Liquid pumping mechanism, combined pump and injection system

Abstract

The invention discloses a liquid pumping mechanism, a combined pump and an injection system, and relates to the technical field of high-pressure common rail pumps, the liquid pumping mechanism comprises a plunger part and a liquid pumping part, a plunger cavity and a working cavity which are communicated are formed in a plunger sleeve, a plunger is arranged in the plunger cavity in a sliding mode, and the liquid pumping part is arranged in the working cavity. Different liquid media can be pumped at the same time, the integration degree is high, space waste is reduced during installation, and installation and arrangement are convenient. Engine oil and methyl alcohol are pumped into the methyl alcohol injector through the combined pump at the same time, methyl alcohol injection is controlled through high-pressure engine oil according to the characteristic that the engine oil and methyl alcohol are immiscible, and the problems that a control matching part of the methyl alcohol injector is poor in lubricating performance, and cavitation of a control valve element is serious can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure common rail pumps, and in particular to a pumping mechanism, a combined pump and an injection system. Background Art

[0002] Methanol (chemical formula CH3OH) is the simplest alcohol compound with good combustion performance. Compared with traditional fossil fuels, it produces lower hydrocarbons (HC) and nitrogen oxides (NOx) when burned, making it one of the ideal alternative fuels for internal combustion engines. With the increase in global energy transformation and environmental protection needs, methanol engines using methanol as fuel have broad application prospects in future energy transformation and environmental protection.

[0003] However, when liquid methanol is directly injected into the cylinder, it will be sprayed onto the cylinder wall of the cylinder liner. Since methanol is corrosive to a certain extent, it will corrode the cylinder liner and also dilute the engine oil (methanol, water and engine oil react to cause the engine oil to emulsify).

[0004] The existing Chinese patent document with publication number CN117703602A discloses a dual direct injection engine HPDI system of gaseous methanol and liquid diesel, including an engine, a methanol storage mechanism, a diesel storage mechanism and a heating mechanism. The methanol storage mechanism is connected to the engine and used to provide methanol to the engine; the diesel storage mechanism is connected to the engine and used to provide diesel to the engine; and the heating mechanism is arranged between the methanol storage mechanism and the transmitter, a first booster pump is arranged between the heating mechanism and the engine, and a second booster pump is arranged between the diesel storage mechanism and the engine.

[0005] However, the above-mentioned methanol fuel high-pressure injection system adopts the device corresponding to the dual-fuel injection system, which requires two sets of booster pumps and their additional components, has a low degree of integration, and there will be a certain space between different booster pumps and additional components, resulting in more space required during installation, which in turn leads to difficulties in layout. Summary of the invention

[0006] The object of the present invention is to provide a liquid pumping mechanism with a simple structure.

[0007] To achieve the above object, the present invention adopts the following technical solution: a pumping mechanism, comprising:

[0008] A plunger portion, comprising a plunger sleeve and a plunger;

[0009] A pump liquid part, comprising a fixing assembly and a sealing assembly arranged in the fixing assembly;

[0010] A connected plunger cavity and working cavity are provided in the plunger sleeve, the plunger is slidingly arranged in the plunger cavity, the fixed component is arranged in the working cavity, and the fixed component is connected with the plunger cavity and the working cavity, and the sealing component is used to change the connection state between the fixed component and the working cavity.

[0011] Furthermore, a step surface is formed at the junction of the plunger cavity and the working cavity, and the fixed component includes an inlet valve seat, an outlet valve seat and a liquid outlet valve tight seat which are arranged in sequence from bottom to top, and the inlet valve seat is arranged at the step surface. The sealing component includes a first sealing ball, a first elastic member, a second sealing ball, a second elastic member and a liquid outlet valve spring seat, the first elastic member is arranged in the liquid outlet valve seat, the first sealing ball is arranged between the first elastic member and the inlet valve seat, and is against the inlet valve seat, the second elastic member and the liquid outlet valve spring seat are both arranged in the liquid outlet valve tight seat, and the second sealing ball is arranged between the second elastic member and the liquid outlet valve seat, and is against the liquid outlet valve seat.

