Oil replenishment pump control system and control method for pitch ship loaders

Abstract

This invention relates to the field of hydraulic system replenishing pump control technology, specifically a replenishing pump control system and method for a pitching ship loader. The system includes: a variable displacement piston pump whose suction port is connected to an oil tank, and whose outlet port is connected to the replenishing port of the main pump assembly of the pitching ship loader; a control valve assembly mounted on the variable displacement mechanism of the variable displacement piston pump, energized or de-energized by a control signal for the pitching action of the pitching ship loader; when the pitching ship loader performs a pitching action, the control signal energizes the control valve assembly, and the pressurized oil at the outlet of the variable displacement piston pump is guided through the control valve assembly to the springless side chamber of its variable displacement piston, pushing the swashplate of the variable displacement piston pump to deflect to the maximum displacement angle; when the pitching ship loader is in standby mode, the control valve assembly is de-energized, and the swashplate of the variable displacement piston pump returns to the zero displacement angle under the action of a return spring. This invention solves the problems of continuous overflow in the replenishing pump circuit, oil overheating and aging, and energy waste in the prior art.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system replenishment pump control technology, and in particular to a replenishment pump control system and control method for a pitching ship loader. Background Technology

[0002] Hydraulic tilt-and-reach ship loaders, a key piece of machinery in bulk cargo terminals for boom tilting and reaching operations, are crucial for port loading and unloading. The stability and efficiency of their hydraulic systems directly impact equipment availability and operational efficiency. With increasing port automation and stringent energy conservation requirements, the design and economic efficiency of the hydraulic systems for this type of equipment have received widespread attention.

[0003] Currently, most common hydraulic tilting ship loaders employ a semi-closed hydraulic system, where an electric motor and hydraulic pumps of varying displacements work together to drive the cylinders. Taking a typical model as an example, the system is equipped with two large-displacement closed-loop piston pumps as the main pumps, and two additional gear pumps connected in series specifically for replenishing oil to the main pumps, cooling them, and filtering the circuit. The replenishing pumps operate continuously during equipment operation, and their output pressure is maintained at a constant back pressure by an overflow valve installed in the circuit. Because the main pump group uses servo control, the system does not allow frequent start-stop of the replenishing pumps. Furthermore, to ensure timely response of the boom movements, the replenishing pumps are typically kept running continuously.

[0004] However, the above-mentioned oil replenishment circuit design has obvious flaws: during the pitching intervals or standby of the ship loader, the oil replenishment pump continues to operate at its rated speed, and the output hydraulic oil continuously overflows under high pressure through the relief valve. This not only causes a sharp increase in oil temperature and accelerates the aging of seals, but also results in a large amount of wasted power. After long-term operation, the hydraulic system frequently experiences overheating failures, and the equipment failure rate remains high, increasing maintenance costs and severely restricting the improvement of production efficiency and energy utilization. Summary of the Invention

[0005] This invention provides a control system and method for a replenishment pump for a pitching ship loader, in order to solve the problems of continuous overflow in the replenishment pump circuit, oil heating and aging, and energy waste in the prior art.

[0006] In a first aspect, embodiments of the present invention provide a replenishment pump control system for a pitching ship loader, comprising: a variable displacement piston pump and a control valve assembly; The suction port of the variable piston pump is connected to the oil tank, and its outlet is connected to the replenishment port of the main pump group of the pitching ship loader through the replenishment oil line, so as to supply replenishment oil flow to the main pump group. The control valve group is installed on the variable mechanism of the variable piston pump and is energized or de-energized by the control signal of the pitching action of the pitching ship loader. When the pitching ship loader performs a pitching action, the control signal controls the control valve group to be energized, and the pressure oil at the oil outlet of the variable piston pump is guided through the control valve group to the springless side chamber of its variable piston, pushing the swashplate of the variable piston pump to deflect to the maximum displacement angle, so that the variable piston pump outputs the maximum replenishment flow rate. When the pitch ship loader is in pitch standby mode, the control signal disappears, the control valve group is de-energized, the pressure oil in the springless side chamber of the variable piston is unloaded to the oil tank through the oil drain port of the control valve group, and the swashplate of the variable piston pump returns to the zero displacement angle under the action of the return spring.

[0007] In one possible implementation, the variable displacement piston pump is an axial variable displacement piston pump, and its variable control method is load pressure control.

[0008] In one possible implementation, the control valve assembly is a two-position two-way solenoid valve.

[0009] In one possible implementation, the control valve assembly further includes: a throttling orifice; The throttling orifice is located in the pilot pressure oil line between the outlet of the variable displacement piston pump and the two-position two-way solenoid valve, so as to generate a pressure difference upstream and downstream of the throttling orifice, maintain a constant pressure drop, and keep the flow rate of the variable displacement piston pump constant. When the pressure difference increases, the swashplate of the variable displacement piston pump is at the maximum displacement angle, and when the pressure difference decreases, the swashplate of the variable displacement piston pump is at the minimum displacement angle, until the pressure difference returns to the set value.

[0010] In one possible implementation, the diameter of the throttling orifice ranges from 0.6 mm to 0.9 mm; The pressure difference ranges from 14 bar to 25 bar.

