Integrated methanol pump for forklift and driving system of integrated methanol pump

Abstract

The invention discloses an integrated methanol pump for a forklift and a driving system of the integrated methanol pump, and belongs to the technical field of methanol engines, the integrated methanol pump comprises a controller, a methanol pressure regulating valve, a liquid level meter, a pump body, a fixing support, a mounting flange, an oil nozzle, a first plug, a second plug, a third plug, a rubber pipe and a methanol filter, the fixing support is fixedly connected with the installation flange, the liquid level meter is installed between the fixing support and the installation flange and connected with the controller in parallel, the pump body is installed between the fixing support and the installation flange and connected with the oil nozzle through the rubber pipe, the oil nozzle is installed on the installation flange, and the methanol pressure regulating valve is installed on the rubber pipe. And the methanol filter is arranged at the liquid inlet of the pump body. Through the integrated arrangement, extra pipeline extension space is not needed, the space needed by arrangement is reduced, the adaptability of the forklift truck compact structure is improved, all the components are connected with the installation flange or the fixing support respectively and are independent of one another, and overhauling and replacing are convenient.

Description

Technical Field

[0001] This invention belongs to the field of methanol engine technology, specifically relating to an integrated methanol pump and its drive system for forklifts. Background Technology

[0002] With the urgent global demand for clean energy and low carbon emissions, methanol, as a widely available, conveniently stored and transported, and clean-burning alternative fuel, is receiving increasing attention in the application of commercial and industrial vehicles (such as forklifts). The methanol pump, which provides a stable and reliable fuel supply to methanol engines or methanol fuel cell systems, is one of their core key components.

[0003] Due to the unique physicochemical properties of methanol and the compact structure of forklifts, current methanol supply systems for methanol-fueled forklifts have the following problems: 1. Due to the compact structure of forklifts, there is limited space for the methanol supply system components, making maintenance difficult; 2. Methanol is corrosive, which can shorten the lifespan of parts that come into contact with it, requiring frequent maintenance. Summary of the Invention

[0004] To address some or all of the technical problems existing in the prior art, the present invention provides an integrated methanol pump for a forklift, comprising: a controller, a methanol pressure regulating valve, a level gauge, a pump body, a mounting bracket, a mounting flange, a fuel injector, a first plug, a second plug, a third plug, a rubber hose, and a methanol filter. The controller is connected to the vehicle's power supply via the second plug, and is connected to the methanol pump via the first plug for powering and controlling the methanol pump. The third plug is connected to the vehicle's wiring harness for powering the level gauge and transmitting the level gauge signal to the vehicle's instrument panel for level display. The mounting bracket is fixedly connected to the mounting flange. The level gauge is installed between the mounting bracket and the mounting flange and is connected in parallel with the controller. The pump body is installed between the mounting bracket and the mounting flange and is connected to the fuel injector via the rubber hose. The fuel injector is installed on the mounting flange. The methanol pressure regulating valve is installed on the rubber hose. The methanol filter is located at the inlet of the pump body.

[0005] Furthermore, a sealing ring, made of fluororubber, is provided at the connection between the mounting flange and the methanol tank.

[0006] Furthermore, the level gauge is a sliding resistor and the housing is made of stainless steel with a passivated surface.

[0007] Furthermore, the drive motor of the pump body is a brushless motor.

[0008] Furthermore, the rubber tube is made of fluororubber, and the fuel injector is made of stainless steel with a passivated surface.

[0009] In another aspect of the invention, the provided integrated methanol pump driving method for a forklift includes: Starting torque control, the starting torque is 2.2 times the rated torque; The power supply regulation and control adopts a vector control algorithm, which dynamically adjusts the frequency and voltage of the three-phase AC power based on the load characteristics of the main body. Operation monitoring involves monitoring the operating status of the pump's drive motor and adjusting the motor speed in real time.

[0010] Furthermore, the frequency adjustment range of the three-phase AC power is 50-60Hz, and the voltage adjustment range of the three-phase AC power is 0-380V.

[0011] Furthermore, the operational monitoring includes: Overcurrent protection: Real-time monitoring of the drive motor's operating current; When the drive motor's operating current is outside the allowable current fluctuation range, a shutdown operation is executed. Overvoltage protection: Real-time monitoring of the input power supply voltage. When the input power supply voltage is not within the allowable voltage fluctuation range or the fluctuation difference is greater than the maximum allowable fluctuation difference, a shutdown operation is performed. Overheat protection adjusts the motor speed based on the motor operating temperature and methanol temperature.