[0012] Further,

[0013] A working chamber, in which a first low-pressure chamber is opened;

[0014] The plunger sleeve has a first passage connecting the first low-pressure chamber and the outside formed on its side wall;

[0015] A liquid inlet valve seat, in which a third channel, a second low-pressure chamber and a second channel connecting the first low-pressure chamber and the second low-pressure chamber are formed;

[0016] The liquid outlet valve seat has an intermediate cavity connected with the second low-pressure cavity, a third channel is used to connect the intermediate cavity and the plunger cavity, a first elastic member is fixedly installed in the intermediate cavity, a first sealing ball is arranged between the first elastic member and the second low-pressure cavity, and the first sealing ball is used to seal the second low-pressure cavity;

[0017] The liquid outlet valve tight seat has a liquid outlet cavity connected to the middle cavity, the liquid outlet valve spring seat is fixedly installed in the liquid outlet cavity, the second elastic member is fixedly installed on the liquid outlet valve spring seat, the second sealing ball is arranged between the second elastic member and the middle cavity, and the second sealing ball is used to seal the middle cavity.

[0018] The technical principle of the present invention is as follows: when the plunger moves downward, the liquid medium enters the first low-pressure chamber through the first channel, and then enters the second low-pressure chamber through the second channel. Under the action of the hydraulic pressure, the first sealing ball is pushed open, the first elastic part contracts, the liquid medium enters the middle chamber, and then enters the plunger chamber through the third channel.

[0019] When the plunger moves upward, under the action of gravity and the elastic force of the first elastic member, the first sealing ball seals the second low-pressure chamber, the volume of the plunger chamber decreases, and the pressure gradually increases. The liquid medium in the plunger chamber enters the middle chamber through the third channel, and the pressure in the middle chamber gradually increases until the second sealing ball is pushed open, the second elastic member contracts, and the high-pressure liquid medium in the middle chamber is ejected from the liquid outlet chamber.

[0020] Another object of the present invention is to provide a combined pump which has a high degree of integration and is easy to install and arrange.

[0021] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a combined pump, comprising the above-mentioned pumping mechanism, and also comprising a pump body, an infusion pump arranged on the pump body, a camshaft arranged in the pump body, and a roller body assembly arranged between the camshaft and the plunger sleeve, the pumping mechanism is arranged in the pump body, and the number of the pumping mechanisms is at least 2, the camshaft is used for the movement of the roller body assembly to drive the plunger to reciprocate in the plunger cavity, a liquid inlet cavity connected to the first channel is reserved between the plunger sleeve and the pump body, a first liquid inlet port and a second liquid inlet port are opened on the pump body, and the first liquid inlet port and the second liquid inlet port are both connected to the liquid inlet cavity in the pumping mechanism (4).

[0022] Furthermore, the roller body assembly includes a roller seat, a roller and a pin shaft, the pin shaft passes through the roller seat and is fixedly installed in the roller seat, the roller coaxial sleeve is arranged in the roller seat, and the roller is against the camshaft, and a return spring seat is arranged on the roller seat to resist the plunger, and a third elastic member is arranged on the coaxial sleeve outside the plunger sleeve, and the third elastic member is arranged between the plunger sleeve and the return spring seat.

[0023] Furthermore, a liquid return annular groove is provided in the plunger cavity, and a liquid return channel connecting the liquid return annular groove and the liquid inlet cavity is provided in the plunger sleeve.

[0024] Furthermore, a first sealing ring and a second sealing ring are disposed on the outer sleeve of the plunger, and the first sealing ring and the second sealing ring are respectively located at the upper and lower sides of the liquid inlet cavity.

