JP5054819B2 - Non-contact positive displacement fuel pump for LPG automobile with lubricant isolation structure - Google Patents

Description

  The present invention relates to a reduction in pump efficiency due to mechanical wear and pressure drop caused by low LPG viscosity in a positive displacement fuel pump of an LPG vehicle, and vibration, noise, and erosion due to cavitation, which are problems of a turbo pump of an LPG vehicle. In addition to preventing problems such as internal damage, the interior is filled with lubricant to minimize friction between the piston rod and the bearing, and the filled lubricant is isolated from the LPG fuel pumping space. Thus, the present invention relates to a non-contact positive displacement fuel pump for an LPG vehicle having a lubricant isolating structure that can prevent the lubricant from being exhausted and prevent the lubricant from being mixed with LPG.

  In general, the fuel pump of an LPG vehicle is largely composed of a positive displacement pump and a turbo type (centrifugal or regenerative) pump.

  However, unlike general gasoline and diesel, LPG fuel has very low viscosity and vapor pressure due to its characteristics.

  Due to the low viscosity, when a positive displacement pump is used for LPG fuel, there is a problem that the performance such as the flow rate, pressure and efficiency of the pump gradually deteriorates due to leakage due to mechanical wear and pressure drop.

  Even when a turbo pump is used, the vapor pressure is low, so the pressure decreases on the inlet side of the pump, vibration and noise increase due to the occurrence of cavitation (cavitation phenomenon), and damage to equipment due to internal erosion. There are problems that occur.

  As a result, the fuel supply of the automobile is not properly adjusted in the end, and there is a problem that the output of the LPG vehicle is reduced.

  The object of the present invention is to use a positive displacement fuel pump that has no cavitation phenomenon and good pumping efficiency, and generates constant pressure without mechanical wear, which is a problem of LPG fuel pumps. It is an object of the present invention to provide a non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure, which is a non-contact fuel pump capable of improving the performance.

  In order to achieve the above object, a non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure generates a pressure in the pump body having a suction port / discharge port on one side and the pump body. A piston that is pivotally supported by the pump body, a linear motor that is coupled to the piston rod so that the piston can be reciprocated, and the piston rod is strongly supported in the radial direction. In order to fix the piston reciprocating in the pump body at a certain radial position, the bearings arranged on both sides of the linear motor and the lubricant filled therein are sealed and reciprocated. In order to impart flexibility to the piston rod, it is characterized by comprising a diaphragm disposed between the bearing and the piston.

  The non-contact positive displacement fuel pump for LPG vehicles according to the present invention can prevent the problem that the performance of the pump deteriorates due to the pressure drop due to mechanical wear generated in the positive displacement fuel pump of the LPG vehicle. The contact-type piston structure can maintain the pressure at all times without deteriorating the performance of the pump, so that the life of the device can be made permanent and the durability can be improved.

  Further, since the piston can be prevented from being rubbed against the pump body by its own weight, pumping load and external impact through the linear bearing, there is an advantage that the pressure can be kept constant without decreasing the pressure.

  In addition, it has a diaphragm inside and can isolate the filler to minimize the friction between the piston rod and the bearing, and also gives the piston rod flexibility and shows a large output with a small electric power. There is an advantage that you can.

1 is a cross-sectional configuration diagram of a non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure according to an embodiment of the present invention. FIG. 4 is an operational state diagram of a non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure according to an embodiment of the present invention. FIG. 5 is a cross-sectional view of a non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure according to another embodiment of the present invention. FIG. 6 is an operational state diagram of a non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure according to another embodiment of the present invention.

  A non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolating structure according to the present invention is configured so that a pump body having a suction port / discharge port on one side and pressure generated by the pump body. A piston pivotally supported by the pump body, a linear motor coupled to the piston rod so as to reciprocate the piston, and the piston rod strongly supported in a radial direction, In order to fix the reciprocating piston at a certain radial position, the bearings arranged on both sides of the linear motor and the lubricant filled inside are sealed to provide flexibility to the reciprocating piston rod. LP having a lubricant isolation structure, characterized in that it comprises a diaphragm disposed between a bearing and a piston for imparting It is accomplished by a non-contact type displacement type fuel pump for automobiles.

  In addition, a pump body having a suction port / discharge port at a central part, a piston pivotally supported on both sides of the pump body so that pressure can be generated by the pump body, and a reciprocating motion of each piston The linear motor coupled to each piston rod and the piston rod that strongly supports each piston rod in the radial direction so that the piston that reciprocates on both sides of the pump body is fixed at a certain radial position. Bearings arranged on both sides of each linear motor so as to be able to seal and seal the lubricant filled inside, and to give flexibility to each piston rod reciprocating on both sides And a diaphragm disposed between the piston and the piston, and a non-contact positive displacement fuel for an LPG automobile having a lubricant isolating structure It is achieved by the pump.

  The piston is a non-contact type in which a seal gap is formed with the pump body, and a large number of seals are provided on the outer peripheral surface to prevent LPG fuel leaking into the pump body from leaking to the subsequent stage. A groove is preferably formed.

