A silencing device for a hydraulic system

Abstract

The application discloses a silencing device for a hydraulic system, and relates to the field of hydraulic systems of forklifts.The silencing device comprises a first diffusion pipe, oil inlets and outlets are formed at two ends of the first diffusion pipe respectively, a plurality of first diffusion holes are formed in the circumferential wall of the first diffusion pipe, a second diffusion pipe is arranged on the circumference of the first diffusion pipe, a plurality of second diffusion holes are formed in the circumferential wall of the second diffusion pipe, a closed pipe is arranged on the circumference of the second diffusion pipe, and a plurality of silencing cavities are arranged between the closed pipe and the second diffusion pipe.The application is helpful to reduce the vibration and noise of the hydraulic system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of forklift hydraulic systems, in particular to a silencing device for hydraulic systems. BACKGROUND

[0002] At present, the forklift hydraulic system adopts a volumetric pump. When the oil flows, pressure pulsation occurs. Due to the impedance effect of the pipeline, pressure pulses are generated, and then vibration and noise occur. When the forklift is continuously operating under full load for a long time, the vibration will affect the efficiency of the hydraulic system; and the long-time noise will have an adverse effect on the workers. SUMMARY

[0003] In order to reduce the vibration and noise of the hydraulic system, the present application provides a silencing device for hydraulic systems.

[0004] The silencing device for hydraulic systems provided by the present application adopts the following technical scheme:

[0005] A silencing device for hydraulic systems, comprising a first diffusion pipe, the two ends of the first diffusion pipe are respectively formed with an oil inlet and an oil outlet, a plurality of first diffusion holes are opened on the circumferential wall of the first diffusion pipe, a second diffusion pipe is arranged on the circumferential side of the first diffusion pipe, a plurality of second diffusion holes are opened on the circumferential wall of the second diffusion pipe, a closed pipe is arranged on the circumferential side of the second diffusion pipe, and a plurality of silencing cavities are arranged between the closed pipe and the second diffusion pipe.

[0006] By adopting the above technical scheme, when high-pressure oil enters the first diffusion pipe from the oil inlet, it will diffuse outward from the first diffusion holes of the first diffusion pipe, and then between the first diffusion pipe and the second diffusion pipe. At this time, the high-pressure oil will resonate and attenuate between the first diffusion holes and the second diffusion holes, absorbing the pressure pulsation, and then the silencing cavities will absorb the pressure pulsation again, which helps to greatly reduce the vibration and noise caused by the high-pressure oil in the pipeline.

[0007] Preferably, a corrugated plate is arranged in the closed pipe and the second diffusion pipe, and the silencing cavities are formed between the corrugated plate and the closed pipe.

[0008] By adopting the above technical scheme, when the high-pressure oil enters the closed pipe from the second diffusion hole, the noise will be transmitted into the closed pipe. Due to the characteristics of the corrugated plate, the high-pressure oil will not enter the silencing cavities, and the silencing cavities will absorb the noise. In addition, the corrugated plate increases the contact area with the high-pressure oil, and the absorption effect of the pulsation is better, which helps to reduce the vibration and noise.

[0009] Preferably, both the first and second diffuser tubes are square tubes. First diffuser plates are formed on the upper and lower sides of the first diffuser tube. First diffuser holes are formed on the two first diffuser plates, arranged in 7 rows and 15 columns. The center distance between each row of first diffuser holes is 7.4 mm, and the center distance between each column of first diffuser holes is 10.5 mm. The length of each first diffuser hole is 5.5 mm, and the diameter of each first diffuser hole is 1.2 mm. Similarly, second diffuser tubes are formed on the upper and lower sides of the second diffuser tube. Second diffuser holes are formed on the two second diffuser plates, arranged in 7 rows and 15 columns. The center distance between each row of second diffuser holes is 7.4 mm, and the center distance between each column of second diffuser holes is 10.5 mm. The length of each second diffuser hole is 5.5 mm, and the diameter of each second diffuser hole is 1.2 mm.