[0025] Furthermore, a VCV valve and an overflow valve are provided on the pump body, the VCV valve is provided between the first liquid inlet and / or the second liquid inlet and the liquid inlet cavity, and the overflow valve is communicated with the first liquid inlet and / or the second liquid inlet.

[0026] Furthermore, an oil lubrication passage is provided in the pump body, an oil injection port connected to the oil lubrication passage is provided on the pump body, and a one-way valve is arranged at the oil injection port.

[0027] Another object of the present invention is to provide an injection system, which can improve the lubrication performance of the control parts of the methanol injector and reduce the cavitation of the control valve core.

[0028] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an injection system, including the combination pump described above, and also including a methanol injector, a high-pressure common rail pipe is arranged between the combination pump and the methanol injector, the methanol injector is arranged on the engine cylinder, and a high-temperature electric glow plug is arranged in the engine cylinder.

[0029] The beneficial effects of the present invention are:

[0030] 1. By controlling the stiffness of the second elastic member, pressurization treatment of different liquid media can be achieved, and the structure is simple and easy to install;

[0031] 2. By setting multiple pumping mechanisms on the same pump body, different liquid media can be pumped at the same time, with a high degree of integration, reducing space waste during installation and facilitating installation and layout;

[0032] 3. By using a combination pump to simultaneously pump engine oil and methanol into the methanol injector, and based on the immiscible characteristics of engine oil and methanol, high-pressure engine oil is used to control methanol injection, which can solve the problems of poor lubrication performance of the control parts of the methanol injector and severe cavitation of the control valve core. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of the present invention;

[0034] Figure 2 is a side view of the present invention;

[0035] Figure 3 is a cross-sectional view of the present invention;

[0036] Figure 4 It is a cross-sectional view of the pump mechanism of the present invention;

[0037] Figure 5 A perspective view of a plunger sleeve of the present invention;

[0038] Figure 6 A perspective view of a liquid inlet valve seat of the present invention;

[0039] Figure 7 A perspective view of a liquid outlet valve seat of the present invention;

[0040] Figure 8 A perspective view of the liquid outlet valve seat of the present invention;

[0041] Fig. 9 It is a schematic diagram of the injection system of the present invention.

[0042] In the above drawings:

[0043] 1. Pump body; 101. First liquid inlet; 102. Second liquid inlet;

[0044] 2. Infusion pump; 3. Camshaft;

[0045] 4. Pumping mechanism; 401. Plunger sleeve; 4011. Plunger chamber; 4012. Working chamber; 402. Plunger; 403. Liquid inlet valve seat; 404. Liquid outlet valve seat; 405. Liquid outlet valve seat; 406. First sealing ball; 407. First elastic member; 408. Second sealing ball; 409. Second elastic member; 410. Liquid outlet valve spring seat;

[0046] 5. Roller body assembly; 501. Roller seat; 502. Roller; 503. Pin; 504. Return spring seat; 505. Third elastic member;

[0047] 6. First sealing ring; 7. Second sealing ring;

[0048] 8. VCV valve; 9. Overflow valve; 10. Oil injection port; 11. Check valve; 12. Cam timing sensor; 13. Methanol injector; 14. High temperature glow plug;

[0049] A1, first channel; A2, second channel; A3, third channel; A4, fourth channel; A5, liquid return channel;

[0050] B1, first low-pressure chamber; B2, second low-pressure chamber; B3, middle chamber; B4, liquid outlet chamber; B5, liquid return ring groove; B6, liquid inlet chamber. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; the structures described in various embodiments can be freely combined without any conflict in structure or principle.

