CN117605718A - Variable boost ratio hydraulic boosting system and control method - Google Patents

Abstract

The invention is applicable to the field of hydraulic systems and discloses a variable pressure ratio hydraulic pressure boosting system and a control method. The variable pressure pressure ratio hydraulic pressure boosting system includes a first pressure source, a second pressure source and a pressure boosting cylinder. The pressure boosting cylinder It includes a cylinder barrel, a piston and a piston rod. The piston is set at the end of the piston rod. The piston and piston rod are set in the cylinder barrel and divides the inner cavity of the cylinder barrel into a low pressure chamber, a pressure regulating chamber and a high pressure chamber. The first pressure The source and the low-pressure chamber are connected through a first pipeline, and a directional control valve is provided between the first pressure source and the low-pressure chamber. The first pressure source is connected to a first proportional pressure valve, and the second pressure source and the pressure regulating chamber are connected through a second pipeline. connection, the second pressure source is connected to a second proportional pressure valve, and a one-way valve is provided between the pressure adjustment chamber and the directional control valve. The system realizes the boosting system by controlling the input of the first pressure source and the input of the second pressure source. The boost ratio is variable, and the boost ratio adjustment range is wider.

Description

Variable boost ratio hydraulic boosting system and control method

Technical field

The invention relates to the field of hydraulic systems, and in particular to a variable pressure ratio hydraulic pressure boosting system and a control method.

Background technique

Generally, the boost ratio of a booster cylinder is fixed and can be called a hard boost ratio. As shown in Figure 3, S _1' is the effective area of the piston in the low-pressure input chamber, and S _2' is the effective area of the booster rod in the high-pressure output chamber. According to the formula P _1' *S _1' = P _2' *S _2' , Pressure ratio=S _1' :S _2' =P _2' :P _1' . Once the boosting cylinder is determined, the hard boosting ratio cannot be changed. The minimum controllable range of P _2' is the minimum value of P ₁ * boost ratio. With the development of process technology and the popularization and application of internal high-pressure forming technology, the requirements for forming pressure are getting higher and higher. Now the requirements are generally above 150-200MPa. At this time, the boosting ratio of the boosting cylinder is often above 10:1, and the conventional proportional pressure The adjustment dead zone of the valve is around 2MPa, that is, the minimum output pressure of the booster cylinder is around 20MPa. This pressure range does not have a great impact on the internal high-pressure forming process of general conventional materials, but for some soft materials (such as precious metals, silver, thin-walled soft copper, etc.), the initial expansion pressure is generally <20MPa, which is easy to cause The blank is directly in the stage of large deformation. Even if a high-precision proportional pressure valve is used, it is difficult to ensure the matching of the pressure curve and the material bulging route, causing an increase in the scrap rate and thus increasing the production cost of the product.

For some composite processes, manufacturers often require the output pressure control accuracy in the initial stage to be within 1MPa, and the overall pressure output range ranges from 10MPa to 20MPa at low pressure to more than 100MPa at high pressure. At this time, the solution is generally to equip an additional set of booster cylinders with a low boost ratio, or to find some proportional pressure valves with ultra-high control accuracy. In either case, it increases the equipment manufacturing cost and the difficulty of controlling the pressure accuracy of the system.

Therefore, the existing technology still needs to be improved and developed.

Contents of the invention

The first object of the present invention is to provide a variable boosting ratio hydraulic boosting system, which realizes a variable boosting ratio of the boosting system by controlling the input of the first pressure source and the input of the second pressure source. Wider than adjustment range.

In order to achieve the above objects, the solution provided by the present invention is:

A variable pressure boosting ratio hydraulic boosting system includes a first pressure source, a second pressure source and a boosting cylinder. The boosting cylinder includes a cylinder barrel, a piston and a piston rod. The piston is arranged on the piston rod. The end of the cylinder, the piston and the piston rod are arranged in the cylinder, and the inner cavity of the cylinder is divided into a low-pressure chamber, a pressure adjustment chamber and a high-pressure chamber, and the first pressure source and the The low-pressure chamber is connected through a first pipeline, and a directional control valve is provided between the first pressure source and the low-pressure chamber. The first pressure source is connected to a first proportional pressure valve, and the second pressure source is connected to the low-pressure chamber. The pressure regulating chamber is connected through a second pipeline, the second pressure source is connected to a second proportional pressure valve, and a one-way valve is provided between the pressure regulating chamber and the directional control valve.

