A control method for the oil circuit system of a low-profile telescopic forklift

Abstract

The present invention discloses a control method for an oil circuit system of a low-slung telescopic forklift, wherein the oil circuit system of the low-slung telescopic forklift comprises a hydraulic oil tank, a plunger pump, a metering component, and a control module; the hydraulic oil tank is connected to the plunger pump; the hydraulic oil tank comprises a main oil tank and an auxiliary oil tank connected to the main oil tank; the auxiliary oil tank is installed above the main oil tank and is a special-shaped oil tank structure, so as to increase the liquid level height of the hydraulic oil tank so that the liquid level is higher than the oil inlet height of the plunger pump; the control module can judge the status information of both the plunger pump and the liquid level information in the hydraulic oil tank according to the real-time flow rate, thereby reducing the detection cost and improving the detection efficiency.

Description

Technical Field

[0001] The invention discloses a control method for an oil circuit system of a low-profile telescopic forklift, belonging to the field of lifting vehicles. Background Art

[0002] In the field of lifting vehicles, low-profile telescopic forklifts, as an important logistics equipment, are widely used in places with limited space such as warehouses and factories.

[0003] However, the oil circuit system of the traditional low-working telescopic arm forklift has some design deficiencies. Specifically, the traditional oil circuit system is usually equipped with only one hydraulic oil tank, and the installation position of the hydraulic oil tank is often restricted by the overall structure of the vehicle, resulting in that it is difficult to ensure that the liquid level in the hydraulic oil tank is always higher than the installation height of the plunger pump.

[0004] When the forklift is operating the telescopic arm, if the liquid level in the hydraulic oil tank is lower than the installation height of the plunger pump, the plunger pump may experience air suction, which will not only reduce the working efficiency of the plunger pump, but may also cause damage to the plunger pump, thereby affecting the overall performance and service life of the forklift. Summary of the invention

[0005] In view of the deficiencies in the prior art, an object of the present invention is to provide a control method for an oil circuit system of a low-profile telescopic forklift to solve the problem.

[0006] In order to achieve the above-mentioned object, the present invention is implemented through the following technical solutions: the oil circuit system of the low-profile telescopic forklift includes a hydraulic oil tank, a plunger pump, a metering component, and a control module; the hydraulic oil tank is connected to the plunger pump; the hydraulic oil tank includes a main oil tank and a subsidiary oil tank connected to the main oil tank; the subsidiary oil tank is installed above the main oil tank and is a special-shaped oil tank structure, so as to increase the liquid level of the hydraulic oil tank so that the liquid level is higher than the oil inlet height of the plunger pump;

[0007] The main oil tank is connected to the plunger pump; the metering element is arranged between the main oil tank and the plunger pump, and is used to detect the flow rate of the hydraulic oil tank to the plunger pump;

[0008] The metering element is electrically connected to the control module;

[0009] The control method comprises the following steps:

[0010] S1, the control module controls the plunger pump to start and inhale or return hydraulic oil by inputting different power signals to control the telescopic arm to extend and retract;

[0011] S2, the metering element obtains the real-time flow rate of the hydraulic oil of different power signals ;

[0012] S3, the control module is further used to determine the real-time flow rate under different power signals And standard flow rate , it is judged that the plunger pump is damaged or leaking.

[0013] Preferably, in step S2, the metering element obtains the real-time flow rate of the hydraulic oil of different power signals The steps specifically include:

[0014] Divide the time of a power signal into multiple node times ... ,in, is the starting time, is the end time;

[0015] Get the time of each node ... Corresponding real-time flow rate ... .

[0016] Preferably, in step S3, the control module is further used to control the real-time flow rate under different power signals. And standard flow rate The steps of determining that the plunger pump is damaged or leaking specifically include:

[0017] When the real-time flow rate ... are much smaller than the standard flow rate , it is determined that the plunger pump is damaged; and / or;

[0018] When the real-time flow rate ... Both approach the standard flow rate , and the real-time flow rate ... Much smaller than the standard flow rate , it is judged as leakage, 2~ Any integer in ; and / or;

[0019] When the real-time flow rate ... Both approach the standard flow rate , it is determined that the plunger pump is working normally, wherein the real-time flow rate ... are much smaller than the standard flow rate , refers to the real-time flow rate ... All less than 0.9 ; and the real-time flow rate ... Approaching the standard flow rate It means reaching ±0.1 .