[0012] The integrated methanol pump and its drive system for forklifts of the present invention have the following advantages and beneficial effects: The pump body, methanol filter, methanol pressure regulating valve, and level gauge are integrated with the mounting flange via a fixed bracket, eliminating the need for additional piping extension space. This reduces the required space by 60% compared to an independent component layout, improving compatibility with the compact structure of forklifts. The integrated connection method facilitates installation and disassembly, increasing installation efficiency by 75% compared to an independent layout. Each component is connected to a mounting flange or fixed bracket independently, facilitating maintenance and replacement, and improving maintenance efficiency by 75%-83.3% compared to an independent layout.

[0013] This application adopts an integrated design, which reduces the number of pipelines and connection points by 65% ​​compared to the separate design. This significantly reduces the probability of fuel leakage and reduces pipeline pressure loss (approximately 0.5-0.8 bar), effectively solving the problems of incomplete combustion and cylinder flooding in methanol engines. At the same time, it greatly improves the safety and reliability of the fuel supply system. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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 for further understanding of the embodiments of the present invention and constitute a part of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the overall assembly of the integrated methanol pump for forklifts according to the present invention; Figure 2 This is a schematic diagram of the integrated methanol pump for forklifts according to the present invention; Figure 3 Electrical schematic diagram of the integrated methanol pump for forklifts of the present invention; Figure 4 The working principle diagram of the integrated methanol pump for forklifts of the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Controller; 2. Methanol pressure regulating valve; 3. Level gauge; 4. Pump body; 5. Methanol filter; 6. Mounting bracket; 7. Mounting flange; 8. Sealing ring; 9. Injector; 10. First plug; 11. Rubber hose; 12. Second plug; 13. Third plug. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0017] like Figure 1-4As shown, the integrated methanol pump for forklifts provided by the present invention includes: a controller 1, a methanol pressure regulating valve 2, a level gauge 3, a pump body 4, a fixed bracket 6, a mounting flange 7, a fuel injector 9, a first plug 10, a second plug 12, a third plug 13, a rubber hose 11, and a methanol filter 5. The controller 1 is connected to the vehicle power supply via the second plug 12. The controller is connected to the methanol pump via the first plug 10 for powering and controlling the methanol pump. The third plug 13 is connected to the vehicle wiring harness for powering the level gauge and transmitting the level gauge signal to the vehicle instrument panel for level display. The fixed bracket 6 is fixedly connected to the mounting flange 7. The level gauge 3 is installed between the fixed bracket 6 and the mounting flange 7 and is connected in parallel with the controller 1. The pump body 4 is installed between the fixed bracket 6 and the mounting flange 7 and is connected to the fuel injector 9 via the rubber hose 11. The fuel injector 9 is installed on the mounting flange 7. The methanol pressure regulating valve 2 is installed on the rubber hose 11. The methanol filter 5 is located at the inlet of the pump body 4.

[0018] The pump body 4, methanol filter 5, methanol pressure regulating valve 2, and level gauge 3 are integrated with the mounting flange 7 via the fixed bracket 6, eliminating the need for additional pipeline extension space. This reduces the space required by the arrangement by 60% compared to the independent arrangement of each component, improving the compatibility with the compact structure of the forklift. The integrated connection method facilitates installation and disassembly, increasing installation efficiency by 75% compared to the independent arrangement. Each component is connected to the mounting flange 7 or the fixed bracket 6 independently, facilitating maintenance and replacement. This improves maintenance efficiency by 75%-83.3% compared to the independent arrangement.

[0019] In this application, the fuel supply pressure of the methanol engine injector is 4 bar.

[0020] This application adopts an integrated design, which reduces the number of pipelines and connection points by 65% ​​compared to the separate design. This significantly reduces the probability of fuel leakage and reduces pipeline pressure loss (approximately 0.5-0.8 bar), effectively solving the problems of incomplete combustion and cylinder flooding in methanol engines. At the same time, it greatly improves the safety and reliability of the fuel supply system.

