CN116428232A - Triangular groove overflow hole type hydraulic distributor - Google Patents

Abstract

The invention provides a triangular groove overflow hole type hydraulic distributor, which aims at the problem of impact noise caused by too fast reversing of an electromagnetic hydraulic distributor, and by optimally designing a valve sleeve of a main valve core, the edge of one overflow hole selected from two groups of overflow holes of the valve sleeve is provided with a buffer notch, so that the gradient of the overflow area can be reduced when a main valve is opened and closed, the output flow of the distributor is slowly changed, the switching speed of the main valve core is slowed down by changing the overflow area of the valve sleeve under the condition that the stable working flow is kept unchanged, and the reversing time is prolonged, so that the purpose of reducing hydraulic impact is achieved.

Description

A Triangular Groove Flow Hole Type Hydraulic Distributor

technical field

The invention belongs to the technical field of electromagnetic hydraulic distributors, and in particular relates to a triangular groove flow hole type hydraulic distributor.

Background technique

The electromagnetic hydraulic distributor realizes the reciprocating swing of the driving cylinder by controlling the flow direction of the hydraulic oil, and then realizes the opening and closing of the sea valve. The distributor drives the pilot valve to switch the liquid flow through the electromagnetic coil. Due to the strong hydraulic pressure, the main valve can easily realize the reversing, but it may cause shock vibration caused by too fast reversing.

The block diagram of the hydraulic principle of Tonghai valve is shown in Figure 1. In the hydraulic drive system of Tonghai valve, the role of the electromagnetic hydraulic distributor is to make use of the change of the position of the valve core relative to the valve body to make the oil circuit in the system communicate, cut off or change the working medium. The direction of flow, and then control the actuator components such as sea valves to start, stop or change the direction of movement.

In the reversing valve, the electromagnetic reversing valve uses the characteristics of the electromagnet's power-on attraction and power-off separation to directly push the valve core and then control the direction of the liquid flow. The electromagnet's power-on and power-off needs to be controlled by electrical signals. In the middle, the button switch controls the power on and off of the electromagnet, but limited by the size of the electromagnet and the electromagnetic thrust, the electromagnetic reversing valve can only control the small flow of liquid flow, the solenoid valve responds quickly, and the short reversing time is easy to cause hydraulic pressure. The impact will cause the instability of the actuator and even the vibration of the pipeline during the movement of the spool. If you want to increase the flow rate of the electromagnetic reversing valve, in order to overcome the forces hindering the movement of the valve core, such as steady-state hydraulic force, kinetic friction, radial clamping force, and elastic force of the return spring, you must increase the thrust of the electromagnet. , but to ensure that the pressure loss is not too large when passing a large flow rate, the diameter of the spool must be increased, which in turn causes an increase in resistance. The hydraulic reversing valve uses the oil pressure difference in the control oil circuit to realize the change of the spool position. The reversing speed of the hydraulic reversing valve is easy to control and the action is stable, but there is a large hydraulic driving force, which is only suitable for large flow of work. Situation. The electromagnetic hydraulic distributor in the opening and closing drive system of Tonghai valve is an electrohydraulic valve that installs the solenoid valve and the hydraulic reversing valve together. The solenoid valve plays a leading role in the work of the distributor and is responsible for controlling the main valve, that is, the hydraulic valve control For the reversing of the oil circuit, after the pilot valve is reversing, the control oil circuit of the main valve will form a pressure difference, which will push the spool of the main valve to move, and complete the reversing of the entire oil circuit. Control the reversing of large diameter hydraulic valves. Due to the strong hydraulic power, the electromagnetic hydraulic distributor can easily complete the reversing action, but the possible problem is: because the valve core moves too fast, it is easy to cause hydraulic shock, and damping holes are generally installed at both ends of the valve core to slow down The switching speed of the main spool.

The structural principle of the electromagnetic hydraulic distributor is shown in Figure 2. The electromagnetic hydraulic distributor is essentially a pilot-operated electro-hydraulic valve composed of an electromagnet, a pilot valve and a main valve. The distributor has two control methods: one is the electric control One is to use the power on and off of the electromagnet to push the pilot spool to realize the reversing of the main oil circuit; one is to directly use the handle to manipulate the position change of the pilot spool to realize the reversing of the main oil circuit.

