Automatic oil discharge device of hydraulic system

Abstract

An automatic oil discharge device of a hydraulic system comprises a nitrogen cylinder, the nitrogen cylinder is vertically arranged, the top of the nitrogen cylinder is connected with the top of an energy accumulator through a connecting pipe, the bottom of the nitrogen cylinder is connected with the top of a residual oil collector, and oil in the nitrogen cylinder can enter the residual oil collector under the action of gravity; comprising an electromagnetic valve, the residual oil collector is connected with an oil tank through the electromagnetic valve, and the electromagnetic valve controls connection or disconnection between the residual oil collector and the oil tank. The oil liquid upper sensor provides a signal for the electromagnetic valve, and oil liquid unloading is automatically started; according to the capacity of the residual oil collector and the detection calibration time of the unloading speed of the electromagnetic valve, the electromagnetic valve obtains a signal, then the residual oil unloading process is automatically closed, and manual control is not needed.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic pressure, in particular to an automatic oil discharge device for a hydraulic system. Background Art

[0002] The accumulator is a crucial component of the die-casting machine's hydraulic system, playing a crucial role in storing and releasing energy. Its performance directly impacts the performance of the machine's hydraulic system. During the long-term storage and discharge process, the accumulator piston undergoes frequent reciprocating motion, causing friction between the seals in the piston and the accumulator's inner wall, increasing the risk of seal wear and aging. Over time, this deteriorates the sealing performance of the accumulator piston, allowing hydraulic oil to leak through gaps between the seals and the accumulator's inner wall into the accumulator's gas port. As the volume of oil entering the accumulator's gas port increases, the movement of the accumulator piston forces the oil into the nitrogen cylinder connected to the accumulator. This not only reduces the gas volume in both the accumulator and the nitrogen cylinder, but also causes a drop in the accumulator's stored pressure, impacting the accumulator's volumetric efficiency and reducing its efficiency.

[0003] For example, the Chinese utility model patent with authorization publication number CN211525557U, titled "An Oil Drain Valve, Nitrogen Cylinder, and Accumulator Station," discharges hydraulic oil from the bottom of the cylinder by rotating the valve core in the forward direction. While this patent achieves hydraulic oil discharge from the bottom of the cylinder, it fails to achieve automatic unloading of the hydraulic oil.

[0004] For example, the Chinese utility model patent, entitled "An Accumulator for a Die-Casting Machine with Oil Discharge Function," with authorization publication number CN203635894U, features a special-shaped accumulator with a larger diameter at the upper gas end than at the lower oil end, acting as a piston limiter. An external port is provided at the bottom of the upper gas end, connected to a residual oil unloading device to discharge the oil from the upper portion of the accumulator. While this patent allows for the discharge of hydraulic oil from the accumulator, the accumulator's unique structure requires custom fabrication, precluding industrial mass production and lacking universal applicability.

[0005] For example, the Chinese utility model patent, entitled "A Pneumatic Oil Drain System for a Hydraulic Cylinder," with authorization publication number CN205715070U, features two external ports on the hydraulic cylinder, one connected to an air source and the other to an oil drain port. At the start of the oil drain operation, the air source introduces high-pressure air, unloading the remaining oil from the cylinder through the drain port. While this patent solves the problem of automatically unloading residual oil, it requires an additional air source and lacks precise control over the unloading process.

[0006] Based on the above technical problems, an automatic oil discharge device for the hydraulic system is proposed. Without changing the shape of the nitrogen cylinder, it ensures that when the residual oil at the bottom of the nitrogen cylinder exceeds the preset value, the residual oil is automatically unloaded when the nitrogen cylinder is under pressure, effectively solving the problems of reduced life of the accumulator and nitrogen cylinder caused by residual oil accumulation. Utility Model Content

[0007] The utility model aims to overcome the defects in the above-mentioned prior art and provides an automatic oil discharge device for a hydraulic system. Without changing the structure of the nitrogen cylinder, the utility model ensures that when the residual oil at the bottom of the nitrogen cylinder exceeds a preset value, the residual oil is automatically unloaded under the pressure of the nitrogen cylinder, thereby effectively solving the problem of reduced service life of the accumulator and the nitrogen cylinder caused by residual oil accumulation.

[0008] In order to achieve the above purpose, the technical solution adopted by the present invention is: an automatic oil discharge device for a hydraulic system, comprising a nitrogen bottle, which is vertically arranged, the top of the nitrogen bottle is connected to the top of an accumulator through a connecting pipe, and the bottom of the nitrogen bottle is connected to the top of a residual oil collector, and the oil in the nitrogen bottle will enter the residual oil collector under the action of its own gravity; and comprising a solenoid valve, the residual oil collector is connected to the oil tank through the solenoid valve, and the solenoid valve controls the connection or disconnection between the residual oil collector and the oil tank.

