratio in the vertical direction is less than 0.3, showing very excellent shock absorption effect.

[0026] Embodiment 2:

[0027] In this embodiment, the connecting head 6, the push rod 5, the hydraulic cylinder 3, and the damping head 2 are all made of aluminum alloy and are all separable structural devices, which are connected by threads and adhesive. The damping head 2 is made of 304 stainless steel and is a flat three-layer structure with a diameter of 18mm and a thickness of 1mm. The inner diameter of the hydraulic cylinder 3 is 21mm and is fixed to the free end of the push rod 5 by rivets. The sealing ring 4 is made of polytetrafluoroethylene, and the rubber ring is a silicone rubber ring.

[0028] In this embodiment, the pseudoplastic fluid is a composite preparation made of various solvents and solutes, and the specific components are: silicone oil: guar gum: citric acid: surfactant: ethylene glycol water = 5%: 15%: 15%: 10%: 20%: 35%. At 20°C, the viscosity at a rotational speed of 1 rpm is 35000 m cP, and the viscosity at a rotational speed of 200 rpm is 6000 m cP. As the measured rotational speed increases, the viscosity decreases significantly. The volume ratio of the pseudoplastic fluid in the hydraulic cylinder 3 is about 70%.

[0029] Install the shock absorber on the four support feet inside the drum washing machine, and perform high-speed dehydration with a 300g eccentric mass block. The vibration isolation transfer ratio is less than 0.22, showing very excellent shock absorption effect.

[0030] It can be seen that the shock absorber provided by the present invention has shock absorption effects in both the horizontal and vertical directions, can better reduce the vibration of the washing machine under high-frequency conditions, improve the product quality, and meet the requirements of users for the comfort experience of the product.

[0031] The above embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A pseudoplastic fluid variable damping shock absorber, the shock absorber comprising a shock absorption cavity (1) and a damping head (2) disposed within the shock absorption cavity (1), characterized in that, The damping cavity (1) is filled with a pseudoplastic fluid, and damping force is generated by the movement of the damping head (2) in the pseudoplastic fluid under the action of an external force to achieve vibration damping; The shock absorber further includes a liquid cylinder (3), a sealing ring (4), a push rod (5) and a connecting head (6). One end of the liquid cylinder (3) is open and is encapsulated by the sealing ring (4) to form a damping cavity (1) inside the liquid cylinder (3). One end of the push rod (5) extends into the damping cavity (1) movably through the sealing ring (4) and is connected to the damping head (2). There are two connecting heads (6), and the two connecting heads (6) are respectively arranged at the other end of the push rod (5) and the other end of the liquid cylinder (3); The damping head (2) has no contact with the inner wall of the liquid cylinder (3), and the ratio of the inner diameter of the liquid cylinder (3) to the outer diameter of the damping head (2) is 3 - 1.1:1; The shock absorber is applied to the vibration damping system of a drum washing machine to damp vibration in the horizontal and vertical directions and reduce the vibration of the washing machine under high-frequency working conditions; The components and volume ratio of the pseudoplastic fluid are silicone oil: guar gum: citric acid: surfactant: ethylene glycol: water = 0 - 10%: 5 - 15%: 15 - 20%: 5 - 10%: 10 - 30%: 25 - 60%.

2. The pseudo-plastic fluid variable damping shock absorber according to claim 1, characterized in that At room temperature, the viscosity of the pseudoplastic fluid is 6000 - 40000 m cP at a rotational speed of 1 rpm and 100 - 8000 m cP at a rotational speed of 200 rpm.

3. A pseudoplastic fluid variable damping shock absorber according to claim 1, characterized in that, The pseudoplastic fluid remains in a liquid state at temperatures above -40 °C.

4. A pseudo-plastic fluid variable damping shock absorber according to claim 1, characterized in that, The volume ratio of the pseudoplastic fluid in the damping cavity (1) is 70 - 85%.

5. A pseudo-plastic fluid variable damping shock absorber according to claim 1, characterized in that, The damping head (2) is conical, flat, multi-layered or sieve-plate shaped.

6. The pseudo-plastic fluid variable damping shock absorber according to claim 1, wherein The liquid cylinder (3), the sealing ring (4), the push rod (5) and the connecting head (6) are made of plastic material by injection molding or made of metal material by machining. Among them, the connecting head (6) and the push rod (5) and the liquid cylinder (3) are of a separable structure or an integral structure.

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