Preferably, the functional expression of the output pressure value P ₂ of the boosting system is expressed as:

P ₂ =(P ₁ *S ₁ -P ₃ *S ₃ )/S ₂

In the formula, P ₁ represents the input pressure value of the low-pressure chamber, P ₃ represents the input pressure value of the pressure regulating chamber, S ₁ represents the area of the low-pressure chamber, S ₂ represents the area of the high-pressure chamber, and S ₃ represents the area of the pressure regulating chamber.

Preferably, a first pressure sensor is provided at the input end of the first proportional pressure valve.

Preferably, a second pressure sensor is provided at the input end of the second proportional pressure valve.

Preferably, a third pressure sensor is provided at the output end of the high-pressure chamber.

Preferably, the input end of the first proportional pressure valve and the input end of the second proportional pressure valve are respectively connected to a sampling circuit, and the sampling circuit includes a fourth pressure sensor, a current amplifier, an analog-to-digital converter and a reference power supply. , the output end of the fourth pressure sensor is connected to the input end of the analog-to-digital converter, the output end of the analog-to-digital converter is connected to the input end of the current amplifier, and the reference power supply is connected to the analog-to-digital converter. The power input end of the converter is connected, the fourth pressure sensor of the sampling circuit connected to the first proportional pressure valve is connected to the input end of the first proportional pressure valve, and all the sensors of the sampling circuit connected to the first proportional pressure valve are connected. The output end of the current amplifier is connected to the input end of the first proportional pressure valve, the fourth pressure sensor of the sampling circuit connected to the second proportional pressure valve is connected to the input end of the second proportional pressure valve, and is connected to the input end of the second proportional pressure valve. The output end of the current amplifier of the sampling circuit connected to the second proportional pressure valve is connected to the input end of the second proportional pressure valve.

The second object of the present invention is to provide a variable boost ratio hydraulic boost control method. The variable boost ratio hydraulic boost control method includes: obtaining a functional expression of the output pressure value of the boost system and the target output pressure. value; substitute the target output pressure into the functional formula of the output pressure value of the boosting system, and calculate the input pressure of the low-pressure chamber and the input pressure of the pressure adjustment chamber; adjust according to the calculated input pressure of the low-pressure chamber and the pressure value of the first pressure source the opening of the first proportional pressure valve, and adjust the opening of the second proportional pressure valve according to the calculated input pressure of the pressure regulating chamber and the pressure value of the second pressure source so that the output pressure value of the high-pressure chamber is equal to the target output pressure value .

Preferably, after adjusting the opening of the first proportional pressure valve and the opening of the second proportional pressure valve, the method further includes: regularly obtaining the real-time pressure of the high-pressure chamber, and fine-tuning the opening of the first proportional pressure valve according to the real-time pressure of the high-pressure chamber. and the opening of the second proportional pressure valve so that the output pressure value of the high-pressure chamber is equal to the target output pressure value.

In this solution, the inner chamber of the boosting cylinder is divided into a low-pressure chamber, a pressure regulating chamber and a high-pressure chamber, and is equipped with a first pressure source connected to the low-pressure chamber and a second pressure source connected to the pressure regulating chamber. In the case of a hard boosting ratio of the boosting cylinder, the input pressure of the pressure chamber and the input pressure of the low-pressure chamber are added through system control to form a soft boosting ratio. The soft boosting ratio is used to actually control the output pressure of the high-pressure chamber, thereby expanding the The wide pressure ratio adjustment range of the supercharging system can even achieve a pressure ratio <1 when the hard pressure ratio is >>1.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a variable pressure boosting ratio hydraulic boosting system provided by an embodiment of the present invention;

Figure 2 is a flow chart of a variable pressure pressure ratio hydraulic pressure boost control method provided by an embodiment of the present invention.

Figure 3 shows the existing boosting system.

Explanation of reference numbers:

10. First pressure source; 20. Second pressure source; 30. Boosting cylinder; 31. Cylinder barrel; 32. Piston; 33. Piston rod; 34. Low pressure chamber; 35. Pressure regulating chamber; 36. High pressure chamber; 40. Directional control valve; 50. First proportional pressure valve; 60. Second proportional pressure valve; 70. One-way valve; 80. First pipeline; 90. Second pipeline.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relationship between each component in a specific posture (as shown in the accompanying drawings). The relative positional relationship, movement conditions, etc., if the specific posture changes, the directional indication will also change accordingly.