[0052] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral 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 connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0054] Some embodiments of the present invention are described below in conjunction with the accompanying drawings:

[0055] like Figures 1 to 9 As shown, the present invention proposes a liquid pumping mechanism 4, comprising:

[0056] The plunger 402 comprises a plunger sleeve 401 and a plunger 402;

[0057] A pump liquid part, comprising a fixing assembly and a sealing assembly arranged in the fixing assembly;

[0058] A connected plunger cavity 4011 and a working cavity 4012 are provided in the plunger sleeve 401. The plunger 402 is slidably arranged in the plunger cavity 4011. The fixed component is arranged in the working cavity 4012, and the fixed component is connected to both the plunger cavity 4011 and the working cavity 4012. The sealing component is used to change the connection state between the fixed component and the working cavity 4012.

[0059] Furthermore, a step surface is formed at the junction of the plunger cavity 4011 and the working cavity 4012, and the fixed component includes a liquid inlet valve seat 403, a liquid outlet valve seat 404 and a liquid outlet valve tight seat 405 which are arranged in sequence from bottom to top, and the liquid inlet valve seat 403 is arranged at the step surface, and the sealing component includes a first sealing ball 406, a first elastic member 407, a second sealing ball 408, a second elastic member 409 and a liquid outlet valve spring seat 410, the first elastic member 407 is arranged in the liquid outlet valve seat 404, the first sealing ball 406 is arranged between the first elastic member 407 and the liquid inlet valve seat 403, and is against the liquid inlet valve seat 403, the second elastic member 409 and the liquid outlet valve spring seat 410 are both arranged in the liquid outlet valve tight seat 405, and the second sealing ball 408 is arranged between the second elastic member 409 and the liquid outlet valve seat 404, and is against the liquid outlet valve seat 404.

[0060] Further,

[0061] The working chamber 4012 has a first low-pressure chamber B1 therein;

[0062] The plunger sleeve 401 has a first passage A1 on its side wall that connects the first low-pressure chamber B1 with the outside;

[0063] The liquid inlet valve seat 403 has a third channel A3, a second low-pressure chamber B2 and a second channel A2 connecting the first low-pressure chamber B1 and the second low-pressure chamber B2;

[0064] The liquid outlet valve seat 404 has an intermediate cavity B3 in communication with the second low-pressure cavity B2, and a third channel A3 is used to connect the intermediate cavity B3 and the plunger cavity 4011. The first elastic member 407 is fixedly installed in the intermediate cavity B3, and the first sealing ball 406 is arranged between the first elastic member 407 and the second low-pressure cavity B2. The first sealing ball 406 is used to seal the second low-pressure cavity B2;

[0065] The liquid outlet valve seat 405 has a liquid outlet cavity B4 connected to the middle cavity B3, the liquid outlet valve spring seat 410 is fixedly installed in the liquid outlet cavity B4, the second elastic member 409 is fixedly installed on the liquid outlet valve spring seat 410, and the second sealing ball 408 is arranged between the second elastic member 409 and the middle cavity B3. The second sealing ball 408 is used to seal the middle cavity B3.

[0066] like Figure 3-Figure 8 As shown, the first elastic member 407 and the second elastic member 409 are both springs, and the first sealing ball 406 and the second sealing ball 408 are both made of steel, and are both made of a material resistant to methanol corrosion (such as stainless steel 316L, with a nickel-plated surface). The inlet valve seat 403 abuts against the step surface and is fixed by threads or interference fit. The inlet valve seat 403, the outlet valve seat 404 and the outlet valve tight seat 405 are arranged in the plunger sleeve 401 from bottom to top. The position where the upper side of the inlet valve seat 403 contacts the first sealing ball 406 and the position where the lower side of the outlet valve seat 404 contacts the second sealing ball 408 are both conical surfaces, and the first elastic member 407 and the second elastic member 409 have pre-tightening force on the first sealing ball 406 and the second sealing ball 408 respectively, and the pre-tightening force is greater than the pressure fluctuation range of the liquid medium, ensuring that the first sealing ball 406 and the second sealing ball 408 can be strictly sealed when there is no pressure. The first sealing ball 406 and the second sealing ball 408 can both move slightly (about 0.1-0.5mm) on the conical surface to respond to changes in the pressure of the liquid medium, but will not separate from the inlet valve seat 403 and the outlet valve seat 404.