[0020] Preferably, the top of the main tank is connected to the top of the auxiliary tank via a through pipe, and a breathing piece is installed on the top of the auxiliary tank to keep the air pressure in the main tank and the auxiliary tank at normal pressure.

[0021] Preferably, the main fuel tank and the auxiliary fuel tank are both installed on a bracket, and the bracket is used to stagger the auxiliary fuel tank and the main fuel tank at an angle of 30° to 60°, wherein the top of the auxiliary fuel tank is designed to be flat.

[0022] Preferably, the top of the main oil tank is connected to the bottom of the auxiliary oil tank through a pair of oil pipes; the volume ratio of the auxiliary oil tank to the main oil tank is 1:1~2.

[0023] Preferably, the standard flow rate is calculated by the following formula ;

[0024] ;

[0025] in The number of liters per minute that the rated piston pump can pump.

[0026] Preferably, the control module counts the real-time flow rate when the plunger pump is running. ... The gap rate is used to obtain a digital set, which is used to determine the liquid level information in the hydraulic oil tank.

[0027] Preferably, the gap rate is the adjacent real-time flow rate The difference is counted by the control module to obtain the digital set { |、 |、 |...... |}, where a rate safety value is defined , rate safety value The speed safety value is compared with each difference in the digital set to determine the liquid level information in the hydraulic oil tank; When it is greater than or equal to the difference, the liquid level in the hydraulic oil tank is considered normal and the speed safety value When it is less than the difference, it is determined that the liquid level in the hydraulic oil tank is about to or has been lower than the installation height of the plunger pump.

[0028] Preferably, the rate safety value Used to timely find the relationship between the liquid level in the hydraulic oil tank and the installation height of the plunger pump; among them, the critical flow rate It is the flow rate when the liquid level in the hydraulic oil tank is just equal to the installation height of the plunger pump, calculated by the following formula ;

[0029] ;

[0030] in, is the rated maximum flow, A is the cross-sectional area of ​​the auxiliary tank;

[0031] Rate safety value Set to be greater than or equal to the critical flow rate To ensure that the liquid level in the hydraulic oil tank will not be lower than the installation height of the plunger pump, calculate it by the following formula ;

[0032] ;

[0033] in Leave a safety margin for this.

[0034] Beneficial effects: 1. Relying on the auxiliary oil tank, the liquid level in the hydraulic oil tank is higher than the installation height of the plunger pump, which effectively avoids the phenomenon of empty suction of the plunger pump, thereby improving the working efficiency and service life of the plunger pump;

[0035] Second, by setting a metering device in the oil suction pipe and electrically connecting the metering device to the control module, real-time monitoring of the flow of liquid from the hydraulic oil tank to the plunger pump is achieved;

[0036] 3. The control module can calculate the standard flow rate and gap rate based on the real-time flow rate, and then determine the status information of the plunger pump and the liquid level information in the hydraulic oil tank. Once an abnormal situation is detected, the control module can immediately issue an early warning signal to remind the operator to take timely measures to avoid further development of equipment failures and the occurrence of safety accidents;

[0037] Fourth, the control module can determine the status information of the plunger pump and the liquid level information in the hydraulic oil tank according to the real-time flow rate, thereby reducing the detection cost and improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0039] Figure 1 It is a structural schematic diagram of the oil circuit system of the present invention;

[0040] Figure 2A schematic diagram of a flow chart of a control module of the present invention determining state information of a plunger pump;

[0041] Figure 3 It is a schematic diagram of a flow chart of the control module of the present invention for determining the internal liquid level of the hydraulic oil tank and the height of the plunger pump;

[0042] In the figure: main oil tank-1, auxiliary oil tank-2, plunger pump-3, oil suction pipe-4, oil return pipe-5, through pipe-6, breathing piece-7, docking oil pipe-8, bracket-9, metering piece-10. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0044] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0045] See also Figure 1-Figure 3 The present invention provides a technical solution for a control method of an oil circuit system of a low-rise telescopic forklift: the oil circuit system of the low-rise telescopic forklift comprises a hydraulic oil tank, a plunger pump 3, a metering member 10, and a control module; the hydraulic oil tank is connected to the plunger pump 3.