It should also be noted that when an element is referred to as being "mounted" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is said to be "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

In addition, descriptions involving "first", "second", etc. in the present invention are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions in various embodiments can be combined with each other, but it must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist. , nor within the protection scope required by the present invention.

As shown in Figure 1, it is a variable pressure boosting ratio hydraulic pressure boosting system according to an embodiment of the present invention.

Please refer to Figure 1. The variable pressure boosting ratio hydraulic boosting system according to the embodiment of the present invention includes a first pressure source 10, a second pressure source 20 and a boosting cylinder 30. The boosting cylinder 30 includes a cylinder tube 31, a piston 32 and a piston. The rod 33 and the piston 32 are arranged at the end of the piston rod 33. The piston 32 and the piston rod 33 are arranged in the cylinder 31 and divide the inner cavity of the cylinder 31 into a low pressure chamber 34, a pressure adjustment chamber 35 and a high pressure chamber 36. The first pressure source 10 and the low pressure chamber 34 are connected through the first pipeline 80, and a directional control valve 40 is provided between the first pressure source 10 and the low pressure chamber 34. The first pressure source 10 is connected to a first proportional pressure valve 50. The two pressure sources 20 and the pressure regulating chamber 35 are connected through a second pipe 90 . The second pressure source 20 is connected to a second proportional pressure valve 60 . A one-way valve 70 is provided between the pressure regulating chamber 35 and the directional control valve 40 .

It can be understood that the functional formula of the output pressure value P ₂ of the boosting system is expressed as: P ₂ =(P ₁ *S ₁ -P ₃ *S ₃ )/S ₂ , where P ₁ represents the input pressure of the low pressure chamber 34 value, P ₃ represents the input pressure value of the pressure regulating chamber 35 , S ₁ represents the area of the low pressure chamber 34 , S ₂ represents the area of the high pressure chamber 36 , and S ₃ represents the area of the pressure regulating chamber 35 . P ₃ is an adjustable item of the system. For a fixed booster cylinder 30 , the actual required pressure output P ₂ can be achieved by adjusting P ₁ and P ₃ . Assume that the hard boost ratio of the booster cylinder 30 is 10:1, S ₁ :S ₂ =10, S ₃ :S ₂ =9, when the maximum boost ratio output is required, let P ₃ =0, the booster cylinder 30 The supercharging ratio is S ₁ :S ₂ =10:1, that is, P ₂ =10*P ₁ ; when P ₃ =P ₁ , the supercharging ratio is (S ₁ -S ₃ ):S ₂ =1:1, That is, P ₂ =P ₁ ; when P ₃ =1.1*P ₁ , the boost ratio

=(S ₁ -1.1*S ₃ ):S ₂ =1:10, that is, P ₂ =0.1*P ₁ ; By adjusting different P ₃ values, the soft boost ratio of the boosting cylinder 30 can be adjusted, and The adjustment range is very large, and it can even achieve a pressure ratio <1 when the hard pressure ratio is >>1. At this time, even if the dead zone of a conventional proportional pressure valve is 2MPa, the minimum output pressure can still meet the situation of ≤2MPa, and meet the working condition requirement of control accuracy within 20MPa of 1MPa.

The variable boosting ratio hydraulic boosting system of the embodiment of the present invention divides the inner cavity of the boosting cylinder 30 into a low-pressure chamber 34, a pressure adjustment chamber 35 and a high-pressure chamber 36, and is configured with a first pressure source connected to the low-pressure chamber 34. 10 and the second pressure source 20 connected to the pressure regulating chamber 35, without changing the hard boosting ratio of the boosting cylinder 30, the input pressure of the adjusting pressure chamber and the input pressure of the low pressure chamber 34 are added through system control to form a soft boosting ratio, the soft boost ratio is used to actually control the output pressure of the high-pressure chamber 36, thereby broadening the boost ratio adjustment range of the boost system, and even achieving a boost ratio < when the hard boost ratio >>1 1 situation.

Referring to FIG. 1 , for example, in some embodiments, the input end of the first proportional pressure valve 50 is provided with a first pressure sensor (not shown). By providing the first pressure sensor, the first pressure sensor can be configured. The output pressure of the pressure source 10 is monitored and controlled to ensure that the hydraulic system maintains a stable pressure during the working process and is adjusted and controlled according to actual needs to improve the performance and reliability of the system.