[0010] By adopting the above technical solution, and through force analysis of the liquid column in the first and second diffuser holes, combined with the flow continuity equation, it can be found that when the hole parameters are 7 rows and 15 columns, the hole length is 5.5 mm, the diameter is 1.2 mm, the center distance between rows is 7.4 mm, and the center distance between columns is 10.5 mm, the amplitude of pressure pulsation is 0.25 MPa, while the amplitude was 0.65 MPa when the silencing device was not installed. The difference is about 61.5%, which helps to reduce the vibration and noise of the hydraulic system.

[0011] Preferably, it also includes a heat sink, which is connected to one end of the first diffuser tube through a connecting hole, the oil inlet is opened on the heat sink, and a zigzag flow channel is formed inside the heat sink.

[0012] By adopting the above technical solution, high-pressure oil enters the cooling box from the oil inlet and passes through the zigzag flow channel, which increases the length of the internal circulation, helps to reduce the temperature of the high-pressure oil, and thus helps to improve the working efficiency of the hydraulic system.

[0013] Preferably, the heat sink is provided with two partitions, which are staggered. The two partitions form a first flow channel, a second flow channel, and a third flow channel in the vertical direction within the heat sink. The first flow channel, the second flow channel, and the third flow channel are connected in sequence. The zigzag flow channel is formed by the first flow channel, the second flow channel, and the third flow channel. The oil inlet is connected to the first flow channel, and the connecting hole is connected to the third flow channel.

[0014] By adopting the above technical solution, the first flow channel, the second flow channel and the third flow channel are formed by two staggered partitions, and the three flow channels are connected in sequence, thus realizing the formation of the zigzag flow channel.

[0015] Preferably, both the oil inlet and the oil outlet are provided with connectors, and the ends of the connectors are chamfered at 45 degrees.

[0016] By adopting the above technical solution, most of the pressure loss in hydraulic transmission is converted into heat energy, causing increased oil temperature, increased leakage, and reduced hydraulic transmission efficiency, thus affecting the working performance of the hydraulic system. When oil flows, its flow velocity has a significant impact on pressure loss. In laminar flow, the pressure loss along the flow path is proportional to the first power of the oil flow velocity V; in turbulent flow, the pressure loss along the flow path is proportional to the 1.75-2 power of the oil flow velocity; the local pressure loss of flowing oil is proportional to the square of its flow velocity. It is evident that reducing the flow velocity is crucial for reducing pressure loss. Therefore, setting the connector end with a 45-degree chamfer increases the inlet and outlet area, helping to reduce the flow velocity of high-pressure oil, thereby reducing pressure loss.

[0017] Preferably, both the heat sink and the enclosed tube are provided with mounting plates, and the mounting plates are provided with mounting holes.

[0018] By adopting the above technical solution, the mounting plate is fixed by using bolts to pass through the mounting holes and connect with the external mounting position via threads, thus fixing the muffler device quickly and conveniently.

[0019] Preferably, the heat sink, the first diffuser, the second diffuser, and the sealing tube are all welded from Q235B steel plates.

[0020] By adopting the above technical solution, the heat dissipation box, the first diffuser tube, the second diffuser tube and the sealing tube are all welded from Q235B steel plates, which is low in cost and easy to weld and form.

[0021] In summary, this application includes at least one of the following beneficial technical effects:

[0022] 1. When high-pressure oil diffuses from the first diffuser hole to the second diffuser tube, the high-pressure oil will resonate and attenuate between the first diffuser tube and the second diffuser tube, reducing the pulsating pressure. The silencing cavity is isolated from the high-pressure oil and can absorb the noise generated by the pulsation, which helps to reduce the vibration and noise caused by the high-pressure oil.

[0023] 2. By using a corrugated plate, the contact area with the high-pressure oil is increased, which helps to improve the absorption effect of the pulsating pressure when the pulsating pressure of the high-pressure oil is transmitted to the corrugated plate;

[0024] 3. By increasing the internal circulation length of the high-pressure oil through the zigzag flow channels inside the heat sink, the temperature of the high-pressure oil is reduced, thereby improving the working efficiency of the hydraulic system. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of the overall structure of an embodiment of this application;

[0026] Figure 2 This is the structure of the first diffuser plate in the embodiments of this application;

[0027] Figure 3 This is a data analysis diagram of the pulsating pressure in an embodiment of this application.