[0011] In one possible implementation, the maximum displacement of the variable displacement piston pump is determined based on the replenishment flow requirement of the original replenishment system, wherein the original replenishment system includes a double gear pump, and the double gear pump operates continuously during the standby and operation of the pitching ship loader. The output flow rate of the variable displacement piston pump at the maximum displacement angle is not less than the output flow rate of the double gear pump.

[0012] Secondly, embodiments of the present invention provide a method for controlling a makeup oil pump for a pitch ship loader, employing the makeup oil pump control system for a pitch ship loader described in the first aspect or any possible implementation thereof, comprising: Monitor the pitch movement of the pitch loader in real time and obtain the corresponding control signals; When the control signal for the pitching ship loader to perform a pitching action is received, the control valve group is energized, and the pressure oil at the outlet of the variable piston pump is guided through the control valve group to the springless side chamber of the variable piston, pushing the swashplate of the variable piston pump to deflect to the maximum displacement angle, so that the variable piston pump replenishes oil to the main pump group at the maximum replenishment flow rate. When the pitching action of the pitching ship loader stops, the control valve group is de-energized, the pressure oil in the springless side chamber of the variable piston is unloaded to the oil tank through the drain port of the control valve group, and the swashplate of the variable piston pump returns to the zero displacement angle under the action of the return spring.

[0013] In one possible implementation, the control valve assembly is a two-position two-way solenoid valve.

[0014] In one possible implementation, the variable piston pump is an axial variable piston pump, and its variable control method is load pressure control; The replenishment flow rate supplied by the variable displacement piston pump to the main pump assembly at its maximum replenishment flow rate is determined by a throttle orifice on its variable displacement mechanism. The throttle orifice is located in the pilot pressure oil line between the outlet of the variable displacement piston pump and the two-position two-way solenoid valve, so as to generate a pressure difference upstream and downstream of the throttle orifice, maintain a constant pressure drop, and keep the flow rate of the variable displacement piston pump constant. When the pressure difference increases, the swashplate of the variable displacement piston pump is at its maximum displacement angle; when the pressure difference decreases, the swashplate of the variable displacement piston pump is at its minimum displacement angle, until the pressure difference returns to the set value.

[0015] In one possible implementation, the maximum displacement of the variable displacement piston pump is determined based on the replenishment flow requirement of the original replenishment system, which includes a double gear pump and operates continuously during the standby and operation of the pitching ship loader. The output flow rate of the variable displacement piston pump at the maximum displacement angle is not less than the output flow rate of the double gear pump.

[0016] This invention provides a control system and method for a replenishment pump for a pitch ship loader. In the original system, the double gear pump runs continuously during the standby and operation of the pitch ship loader. There is always a back pressure of 30 bar in the replenishment circuit, which causes the oil output by the replenishment pump to continuously overflow under high pressure through the overflow valve, and the oil temperature rises sharply. In this embodiment of the invention, when the pitch ship loader is in pitch standby mode, the control signal disappears, the control valve group is de-energized, and the pressure oil in the springless side chamber of the variable piston is unloaded to the oil tank through the drain port of the control valve group. The swashplate of the variable piston pump returns to the zero displacement angle under the action of the return spring, and the output flow is zero. The replenishment oil circuit no longer generates high-pressure overflow, thus eliminating the phenomenon of oil overflow and heat generation from the root. Since the high-pressure overflow and oil circulation heat generation in the standby state are eliminated, the oxidation and aging rate of the hydraulic oil is greatly slowed down. At the same time, the hydraulic components are prevented from being worn faster due to long-term high-temperature operation, reducing maintenance costs and replacement frequency. When in standby mode, the displacement of the variable piston pump is zero, the replenishment pump no longer outputs flow, and the standby power is reduced to near zero, resulting in significant energy-saving effect. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the oil replenishment pump control system for a pitching ship loader provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a make-up oil pump control system for a pitching ship loader provided in another embodiment of the present invention; Figure 3 This is a flowchart illustrating the implementation of the oil replenishment pump control method for a pitching ship loader provided in an embodiment of the present invention. Detailed Implementation

[0019] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] In existing technologies, hydraulic tilting ship loaders mostly employ a semi-closed hydraulic system, primarily controlled by a 90KW motor, two 130cc closed-loop piston pumps, a 90cc gear pump, a 63cc gear pump, and a 2.6cc gear pump. When the boom of the tilting ship loader rises, the hydraulic cylinder rod extends, and the 2.6cc gear pump outputs 100bar-160bar pressure to control the valve block, opening the circuit. The two 130cc closed-loop piston pumps then draw oil from the rod chamber and supply it to the rodless chamber. Due to the volume difference between the rod and rodless chambers, a 90KW motor is required. The 0cc and 63cc gear pumps draw oil from the tank and supply it to the rodless chamber to compensate for the volume difference. That is, the main function of the two tandem oil replenishment pumps, the 90cc and 63cc gear pumps, is to replenish the system with oil. When the boom is lowering, the hydraulic cylinder rod retracts, the 2.6cc gear pump outputs pressure to control the valve block, opening the circuit. One main pump (i.e., the 130cc closed plunger pump) draws oil from the rodless chamber and supplies it to the rod chamber. Due to the volume difference, the other main pump is responsible for transporting the excess oil from the rodless chamber back to the tank. During this process, the two tandem oil replenishment pumps do not participate in the motion control.