When the solenoid valve distributor is in different working positions, the power on and off of the electromagnet and the movement of the pilot valve spool and the main spool are as follows:

The distributor is in the middle position: the left electromagnet and the right electromagnet are de-energized, the handle is in the middle state, and the pilot valve core is in the middle position under the action of the spring. At this time, the left control chamber and the right control chamber of the main valve pass through the pilot valve and discharge The ports are connected, and the main spool is in the middle position under the action of the spring force. At this time, the pressure oil port of the main valve is closed, and the open oil port, the closed oil port and the discharge oil port communicate.

The distributor is in the open position: the left electromagnet is energized or the handle is turned to the open position. Under the action of the electromagnetic force or the handle, the pilot valve core moves to the right, and the pressure oil port is supplied to the right control chamber of the main valve through the restrictor, and the left control The cavity is connected through the pilot valve and the discharge oil return port, the main valve core moves to the left under the action of the hydraulic pressure, the open oil port is connected with the pressure oil port, and the closed oil port is connected with the discharge oil port at the same time.

The distributor is in the off position: turn on the right electromagnet or turn the handle to the off position, the pilot spool moves to the left under the action of the electromagnetic force or the handle, and the pressure oil port is supplied to the left control chamber of the main valve through the restrictor, and the right The control chamber is connected to the discharge oil port through the pilot valve, the main valve core moves to the right under the action of hydraulic pressure, the closed oil port is connected to the pressure oil port, and the open oil port is connected to the discharge oil port at the same time.

Contents of the invention

In view of this, the object of the present invention is to provide a triangular groove flow hole type hydraulic distributor, which can reduce hydraulic shock.

A triangular groove flow hole type hydraulic distributor. The hydraulic distributor includes an electromagnet, a pilot valve and a main valve; The holes are arranged on the same circumference of the valve sleeve, and a buffer notch is provided on the edge of any one of the two sets of flow holes in the valve sleeve, and the buffer notch is located on the side where the flow hole is located in the center of the valve sleeve. The edge of the flow hole gradually shrinks to form a triangular notch; the two groups of flow holes are flow holes located at the opening and closing positions of the valve port of the main valve respectively.

Preferably, the height of the buffer notch is 2mm, and the length of the bottom side is 1mm.

The present invention has following beneficial effects:

The invention provides a triangular groove flow hole type hydraulic distributor. Aiming at the impact noise problem caused by too fast reversing of the electromagnetic hydraulic distributor, through the optimized design of the valve sleeve of the main valve core, two sets of flow holes in the valve sleeve Choose a buffer slot on the edge of one of the flow holes, which can reduce the gradient of the flow area when the main valve is opened and closed, so that the output flow of the distributor changes slowly. On the basis of maintaining a stable working flow, by changing The flow area of the valve sleeve slows down the switching speed of the main spool, and prolongs the switching time to reduce the hydraulic shock.

Description of drawings

Figure 1 is a block diagram of the hydraulic principle of the sea valve;

Figure 2 is a structural schematic diagram of the electromagnetic hydraulic distributor;

Figure 3 is a sequence diagram of the action of the sea valve;

Figure 4 shows the transient hydraulic force on the slide valve;

Figure 5 shows the position of the main spool under zero displacement;

Fig. 6 is a simplified diagram for calculating the flow area of the valve port;

Figure 7 is a calculation diagram of the effective flow area of a single flow hole;

Fig. 8 is a curve diagram of the flow area of the valve port;

Fig. 9 is a schematic diagram of a buffer tank;

Figure 10 is a three-dimensional model of the buffer tank;

Figure 11 is a curve diagram of the flow area of the valve port after improvement;

Figure 12 is a curve diagram of the flow area of the valve port before and after improvement;

Figure 13 is a schematic diagram of the flow rate rise curve before and after the improvement of the solenoid valve;

Figure 14 is the simulation model of the valve-controlled sea valve drive cylinder

Figure 15 is the opening amount of the solenoid valve distributor;

Figure 16 is the flow area of P-B;

Fig. 17 is oil cylinder speed-time curve;

Fig. 18 is oil cylinder acceleration-time curve;

Figure 19 is the pressure at port P;

Figure 20 is the T port pressure.