[0028] Reference numerals: 1. Heat sink; 11. Oil inlet; 12. Baffle plate; 121. First flow channel; 122. Second flow channel; 123. Third flow channel; 2. First diffuser tube; 21. Oil outlet; 3. Connecting hole; 4. Second diffuser tube; 5. Sealing tube; 6. First diffuser plate; 61. First diffuser hole; 7. Second diffuser plate; 71. Second diffuser hole; 8. Resonance cavity; 9. Waveform plate; 91. Noise-absorbing cavity; 92. Absorption cavity; 10. Bending flow channel; 20. Connector; 30. Mounting plate; 301. Mounting hole. Detailed Implementation

[0029] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.

[0030] This application discloses a silencer for a hydraulic system.

[0031] Reference Figure 1 The silencing device for the hydraulic system includes a heat sink 1 and a first diffuser 2. The first diffuser 2 and the heat sink 1 are connected by a connecting hole 3 and are welded together. The upper side wall of the heat sink 1 has an oil inlet 11. The end of the first diffuser 2 away from the connecting hole 3 has an oil outlet 21. A second diffuser 4 is sleeved on the outside of the first diffuser 2 and welded to the outer wall of the heat sink 1. A sealing tube 5 is sleeved on the outside of the second diffuser 4 and welded to the heat sink 1.

[0032] Reference Figure 1 and Figure 2 The first diffuser 2 and the second diffuser 4 can be round, elliptical, or square tubes. For ease of manufacturing, the first diffuser 2 and the second diffuser 4 are square tubes. First diffuser plates 6 are formed on both the upper and lower sides of the first diffuser 2, and several first diffuser holes 61 are formed on the first diffuser plates 6. Second diffuser plates 7 are formed on both the upper and lower sides of the second diffuser 4, and several second diffuser holes 71 are formed on the second diffuser plates 7. A resonant cavity 8 is formed between the first diffuser plate 6 and the second diffuser plate 7 on the same side.

[0033] A corrugated plate 9 is welded between the closed tube 5 and the second diffuser 4. The corrugated plate 9 is sinusoidal in shape. A sound-absorbing cavity 91 is formed between the corrugated plate 9 and the closed tube 5. An absorption cavity 92 is formed between the corrugated plate 9 and the second diffuser 7.

[0034] When high-pressure oil enters the first diffuser tube 2, it diffuses into the resonant cavity 8 through multiple first diffuser holes 61, thus dispersing the pulsating pressure of the high-pressure oil. Within the resonant cavity 8, the high-pressure oil is buffered, thereby absorbing the pulsating pressure and reducing noise. In addition, the high-pressure oil enters the absorption cavity 92 through the second diffuser hole 71. The shape of the wave plate 9 increases the contact area with the high-pressure oil, which helps to improve the absorption effect of pulsating pressure. Furthermore, the silencing cavity 91 on the other side is isolated from the high-pressure oil, which helps to absorb noise.

[0035] The first diffusion holes 61 are arranged in 7 rows and 15 columns on the first diffusion plate 6. The center-to-center distance of each row of first diffusion holes 61 is 7.4 mm, the center-to-center distance of each column of first diffusion holes 61 is 10.5 mm, the length of each first diffusion hole 61 is 5.5 mm, and the diameter of each first diffusion hole 61 is 1.2 mm. The second diffusion hole 71 has the same parameters as the first diffusion hole 61.

[0036] The above data was calculated and is detailed below:

[0037] Force analysis was performed on the liquid column flowing through the second diffuser plate 7 and the second diffuser hole 71, and the following results were obtained by combining the flow continuity equation:

[0038] In the formula: The lengths of the first diffusion hole 61 and the second diffusion hole 71;

[0039] Ash is the cross-sectional area of ​​the first diffusion hole 61 and the second diffusion hole 71;

[0040] N′ is the number of holes on the first diffuser plate 6 and the second diffuser plate 7;

[0041] βe is the bulk modulus of the oil.