[0021] The replenishing pump needs to maintain a set operating pressure to replenish oil to the system, and a 30-bar overflow valve is installed in the circuit to provide back pressure. Because the master station system is servo-controlled, the system cannot allow frequent start-stop of the main pump and the replenishing pump. At the same time, in order to reduce the response delay of the boom movement, the system is designed to operate without stopping. However, continuous operation results in a constant 30-bar pressure in the replenishing circuit, which causes continuous overflow in the replenishing pump circuit, oil heating and aging, and energy waste.

[0022] To solve the above problem, see Figure 1 This illustration shows a schematic diagram of a make-up pump control system for a pitch ship loader according to an embodiment of the present invention. The make-up pump control system for a pitch ship loader includes: a variable displacement piston pump 1 and a control valve group 2. Specifically, the variable displacement piston pump 1 replaces the 90cc gear pump and 63cc gear pump connected in series in the prior art, as detailed below: The suction port 11 of the variable piston pump 1 is connected to the oil tank 3, and its outlet port 12 is connected to the oil replenishment port of the main pump group 4 of the pitching ship loader through the oil replenishment line, so as to supply the oil replenishment flow to the main pump group 4. Control valve group 2 is installed on the variable mechanism of variable piston pump 1 and is energized or de-energized by the control signal of the pitching action of the pitching ship loader. When the pitching ship loader performs a pitching action, the control signal controls the control valve group 2 to be energized. The pressure oil at the oil outlet 12 of the variable piston pump 1 is guided through the control valve group 2 to the springless side chamber 13 of its variable piston, pushing the swashplate 14 of the variable piston pump 1 to deflect to the maximum displacement angle, so that the variable piston pump 1 outputs the maximum replenishment flow. When the pitch loader is in pitch standby mode, the control signal disappears, the control valve group 2 is de-energized, the pressure oil in the springless side chamber 13 of the variable piston is unloaded to the oil tank 3 through the oil drain port of the control valve group 2, and the swashplate 14 of the variable piston pump 1 returns to the zero displacement angle under the action of the return spring.

[0023] When the pitch ship loader is in pitch standby mode, the control valve group 2 loses power, and the swashplate 14 of the variable piston pump 1 returns to the zero displacement angle under the action of the return spring, reducing the displacement to approximately zero. This achieves near-zero flow output and low-pressure standby unloading, thus fundamentally solving the problem of hydraulic system oil overflow and heat generation and large standby energy consumption when the pitch ship loader is in standby mode.

[0024] Optionally, the main pump set consists of two 130cc closed-loop piston pumps.

[0025] In one embodiment, the variable displacement piston pump 1 can be an axial variable displacement piston pump, and its variable control method is load pressure control.

[0026] The suction port 11 of the variable displacement piston pump 1 is connected to the oil tank through the original system's main suction pipe, and the discharge port 12 is connected to the outlet filter of the tandem gear pump in the original system. It is then connected to the makeup oil port of the main pump unit of the pitching ship loader through a makeup oil circuit. The drain port of the variable displacement piston pump is connected to the T-port of the pilot valve and returns to the oil tank 3. Here, the tandem gear pump is a 90cc gear pump and a 63cc gear pump connected in series, as is common in the prior art.

[0027] In one embodiment, the control valve assembly 2 is a two-position two-way solenoid valve 21. See also Figure 2 As shown, the two-position two-way solenoid valve 21 is installed on the variable mechanism of the variable piston pump 1 and is energized or de-energized by the control signal of the pitching action of the pitching ship loader.

[0028] In one embodiment, the control valve assembly 2 further includes: a throttle orifice 22; The throttle orifice 22 is located in the pilot pressure oil line between the oil outlet 12 of the variable piston pump 1 and the two-position two-way solenoid valve 21. It is used to limit the flow rate of the pressure oil guided to the variable piston and generate a pressure difference upstream and downstream of the throttle orifice 22 to maintain a constant pressure drop and keep the flow rate of the variable piston pump 1 constant. When the pressure difference increases, the swash plate 14 of the variable piston pump 1 is at the maximum displacement angle, and when the pressure difference decreases, the swash plate 14 of the variable piston pump 1 is at the minimum displacement angle until the pressure difference returns to the set value.

[0029] Optionally, the pressure difference generated by the orifice 22 can be measured by an external pressure gauge, with a pressure difference range of 14 bar to 25 bar.

[0030] Optionally, the pressure difference generated by the throttling orifice 22 can also be calculated based on its diameter, for example, according to The pressure difference is obtained, where, This indicates the pressure difference generated upstream and downstream of the throttling orifice. Indicates the density of hydraulic oil. Indicates the throttling flow rate. Indicates the flow coefficient. Indicates the flow area of ​​the throttling orifice. , This indicates the diameter of the throttling orifice.

[0031] In one embodiment, the diameter of the throttling orifice 22 ranges from 0.6 mm to 0.9 mm. For example, the diameter of the throttling orifice 22 can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, etc. By selecting a throttling orifice 22 of appropriate diameter, a stable differential pressure signal can be established in the pilot pressure oil circuit.