Among them, 1-left solenoid, 2-pilot valve, 3-handle, 4-right solenoid, 5-pilot spool, 6-spring, 7-main spool, 8-main valve, 9-oil port connector.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and examples.

1. Analysis of the working principle of the electromagnetic hydraulic distributor:

The action timing diagram of the sea valve is shown in Figure 3, which analyzes the completion of the sea valve in the control system from sending the control signal to completing the opening and closing action.

In practice, the actual control signal response time of the system should be controlled to be greater than the inherent start-up time of the hydraulic press driven by the sea valve. If the rapid start or stop, the change process time is less than this time, severe pressure shock will occur. When the sea valve drives the hydraulic press, it is required that the opening and closing transition time is not less than this index, that is, the response time of the driving hydraulic press is prolonged, which can effectively weaken the pressure shock amplitude and reduce the shock noise.

Analyze the pressure change of each oil port, and carry out simulation calculation on the basis of the analysis, and analyze the cause of hydraulic shock. Each oil port is shown in Figure 5. Before the solenoid valve distributor is opened, the pressure of P port is the oil source pressure, and the A and B ports are connected to the T port through the pilot valve first. At this time, the A, B and T ports are basically zero. After the electromagnetic hydraulic distributor receives the control signal, the spool of the pilot valve first moves in the direction specified by the control signal under the action of the electromagnetic force or the handle, and the main valve opens to the maximum opening according to its inherent dynamic characteristics, and the P port of the electromagnetic hydraulic distributor When port A is just connected (assuming that the electromagnetic hydraulic distributor is opened in this direction), the pressure of port A starts to rise, and at this time, the oil flowing from port P into port A is completely used to supplement the volume of hydraulic oil compressed by the pressure rise of port A . At this time, port B and port T are connected. When the pressure difference between port A and port B acts on the piston of the hydraulic machine driven by the sea valve, when the force rises to be greater than the friction force of the hydraulic machine driven by the sea valve and the transmission mechanism, the valve disc of the sea valve starts to accelerate. . As the opening of the electromagnetic hydraulic distributor increases, the flow area of port A increases, the flow into port A increases, and the pressure at port A continues to increase, and the sea valve drives the hydraulic press to continue to accelerate. When the movement speed of the hydraulic press reaches a certain value, as the system flow continues to increase, the pressure loss of the pipeline and valve parts in the hydraulic drive system will also increase until the system except for the pressure loss of the pipeline and valve parts, the remaining pressure acts on the The effect on the oil cylinder is just equal to the friction force, the sea valve drives the hydraulic press to reach a balanced state, and the piston keeps moving at a constant speed. When the driving piston of the sea valve is in a state of motion balance, the control signal remains unchanged, the opening of the solenoid valve distributor remains unchanged, the hydraulic press driven by the sea valve keeps moving at a constant speed, and the pressure of each oil port basically remains unchanged; when the sea valve is fully opened or closed At this time, the hydraulic press driven by the sea valve stops, the control signal of the control system is disconnected, the electromagnetic hydraulic distributor is reset, and the two chambers of the hydraulic press driven by the sea valve are completely closed.

According to the above analysis, the pressure fluctuation at the valve port occurs during the opening and closing process of the sea valve. Prolonging the response time of the electromagnetic hydraulic distributor, that is, slowing down the response speed of the electromagnetic valve, can reduce the pressure fluctuation during the opening and closing process of the valve. The output flow characteristics of the distributor can be changed by optimizing the valve sleeve structure design of the distributor, which is beneficial to improve its switching characteristics, thereby effectively reducing the hydraulic shock.