[0067] When the plunger 402 moves downward, the liquid medium enters the first low-pressure chamber B1 through the first channel A1, and then enters the second low-pressure chamber B2 through the second channel A2. Under the action of the liquid medium pressure, the first sealing ball 406 can be pushed open, causing the first elastic member 407 to contract. The liquid medium enters the middle chamber B3, and then enters the plunger chamber 4011 through the third channel A3.

[0068] When the plunger 402 moves upward, under the action of gravity and the elastic force of the first elastic member 407, the first sealing ball 406 is pressed against the liquid inlet valve seat 403 to seal the second low-pressure chamber B2, the volume of the plunger chamber 4011 is reduced, and the pressure gradually increases. The liquid medium in the plunger chamber 4011 will enter the middle chamber B3 through the third channel A3, and the pressure in the middle chamber B3 will gradually increase until the second sealing ball 408 is pushed open, causing the second elastic member 409 to contract, and the high-pressure liquid medium in the middle chamber B3 will be ejected from the liquid outlet chamber B4.

[0069] like Figure 1-Figure 4 As shown, a combined pump includes the above-mentioned pumping mechanism 4, and also includes a pump body 1, an infusion pump 2 arranged on the pump body 1, a camshaft 3 arranged in the pump body 1, and a roller body assembly 5 arranged between the camshaft 3 and the plunger sleeve 401. The pumping mechanism 4 is arranged in the pump body 1, and the number of the pumping mechanisms 4 is at least 2. The camshaft 3 is used for the movement of the roller body assembly 5 to drive the plunger 402 to reciprocate in the plunger cavity 4011. A liquid inlet cavity B6 connected to the first channel A1 is reserved between the plunger sleeve 401 and the pump body 1. A first liquid inlet port 101 and a second liquid inlet port 102 are opened on the pump body 1, and the first liquid inlet port 101 and the second liquid inlet port 102 are both connected to the liquid inlet cavity B6 in the pumping mechanism 4.

[0070] When the number of the pumping mechanisms 4 is 2, different liquid media, such as methanol and engine oil, are respectively injected into the two pumping mechanisms 4 through the first liquid inlet 101 and the second liquid inlet 102, and the camshaft 3 is driven by the engine to rotate, thereby driving the infusion pump 2 to work, and methanol can be pumped into the pumping mechanism 4, and the engine oil can be pumped into another pumping mechanism 4 through an additional engine oil pump. Under the action of the camshaft 3, the methanol and engine oil in the pumping mechanism 4 can be pumped out.

[0071] When the number of the pumping mechanisms 4 is greater than 2, such as when the number of the pumping mechanisms 4 is 3, two of the pumping mechanisms 4 can pump methanol, and the other pumping mechanism 4 can pump engine oil. When the two pumping mechanisms 4 pump methanol, a fourth channel A4 connecting the two pumping mechanisms 4 is opened in the pump body 1, and when methanol enters the first channel A1 through the first liquid inlet 101, part of the methanol enters the plunger cavity 4011 of the first pumping mechanism 4 as described above, and the other part of the methanol enters the plunger cavity 4011 of the second pumping mechanism 4 through the fourth channel A4, and the engine oil enters the third pumping mechanism 4 through the second liquid inlet 102, so that different liquid media can be pumped simultaneously through the same combined pump.

[0072] By analogy, the number of specific pumping mechanisms 4 is determined according to actual needs, such as setting four pumping mechanisms 4, three pumping mechanisms 4 are connected to pump methanol, one pumping mechanism 4 pumps engine oil, or two pumping mechanisms 4 pump methanol, and one pumping mechanism 4 pumps engine oil, and the principle is the same as the principle of the above-mentioned pumping mechanism 4. In addition, the combined pump can also be used to pump other different liquid media, such as pumping methanol-diesel, etc.