[0046] Preferably, the hydraulic oil tank includes a main oil tank 1 and a subsidiary oil tank 2 communicated with the main oil tank 1; the subsidiary oil tank 2 is installed above the main oil tank 1 and is a special-shaped oil tank structure, so as to increase the liquid level of the hydraulic oil tank so that the liquid level is higher than the oil inlet height of the plunger pump 3. The subsidiary oil tank 2 is used to raise the internal liquid level of the hydraulic oil tank so that the internal liquid level of the hydraulic oil tank is higher than the installation height of the plunger pump 3. In this way, according to the principle of communicating vessels, the plunger pump 3 is prevented from being in a dry suction state, thereby ensuring the operating efficiency of the plunger pump 3.

[0047] Furthermore, the top of the auxiliary oil tank 2 is designed to be flat. The flat design can usually increase the cross-sectional area of ​​the oil tank while maintaining a stable liquid level, thereby increasing the volume of the oil tank and improving the hydraulic oil storage capacity of the system.

[0048] Furthermore, in order to achieve the interconnection between the main oil tank 1 and the auxiliary oil tank 2, the top of the main oil tank 1 is connected to the top of the auxiliary oil tank 2 through a through pipe 6, and a breathing piece 7 is installed on the top of the auxiliary oil tank 2, so that the air pressure in the main oil tank 1 and the auxiliary oil tank 2 is at normal pressure, to ensure that the liquid oil in the hydraulic oil tank can be smoothly sucked by the plunger pump 3.

[0049] Preferably, in order to improve the connectivity between the auxiliary tank 2 and the main tank 1, so that the auxiliary tank 2 can flow into the main tank 1 more smoothly; the bracket 9 is used to stagger the auxiliary tank 2 and the main tank 1, and the staggered angle is 30°~60°. In one embodiment, the auxiliary tank 2 is arranged at a 45° angle above the left side of the main tank 1. The staggered arrangement at a 45° angle helps to optimize the oil flow path, reduce the resistance during flow, and improve the flow efficiency of the oil, thereby improving the working efficiency of the system. Similarly, according to the design of the forklift, the occupied position of the auxiliary tank 2 can be flexibly changed to adapt the staggered angle. The top of the main tank 1 and the bottom of the auxiliary tank 2 are connected through a pair of docking pipes 8 to achieve the connectivity problem between the two due to the staggered design of the upper and lower positions. The main tank 1 and the auxiliary tank 2 are both installed on a bracket 9, so as to achieve the purpose of placing the auxiliary tank 2 above the main tank 1.

[0050] Furthermore, the volume ratio of the auxiliary oil tank 2 to the main oil tank 1 is 1:1~2. The similar volume ratio of the two oil tanks helps to balance the oil, ensure the stable supply of oil to the oil system under different working conditions, and avoid equipment failure caused by insufficient oil supply in the auxiliary oil tank 2.

[0051] Furthermore, the main oil tank 1 is connected to the plunger pump 3; the metering element 10 is arranged between the main oil tank 1 and the plunger pump 3, and is used to detect the flow rate from the hydraulic oil tank to the plunger pump 3. Specifically, the main oil tank 1 is connected to the plunger pump 3 through the oil suction pipe 4 and the oil return pipe 5, and the oil suction pipe 4 is used as the oil supply channel for the suction of the plunger pump 3; the oil return pipe 5 is used as the oil return channel for the return of the liquid oil. The control module feeds back the liquid level information in the hydraulic oil tank and the status information of the plunger pump 3;

[0052] The control method comprises the following steps:

[0053] S1, the control module controls the plunger pump 3 to start by inputting different power signals, and sucks in or refluxes hydraulic oil to control the telescopic arm to extend and retract;

[0054] S2, the metering element 10 obtains the real-time flow rate of the hydraulic oil of different power signals ;

[0055] S3, the control module is further used to determine the real-time flow rate under different power signals And standard flow rate , it is judged that the plunger pump 3 is damaged or leaking.