2. Theoretical calculation analysis

Hydraulic shock occurs during the opening and closing process of the distributor. When the hydraulic shock occurs, the pressure peak is several times the stable working pressure, which will cause the vibration of the pipeline to generate noise and endanger the normal use of the pipeline components. When the distributor switches between different working positions, the flow rate and direction of the hydraulic oil in the pipeline will change, generating hydraulic power. Among them, the hydraulic force is divided into steady-state hydraulic force and transient hydraulic force. The steady-state hydraulic force is the force acting on the valve core caused by the change of pressure oil momentum after the opening of the valve is fixed, which always makes the slide valve work tend to Stable; the transient hydraulic force is the force acting on the spool due to the speed change of the oil when the opening changes during the movement of the spool. The transient hydraulic force exists only during the opening or closing process of the valve. When the spool does not move, there is no transient hydraulic force. Therefore, the transient hydraulic force is closely related to the hydraulic shock. The calculation formula of the transient hydraulic force is as follows:

In the formula, L represents the length between the center of the oil inlet port and the center of the oil return port of the spool valve, which is called the damping length; C _d represents the flow coefficient of the valve port; w represents the oil passage length around the valve port, that is, the area gradient; ρ represents the flow through the spool valve hydraulic oil density; x _v represents the opening of the valve port;

From the formula (3.3.1), it can be seen that the transient hydraulic power received by the spool is proportional to the moving speed of the spool and proportional to the damping length of the slide valve, and its direction is always opposite to the direction of the acceleration of the liquid flow in the valve, so it can be passed The direction of acceleration determines the direction of the transient hydraulic force, and the transient hydraulic force received by the slide valve is shown in Figure 4.

Assuming that the spool moves to the right, when the hydraulic oil flows out of the valve port as shown in Figure 4(a), the acceleration of the hydraulic oil between the spool and the valve sleeve moves to the left to hinder the movement of the spool, and the direction of the transient hydraulic force on the spool is In the same direction as the spool movement, when hydraulic oil flows into the valve port as shown in Figure 4(b), the transient hydraulic force on the spool is opposite to the movement direction of the spool.

According to the combination of spool shoulder and spool groove width, the structure of cylindrical spool valve can be divided into three types, positive opening valve, zero opening valve and negative opening valve. Valves with different opening degrees have different flow gains. curve. According to the structural analysis of the distributor in Figure 1, it can be known that the valve is a negative opening valve, but in fact, it is more practical to determine the opening form of the valve by considering the shape of the flow gain curve of the valve core at zero displacement, and it can better reflect the displacement of the flow rate with the valve. The relationship between changes, as shown in Figure 5, is the position of the spool under zero displacement of the valve.

When the displacement of the main spool is zero, the pressures in the left and right control chambers of the main valve are equal, the P port is the pressure value of the oil source, and the A, B, and T ports are connected. The form of the throttling groove on the spool of the main valve is full-circle opening, so the flow curve of the slide valve depends on the shape of the flow hole of the valve sleeve. The main valve sleeve of the distributor electromagnetic valve is provided with eight circumferentially juxtaposed flow holes, wherein the diameter of each flow hole is 3mm. According to the form of the valve port of the solenoid valve, the valve port can be regarded as a thin-walled hole composed of eight flow-through areas in parallel. The parallel-connected valve ports can be approximately considered to have the same pressure difference before and after each small flow-through hole. For the valve port The sum of the total flow should be the sum of the flow of each hole, then the equivalent area of the valve port of the distributor can be deduced as:

A＝A _d1 +A _d2 +...+A _d8 (3.3.2)

Among them, the eight flow holes are evenly distributed in the same circle. For the same opening, the flow area of each flow hole is equal, then:

A _d =8A _d1 (3.3.3)

In the formula (3.3), A _d represents the equivalent area of the valve port, and A _d1 represents the equivalent flow area of a single flow hole. During the opening and closing process of the valve, the flow through the valve port is calculated according to the flow formula (3.3.4) of the thin edge:

In the formula, q _v represents the total flow through the valve port, Δp represents the pressure difference before and after the valve port, ρ represents the oil density, and A is an area function related to the opening of the valve.