[0032] Optionally, the pressure differential ranges from 14 bar to 25 bar. In this embodiment, for example, the pressure differential can be set to pressure values ​​such as 14 bar, 15 bar, 20 bar, and 25 bar.

[0033] When the pitching ship loader performs a pitching motion, the control signal energizes the two-position two-way solenoid valve 21. The electromagnet of the two-position two-way solenoid valve 21 pushes the valve core to switch directions, opening the pilot pressure oil circuit. The pressurized oil at the outlet 12 of the variable piston pump 1 is throttled through the throttle orifice 22 and guided to the springless side chamber 13 of the variable piston through the two-position two-way solenoid valve 21. As pressurized oil is continuously injected, the oil pressure acts on the end face of the variable piston, generating a thrust sufficient to overcome the return spring force, pushing the swashplate 14 of the variable piston pump 1 to deflect to the maximum displacement angle, so that the variable piston pump 1 outputs the maximum replenishment oil flow to replenish the main pump group 4.

[0034] When the pitch cylinder extends (boom rises), both closed-loop main pumps simultaneously output pressurized oil into the rodless chamber of the cylinder. The 2-position 2-way solenoid valve 21 at the outlet 12 of variable displacement piston pump 1 is energized, controlling the swashplate 14 of variable displacement piston pump 1 to adjust to its maximum angle, outputting maximum flow to replenish the main pump. When the pitch cylinder retracts (boom lowers), the amplifier boards of both closed-loop main pumps simultaneously input control voltage. The pitch cylinder retracts, the 2-position 2-way solenoid valve 21 at the outlet 12 of variable displacement piston pump 1 is energized, controlling the swashplate 14 of variable displacement piston pump 1 to adjust to its maximum angle, outputting maximum flow to replenish the main pump.

[0035] When the pitch loader is in pitch standby mode, the control signal disappears, and the 2-position 2-way solenoid valve 21 is de-energized. The valve core of the 2-position 2-way solenoid valve 21 is reset under the action of the spring, cutting off the pilot oil supply. The pressure oil in the springless side chamber 13 of the variable piston is unloaded to the oil tank through the drain port (T port) of the 2-position 2-way solenoid valve 21. After the variable piston loses the oil pressure thrust, the swashplate 14 of the variable piston pump 1 returns to the zero displacement angle (i.e., zero displacement) under the action of the return spring, and the output flow is approximately zero. The oil supply circuit is in a low-pressure unloading state, which fundamentally solves the problem of hydraulic system oil overflow and heat generation and large amount of standby energy consumption in the standby state of the ship loader.

[0036] In one embodiment, the maximum displacement of the variable displacement piston pump 1 is determined according to the replenishment flow requirement of the original replenishment system, wherein the original replenishment system includes a double gear pump, and the double gear pump operates continuously during the standby and operation of the pitch ship loader. The output flow rate of variable displacement piston pump 1 at the maximum displacement angle is not less than the output flow rate of double gear pump.

[0037] Optionally, the original oil replenishment system includes a double gear pump consisting of a 90cc gear pump and a 63cc gear pump connected in series, and an overflow valve installed on the oil replenishment circuit to provide a back pressure of 30 bar. The double gear pump operates continuously during the standby and operation of the pitch loader, and its main functions are system oil replenishment, radiator oil supply, and system oil filtration.

[0038] At the maximum displacement of variable displacement piston pump 1, firstly, based on the original replenishment system's replenishment flow rate requirements, calculate the required replenishment flow rate of the original replenishment system. The calculation formula is: ; in, This indicates the required replenishment flow rate of the original replenishment system, in L / min. This indicates the total geometric displacement of the double gear pump, expressed in cc / rev. This indicates the drive speed of the double gear pump, in rpm. This indicates the volumetric efficiency of the double gear pump.

[0039] Therefore, the maximum displacement of the selected variable displacement piston pump 1 should satisfy: That is, the output flow rate of the selected variable displacement piston pump 1 at the maximum displacement angle should not be less than the output flow rate of the original double gear pump, so as to ensure that the oil replenishment needs of the main pump group can be met during the pitching action.

[0040] in, This indicates the output flow rate of the variable displacement piston pump at its maximum displacement angle, expressed in L / min. This represents the total geometric displacement of the variable displacement piston pump, expressed in cc / rev. This indicates the drive speed of the variable displacement piston pump, in rpm. This indicates the volumetric efficiency of a variable displacement piston pump.

[0041] In this embodiment, taking a hydraulic pitching ship loader in Qinhuangdao as an example, the original double gear pump's total geometric displacement is... cc / rev, drive speed rpm, volumetric efficiency The required replenishment flow rate of the system can be calculated as follows: L / min 。

[0042] Total geometric displacement of the replacement variable displacement piston pump cc / rev, drive speed rpm, volumetric efficiency The output flow rate of the variable displacement piston pump at the maximum displacement angle can be calculated to be 204.56 L / min. 。

[0043] Calculations show that the output flow rate of variable displacement piston pump 1 at its maximum displacement angle is slightly greater than that of the original double gear pump, which is sufficient to meet the oil replenishment requirements. Through the above selection method, while ensuring that the flow and pressure of the hydraulic system remain unchanged under all operating conditions of the ship loader, an equivalent replacement of the original double gear pump with a variable displacement piston pump is achieved.