[0009] As a preferred solution of the utility model, it includes an oil upper sensor, which is arranged on the residual oil collector and can feed back the oil value inside the residual oil collector.

[0010] As a preferred solution of the present invention, the oil upper sensor is electrically connected to the solenoid valve, and the oil upper sensor can transmit an electrical signal to the solenoid valve to control the opening of the solenoid valve.

[0011] As a preferred solution of the present utility model, the oil upper sensor is located at 3 / 4 of the scale of the residual oil collector.

[0012] As a preferred solution of the utility model, it includes an oil lower level sensor, which is electrically connected to the solenoid valve. The oil lower level sensor can transmit an electrical signal to the solenoid valve to control the solenoid valve to close.

[0013] As a preferred solution of the present utility model, the oil lower position sensor is located between 1 / 4 and 1 / 10 of the residual oil collector scale.

[0014] As a preferred solution of the present invention, an oil end interface is provided at the bottom of the accumulator, and the accumulator is connected to the hydraulic main oil circuit through the oil end interface.

[0015] As a preferred solution of the present invention, an air outlet is formed on the top of the accumulator, and the air outlet is connected to the connecting pipe.

[0016] As a preferred solution of the present invention, a threaded hole is provided at the bottom of the nitrogen bottle, and the nitrogen bottle and the residual oil collector are threadedly connected.

[0017] As a preferred solution of the present invention, oil needs to be left in the residual oil collector, and the oil accounts for 1 / 10-1 / 20 of the total volume of the residual oil collector.

[0018] The beneficial effects of the utility model are:

[0019] 1. Compared with the prior art, the present invention can realize automatic oil discharge of the nitrogen cylinder without changing the shape of the nitrogen cylinder.

[0020] 2. Compared with the existing technology, the utility model has an oil upper level sensor connected to the residual oil collector. When the residual oil level is higher than the set scale, the oil upper level sensor provides a signal to the solenoid valve to automatically start oil unloading; according to the capacity of the residual oil collector and the detection calibration time of the solenoid valve's unloading speed, the solenoid valve receives a signal and then automatically closes the residual oil unloading process without the need for manual control.

[0021] 3. The utility model can set the automatic closing time of the solenoid valve according to the capacity of the residual oil collector and the detection calibration of the solenoid valve, so as to prevent the nitrogen in the nitrogen bottle from being discharged along with the oil.

[0022] 4. The present invention does not require an external gas source for oil drainage. On the one hand, the oil in the nitrogen bottle is collected in the residual oil collector under the action of its own gravity. After the solenoid valve 5 is opened, the residual oil can be discharged out of the device by utilizing the gas pressure of the nitrogen bottle.

[0023] 5. The utility model does not occupy the gas volume of the accumulator and the nitrogen cylinder, thereby ensuring the normal operation of the accumulator and the nitrogen cylinder and prolonging the service life of the accumulator and the nitrogen cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of the first embodiment of the present invention;

[0025] Figure 2 This is a schematic structural diagram of the second embodiment of the present utility model;

[0026] Reference numerals in the figure: 1. accumulator, 2. nitrogen cylinder, 3. oil upper sensor, 4. residual oil collector, 5. solenoid valve, 6. oil tank, 7. oil end interface, 8. oil lower sensor, 11. air outlet. DETAILED DESCRIPTION

[0027] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings.

[0028] Example 1:

[0029] like Figure 1 As shown, an automatic oil discharge device for a hydraulic system includes a nitrogen cylinder 2, which is vertically arranged. The top of the nitrogen cylinder 2 is connected to the top of the accumulator 1 through a connecting pipe, and the bottom of the nitrogen cylinder 2 is connected to the top of the residual oil collector 4. The oil in the nitrogen cylinder 2 will enter the residual oil collector 4 under the action of its own gravity; and includes a solenoid valve 5. The residual oil collector 4 is connected to the oil tank 6 through the solenoid valve 5, and the solenoid valve 5 controls the connection or disconnection between the residual oil collector 4 and the oil tank 6.

[0030] Among them, the nitrogen cylinder 2 is a universal structure.

[0031] When the automatic oil drain device is used, the capacity of the residual oil collector 4 and the unloading speed of the solenoid valve 5 need to be tested and calibrated.