[0073] Furthermore, if Figure 3 As shown, the roller body assembly 5 includes a roller seat 501, a roller 502 and a pin 503. The pin 503 passes through the roller seat 501 and is fixedly installed in the roller seat 501. The roller 502 is coaxially sleeved in the roller seat 501, and the roller 502 is against the camshaft 3. A return spring seat 504 is provided on the roller seat 501 to abut against the plunger 402. A third elastic member 505 is coaxially sleeved outside the plunger sleeve 401, and the third elastic member 505 is provided between the plunger sleeve 401 and the return spring seat 504.

[0074] The third elastic member 505 is selected as a spring here. When the camshaft 3 rotates, the roller 502 that is against the camshaft 3 rotates synchronously, driving the plunger 402 and the roller seat 501 to move synchronously. Under the action of the third elastic member 505, the roller 502 can always be against the camshaft 3, thereby maintaining the stability of the operation of the device.

[0075] Furthermore, if Figure 5 As shown, a liquid return groove B5 is provided in the plunger cavity 4011, and a liquid return channel A5 connecting the liquid return groove B5 and the liquid inlet cavity B6 is provided in the plunger sleeve 401.

[0076] When the liquid medium in the plunger cavity 4011 leaks, it flows into the liquid inlet cavity B6 through the liquid return groove B5 and the liquid return channel A5, thereby reducing the leakage of the liquid medium.

[0077] Furthermore, if Figure 4 As shown, the plunger sleeve 401 is provided with a first sealing ring 6 and a second sealing ring 7, and the first sealing ring 6 and the second sealing ring 7 are respectively located at the upper and lower sides of the liquid inlet cavity B6.

[0078] By providing the first sealing ring 6 and the second sealing ring 7, the liquid inlet cavity B6 can be sealed, thereby reducing the leakage of the liquid medium in the liquid inlet cavity B6.

[0079] Furthermore, if Figure 1 and Figure 2 As shown, a VCV valve 8 and a relief valve 9 are provided on the pump body 1. The VCV valve 8 is provided between the first liquid inlet 101 and / or the second liquid inlet 102 and the liquid inlet chamber B6, and the relief valve 9 is communicated with the first liquid inlet 101 and / or the second liquid inlet 102. A cam timing sensor 12 for detecting the rotation angle of the cam is provided on the pump body 1.

[0080] The liquid medium entering the pump body 1 through the first liquid inlet 101 will first pass through the VCV valve 8 and then enter the liquid inlet chamber B6. Through the setting of the VCV valve 8, the flow rate of the liquid medium can be accurately adjusted, and at the same time, the precise coordinated adjustment of methanol and engine oil can be achieved, avoiding the crosstalk problem of traditional single valve control. The VCV valve 8 is directly integrated into the pump body 1 to reduce external pipelines, thereby reducing the risk of leakage.

[0081] The overflow valve 9 is a normally closed valve. When the pressure of the liquid medium is greater than the set pressure value, the overflow valve 9 opens, and methanol flows into the oil return port through the overflow valve 9 and returns to the methanol tank.

[0082] By setting the cam timing sensor 12, the position and speed of the camshaft 3 can be detected, an oil injection phase signal can be provided, valve core lubrication can be optimized, a methanol injection frequency reference can be provided, and the common rail pressure can be controlled.

[0083] Furthermore, if Figure 1 and Figure 2 As shown, an oil lubrication passage is provided in the pump body 1, an oil injection port 10 connected to the oil lubrication passage is provided on the pump body 1, and a check valve 11 is provided at the oil injection port 10. The camshaft 3 can be lubricated through the oil injection port 10 and the oil lubrication passage, thereby increasing the service life of the camshaft 3.

[0084] like Fig. 9 As shown, an injection system includes the above-mentioned combined pump and a methanol injector 13. A high-pressure common rail pipe is arranged between the combined pump and the methanol injector 13. The methanol injector 13 is arranged on the engine cylinder. A high-temperature glow plug 14 is arranged in the engine cylinder.