Similarly, the input end of the second proportional pressure valve 60 is provided with a second pressure sensor (not shown). By providing the second pressure sensor, the output pressure of the second pressure source 20 can be monitored and controlled, thus ensuring that the hydraulic pressure The system maintains stable pressure during work and is adjusted and controlled according to actual needs to improve system performance and reliability.

Further, a third pressure sensor (not shown) is provided at the output end of the high-pressure chamber 36, and the output pressure value of the high-pressure chamber 36 (ie, the output pressure value of the supercharging system) is monitored through the third pressure sensor.

Please refer to Figure 1. Exemplarily, in some embodiments, a sampling circuit (not shown) is also included. The sampling circuit includes a fourth pressure sensor (not shown), a current amplifier (not shown), an analog digital converter (not shown) and reference power supply (not shown), the fourth pressure sensor is connected to the input end of the first proportional pressure valve 50, the output end of the fourth pressure sensor is connected to the input end of the analog-to-digital converter, The output terminal of the analog-to-digital converter is connected to the input terminal of the current amplifier, the output terminal of the current amplifier is connected to the input terminal of the first proportional pressure valve 50, the reference power supply is connected to the power input terminal of the analog-to-digital converter, and is obtained by setting the sampling circuit The input pressure of the first pressure source 10 is adjusted according to the target output pressure and the input pressure of the first pressure source 10. Through digital processing and control, precise pressure adjustment can be achieved, and the opening of the first proportional pressure valve 50 can be adjusted according to the target output pressure and the input pressure of the first pressure source 10. Flexible parameter adjustment and optimization according to actual needs. At the same time, due to the characteristics of digital control, remote monitoring and control can also be achieved, improving the convenience and operability of the system.

It can be understood that the pressure sensor is a voltage type or a current type. When the pressure sensor is a voltage type pressure sensor, the reference power supply is a voltage source. When the pressure sensor is a current type pressure sensor, the reference power supply is a current source.

Similarly, the input end of the second proportional pressure valve 60 is also provided with a sampling circuit. The specific structure is as described above. Without going into details, the difference is that the fourth pressure sensor is connected to the input end of the second proportional pressure valve 60 and the current amplifier The output end is connected to the input end of the second proportional pressure valve 60. The input pressure of the second pressure source 20 is obtained by setting a sampling circuit, and then the second proportional pressure valve 60 is adjusted according to the target output pressure and the input pressure of the second pressure source 20. the opening.

It can be understood that if the input end of the first proportional pressure valve 50 is provided with a sampling circuit, there is no need to provide a pressure sensor.

Referring to Figure 2, an embodiment of the present invention also provides a variable boost ratio hydraulic boost control method, including:

S101. Obtain the functional formula of the output pressure value of the boosting system and the target output pressure value;

S102. Substitute the target output pressure into the functional formula of the output pressure value of the boosting system to calculate the input pressure of the low-pressure chamber 34 and the input pressure of the pressure adjustment chamber 35;

S103. Adjust the opening of the first proportional pressure valve 50 according to the calculated input pressure of the low-pressure chamber 34 and the pressure value of the first pressure source 10, and adjust the opening of the first proportional pressure valve 50 according to the calculated input pressure of the chamber 35 and the second pressure source 20. The pressure value adjusts the opening of the second proportional pressure valve 60 so that the output pressure value of the high-pressure chamber 36 is equal to the target output pressure value.

Furthermore, in order to achieve high control accuracy and avoid the system being disturbed during long-term operation, causing the output pressure value of the high-pressure chamber 36 to deviate from the target output pressure value, the variable pressure pressure ratio hydraulic pressure pressure control method also includes: S104, regularly obtaining The real-time pressure of the high-pressure chamber 36 is adjusted, and the opening of the first proportional pressure valve 50 and the opening of the second proportional pressure valve 60 are finely adjusted according to the real-time pressure of the high-pressure chamber 36 so that the output pressure value of the high-pressure chamber 36 is equal to the target output pressure value.

In this solution, the input pressure of the low-pressure chamber 34 and the input pressure of the pressure regulating chamber 35 are calculated according to the functional formula of the output pressure value of the boosting system and the target output pressure value. By controlling the input of the first pressure source 10 and the second pressure source The input of 20 realizes the variable pressure ratio of the supercharging system, which can widen the pressure ratio adjustment range of the supercharging system, and can even realize the pressure ratio <1 when the hard pressure ratio >>1.