[0042] βa is the gas elastic modulus;

[0043] VH represents the volume of the resonant cavity;

[0044] PH is the pressure in the resonant cavity.

[0045] Pa represents the pressure in the absorption chamber at 92°.

[0046] Va is the initial volume of the absorption cavity 92;

[0047] Rf represents steady-state tube friction.

[0048] Force analysis of the liquid column flowing through the first diffuser tube 2 and the first diffuser hole 61 yields the following results:

[0049]

[0050] In the formula: Qsh is the flow rate through the first diffuser hole 61;

[0051] As a resistance factor;

[0052] cf is the speed of sound in the oil;

[0053] k′ is the wave vector;

[0054] Ps represents the system pressure;

[0055] Two differential equations constitute the mathematical model of the silencing device. The calculated parameters are as follows: the number of the first diffusion hole 61 and the second diffusion hole 71 are: n = 7 rows, 15 columns, N′ = 105 holes, hole length = 5.5 mm, hole diameter dh = 1.2 mm, the center distance between rows is set to 7.4 mm, and the center distance between columns is set to 10.5 mm.

[0056] Experimental data analysis reference Figure 3 In Figure ①, the amplitude curve of the hydraulic system without the silencing device is shown, with a pulsation amplitude of 0.65 MPa; in Figure ③, the amplitude curve of the hydraulic system with the silencing device is shown, with a pulsation amplitude of 0.25 MPa, which is a decrease of about 61.5%.

[0057] Two partitions 12 are welded and fixed inside the heat sink 1. These two partitions 12 are staggered vertically. Within the heat sink 1, the two partitions 12 sequentially form a first flow channel 121, a second flow channel 122, and a third flow channel 123 along the vertical direction. These three flow channels are connected sequentially to form a zigzag flow channel 10. The oil inlet 11 is connected to the first flow channel 121, and the connecting hole 3 is connected to the third flow channel 123. By utilizing the first flow channel 121, the second flow channel 122, and the third flow channel 123 to form the zigzag flow channel 10, the flow length of the oil is increased, and the flow velocity of the oil is reduced. This helps to reduce the pulsating pressure of the high-pressure oil and also helps to lower the oil temperature, thereby improving the working efficiency of the hydraulic system.

[0058] Both the oil inlet 11 and the oil outlet 21 are equipped with connectors 20. The ends of the connectors 20 are all chamfered at 45 degrees, which increases the oil inlet and outlet area and helps to reduce the flow rate of high-pressure oil.

[0059] In hydraulic transmission, most of the pressure loss is converted into heat energy, causing increased oil temperature, increased leakage, and reduced hydraulic transmission efficiency, thus affecting the working performance of the hydraulic system. The flow velocity of the oil significantly impacts pressure loss. In laminar flow, the pressure loss along the flow path is proportional to the first power of the oil flow velocity V; in turbulent flow, the pressure loss along the flow path is proportional to the 1.75-2 power of the oil flow velocity; the local pressure loss of flowing oil is proportional to the square of its flow velocity. Therefore, reducing the flow velocity is crucial for minimizing pressure loss. Thus, utilizing the 45-degree chamfer of the bend in the flow channel 10 and the connector 20 to reduce the flow velocity helps to significantly reduce pressure loss.

[0060] Mounting plates 30 are welded and fixed on both the heat dissipation box 1 and the closed tube 5. Mounting plates 30 have mounting holes 301. In actual installation, bolts are used to pass through the mounting holes 301 and connect to the external mounting position by thread, thereby fixing the mounting plate 30 and installing the silencer. This is quick and convenient.

[0061] The heat sink 1, the first diffuser tube 2, the second diffuser tube 4, and the sealing tube 5 are all welded from Q235B steel plates, which is low in cost and easy to weld and form.

[0062] The implementation principle of a silencing device for a hydraulic system according to an embodiment of this application is as follows: High-pressure oil enters the deflecting flow channel 10, and after deceleration and cooling, it enters the first diffuser 2, and then enters the resonant cavity 8 through the first diffuser hole 61. In the resonant cavity 8, when the high-pressure oil enters intermittently, it will buffer the high-pressure oil and absorb the pulsating pressure. At the same time, the high-pressure oil will enter the absorption cavity 92 from the second diffuser hole 71. The absorption cavity 92 is wavy, which increases the contact area with the high-pressure oil. In addition, the change curve of the pulsating pressure is also wavy. The two have the same shape, which helps to further improve the absorption effect of pulsating pressure, thereby reducing vibration and noise.