[0044] Optionally, the power saved by the make-up oil pump control system for the pitch ship loader during the ship loader's pitch standby state can be calculated using a formula, i.e., based on... Calculate the power saved when the ship loader is in pitch standby mode, where, Indicates the power saved. This indicates the back pressure (bar) set by the overflow valve in the original system's oil replenishment circuit. This indicates the overflow flow rate (L / min) of the oil replenishment pump in the original system's standby state. For overall efficiency.

[0045] In an embodiment of a hydraulic pitching ship loader application in Qinhuangdao, the standby power of the original system under a back pressure of 30 bar was: ; Based on the overflow flow rate of the fuel pump in standby mode, the current standby power can be calculated as follows: . This represents the minimum discharge flow rate corresponding to the zero-position angle of the variable displacement piston pump. It should be noted that the minimum discharge flow rate of the variable displacement piston pump is close to zero, so we use 0 to represent it. Therefore, compared with the original system, this solution can save energy and generate no heat in standby mode.

[0046] Figure 2In the diagram, the connection point between the main oil circuit and the 2.6cc gear pump is marked as 15.

[0047] This invention provides a make-up oil pump control system for a pitch ship loader, comprising: a variable displacement piston pump and a control valve group; the suction port of the variable displacement piston pump is connected to an oil tank, and its outlet is connected to the make-up oil port of the main pump group of the pitch ship loader through a make-up oil circuit, for supplying make-up oil flow to the main pump group; the control valve group is installed on the variable displacement mechanism of the variable displacement piston pump and is energized or de-energized by a control signal for the pitch movement of the pitch ship loader; when the pitch ship loader performs a pitch movement, the control signal energizes the control valve group, and the pressure oil at the outlet of the variable displacement piston pump is guided through the control valve group to the springless side chamber of its variable displacement piston, pushing the swashplate of the variable displacement piston pump to deflect to the maximum displacement angle, so that the variable displacement piston pump outputs the maximum make-up oil flow; when the pitch ship loader is in a pitch standby state, the control signal disappears, the control valve group is de-energized, the pressure oil in the springless side chamber of the variable displacement piston is unloaded to the oil tank through the drain port of the control valve group, and the swashplate of the variable displacement piston pump returns to the zero displacement angle under the action of the return spring.

[0048] In the original system, the double gear pump operated continuously during both standby and operation of the pitch loader, resulting in a constant back pressure of 30 bar in the oil replenishment circuit. This caused the oil output from the replenishment pump to continuously overflow under high pressure through the relief valve, leading to a sharp increase in oil temperature. In this embodiment of the invention, during standby, the swashplate of the variable displacement piston pump returns to its zero displacement angle, resulting in zero output flow. High-pressure overflow in the oil replenishment circuit is no longer generated, eliminating the phenomenon of oil overflow and heat generation at its source. Because the high-pressure overflow and oil circulation heat generation during standby are eliminated, the oxidation and aging rate of the hydraulic oil is significantly slowed down. Simultaneously, accelerated wear of hydraulic components due to prolonged high-temperature operation is avoided, reducing maintenance costs and replacement frequency. With zero displacement of the variable displacement piston pump during standby and no output flow from the replenishment pump, standby power is reduced to near zero, resulting in significant energy savings.

[0049] In this embodiment of the invention, the energization and de-energization of the two-position two-way solenoid valve are directly controlled by the pitch motion control signal, eliminating the need for additional sensors or complex control algorithms. The control logic is simple and reliable. When the motion signal is present, the valve immediately switches to the maximum displacement position; when the signal disappears, it immediately switches to the zero position, ensuring timely response and not affecting the rapid response requirements of the pitch motion. The output flow rate of the variable displacement piston pump at its maximum displacement angle is consistent with the output flow rate of the original double gear pump, ensuring that the oil replenishment capability is not reduced during pitch motion and that the original operating performance is not altered.

[0050] This invention provides a method for controlling a makeup oil pump for a pitch ship loader. The method utilizes the makeup oil pump control system for a pitch ship loader provided in any of the above embodiments, such as... Figure 3 As shown, the oil replenishment pump control method for a pitching ship loader includes the following steps: Step 301: Monitor the pitching motion of the pitching ship loader in real time and obtain the corresponding control signals.

[0051] During the operation of the pitch ship loader, the oil replenishment pump control system used for the pitch ship loader monitors the operational status of the pitch mechanism in real time. The pitch movement of the pitch ship loader is commanded by the operator through a console or remote control. After the command is processed by the central control system of the pitch ship loader, a corresponding pitch movement control signal is generated.

[0052] Specifically, when the operator performs boom pitching operations, the make-up oil pump control system for pitching the ship loader synchronously sends control signals to the main pump group and the make-up oil pump control system of the pitching mechanism. This control signal serves two purposes: firstly, it drives the main pump group to perform pitching actions (boom raising or lowering), and secondly, it serves as the energizing trigger signal for the two-position two-way solenoid valve 21 in the make-up oil pump control system.