The equivalent throttling area of a single flow hole can be regarded as two areas connected in series in Figure 6, and the equivalent throttling area calculation formula of the series throttling area is:

A ₁ is the projected area of the valve sleeve flow hole on the valve core, A ₂ is a rectangular cross-section, the calculation diagram of A ₁ is shown in Figure 7, where x represents the opening of the valve, and the first throttling area is when the valve opening is x. The flow area is expressed as the arcuate area in the figure, where R represents the radius of the flow hole.

Use the integral to find the function of the arcuate area with the valve opening, and calculate the integral for the valve opening from 0 to x:

Substituting R as 1.5mm into the expression solves the integral result as follows:

则分配器阀口的第一个节流总面积为：Wherein C represents any constant, put x=0, A ₁ =0 into formula (3.3.7) to solve the constant

Then the total area of the first throttling of the distributor valve port is:

The second throttle surface is a rectangular section, and the calculation is shown in formula (3.3.9):

A ₂ =2bW (3.3.9)

b represents the gap between the spool and the valve sleeve. The value in the distributor is 1mm. Substituting the data, when the spool moves to the center of the flow hole, keep the maximum value of 3mm ² , then the second equivalent of the distributor valve port The total throttle area is:

According to Equation (3.3.5), Equation (3.3.8) and Equation (3.3.10), the curve of the flow area of the valve port can be obtained as shown in Figure 8, where the maximum opening of the valve port is 3mm, and the valve port of the distributor The equivalent throttling area of the valve port is 22.09mm ² at the maximum opening, and the gradient of the flow area is relatively large during the opening process of the valve port.

According to formula (3.3.1), during the movement of the cylindrical slide valve, the instantaneous area gradient w of the opening and closing of the valve port is larger, and the greater the transient hydraulic force at the moment of opening and closing of the distributor, the more severe the hydraulic shock caused. During the opening process of the distributor, due to the large gradient of the flow area of the valve sleeve, the flow area quickly transitions to the maximum flow area with the increase of the valve opening. According to the formula (3.3.4), the flow coefficient of the slide valve during the movement C _d is a constant, generally selected according to the Reynolds number of the liquid flow, the oil density ρ is constant, and Δp is obtained according to the actual measurement. When the external load is constant, the output flow characteristics of the distributor can be characterized by the flow area . The larger the gradient of the flow area, the sooner the output flow of the distributor enters the stable working flow, that is, the faster the response time of the distributor.

In the opening and closing control system of Tonghai valve, the faster the response speed of the electromagnetic hydraulic distributor, the stronger the hydraulic shock caused. Therefore, in terms of noise control, it is hoped that the switching characteristics of the distributor can be improved so that it can meet other functional requirements. , with the function of slow opening and slow closing, the output flow is also a process of slow change. The previous analysis shows that the gradient of the flow area of the valve sleeve under the original distributor is large, resulting in faster flow output and causing hydraulic shock. To optimize and improve the distributor, it is only necessary to process the flow hole of the valve sleeve of the distributor to reduce the flow rate. The area gradient makes the output flow of the distributor change slowly, so as to control the slow start and close of the sea valve, and reduce the noise caused by the too fast start or stop of the actuator. Changing the flow area only needs to deal with the flow hole of the valve sleeve, only change the internal parts of the distributor, does not involve external interface problems and will not cause assembly problems, the risk is small, and it is easy to carry out.

If you want to reduce the area gradient, you must choose a notch shape that is smaller than the area gradient of the circular hole. Here, you choose to open a triangular buffer notch in the opening direction of the flow hole. The shape is shown in Figure 9.