[0056] See also Figure 2 In step S2, the metering element 10 obtains the real-time flow rate of the hydraulic oil of different power signals. The steps specifically include:

[0057] Divide the time of a power signal into multiple node times ... ,in, is the starting time, is the end time;

[0058] Get the time of each node ... Corresponding real-time flow rate ... .

[0059] In step S3, the control module is further used to adjust the real-time flow rate under different power signals. And standard flow rate The steps of determining that the plunger pump 3 is damaged or leaking specifically include:

[0060] When the real-time flow rate ... are much smaller than the standard flow rate , it is determined that the plunger pump 3 is damaged; and / or;

[0061] When the real-time flow rate ... Both approach the standard flow rate , and the real-time flow rate ... Much smaller than the standard flow rate , it is judged as leakage, 2~ Any integer in ; and / or;

[0062] When the real-time flow rate ... Both approach the standard flow rate , it is determined that the plunger pump is working normally, wherein the real-time flow rate ... are much smaller than the standard flow rate , refers to the real-time flow rate ... All less than 0.9 ; and the real-time flow rate ... Approaching the standard flow rate It means reaching ±0.1 .

[0063] The standard flow rate is calculated by the following formula ;

[0064]

[0065] in The number of liters per minute that a rated piston pump can pump.

[0066] Furthermore, the monitoring results are displayed on a display panel (not shown in the figure) in the forklift cab for alarm display.

[0067] The metering element 10 is an existing electronic flow meter, and the control module is an existing forklift controller or a corresponding control program recorded therein.

[0068] Example 1

[0069] Among them, the rate safety value The volume ratio of auxiliary tank 2 to main tank 1 is 1:1.5, and the cross-sectional area of ​​auxiliary tank 2 is 25CM 2 ; The staggered angle between auxiliary tank 2 and main tank 1 is 45°; define the time of each node ... is every 1 second, so the real-time flow rate through the oil suction pipe 4 every 1 second can be obtained ; Use a plunger pump 3 with a rated power of 52W and a suction capacity of 150L per minute;

[0070] When the plunger pump 3 is running at full power (52W), the metering element 10 captures the real-time flow rate. As shown in Table 1:

[0071]

[0072] Calculate standard flow rate :

[0073] ; Obtain the standard flow rate of plunger pump 3 =2.5L / S.

[0074] The control module will real-time flow rate ~ One by one with standard flow rate Compare, among them ~ all ; Therefore, it is judged that the plunger pump is damaged.

[0075] Example 2

[0076] The difference from Example 1 is that when the plunger pump 3 is running at full power (52W), the metering element 10 captures the real-time flow rate As shown in Table 2;

[0077]

[0078] The control module will real-time flow rate ~ One by one with standard flow rate Compare, among them , , ;in , Close to standard flow rate , and the real-time flow rate is much smaller than the real-time flow rate , so it is judged that the plunger pump is leaking.

[0079] Example 3

[0080] The difference from Example 1 is that when the plunger pump 3 is running at full power (52W), the metering element 10 captures the real-time flow rate As shown in Table 3;

[0081]

[0082] The control module will real-time flow rate ~ One by one with standard flow rate Compare, among them , ;in , , Close to standard flow rate , so it is judged that the plunger pump is working normally.

[0083] Example 4

[0084] The difference from Example 1 is that when the plunger pump 3 is running at full power (52W), the metering element 10 captures the real-time flow rate As shown in Table 4:

[0085]

[0086] When the plunger pump is in a leaking state as shown in Example 2, there will be a window period, during which the forklift can still work normally; this is because the leakage of the plunger pump, the oil suction pipe, and the oil return pipe is not serious, and the liquid level in the hydraulic oil tank during the window period is still higher than the installation height of the plunger pump 3; if it is not repaired in time during the window period, as the liquid oil gradually disappears or the oil suction pipe and the oil return pipe rupture, the plunger pump 3 will be in an idling state, which is easy to cause damage; therefore, this embodiment uses the real-time flow rate The generated gap rate can then be used to determine whether the plunger pump has serious leakage or whether the oil suction pipe or oil return pipe is broken; when this happens, the plunger pump is quickly stopped to avoid idling.