[0053] In this embodiment, the control signal is an electrical signal, output by the central control system of the ship loader. The presence or absence of this control signal directly reflects whether the pitch ship loader is in a pitching state—the presence of a control signal indicates that the pitch ship loader is performing a pitching action, while the absence of a control signal indicates that the pitch ship loader is in a pitching standby state.

[0054] The replenishment pump control system for the pitch loader accurately determines the current operating status of the pitch loader by monitoring the status of this control signal in real time: when the control signal is detected, the loader is determined to perform a pitching action; when the control signal disappears, the loader is determined to enter a pitch standby state. This monitoring process is continuous, ensuring that the system can respond promptly to the start and stop of the pitching action, thereby precisely controlling the working status of the replenishment pump.

[0055] Step 302: When the control signal for the pitching ship loader to perform the pitching action is obtained, the control valve group is energized, and the pressure oil at the outlet of the variable piston pump is guided through the control valve group to the springless side chamber of the variable piston, pushing the swashplate of the variable piston pump to deflect to the maximum displacement angle, so that the variable piston pump replenishes oil to the main pump group at the maximum replenishment flow rate.

[0056] Step 303: When the pitching action of the pitching ship loader stops, the control valve group is de-energized, and the pressure oil in the springless side chamber of the variable piston is unloaded to the oil tank through the drain port of the control valve group. The swashplate of the variable piston pump returns to the zero displacement angle under the action of the return spring.

[0057] In this embodiment, the control valve group is a two-position two-way solenoid valve 21. When the pitch loader performs a pitching action, the control signal output by the central control system of the pitch loader energizes the two-position two-way solenoid valve 21. The electromagnet of the two-position two-way solenoid valve 21 pushes the valve core to switch direction, opening the pilot oil circuit.

[0058] In one embodiment, the variable piston pump 1 is an axial variable piston pump, and its variable control method is load pressure control; The replenishment flow rate supplied by the variable displacement piston pump 1 to the main pump group 4 at its maximum replenishment flow rate is determined by the throttle orifice 22 on its variable displacement mechanism. The throttle orifice 22 is set in the pilot pressure oil line between the outlet 12 of the variable displacement piston pump 1 and the two-position two-way solenoid valve 21, so as to generate a pressure difference upstream and downstream of the throttle orifice 22, maintain a constant pressure drop, and keep the flow rate of the variable displacement piston pump 1 constant. When the pressure difference increases, the swash plate 14 of the variable displacement piston pump 1 is at the maximum displacement angle, and when the pressure difference decreases, the swash plate 14 of the variable displacement piston pump 1 is at the minimum displacement angle, until the pressure difference returns to the set value.

[0059] That is, the pressurized oil at the outlet 12 of the variable piston pump 1 is throttled by the throttle orifice 22 set in the pilot pressure oil line and then guided to the springless side chamber 13 of the variable piston through the two-position two-way solenoid valve 21. As the pressurized oil is continuously filled in, the oil pressure acts on the end face of the variable piston, generating a thrust sufficient to overcome the spring force of the return spring, pushing the swashplate 14 of the variable piston pump 1 to deflect to the maximum displacement angle, so that the variable piston pump 1 replenishes oil to the main pump group at the maximum replenishment flow rate.

[0060] Specifically, when the pitch cylinder extends (boom rises), the main pump unit 4 simultaneously outputs pressurized oil into the rodless chamber of the cylinder. The 2-position 2-way solenoid valve 21 at the outlet 12 of the variable displacement piston pump 1 is energized, controlling the swashplate of the variable displacement piston pump 1 to adjust to its maximum angle, outputting maximum flow to replenish the main pump. When the pitch cylinder retracts (boom lowers), the amplifier board of the main pump unit 4 simultaneously inputs control voltage, causing the pitch cylinder to retract. The 2-position 2-way solenoid valve 21 at the outlet 12 of the variable displacement piston pump 1 is energized, controlling the swashplate 14 of the variable displacement piston pump 1 to adjust to its maximum angle, outputting maximum flow to replenish the main pump.

[0061] The orifice 22 is used to limit the flow rate of pressurized oil guided to the variable piston and to create a pressure difference across the orifice 22. Maintaining a constant pressure drop across the orifice 22 ensures a constant flow rate for the variable piston pump 1. When the pressure difference increases, the swashplate 14 of the variable piston pump 1 is at its maximum displacement angle; when the pressure difference decreases, the swashplate 14 is at its minimum displacement angle until the pressure difference across the orifice 22 returns to the set value. In other words, the displacement of the variable piston pump 1 automatically adjusts with changes in pressure difference, ultimately maintaining a constant output flow rate. In this embodiment, the pressure difference is set within a range of 14 bar to 25 bar; for example, the pressure difference can be set to pressure values ​​such as 14 bar, 15 bar, 20 bar, and 25 bar.

[0062] In one embodiment, the maximum displacement of the variable displacement piston pump 1 is determined according to the replenishment flow requirement of the original replenishment system, which includes a double gear pump, and the double gear pump operates continuously during the standby and operation of the pitch ship loader. The output flow rate of variable displacement piston pump 1 at the maximum displacement angle is not less than the output flow rate of double gear pump.