  It is preferable that the piston rod is pivotally supported by a moving element of a linear motor.

  The bearing is preferably a linear bearing having high radial rigidity and low axial rigidity so that the piston rod can smoothly reciprocate inside.

  The present invention will be further clarified by preferred embodiments described below with reference to the accompanying drawings. The embodiments of the present invention are described in detail below so that those skilled in the art can easily understand and reproduce them.

  FIG. 1 is a cross-sectional configuration diagram of a non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure according to an embodiment of the present invention, and FIG. 2 is an LPG having a lubricant isolation structure according to an embodiment of the present invention. It is an operation | movement state figure of the non-contact-type positive displacement fuel pump for motor vehicles.

  As shown in FIG. 1 and FIG. 2, the present invention is effective in reducing pump performance due to mechanical wear and pressure drop generated between a piston and a pump body due to low LPG viscosity in a positive displacement fuel pump of an LPG vehicle. Reduces and prevents problems such as vibration and noise due to cavitation, which is a problem of turbo type pumps of LPG cars, and internal damage of equipment due to erosion, and minimizes friction between piston rod and bearing Therefore, it is possible to prevent the lubricant from being exhausted and to prevent the lubricant from mixing with the LPG by filling the inside with a lubricant and isolating the filled lubricant from the LPG fuel pumping space. The present invention relates to a non-contact positive displacement fuel pump 1000 for an LPG automobile having a lubricant isolation structure having a structure capable of performing the same.

  The fuel pump 1000 is mainly composed of five parts, which are a pump body 200, a piston 300 pivotally supported in the pump body 200, and a linear motor 400 that reciprocates the piston 300. In order to isolate the lubricant and impart flexibility to the piston rod 320, a bearing that supports the piston rod 320 and a diaphragm 500 disposed between the bearing and the piston 300 are configured.

  Here, in the fuel pump 1000, a single piston 300 is pivotally supported inside the pump body 200 in order to generate pressure. At this time, the piston 300 is in a non-contact manner with the pump body 200, and the outer diameter of the piston 300 is determined so that a seal gap G for minimizing pressure loss is formed. Must be preceded.

  In addition, on one side of the pump body 200, a suction port 210 / a discharge port 220 capable of sucking and discharging LPG fuel by compression and suction by reciprocation of the piston 300 is formed. At this time, check valves 211 and 221 are connected to the suction port 210 and the discharge port 220, respectively, and are intermittently connected by the suction stroke and the discharge stroke of the piston 300.

  In addition, the piston 300 has a structure in which a linear motor 400 is mounted so that the piston 300 can be reciprocated by the pump body 200.

  Referring to FIG. 2 in detail, the stator 420 of the linear motor 400 is fixed to the pump body 200 and the mover 410 is coupled to a piston rod 320 extended from the piston 300 as shown in FIG. Is done. At this time, when the piston 410 is inserted into the moving element 410 and the moving element 410 is reciprocated by the magnetic field with the stator 420, the piston load 320 is also moved.

  Meanwhile, the bearing 100 strongly supports the piston rod 320 in the radial direction, so that the piston 300 reciprocating in the pump body 200 can be fixed at a certain radial position. Located on both sides.

  The bearing 100 is preferably a linear bearing 100 having high radial rigidity and low axial rigidity so that the piston rod can smoothly reciprocate inside.

  Therefore, even if the piston 300 reciprocates, a structure is provided in which the seal gap G formed between the pump body 200 through the linear bearing 100 can be stably maintained.

  Meanwhile, the piston 300 is a non-contact type in which a seal gap G is formed with the pump body 200, and LPG fuel flowing into the pump body 200 is leaked to the rear stage on the outer peripheral surface. In order to prevent this, a plurality of seal grooves 330 are formed.

  Such a structure is a Labyrinth type which is one of non-contact seals, and LPG fuel flows in along the seal gap G, and the pressure gradually decreases due to pressure loss while passing through a large number of seal grooves 330. Then, the pressure difference between the inside and outside of the pump displacement volume is maintained, and by using this pressure difference, fuel leakage to the outside is suppressed in the intake stroke and in the discharge stroke (indicated by a two-dot chain line in FIG. 2). (Illustrated).

  Further, the diaphragm 500 is disposed between the bearing 100 and the piston 300 in order to seal the lubricant 600 filled therein in a flexible bent form and to give flexibility to the piston rod 320 that reciprocates. Is done.

  Through the diaphragm 500, the lubricant 600 for minimizing the friction between the piston rod 320 and the bearing 100 can be filled, and the filled lubricant 600 is isolated from the LPG fuel pumping space. Thus, it is possible to prevent the lubricant 600 from being exhausted, and to prevent the lubricant 600 from being mixed with LPG.

  FIG. 3 is a cross-sectional view of a non-contact positive displacement fuel pump for an LPG vehicle having a lubricant isolation structure according to another embodiment of the present invention, and FIG. 4 is a lubricant isolation according to another embodiment of the present invention. It is an operation state figure of the non-contact type positive displacement fuel pump for LPG vehicles which has a structure.