The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Under the inventive concept of the present invention, equivalent structural transformations can be made using the contents of the description and drawings of the present invention, or direct/indirect applications. Other related technical fields are included in the patent protection scope of the present invention.

Claims (8)

1. A variable pressure boosting ratio hydraulic boosting system, characterized in that it includes a first pressure source, a second pressure source and a boosting cylinder. The boosting cylinder includes a cylinder barrel, a piston and a piston rod. The piston is arranged at the end of the piston rod, the piston and the piston rod are arranged in the cylinder barrel, and divides the inner cavity of the cylinder barrel into a low pressure chamber, a pressure adjustment chamber and a high pressure chamber, and the third A pressure source is connected to the low-pressure chamber through a first pipeline, and a directional control valve is provided between the first pressure source and the low-pressure chamber. The first pressure source is connected to a first proportional pressure valve, and the The second pressure source is connected to the pressure regulating chamber through a second pipeline, the second pressure source is connected to a second proportional pressure valve, and a one-way valve is provided between the pressure regulating chamber and the directional control valve. 2. The variable pressure boosting ratio hydraulic boosting system as claimed in claim 1, characterized in that the functional expression of the output pressure value _P2 of the boosting system is expressed as: P ₂ =(P ₁ *S ₁ -P ₃ *S ₃ )/S ₂ In the formula, P ₁ represents the input pressure value of the low-pressure chamber, P ₃ represents the input pressure value of the pressure regulating chamber, S ₁ represents the area of the low-pressure chamber, S ₂ represents the area of the high-pressure chamber, and S ₃ represents the area of the pressure regulating chamber. 3. The variable boost ratio hydraulic boosting system according to claim 1, wherein a first pressure sensor is provided at the input end of the first proportional pressure valve. 4. The variable boost ratio hydraulic boosting system according to claim 1, wherein a second pressure sensor is provided at the input end of the second proportional pressure valve. 5. The variable boosting ratio hydraulic boosting system according to claim 1, wherein a third pressure sensor is provided at the output end of the high-pressure chamber. 6. The variable boost ratio hydraulic boosting system according to claim 1, wherein the input end of the first proportional pressure valve and the input end of the second proportional pressure valve are respectively connected to a sampling circuit, The sampling circuit includes a fourth pressure sensor, a current amplifier, an analog-to-digital converter and a reference power supply. The output end of the fourth pressure sensor is connected to the input end of the analog-to-digital converter. The output of the analog-to-digital converter terminal is connected to the input terminal of the current amplifier, the reference power supply is connected to the power input terminal of the analog-to-digital converter, and the fourth pressure sensor of the sampling circuit connected to the first proportional pressure valve is connected to the first proportional pressure The input end of the valve is connected, the output end of the current amplifier of the sampling circuit connected to the first proportional pressure valve is connected to the input end of the first proportional pressure valve, and the sampling circuit connected to the second proportional pressure valve The fourth pressure sensor of the circuit is connected to the input end of the second proportional pressure valve, and the output end of the current amplifier of the sampling circuit connected to the second proportional pressure valve is connected to the input end of the second proportional pressure valve. 7. A variable pressure pressure ratio hydraulic pressure pressure control method, characterized in that the variable pressure pressure ratio hydraulic pressure pressure control method includes: Obtain the functional formula of the output pressure value of the boosting system and the target output pressure value; Substituting the target output pressure into the functional formula of the output pressure value of the boosting system, calculate the input pressure of the low-pressure chamber and the input pressure of the pressure adjustment chamber; Adjust the opening of the first proportional pressure valve according to the calculated input pressure of the low-pressure chamber and the pressure value of the first pressure source, and adjust the second proportion according to the calculated input pressure of the pressure adjustment chamber and the pressure value of the second pressure source The opening of the pressure valve is such that the output pressure value of the high-pressure chamber is equal to the target output pressure value. 8. The variable boost ratio hydraulic pressure boost control method as claimed in claim 7, wherein after adjusting the opening of the first proportional pressure valve and the opening of the second proportional pressure valve, it further includes: regularly obtaining The real-time pressure of the high-pressure chamber, and fine-tuning the opening of the first proportional pressure valve and the opening of the second proportional pressure valve according to the real-time pressure of the high-pressure chamber so that the output pressure value of the high-pressure chamber is equal to the target output pressure value.