[0063] The original oil replenishment system consisted of a double gear pump consisting of a 90cc gear pump and a 63cc gear pump connected in series, as well as an overflow valve installed on the oil replenishment circuit to provide a back pressure of 30 bar. The double gear pump operated continuously during the standby and operation of the pitch loader, and its main functions were system oil replenishment, radiator oil supply, and system oil filtration.

[0064] The maximum displacement of variable displacement piston pump 1 is determined as follows. First, based on the replenishment flow rate requirements of the original replenishment system, the required replenishment flow rate of the original replenishment system is calculated using the following formula: .

[0065] Therefore, the maximum displacement of the selected variable displacement piston pump 1 should satisfy: That is, the output flow rate of the selected variable displacement piston pump 1 at the maximum displacement angle should not be less than the output flow rate of the original double gear pump, so as to ensure that the oil replenishment needs of the main pump group can be met during the pitching action.

[0066] In this embodiment, taking a hydraulic pitching ship loader in Qinhuangdao as an example, the original double gear pump's total geometric displacement is... cc / rev, drive speed rpm, volumetric efficiency The required replenishment flow rate of the system can be calculated as follows: L / min 。

[0067] Total geometric displacement of the replacement variable displacement piston pump cc / rev, drive speed rpm, volumetric efficiency The output flow rate of the variable displacement piston pump at the maximum displacement angle can be calculated to be 204.56 L / min. 。

[0068] Calculations show that the output flow rate of variable displacement piston pump 1 at its maximum displacement angle is slightly greater than that of the original double gear pump, which is sufficient to meet the oil replenishment requirements. Through the above selection method, while ensuring that the flow and pressure of the hydraulic system remain unchanged under all operating conditions of the ship loader, an equivalent replacement of the original double gear pump with a variable displacement piston pump is achieved.

[0069] Optionally, the power saved by the make-up oil pump control system for the pitch ship loader during the ship loader's pitch standby state can be calculated using a formula, i.e., based on... Calculate the power saved when the ship loader is in pitch standby mode, where, Indicates the power saved. This indicates the back pressure (bar) set by the overflow valve in the original system's oil replenishment circuit. This indicates the overflow flow rate (L / min) of the oil replenishment pump in the original system's standby state. For overall efficiency.

[0070] In an embodiment of a hydraulic pitching ship loader application in Qinhuangdao, the standby power of the original system under a back pressure of 30 bar was: ; Based on the overflow flow rate of the fuel pump in standby mode, the current standby power can be calculated as follows: . This represents the minimum discharge flow rate corresponding to the zero-position angle of the variable displacement piston pump. It should be noted that the minimum discharge flow rate of the variable displacement piston pump is close to zero, so we use 0 to represent it. Therefore, compared with the original system, this solution can save energy and generate no heat in standby mode.

[0071] This invention provides a method for controlling a make-up oil pump for a pitch ship loader. The make-up oil pump control system for the pitch ship loader includes: real-time monitoring of the pitch movement of the pitch ship loader and obtaining the corresponding control signal. When the control signal for the pitching ship loader to perform the pitching action is received, the control valve group is energized, and the pressure oil at the outlet of the variable piston pump is guided through the control valve group to the springless side chamber of the variable piston, pushing the swashplate of the variable piston pump to deflect to the maximum displacement angle, so that the variable piston pump replenishes oil to the main pump group at the maximum replenishment flow rate. When the pitching action of the pitching ship loader stops, the control valve group is de-energized, and the pressure oil in the springless side chamber of the variable piston is unloaded to the oil tank through the drain port of the control valve group. The swashplate of the variable piston pump returns to the zero displacement angle under the action of the return spring.

[0072] In the original system, the double gear pump operated continuously during both standby and operation of the pitch loader, resulting in a constant back pressure of 30 bar in the oil replenishment circuit. This caused the oil output from the replenishment pump to continuously overflow under high pressure through the relief valve, leading to a sharp increase in oil temperature. In this embodiment of the invention, during standby, the swashplate of the variable displacement piston pump returns to its zero displacement angle, resulting in zero output flow. High-pressure overflow in the oil replenishment circuit is no longer generated, eliminating the phenomenon of oil overflow and heat generation at its source. Because the high-pressure overflow and oil circulation heat generation during standby are eliminated, the oxidation and aging rate of the hydraulic oil is significantly slowed down. Simultaneously, accelerated wear of hydraulic components due to prolonged high-temperature operation is avoided, reducing maintenance costs and replacement frequency. With zero displacement of the variable displacement piston pump during standby and no output flow from the replenishment pump, standby power is reduced to near zero, resulting in significant energy savings.

[0073] In this embodiment of the invention, the energization and de-energization of the two-position two-way solenoid valve are directly controlled by the pitch motion control signal, eliminating the need for additional sensors or complex control algorithms. The control logic is simple and reliable. When the motion signal is present, the valve immediately switches to the maximum displacement position; when the signal disappears, it immediately switches to the zero position, ensuring timely response and not affecting the rapid response requirements of the pitch motion. The output flow rate of the variable displacement piston pump at its maximum displacement angle is consistent with the output flow rate of the original double gear pump, ensuring that the oil replenishment capability is not reduced during pitch motion and that the original operating performance is not altered.