[0032] Specifically, the oil in the accumulator 1 enters the nitrogen cylinder 2. Since the nitrogen cylinder 2 is arranged vertically, the oil in the nitrogen cylinder 2 will enter the residual oil collector 4 under the action of gravity. The opening and closing of the solenoid valve 5 are controlled regularly so that the oil in the residual oil collector 4 does not fill the residual oil collector 4 and can enter the oil tank 6 and be collected, thereby ensuring the normal use of the nitrogen cylinder 2 and the accumulator 1.

[0033] In order to more efficiently control the opening and closing of the solenoid valve 5 and accurately control the oil level in the residual oil collector 4, the residual oil collector 4 is provided with the oil upper level sensor 3, which is located at 3 / 4 of the scale of the residual oil collector 4. The oil upper level sensor 3 can feedback the oil level inside the residual oil collector 4.

[0034] The oil upper level sensor 3 is electrically connected to the solenoid valve 5 , and the oil upper level sensor 3 can transmit an electrical signal to the solenoid valve 5 to control the opening of the solenoid valve 5 .

[0035] Specifically, when the oil in the residual oil collector 4 exceeds 3 / 4 of the scale on the residual oil collector 4, the oil upper sensor 3 receives a signal and controls the solenoid valve 5 to open, unloading the oil in the residual oil collector 4 back to the oil tank 6. Since the unloading speed of the solenoid valve 5 is detected and calibrated in advance, the solenoid valve 5 can automatically close after a certain period of time.

[0036] An oil end interface 7 is provided at the bottom of the accumulator 1 , and the accumulator 1 is connected to the main hydraulic oil circuit via the oil end interface 7 , thereby ensuring the normal operation of the entire hydraulic system.

[0037] An air outlet 11 is formed at the top of the accumulator 1 , and the air outlet 11 is connected to a connecting pipe to ensure that the air outlet 11 of the accumulator 1 is connected to the top of the nitrogen cylinder 2 . The connecting pipe is an air pipe.

[0038] A threaded hole is provided at the bottom of the nitrogen bottle 2, and the nitrogen bottle 2 and the residual oil collector 4 are threadedly connected. The provision of the threaded hole facilitates the installation and use of the nitrogen bottle.

[0039] A small amount of oil is reserved in the residual oil collector 4 to prevent gas leakage in the nitrogen bottle 2 during unloading, which would cause a drop in nitrogen pressure. The oil accounts for 1 / 10-1 / 20 of the total volume of the residual oil collector 4 .

[0040] Compared with the prior art, the utility model is characterized in that the residual oil collector is connected to an oil upper level sensor. When the residual oil level is higher than the set scale, the oil upper level sensor provides a signal to the solenoid valve to automatically open the oil unloading process. According to the capacity of the residual oil collector and the detection calibration time of the solenoid valve unloading speed, the solenoid valve receives a signal and then automatically closes the residual oil unloading process without the need for manual control.

[0041] The utility model does not require an external gas source for oil drainage. The residual oil in the nitrogen bottle is collected in the residual oil collector under the action of gravity. After the solenoid valve 5 is opened, the residual oil can be discharged out of the device by utilizing the gas pressure of the nitrogen bottle.

[0042] The utility model can set the automatic closing time of the electromagnetic valve according to the capacity of the residual oil collector and the detection calibration of the electromagnetic valve, thereby preventing the nitrogen in the nitrogen bottle from being discharged along with the oil.

[0043] Example 2:

[0044] like Figure 2 As shown, on the basis of embodiment 1, it also includes an oil lower level sensor 8, which is located between 1 / 4 and 1 / 10 of the scale of the residual oil collector 4. The oil lower level sensor 8 is electrically connected to the solenoid valve 5. The oil lower level sensor 8 can transmit an electrical signal to the solenoid valve 5 to control the solenoid valve 5 to close.

[0045] The oil level sensor 8 can directly detect when the oil level in the residual oil collector 4 is lower than 1 / 4-1 / 10 of the scale of the residual oil collector 4, thereby sending an electrical signal to control the closing of the solenoid valve 5. Compared with indirectly closing the solenoid valve 5 by unloading the solenoid valve 5, this is more direct and convenient.

[0046] Specifically, when the oil in the residual oil collector 4 exceeds 3 / 4 of the scale of the residual oil collector 4, the oil upper sensor 3 receives a signal, controls the solenoid valve 5 to open, and unloads the oil in the residual oil collector 4 back to the oil tank 6; when the oil in the residual oil collector 4 is lower than the lower set value of the scale of the residual oil collector 4, the oil lower sensor 8 receives a signal, controls the solenoid valve 5 to close, and the residual oil collector 4 continues to collect the oil in the nitrogen bottle 2.