In order to obtain a lower area gradient, here L is set to 5mm, and h is set to 1mm. At this time, the flow calculation formula of the valve port still satisfies the formula (3.3.4). For the processed flow hole, the maximum opening of the valve port Changes have taken place, and the maximum flow area has also changed. Here, the overlapping area of the triangular notch and the round hole is small. The calculation of the first flow area is performed. When the valve opening is from 0 to 2mm, the flow area is calculated according to Triangular area calculation, valve opening from 3mm to 5mm is still regarded as a round hole for calculation. The maximum opening of the valve port is changed from 3mm to 5mm, and the first flow area is increased from 7.07mm ² to 8.07mm ² (in fact, the maximum flow area should be slightly smaller than 8.07mm ² ), in order to ensure the stability of the distributor The working flow is constant, and the change of the flow area under the maximum opening should be reduced as much as possible. Here, only one flow hole is selected to be slotted, and the remaining seven holes remain unchanged. The three-dimensional model of the buffer tank is shown in Figure 10.

As shown in Figure 10, after slotting at the flow hole, the damping length of the spool becomes smaller during the movement, and the area gradient decreases. According to formula (3.3.1), it can be known that the transient hydrodynamic force caused by the spool moving has declined. For a flow hole with a buffer groove, the expression of the first flow area with the opening of the valve port is divided into two sections, which can be approximately expressed as:

The second flow area can be expressed as:

In fact, because the valve sleeve has a flow hole and a buffer slot, the pressure difference between the slotted hole and the other seven holes is inconsistent, and the output flow is not equal. Considering the small opening area of the slot, the eight holes are approximated as simple parallel relationship. Then, according to formula (3.3.5), formula (3.3.11) and formula (3.3.12), the curve diagram of the improved valve port flow area is shown in Figure 11.

After the distributor is improved, the maximum opening of the valve port is 5mm, and the maximum throttle area is approximately 22.15mm ² , an increase of about 0.06mm ² compared with 22.09mm ² before the improvement, and the equivalent throttle area is almost unchanged. According to The stable working flow rate of the distributor improved by formula (3.3.4) is almost constant. According to formula (3.3.5), formula (3.3.8), formula (3.3.10), formula (3.3.11) and formula (3.3.12), the equivalent flow area of valve sleeve flow hole before and after improvement The curve is shown in Figure 12.

Before the improvement, the flow area of the valve port is opened from the spool movement to the 2mm position, the oil inlet port communicates with the working oil port, and the output flow begins to increase with a large area gradient, where the area gradient suddenly changes from zero at this position , the sudden change in the flow area will cause the distributor to output a sudden change in flow rate, which will bring hydraulic shock to the driving hydraulic machine; The small area gradient rises to a certain flow area, and when the valve core continues to move to 2mm, the valve opening increases and the area gradient increases again. After the flow hole is slotted, the area gradient of the valve port has a buffer. First, a small area gradient is obtained at the slot and then gradually increases. Therefore, the output flow is also a gradual process, thereby improving the switching characteristics of the distributor. .

The above is an analysis of the influence of the flow hole and the notch on the distributor from the perspective of the displacement of the spool. After the improvement, the speed of the spool decreases during the opening process of the distributor, and the time from the opening to the maximum opening of the distributor is prolonged, that is, the distributor reaches The rise time of the stable working flow, and the flow rise curve before and after improvement are shown in Figure 13.

In Figure 13, _Q0 represents the stable working flow of the distributor, t1 represents the time required for the original distributor to fully open, and _t2 represents the time from the opening of the improved distributor to outputting a stable working flow. After the orifice is slotted and buffered, the rise time for the distributor to reach a stable working flow can be prolonged, so that the output flow of the distributor changes slowly, thereby suppressing the hydraulic shock caused by the sudden change of the flow.

3. Modeling and simulation based on AMESim

In order to verify the influence of the opening time of the electromagnetic hydraulic distributor on the opening and closing process of the sea valve, the components in the mechanical library (Mechanical), the standard hydraulic library (Hydraulic, HYD) and the signal library (Signal, Control) were used in AMEsim to jointly build the following The simulation model shown in Figure 14.

The rated current of the solenoid valve distributor is 40mA, and the maximum value of the electrical signal is 40, which means that the distributor is fully open when the electrical signal is at the maximum value. In order to facilitate the adjustment of the dynamic performance of the system, the corresponding characteristics of the system are changed by adjusting the characteristics of the input signal. In the parameter mode, the parameter research is carried out on the input change time (the opening time of the distributor), and the response time of the distributor is set to 0.1s and 0.2s respectively. , 0.3s, 0.4s, 0.5s, 0.6s, the opening of the dispenser after running the model in batch processing is shown in Figure 15.