[0074] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0075] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0076] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A replenishment pump control system for a pitching ship loader, characterized in that, include: Variable displacement piston pump and control valve assembly; The suction port of the variable piston pump is connected to the oil tank, and its outlet is connected to the replenishment port of the main pump group of the pitching ship loader through the replenishment oil line, so as to supply replenishment oil flow to the main pump group. The control valve group is installed on the variable mechanism of the variable piston pump and is energized or de-energized by the control signal of the pitching action of the pitching ship loader. When the pitching ship loader performs a pitching action, the control signal controls the control valve group to be energized, and the pressure oil at the oil outlet of the variable piston pump is guided through the control valve group to the springless side chamber of its variable piston, pushing the swashplate of the variable piston pump to deflect to the maximum displacement angle, so that the variable piston pump outputs the maximum replenishment flow rate. When the pitch ship loader is in pitch standby mode, the control signal disappears, the control valve group is de-energized, the pressure oil in the springless side chamber of the variable piston is unloaded to the oil tank through the oil drain port of the control valve group, and the swashplate of the variable piston pump returns to the zero displacement angle under the action of the return spring.

2. The oil replenishment pump control system for a pitching ship loader according to claim 1, characterized in that, The variable displacement piston pump is an axial variable displacement piston pump, and its variable control method is load pressure control.

3. The oil replenishment pump control system for a pitching ship loader according to claim 2, characterized in that, The control valve group is a two-position two-way solenoid valve.

4. The oil replenishment pump control system for a pitching ship loader according to claim 3, characterized in that, The control valve assembly further includes: a throttling orifice; The throttling orifice is located in the pilot pressure oil line between the outlet of the variable displacement piston pump and the two-position two-way solenoid valve, so as to generate a pressure difference upstream and downstream of the throttling orifice, maintain a constant pressure drop, and keep the flow rate of the variable displacement piston pump constant. When the pressure difference increases, the swashplate of the variable displacement piston pump is at the maximum displacement angle, and when the pressure difference decreases, the swashplate of the variable displacement piston pump is at the minimum displacement angle, until the pressure difference returns to the set value.

5. The oil replenishment pump control system for a pitching ship loader according to claim 4, characterized in that, The diameter of the throttling orifice ranges from 0.6 mm to 0.9 mm; The pressure difference ranges from 14 bar to 25 bar.

6. The make-up oil pump control system for a pitching ship loader according to any one of claims 1-5, characterized in that, The maximum displacement of the variable displacement plunger pump is determined according to the replenishment flow requirement of the original replenishment system. The original replenishment system includes a double gear pump, and the double gear pump operates continuously during the standby and operation of the pitching ship loader. The output flow rate of the variable displacement piston pump at the maximum displacement angle is not less than the output flow rate of the double gear pump.

7. A method for controlling a makeup oil pump for a pitching ship loader, characterized in that, The make-up oil pump control system for a pitching ship loader according to any one of claims 1-6 comprises: Real-time monitoring of the pitch movement of the pitch loader to obtain corresponding control signals; When the control signal for the pitching ship loader to perform a pitching action is received, the control valve group is energized, and the pressure oil at the outlet of the variable piston pump is guided through the control valve group to the springless side chamber of the variable piston, pushing the swashplate of the variable piston pump to deflect to the maximum displacement angle, so that the variable piston pump replenishes oil to the main pump group at the maximum replenishment flow rate. When the pitching action of the pitching ship loader stops, the control valve group is de-energized, the pressure oil in the springless side chamber of the variable piston is unloaded to the oil tank through the drain port of the control valve group, and the swashplate of the variable piston pump returns to the zero displacement angle under the action of the return spring.

8. The method for controlling the make-up oil pump for a pitching ship loader according to claim 7, characterized in that, The control valve group is a two-position two-way solenoid valve.

9. The method for controlling the make-up oil pump for a pitching ship loader according to claim 7, characterized in that, The variable displacement piston pump is an axial variable displacement piston pump, and its variable control method is load pressure control; The replenishment flow rate supplied by the variable displacement piston pump to the main pump assembly at its maximum replenishment flow rate is determined by a throttle orifice on its variable displacement mechanism. The throttle orifice is located in the pilot pressure oil line between the outlet of the variable displacement piston pump and the two-position two-way solenoid valve, so as to generate a pressure difference upstream and downstream of the throttle orifice, maintain a constant pressure drop, and keep the flow rate of the variable displacement piston pump constant. When the pressure difference increases, the swashplate of the variable displacement piston pump is at its maximum displacement angle; when the pressure difference decreases, the swashplate of the variable displacement piston pump is at its minimum displacement angle, until the pressure difference returns to the set value.

10. The method for controlling the make-up oil pump for a pitching ship loader according to claim 7, characterized in that, The maximum displacement of the variable displacement plunger pump is determined according to the replenishment flow requirement of the original replenishment system. The original replenishment system includes a double gear pump, and the double gear pump operates continuously during the standby and operation of the pitching ship loader. The output flow rate of the variable displacement piston pump at the maximum displacement angle is not less than the output flow rate of the double gear pump.

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