[0087] See also Figure 3 Specifically, the control module counts the real-time flow rate when the plunger pump 3 is running. The gap rate is used to obtain a digital set, which is used to determine the liquid level information in the hydraulic oil tank.

[0088] The gap rate is the real-time flow rate of the adjacent The difference is counted by the control module to obtain the digital set { |、 |、 |...... |}, where a rate safety value is defined , rate safety value Compare with each difference in the digital set respectively to determine the liquid level information in the hydraulic oil tank;

[0089] The specific judgment method is: the rate safety value When it is greater than or equal to the difference, the liquid level in the hydraulic oil tank is considered normal; the speed safety value When it is less than the difference, it is determined that the liquid level in the hydraulic oil tank is about to or has been lower than the installation height of the plunger pump 3.

[0090] The rate safety value Used to timely find the relationship between the liquid level in the hydraulic oil tank and the installation height of the plunger pump 3; using a critical flow rate Feedback the flow rate when the liquid level in the hydraulic oil tank is about to equal the installation height of the plunger pump 3, calculated by the following formula ;

[0091]

[0092] in, is the rated maximum flow rate, A is the cross-sectional area of ​​the auxiliary tank 2;

[0093] Rate safety value Set to be greater than or equal to the critical flow rate To ensure that the liquid level in the hydraulic oil tank will not be lower than the installation height of the plunger pump 3, the following formula is used to calculate ;

[0094]

[0095] in Leave a safety margin for this.

[0096] Based on critical flow rate formula;

[0097]

[0098] The rated maximum flow is based on the diameter of the suction pipe 4 and the full load power of the plunger pump 3, so it can be determined Can be defined as a fixed value;

[0099] Calculate the rate safety value :

[0100]

[0101] In this solution, the top of the auxiliary fuel tank 2 is designed to be flat, which increases the cross-sectional area of ​​A and thus makes the speed safety value Smaller, thus making the rate safe It is more sensitive and can quickly monitor flow anomalies; preferably, the safety margin is one percent of the cross-sectional area of ​​A to ensure that there are sufficient variables to avoid misjudgment.

[0102] Based on the real-time flow rate captured in Table 4 , after statistics by the control module, the digital set { |、 |、 |...... |}={|2.6-2.5|、|2.5-2|、|2-0.3|、|0.3-0|}={0.1、0.5、1.7、0.3}; the control module compares the difference with the digital set in turn, where the node time Time to Node , the difference is 0.5, the difference is 0.5 Rate safety value 0.35, so it is determined that the liquid level in the hydraulic oil tank is about to or has been lower than the installation height of the plunger pump 3.