[0063] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A silencer for a hydraulic system, characterized in that: Includes a first diffuser tube (2), with an oil inlet (11) and an oil outlet (21) formed at both ends of the first diffuser tube (2), and a plurality of first diffuser holes (61) opened on the peripheral sidewall of the first diffuser tube (2). A second diffuser tube (4) is provided on the periphery of the first diffuser tube (2), and a plurality of second diffuser holes (71) are opened on the peripheral sidewall of the second diffuser tube (4). A sealing tube (5) is sleeved on the outside of the second diffuser tube (4), and a plurality of silencing cavities (91) are provided between the sealing tube (5) and the second diffuser tube (4). A corrugated plate (9) is provided inside the closed tube (5) and the second diffuser (4), and a silencing cavity (91) is formed between the corrugated plate (9) and the closed tube (5); a corrugated plate (9) is welded between the closed tube (5) and the second diffuser (4), and the shape of the corrugated plate (9) is sinusoidal. The silencing cavity (91) is formed between the corrugated plate (9) and the closed tube (5), and an absorption cavity (92) is formed between the corrugated plate (9) and the second diffuser (7); Both the first diffuser tube (2) and the second diffuser tube (4) are square tubes. First diffuser plates (6) are formed on the upper and lower sides of the first diffuser tube (2). First diffuser holes (61) are formed on the two first diffuser plates (6). The first diffuser holes (61) are arranged in 7 rows and 15 columns on the first diffuser plates (6). The center distance between each row of first diffuser holes (61) is 7.4 mm, and the center distance between each column of first diffuser holes (61) is 10.5 mm. The length of each first diffuser hole (61) is 5.5 mm. The diameter of 61) is 1.2 mm; the upper and lower sides of the second diffuser tube (4) are both formed with second diffuser plates (7), the second diffuser holes (71) are opened on the two second diffuser plates (7), the second diffuser holes (71) are arranged in 7 rows and 15 columns on the second diffuser plates (7), and the center distance between each row of the second diffuser holes (71) is 7.4 mm, the center distance between each column of the second diffuser holes (71) is 10.5 mm, the length of the second diffuser hole (71) is 5.5 mm, and the diameter of the second diffuser hole (71) is 1.2 mm.

2. The silencer for a hydraulic system according to claim 1, characterized in that: It also includes a heat sink (1), which is connected to one end of the first diffuser (2) through a connecting hole (3). The oil inlet (11) is opened on the heat sink (1), and a zigzag flow channel (10) is formed inside the heat sink (1).

3. A silencer for a hydraulic system according to claim 2, characterized in that: The heat sink (1) is provided with two partitions (12), which are staggered. The two partitions (12) form a first flow channel (121), a second flow channel (122) and a third flow channel (123) in the vertical direction in the heat sink (1). The first flow channel (121), the second flow channel (122) and the third flow channel (123) are connected in sequence. The zigzag flow channel (10) is formed by the first flow channel (121), the second flow channel (122) and the third flow channel (123). The oil inlet (11) is connected to the first flow channel (121) and the connecting hole (3) is connected to the third flow channel (123).

4. A silencer for a hydraulic system according to claim 1, characterized in that: Both the oil inlet (11) and the oil outlet (21) are provided with connectors (20), and the ends of the connectors (20) are provided with chamfers, and the chamfers are set at 45 degrees.

5. A silencer for a hydraulic system according to claim 2, characterized in that: Both the heat dissipation box (1) and the closed tube (5) are provided with mounting plates (30), and the mounting plates (30) are provided with mounting holes (301).

6. A silencer for a hydraulic system according to claim 2, characterized in that: The heat dissipation box (1), the first diffuser (2), the second diffuser (4) and the sealing tube (5) are all welded from Q235B steel plates.

Images