  First, as shown in FIGS. 3 and 4, a non-contact positive displacement fuel pump 1000 for an LPG automobile having a lubricant isolation structure according to another embodiment of the present invention is different from the above embodiment in that the pump Two pistons 300 are provided on both sides inside the body 200.

  Accordingly, the suction port 210 and the discharge port 220 of the pump body 200 are formed in the central region of the pump body 200. At this time, in order to smoothly pump the LPG fuel through the suction port 210 and the discharge port 220, a certain space must be formed in the central region when the piston 300 is compressed.

  As a result, the fuel pump 1000 according to another embodiment can double the pumping function by the two pistons 300 as shown in FIG. 4 and can suppress vibrations by left-right symmetry.

  At this time, each of the pistons 300 includes a linear motor 400 for providing a driving force and a pair of linear bearings 100 for supporting the piston rod 320.

  In addition, a diaphragm 500 is disposed between each linear bearing 100 and the piston 300, and flexibility can be imparted to the piston rod 320 that reciprocates on both sides of the pump body 200, and the piston rod 320. The lubricant 600 can be filled so that the friction between the bearing 100 and the bearing 100 can be minimized.

  At this time, the filled lubricant 600 can be prevented from being exhausted by being isolated from the LPG fuel pumping space through the diamond lamp 500, and the lubricant 600 is mixed with the LPG. This can be prevented.

  As described above, the non-contact positive displacement fuel pump for LPG vehicles according to the present invention is not limited to the fuel pump for LPG vehicles, but can also be applied to DME (Dimethy Ether) gasoline and diesel vehicles. Of course.

  Although the present invention has been described with reference to the preferred embodiments referred to above, various other modifications and variations can be made without departing from the spirit and scope of the invention. Accordingly, the appended claims include such modifications and variations as fall within the true scope of the invention.

  The non-contact positive displacement fuel pump for LPG vehicles according to the present invention can prevent the problem that the performance of the pump deteriorates due to the pressure drop due to mechanical wear generated in the positive displacement fuel pump of the LPG vehicle. The contact-type piston structure can maintain the pressure at all times without deteriorating the performance of the pump, so that the life of the device can be made permanent and the durability can be improved.

  Further, since the piston can be prevented from being rubbed against the pump body by its own weight, pumping load and external impact through the linear bearing, there is an advantage that the pressure can be kept constant without decreasing the pressure.

  In addition, it has a diaphragm inside and can isolate the filler to minimize the friction between the piston rod and the bearing, and also gives the piston rod flexibility and shows a large output with a small electric power. There is an advantage that you can.

100 Linear bearing 200 Pump body 210 Suction port 211 Check valve 220 Discharge port 221 Check valve 300 Piston 330 Seal groove 320 Piston rod 400 Linear motor 410 Moving element 420 Stator 500 Diaphragm 600 Lubricant 1000 Fuel pump G Seal gap

Claims (5)

In LPG automobile fuel pump,
A pump body fitted with suction and discharge ports on one side;
A piston pivotally supported by the pump body so that pressure can be generated in the pump body;
A linear motor coupled to a piston rod so that the piston can reciprocate;
Bearings disposed on both sides of the linear motor so as to strongly support the piston rod in the radial direction and fix the piston reciprocating in the pump body at a certain radial position;
A diaphragm disposed between the bearing and the piston in order to seal the lubricant filled therein and to impart axial flexibility to the piston rod that reciprocates ; and
The diaphragm is non-contact displacement type for LPG vehicles respectively fixed to the outer peripheral surface having a lubricant isolation structure, wherein Rukoto of the inner peripheral surface and the piston rod of the pump body in a form orthogonal to the piston rod Fuel pump. In LPG automobile fuel pump,
A pump body fitted with a suction port and a discharge port in the central part;
Pistons pivotally supported on both sides of the pump body so that pressure can be generated in the pump body;
A linear motor coupled to each piston rod of the piston so that the piston can reciprocate;
Bearings arranged on both sides of each of the linear motors so that the piston rods are strongly supported in the radial direction and the pistons reciprocating on both sides of the pump body can be fixed at a certain radial position. When,
A diaphragm disposed between the bearing and the piston in order to seal the lubricant filled therein and to impart axial flexibility to the piston rod that reciprocates on both sides ; and
The diaphragm are each fixed to the outer peripheral surface of the piston rod of said each and the inner peripheral surface of the pump body in a form orthogonal to the respective piston rod non for LPG motor vehicle with a lubricant isolation structure, wherein Rukoto Contact-type positive displacement fuel pump.   The piston is a non-contact type in which a seal gap is formed with the pump body, and a plurality of pistons are provided on the outer peripheral surface to prevent LPG fuel leaking into the pump body from leaking to the subsequent stage. A non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure according to claim 1, wherein a seal groove is formed.   3. The non-contact positive displacement fuel pump for an LPG automobile having a lubricant isolation structure according to claim 1, wherein the piston rod is pivotally supported by a moving element of the linear motor.   The lubricant according to claim 1 or 2, wherein the bearing is a linear bearing having high radial rigidity and low axial rigidity so that the piston rod can smoothly reciprocate inside. A non-contact positive displacement fuel pump for LPG automobiles having an isolation structure.

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