[0021] When the methanol pump is working, the DC power supply is first converted into three-phase AC power by the controller 1, which then drives the pump body 4 to work. The methanol in the methanol tank is filtered by the methanol filter 5 and then sucked into the pump body 4. After that, it is delivered to the fuel injector 9 for spraying through the rubber hose 11.

[0022] Since the pump body 4 will vibrate when it is working, the rubber hose 11 is used to transport the pump body 4 to the fuel injector 9, which can absorb the vibration of the pump body 4 during operation.

[0023] Furthermore, a sealing ring 8 is provided at the connection between the mounting flange 7 and the methanol tank, and the sealing ring 8 is made of fluororubber material.

[0024] The key connection points are sealed with a fluororubber sealing ring 8 and a stainless steel mounting flange 7, with no exposed threads. This ensures the corrosion resistance and reliability of the parts in the methanol environment and significantly improves the sealing performance of the connection between the mounting flange 7 and the methanol tank. The use of fluororubber to manufacture the sealing ring 8 ensures that the sealing ring 8 has a sufficient service life (no swelling or cracking after methanol immersion test (60℃×1000 hours)), thus avoiding frequent replacement of the sealing ring 8.

[0025] Furthermore, the level gauge 3 is a sliding resistor and its housing is made of stainless steel with a passivated surface.

[0026] By using a sliding resistor as the level gauge 3, the height of the methanol level can be accurately reflected by the change in the resistance signal, thus improving the accuracy of methanol level judgment.

[0027] Furthermore, the drive motor of the pump body 4 is a brushless motor.

[0028] By using a brushless motor, the physical swelling, electrochemical corrosion, and structural damage of the graphite carbon brush by methanol can be avoided, thereby effectively improving the service life of the drive motor of the pump body 4 and increasing the maintenance interval.

[0029] Furthermore, the rubber tube 11 is made of fluororubber, and the fuel injector 9 is made of stainless steel with a passivated surface.

[0030] By using methanol-resistant fluororubber materials and passivated stainless steel materials, the service life of parts is effectively extended, avoiding frequent maintenance.

[0031] The integrated methanol pump driving method for forklifts provided by the present invention includes: Starting torque control, the starting torque is 2.2 times the rated torque; The power supply regulation and control adopts a vector control algorithm, which dynamically adjusts the frequency and voltage of the three-phase AC power based on the load characteristics of the main body. Operation monitoring: By monitoring the operating status of the drive motor of pump body 4, the motor speed is adjusted in real time.

[0032] By setting the starting torque to 2.2 times the rated torque, it ensures that the static friction and starting resistance caused by the increased viscosity of methanol at low temperatures, the static pressure of the fuel line, or the trace impurities that may exist in the fuel can be overcome instantly, thus avoiding the impact of the methanol line caused by the pump body 4 jamming during startup.

[0033] By using a control algorithm based on the specific load characteristics of the methanol pump, the frequency and voltage amplitude of the three-phase AC power output to the motor are dynamically and smoothly adjusted, thereby achieving stepless and precise speed regulation of the motor over a wide range, thus maintaining a fast and stable response of the output torque.

[0034] When the load torque fluctuates within ±15% due to changes in engine operating conditions, the vector control algorithm quickly adjusts to maintain the stability of the set speed, thereby ensuring a constant fuel supply pressure.

[0035] Furthermore, the frequency adjustment range of the three-phase AC power is 50-60Hz, and the voltage adjustment range of the three-phase AC power is 0-380V.

[0036] Furthermore, the operational monitoring includes: Overcurrent protection: Real-time monitoring of the drive motor's operating current; When the drive motor's operating current is outside the allowable current fluctuation range, a shutdown operation is executed. Overvoltage protection: Real-time monitoring of the input power supply voltage. When the input power supply voltage is not within the allowable voltage fluctuation range or the fluctuation difference is greater than the maximum allowable fluctuation difference, a shutdown operation is performed. The fluctuation difference is the difference between the highest and lowest values ​​of the instantaneous voltage over a period of time.

[0037] Overheat protection adjusts the motor speed based on the motor operating temperature and methanol temperature. For example, when the methanol temperature is >65℃, the motor speed is automatically reduced by 10%.

[0038] By monitoring the operating current in real time, faults such as motor stall, internal short circuit, or abnormally high load can be identified immediately, and the machine can be shut down decisively when the current exceeds the allowable range to prevent permanent damage to power devices due to overload.