[0085] The methanol injected from the combination pump is connected to the methanol injector 13 through the methanol high-pressure common rail pipe, and the injected engine oil is connected to the methanol injector 13 through the engine oil high-pressure common rail pipe. The combination pump is used to provide high-pressure engine oil and high-pressure methanol to the methanol injector 13, which can reduce the structural volume of the high-pressure pump. According to the immiscible characteristics of engine oil and methanol, high-pressure engine oil is used to control methanol injection to solve the poor lubrication performance of the control couple of the methanol injector 13 and the serious cavitation of the control valve core. The methanol injector 13 is a prior art and will not be described here. The use of a high-temperature glow plug 14 for ignition can improve the cold start performance of methanol. The high-pressure direct injection methanol single fuel injection system is adopted, which is relatively simple to control and has a small structural volume.

[0086] The device obtains the engine oil by isolating a certain space in the engine oil tank, without the need to set up an additional separate engine oil tank.

Claims

1. A pumping mechanism, characterized in that: include: A plunger portion, comprising a plunger sleeve (401) and a plunger (402); A pump liquid part, comprising a fixing assembly and a sealing assembly arranged in the fixing assembly; A connected plunger cavity (4011) and a working cavity (4012) are provided in the plunger sleeve (401), the plunger (402) is slidably arranged in the plunger cavity (4011), the fixed component is arranged in the working cavity (4012), and the fixed component is connected to both the plunger cavity (4011) and the working cavity (4012), and the sealing component is used to change the connection state between the fixed component and the working cavity (4012).

2. The pumping mechanism according to claim 1, characterized in that: A step surface is formed at the junction of the plunger cavity (4011) and the working cavity (4012); the fixed component comprises a liquid inlet valve seat (403), a liquid outlet valve seat (404) and a liquid outlet valve tight seat (405) arranged in sequence from bottom to top; the liquid inlet valve seat (403) is arranged at the step surface; the sealing component comprises a first sealing ball (406), a first elastic member (407), a second sealing ball (408), a second elastic member (409) and a liquid outlet valve spring seat (410); the first elastic member (409) is provided at the bottom of the liquid inlet valve seat (403); the second elastic member (409) is provided at the bottom of the liquid outlet valve seat (410); the first elastic member (407) is provided at the bottom of the liquid inlet valve seat (403); the second elastic member (409) is provided at the bottom of the liquid outlet valve seat (410); the first elastic member (407) is provided at the bottom of the liquid inlet valve seat (403); the second elastic member (409) is provided at the bottom of the liquid outlet valve seat (410); the first elastic member (407) is provided at the bottom of the liquid inlet valve seat (403); the first elastic member (407 ...10); the first elastic member (407) is provided at the bottom of the liquid outlet valve seat (410); the first elastic member (407) is The component (407) is arranged in the liquid outlet valve seat (404), the first sealing ball (406) is arranged between the first elastic component (407) and the liquid inlet valve seat (403), and is against the liquid inlet valve seat (403), the second elastic component (409) and the liquid outlet valve spring seat (410) are both arranged in the liquid outlet valve tight seat (405), and the second sealing ball (408) is arranged between the second elastic component (409) and the liquid outlet valve seat (404), and is against the liquid outlet valve seat (404).