[0047] Based on the technical solutions of Example 1 and Implementation 2:

[0048] Furthermore, when the accumulator 1 is equipped with multiple nitrogen cylinders 2, the multiple nitrogen cylinders 2 can be connected by a connecting pipe, and the residual oil at the bottom of different nitrogen cylinders 1 is collected in the residual oil collector 4, thereby solving the residual oil discharge requirement of the accumulator 1 equipped with multiple nitrogen cylinders.

[0049] The upper oil level sensor 3 is located at 3 / 4 of the scale of the residual oil collector 4, and the lower oil level sensor 8 is located between 1 / 4 and 1 / 10 of the scale of the residual oil collector 4. These are just example data.

[0050] In actual circumstances, as long as the upper oil sensor 3 is located at the specified position above the residual oil collector 4, and the lower oil sensor 8 is located at the specified position below the residual oil collector 4, the upper oil sensor 3 can also be located at 4 / 5 of the scale of the residual oil collector 4, and the lower oil sensor 8 can also be located at 1 / 15 of the scale of the residual oil collector 4.

[0051] A small amount of oil is reserved in the residual oil collector 4. The oil is not limited to 1 / 10-1 / 20 of the total volume of the residual oil collector 4 in this article. The reserved oil can also be 1 / 8 of the total volume of the residual oil collector 4.

[0052] The numerical values ​​and numerical ranges in this utility model are for reference only, and the actual numerical values ​​and numerical ranges can be diversified as needed.

[0053] Compared with the prior art, the utility model can realize automatic oil discharge of the nitrogen cylinder without changing the shape of the nitrogen cylinder.

[0054] The above description of the disclosed embodiments will enable those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

[0055] Although this article uses the following terms more frequently: 1. accumulator, 2. nitrogen cylinder, 3. upper oil sensor, 4. residual oil collector, 5. solenoid valve, 6. oil tank, 7. oil end interface, 8. lower oil sensor, 11. air outlet, etc., it does not exclude the possibility of using other terms; the use of these terms is only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. An automatic oil drain device for a hydraulic system, characterized by: It comprises a nitrogen bottle (2), the nitrogen bottle (2) is vertically arranged, the top of the nitrogen bottle (2) is connected to the top of the accumulator (1) through a connecting pipe, and the bottom of the nitrogen bottle (2) is connected to the top of the residual oil collector (4), and the oil in the nitrogen bottle (2) will enter the residual oil collector (4) under the action of its own gravity; It comprises a solenoid valve (5), the residual oil collector (4) is connected to the oil tank (6) via the solenoid valve (5), and the solenoid valve (5) controls the connection or disconnection between the residual oil collector (4) and the oil tank (6).

2. The automatic oil drain device for a hydraulic system according to claim 1, characterized in that: The oil upper position sensor (3) is provided on the residual oil collector (4), and the oil upper position sensor (3) can feed back the oil value inside the residual oil collector (4).

3. The automatic oil drain device of a hydraulic system according to claim 2, characterized in that: The oil upper position sensor (3) is electrically connected to the solenoid valve (5), and the oil upper position sensor (3) can transmit an electrical signal to the solenoid valve (5) to control the opening of the solenoid valve (5).

4. The automatic oil drain device for a hydraulic system according to claim 3, characterized in that: The oil upper sensor (3) is located at 3 / 4 of the scale of the residual oil collector (4).

5. The automatic oil drain device for a hydraulic system according to claim 1, characterized in that: The oil lower position sensor (8) is electrically connected to the solenoid valve (5), and the oil lower position sensor (8) can transmit an electrical signal to the solenoid valve (5) to control the solenoid valve (5) to close.

6. The automatic oil drain device for a hydraulic system according to claim 5, characterized in that: The oil lower position sensor (8) is located between 1 / 4 and 1 / 10 of the scale of the residual oil collector (4).

7. The automatic oil drain device for a hydraulic system according to claim 1, characterized in that: An oil end interface (7) is provided at the bottom of the accumulator (1), and the accumulator (1) is connected to the hydraulic main oil circuit via the oil end interface (7).

8. The automatic oil drain device for a hydraulic system according to claim 1, characterized in that: An air outlet (11) is formed at the top of the accumulator (1), and the air outlet (11) is connected to a connecting pipe.

9. The automatic oil drain device for a hydraulic system according to claim 1, characterized in that: A threaded hole is provided at the bottom of the nitrogen bottle (2), and the nitrogen bottle (2) and the residual oil collector (4) are threadedly connected.

10. The automatic oil drain device of a hydraulic system according to claim 1, characterized in that: Oil liquid needs to be left in the residual oil collector (4), and the oil liquid accounts for 1 / 10-1 / 20 of the total volume of the residual oil collector (4).

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