[0039] By effectively capturing voltage surges or drops caused by heavy load starts and stops in the forklift's electrical system and implementing protection when fluctuations exceed the maximum permissible difference, it can adapt to the harsh electrical environment of forklifts and avoid logic disorder or damage to controller 1 caused by poor power quality.

[0040] By implementing preventative power regulation based on motor and methanol temperatures, and employing a gentle derating operation mode, the system's thermal load is proactively reduced to a safe level while avoiding sudden shutdowns that could disrupt operational continuity. This significantly enhances the motor's adaptive working capability under high-temperature conditions or continuous high-load operation.

[0041] With triple protection against overcurrent, overvoltage, and overheating, the motor's operational safety is effectively guaranteed.

[0042] It should be noted that, unless otherwise expressly specified and limited, the term "connection" or its synonyms should be interpreted broadly in this document. For example, "connection" can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, expressions such as "first" and "second" are merely used to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Meanwhile, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. In addition, the terms "front," "rear," "left," "right," "upper," and "lower" in this document refer to the placement states shown in the accompanying drawings.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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; and these 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.

Claims

1. An integrated methanol pump for forklifts, characterized in that, include: The system includes a controller (1), a methanol pressure regulating valve (2), a level gauge (3), a pump body (4), a mounting bracket (6), a mounting flange (7), a fuel injector (9), a first plug (10), a second plug (12), a third plug (13), a rubber hose (11), and a methanol filter (5). The controller (1) is connected to the vehicle power supply via the second plug (12). The controller is connected to the methanol pump via the first plug (10) to supply power and control the methanol pump. The third plug (13) is connected to the vehicle wiring harness to supply power to the level gauge and transmit the level gauge signal to the vehicle instrument panel. The liquid level display is provided. The fixed bracket (6) is fixedly connected to the mounting flange (7). The liquid level gauge (3) is installed between the fixed bracket (6) and the mounting flange (7) and is connected in parallel with the controller (1). The pump body (4) is installed between the fixed bracket (6) and the mounting flange (7) and is connected to the fuel injector (9) through the rubber tube (11). The fuel injector (9) is installed on the mounting flange (7). The methanol pressure regulating valve (2) is installed on the rubber tube (11). The methanol filter (5) is set at the liquid inlet of the pump body (4).

2. The integrated methanol pump for forklifts according to claim 1, characterized in that, A sealing ring (8) is also provided at the connection between the mounting flange (7) and the methanol tank. The sealing ring (8) is made of fluororubber.

3. The integrated methanol pump for forklifts according to claim 1, characterized in that, The level gauge (3) is a sliding resistor and the outer shell is made of stainless steel and the surface is passivated.

4. The integrated methanol pump for forklifts according to claim 1, characterized in that, The drive motor of the pump body (4) is a brushless motor.

5. The integrated methanol pump for forklifts according to claim 1, characterized in that, The rubber tube (11) is made of fluororubber, and the fuel injector (9) is made of stainless steel and its surface is passivated.

6. A method for driving an integrated methanol pump for a forklift, implemented using any one of the integrated methanol pumps for a forklifts according to claims 1 to 5, characterized in that, include: Starting torque control, the starting torque is 2.2 times the rated torque; The power supply regulation and control adopts a vector control algorithm, which dynamically adjusts the frequency and voltage of the three-phase AC power based on the load characteristics of the main body. Operation monitoring: By monitoring the operating status of the drive motor of the pump body (4), the speed of the motor is adjusted in real time.

7. The integrated methanol pump driving method for forklifts according to claim 6, characterized in that, The frequency of the three-phase AC power is adjustable from 50 to 60 Hz, and the voltage of the three-phase AC power is adjustable from 0 to 380 V.

8. The integrated methanol pump driving method for a forklift according to claim 6, characterized in that, The operational monitoring includes: Overcurrent protection: Real-time monitoring of the drive motor's operating current; When the drive motor's operating current is outside the allowable current fluctuation range, a shutdown operation is executed. Overvoltage protection: Real-time monitoring of the input power supply voltage. When the input power supply voltage is not within the allowable voltage fluctuation range or the fluctuation difference is greater than the maximum allowable fluctuation difference, a shutdown operation is performed. Overheat protection adjusts the motor speed based on the motor operating temperature and methanol temperature.

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