3. The pumping mechanism according to claim 2, characterized in that: A working chamber (4012) having a first low-pressure chamber (B1) therein; The plunger sleeve (401) has a first passage (A1) on its side wall that connects the first low-pressure chamber (B1) with the outside; A liquid inlet valve seat (403) having a third channel (A3), a second low-pressure chamber (B2), and a second channel (A2) connecting the first low-pressure chamber (B1) and the second low-pressure chamber (B2); A liquid outlet valve seat (404) is provided with an intermediate cavity (B3) in communication with the second low-pressure cavity (B2); a third channel (A3) is used to connect the intermediate cavity (B3) and the plunger cavity (4011); a first elastic member (407) is fixedly installed in the intermediate cavity (B3); a first sealing ball (406) is arranged between the first elastic member (407) and the second low-pressure cavity (B2); and the first sealing ball (406) is used to seal the second low-pressure cavity (B2); The liquid outlet valve seat (405) has a liquid outlet cavity (B4) in communication with the middle cavity (B3). The liquid outlet valve spring seat (410) is fixedly installed in the liquid outlet cavity (B4). The second elastic member (409) is fixedly installed on the liquid outlet valve spring seat (410). The second sealing ball (408) is arranged between the second elastic member (409) and the middle cavity (B3). The second sealing ball (408) is used to seal the middle cavity (B3).

4. A combination pump, characterized in that: The invention comprises the pumping mechanism as claimed in claim 3, and further comprises a pump body (1), an infusion pump (2) arranged on the pump body (1), a camshaft (3) arranged in the pump body (1), and a roller body assembly (5) arranged between the camshaft (3) and the plunger sleeve (401); the pumping mechanism (4) is fixed to the inside of the pump body (1), and the number of the pumping mechanisms (4) is at least 2; the camshaft (3) is used for the movement of the roller body assembly (5) to drive the plunger (402) to reciprocate in the plunger cavity (4011); a liquid inlet cavity (B6) connected to the first channel (A1) is reserved between the plunger sleeve (401) and the pump body (1); a first liquid inlet port (101) and a second liquid inlet port (102) are opened on the pump body (1), and the first liquid inlet port (101) and the second liquid inlet port (102) are both connected to the liquid inlet cavity (B6) in the pumping mechanism (4).

5. A combined pump according to claim 4, characterized in that: The roller body assembly (5) comprises a roller seat (501), a roller (502) and a pin (503); the pin (503) passes through the roller seat (501) and is fixedly mounted in the roller seat (501); the roller (502) is coaxially sleeved in the roller seat (501), and the roller (502) abuts against the camshaft (3); a return spring seat (504) abutting against the plunger (402) is arranged on the roller seat (501); a third elastic member (505) is coaxially sleeved outside the plunger sleeve (401), and the third elastic member (505) is arranged between the plunger sleeve (401) and the return spring seat (504).

6. A combined pump according to claim 4 or 5, characterized in that: A liquid return annular groove (B5) is provided in the plunger cavity (4011), and a liquid return passage (A5) communicating with the liquid return annular groove (B5) and the liquid inlet cavity (B6) is provided in the plunger sleeve (401).

7. A combined pump according to claim 4 or 5, characterized in that: The plunger sleeve (401) is provided with a first sealing ring (6) and a second sealing ring (7) on its outer sleeve, and the first sealing ring (6) and the second sealing ring (7) are respectively located on the upper and lower sides of the liquid inlet cavity (B6).

8. A combined pump according to claim 4 or 5, characterized in that: A VCV valve (8) and an overflow valve (9) are provided on the pump body (1); the VCV valve (8) is provided between the first liquid inlet (101) and / or the second liquid inlet (102) and the liquid inlet chamber (B6); and the overflow valve (9) is communicated with the first liquid inlet (101) and / or the second liquid inlet (102).

9. A combined pump according to claim 2 or 3, characterized in that: An oil lubrication passage is provided in the pump body (1), an oil injection port (10) communicating with the oil lubrication passage is provided on the pump body (1), and a one-way valve (11) is provided at the oil injection port (10).

10. An injection system, characterized in that: It comprises the combination pump as claimed in any one of claims 4 to 9, and also comprises a methanol injector (13), a high-pressure common rail pipe is arranged between the combination pump and the methanol injector (13), the methanol injector (13) is arranged on the engine cylinder, and a high-temperature glow plug (14) is arranged in the engine cylinder.

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