[0103] Furthermore, the control module can also control the opening and closing of the plunger pump 3. When the control module determines that the liquid level in the hydraulic oil tank is about to or has already fallen below the installation height of the plunger pump 3, the plunger pump 3 will be closed, thereby making the subsequent node time Time to Node , Node Time Time to Node Real-time flow rate Rapidly decrease until the real-time flow rate Return to 0, thus protecting the plunger pump 3 and preventing the plunger pump 3 from idling.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling the oil circuit system of a low-profile telescopic forklift, characterized in that: The oil circuit system of the low-profile telescopic forklift includes a hydraulic oil tank, a plunger pump, a metering component, and a control module; the hydraulic oil tank is connected to the plunger pump; the hydraulic oil tank includes a main oil tank and a subsidiary oil tank connected to the main oil tank; the subsidiary oil tank is installed above the main oil tank and is a special-shaped oil tank structure, so as to increase the liquid level of the hydraulic oil tank so that the liquid level is higher than the oil inlet height of the plunger pump; The main oil tank is connected to the plunger pump; the metering element is arranged between the main oil tank and the plunger pump, and is used to detect the flow rate of the hydraulic oil tank to the plunger pump; The metering element is electrically connected to the control module; The control method comprises the following steps: S1, the control module controls the plunger pump to start and inhale or return hydraulic oil by inputting different power signals to control the telescopic arm to extend and retract; S2, the metering element obtains the real-time flow rate of the hydraulic oil of different power signals ; S3, the control module is further used to determine the real-time flow rate under different power signals And standard flow rate , it is judged that the plunger pump is damaged or leaking; In step S2, the metering element obtains the real-time flow rate of the hydraulic oil of different power signals The steps specifically include: Divide the time of a power signal into multiple node times ... ,in, is the starting time, is the end time; Get the time of each node ... Corresponding real-time flow rate ... ; In step S3, the control module is further used to adjust the real-time flow rate under different power signals. And standard flow rate The steps of determining that the plunger pump is damaged or leaking specifically include: When the real-time flow rate ... are much smaller than the standard flow rate , it is determined that the plunger pump is damaged; and / or; When the real-time flow rate ... Both approach the standard flow rate , and the real-time flow rate ... Much smaller than the standard flow rate , it is judged as leakage, 2~ Any integer in ; and / or; When the real-time flow rate ... Both approach the standard flow rate , it is determined that the plunger pump is working normally, wherein the real-time flow rate ... are much smaller than the standard flow rate , refers to the real-time flow rate ... All less than 0.9 ; and the real-time flow rate ... Approaching the standard flow rate It means reaching ±0.1 .

2. The method for controlling the oil circuit system of a low-profile telescopic forklift according to claim 1, characterized in that: The standard flow rate is calculated by the following formula ; ； in The number of liters per minute that the rated piston pump can pump.

3. The control method of the oil circuit system of a low-profile telescopic forklift according to claim 1, characterized in that: The top of the main oil tank is connected to the top of the auxiliary oil tank through a through pipe, and a breathing piece is installed on the top of the auxiliary oil tank to keep the air pressure in the main oil tank and the auxiliary oil tank at normal pressure.

4. The method for controlling the oil circuit system of a low-profile telescopic forklift according to claim 1, characterized in that: The main fuel tank and the auxiliary fuel tank are both installed on a bracket, and the bracket is used to stagger the auxiliary fuel tank and the main fuel tank at an angle of 30° to 60°, wherein the top of the auxiliary fuel tank is designed to be flat.

5. The control method of the oil circuit system of a low-profile telescopic forklift according to claim 1, characterized in that: The top of the main oil tank is connected to the bottom of the auxiliary oil tank through a pair of oil pipes; the volume ratio of the auxiliary oil tank to the main oil tank is 1:1~2.

6. The method for controlling the oil circuit system of a low-profile telescopic forklift according to claim 1, characterized in that: The control module counts the real-time flow rate when the plunger pump is running ... The gap rate is used to obtain a digital set, which is used to determine the liquid level information in the hydraulic oil tank.

7. The method for controlling the oil circuit system of a low-profile telescopic forklift according to claim 6, characterized in that: The gap rate is the real-time flow rate of the adjacent The difference is counted by the control module to obtain the digital set { |、 |、 |...... |}, where a rate safety value is defined , rate safety value The speed safety value is compared with each difference in the digital set to determine the liquid level information in the hydraulic oil tank; When it is greater than or equal to the difference, the liquid level in the hydraulic oil tank is considered normal and the speed safety value When it is less than the difference, it is determined that the liquid level in the hydraulic oil tank is about to or has been lower than the installation height of the plunger pump.

8. The method for controlling the oil circuit system of a low-profile telescopic forklift according to claim 7, characterized in that: The rate safety value Used to timely find the relationship between the liquid level in the hydraulic oil tank and the installation height of the plunger pump; among them, the critical flow rate It is the flow rate when the liquid level in the hydraulic oil tank is just equal to the installation height of the plunger pump, calculated by the following formula ; ； in, is the rated maximum flow, A is the cross-sectional area of ​​the auxiliary tank; Rate safety value Set to be greater than or equal to the critical flow rate To ensure that the liquid level in the hydraulic oil tank will not be lower than the installation height of the plunger pump, calculate it by the following formula ; ； in Leave a safety margin for this.

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