According to the simulation model Figure 14, the parameters of the distributor are set, and according to the formula (3.4), the density ρ of the HS15/H fire-resistant hydraulic oil is found to be 1115kg/m ³ , and the flow coefficient C _d of the slide valve port is taken as is 0.61, the equivalent throttling area of the valve port is 22.09mm ² calculated from the third section, and the working flow rate of the distributor is 20L/min, then the pressure drop at the valve port is 0.26MPa or 2.6bar. When the electrical signal is positive, the distributor is in the left station, that is, the P port is connected to the B port, and the A port is connected to the T port. The oil cylinder drags the load to move to the left, and the flow area between the P port and the B port is obtained as shown in the figure 16.

When the valve port is fully open, the flow area between port P and port B is 22.04mm ² , and the simulated value is close to the calculated value of 22.09mm ² . The speed-time curve of the cylinder is shown in Figure 17.

When the ramp change time is 0.1s, the peak velocity of the oil cylinder during the opening process of the distributor is 0.06m/s, which is twice the speed value under the smooth movement of the oil cylinder, and the speed oscillates four times during the process; the ramp change time is At 0.2s, the peak velocity of the cylinder is 0.05m/s, the velocity oscillates twice, the amplitude and number of oscillations both decrease, and the velocity fluctuations are similar after the time change is 0.3s. If the ramp change time is long, the speed change is small when the cylinder starts, and the speed drops slowly when the cylinder stops, indicating that extending the response time of the distributor can effectively eliminate the amplitude and number of speed oscillations in the cylinder startup process, and after 0.1s-0.2s Better results can be obtained, and the effect of extending the response time on the cylinder speed becomes smaller.

The acceleration-time curve of the oil cylinder is shown in Figure 18. During the opening process of the distributor, the starting acceleration of the oil cylinder has multiple oscillations. When the slope signal change time is less than or equal to 0.3s, the acceleration peak of the oil cylinder appears. When the response time is 0.1s, the acceleration peak value is 5m/s ² ; when the response time is 0.2s, the acceleration peak value is 2.7m/s ² ; When the time is 0.3s, the peak value of the acceleration is 1.8m/s ² , and when the ramp signal change time is longer than 0.3s, the acceleration of the cylinder changes relatively smoothly. During the deceleration process of the cylinder, the acceleration does not oscillate, but there is a little fluctuation, and the amplitude of the acceleration is similar, indicating that the response time of the distributor has little influence on the acceleration when the cylinder stops.

The pressure curve of the P port of the distributor is shown in Figure 19. When the distributor is opened, the P port pressure transitions rapidly to the steady state pressure. The faster the response time is, the faster the P port pressure changes. When the response time is 0.1s, the P port pressure reaches a stable operation. When the pressure fluctuates slightly, when the response time is greater than 0.1s, the pressure transition is smooth.

The pressure change curve of the T port of the distributor is shown in Figure 20. During the opening process of the distributor, the pressure amplitude of the T port pressure is several times of the steady state value in the process of reaching the steady state pressure. When the response time is 0.1s, P The mouth pressure oscillates multiple times with a large amplitude. After prolonging the response time, both the amplitude and the number of oscillations decrease significantly. After the response time is longer than 0.3s, the pressure oscillations are obviously weakened and the amplitude is also small. When the response time is 0.1s during the cylinder stop process, the pressure at the T port fluctuates and is more obvious, and the pressure transition is smoother after the time is greater than 0.2s.

For the pressure change at port A during the opening process of the distributor, the pressure at port A oscillates multiple times during the opening process of the distributor, and transitions to a steady-state pressure during the pressure oscillation. When the response time is long, the oscillation amplitude is small and the number of oscillations is small, and the change time is At 0.1s, the oscillation amplitude is nearly ten times the steady-state value. When the distributor is closed, the pressure at port A overshoots. When the response time is less than 0.3s, the pressure peaks and the amplitude is also large. When the response time is greater than 0.3s, the pressure changes gradually.

When the distributor is opened, the pressure at port B transitions rapidly to the steady-state pressure. The faster the distributor responds, the more severe the pressure oscillation at port B is, and the longer the oscillation time is. When the response time is 0.1s, the pressure amplitude is large and the number of oscillations is large. The vibration stops about 0.5s after the device is fully turned on. When the response time is 0.2s, the amplitude of the oscillation is weakened by about half compared with before. After the response time is longer than 0.3s, the oscillation of the pressure at port B is obviously weakened. During the closing process of the distributor, the pressure change of port B is hardly affected by the response time, and the change in the whole process is relatively smooth.

According to the analysis of the above simulation results, it can be obtained that:

(1) Under the control of the distributor, the acceleration fluctuates violently at the center of the zero position during the start-up process of the sea valve drive cylinder. When the response time of the distributor is less than or equal to 0.3s, the acceleration amplitude of the cylinder is too large, causing the cylinder speed to oscillate, and the response time The shorter the time, the more severe the vibration of the acceleration and the more violent the fluctuation of the speed; when the response time is greater than 0.3s, it can be found that the amplitude of the acceleration vibration drops significantly, and the speed transition gradually becomes gentle; when the cylinder stops, the acceleration does not oscillate, the transition is smooth, and the speed drops gentle.

(2) During the opening process of the distributor, each oil port of the valve port produces strong pressure fluctuations. The pressure fluctuations when opening are obviously stronger than those when closing. The shorter the response time of the distributor, the higher the pressure fluctuation amplitude of the valve port. The larger the pressure, the longer the pressure oscillation time, that is, the longer it takes for the distributor to reach a stable working pressure.

Through theoretical calculation and simulation experiment analysis, it can be seen that slotting the flow hole of the main valve sleeve of the electromagnetic hydraulic distributor can prolong the response time of the distributor, improve the output flow characteristics and reduce the transient noise of the opening and closing of the sea valve. The simulation results show that when the response time of the distributor is controlled at about 0.3s, the pressure fluctuation of each valve port can be effectively weakened, which will help the distributor to stabilize the output flow sooner.

4. Conclusion

The present invention analyzes the structure of the electromagnetic hydraulic distributor of the sea valve hydraulic drive system, expounds the working principle and noise mechanism of the distributor, and proposes to extend the response time of the distributor to achieve the purpose of controlling the opening and closing noise of the sea valve. Do the job as follows:

(1) Analyze the working principle of the distributor structure, and clarify the reason why the distributor controls the opening and closing of the sea valve. In order to weaken the pressure fluctuation of the distributor during the opening process, a proposal is made for the valve sleeve of the main valve of the distributor. The method of slotting the flow hole to prolong the response time of the distributor.

(2) Carry out theoretical calculation on the flow area of the valve port of the original distributor, and calculate the equivalent throttling area of the valve port of the original distributor to be 22.09mm ² . In order to avoid the pressure shock caused by closing, a triangular groove is chosen to be opened at a flow hole of the main valve sleeve to determine the size of the triangular groove.

(3) Based on AMESim, the simulation model of the valve-controlled sea valve system was established, and the influence of the response time of the distributor on the speed and acceleration of the driving cylinder and the pressure of each valve port of the distributor was studied. The results showed that the response time of the distributor was appropriately extended to 0.3s Left and right can get better control effect.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (2)

1. The triangular groove overflow hole type hydraulic distributor comprises an electromagnet, a pilot valve and a main valve; the main valve comprises a valve core and a valve sleeve arranged on the valve core, wherein a plurality of groups of overflow holes are arranged on the valve sleeve, and each group of overflow holes is arranged on the same circumference of the valve sleeve; the two groups of overflow holes are respectively positioned at the opening starting position and the closing starting position of the valve port of the main valve.

2. A triangular groove flow-through hole type hydraulic distributor according to claim 1, wherein the height of the buffer notch is 2mm and the length of the bottom edge is 1mm.

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