KR20090019626A - Contactless displacement type fuel pump for l p g vehicle - Google Patents

Abstract

A contactless displacement type fuel pump for LPG vehicle is provided to give the piston rod flexibility and maintain a constant gap between the pump body and the piston. A contactless displacement type fuel pump for LPG vehicle comprises a pump body(200) in which an inlet(210) and an outlet(220) are formed, a piston(300) installed on the pump body, a linear motor(400) reciprocating the piston, and a linear flexion bearing(100) arranged on both sides of the linear motor. The linear motor strongly supports the piston rod in the radial direction so that the piston reciprocating in the pump body is fixed at the specific position.

Description

Contactless Displacement Type Fuel Pump For L P G Vehicle

The present invention prevents problems such as a reduction in pump efficiency due to a decrease in pressure due to frictional wear that occurs in a volumetric fuel pump of an LPG vehicle, and an internal damage due to an increase in vibration and noise caused by cavitation, which is a problem of a turbo pump of an LPG vehicle. The present invention relates to a fuel pump for an LPG vehicle having a structure capable of doing so.

In general, the fuel pump of an LPG vehicle is mainly composed of a volumetric pump and a turbo type (centrifugal, regenerative) pump.

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

Therefore, when the volumetric pump is used for LPG fuel, there is a problem that the performance, such as the flow rate, pressure, efficiency of the pump gradually decreases due to leakage and pressure drop due to frictional wear.

Even when a turbo type pump is used, the pressure decreases at the inlet side of the pump due to the low vapor pressure, thereby increasing vibration and noise caused by cavitation (cavitation), as well as damaging the device due to internal erosion.

As a result, there is a problem in that the output of the LPG vehicle is lowered by not properly adjusting the fuel supply of the vehicle.

Therefore, a volumetric fuel pump with good pumping performance without cavitation phenomenon is used, but a non-contact fuel pump is required to generate a constant pressure and improve durability and reliability by eliminating frictional wear, which is a problem of LPG fuel pumps. to be.

The pump body is equipped with a suction inlet / discharge port on one side; and a piston built in the pump body to generate pressure to the pump body; And a linear motor coupled to the piston rod to reciprocate the piston. And bearings disposed on both sides of the linear motor to strongly support the piston rod in the radial direction to fix the piston reciprocating in the pump body at a constant radial position. It is to provide a non-contact volumetric fuel pump.

Non-contact volumetric fuel pump for LPG vehicle according to the present invention, the performance of the pump is deteriorated due to the pressure drop caused by the friction wear appearing in the volumetric fuel pump of the LPG vehicle, the performance of the pump is deteriorated according to the non-contact piston structure The pressure can be maintained at any time without the device's reliability and durability.

In addition, the linear flexure bearing has an advantage of preventing the piston from rubbing against the pump body due to its own weight, pumping load and external impact.

Non-contact volumetric fuel pump for LPG vehicle of the present invention,

A pump body equipped with a suction port / discharge port at one side; and a piston built in the pump body to generate pressure to the pump body; and a linear motor coupled to the piston rod to reciprocate the piston; And bearings disposed on both sides of the linear motor so as to strongly support the piston rod in the radial direction to fix the piston reciprocating in the pump body at a predetermined position. Achieved by a volumetric fuel pump.

In addition, the pump body is equipped with a suction port / discharge port in the central portion; and the piston which is built up on both sides of the pump body to generate pressure to the pump body; and each piston rod to reciprocate each piston A linear motor coupled to; And bearings disposed on both sides of each linear motor so as to strongly support each of the piston rods in the radial direction to fix the piston reciprocating to both sides of the pump body at a constant radial position. Is achieved by a non-contact volumetric fuel pump for LPG vehicles.

The piston is a non-contact type that is formed between the pump body and the seal gap, it is preferable that a plurality of sealing grooves are formed to prevent the LPG fuel flowing into the pump body to the rear end to leak to the rear end.

In the above, the piston rod is preferably arranged in the mover of the linear motor.

Wherein the bearing is made of a linear flexure bearing to provide axial flexibility to the piston rod reciprocating, the linear flexure bearing, a circular ring-shaped hub (hub) with a circular hole in the center and And a hub arm having a plurality of radial arms formed at a right angle with respect to the center of the hub and radially formed around the outer circumference of the hub, and being formed to surround the hub and the hub arm adjacent to an outer end of the hub arm. An annular rim and a rim arm that are equal to each other with respect to the center of the hub so as to be adjacent to one edge of each hub arm, and the same number as the hub arms is radially formed around the inner side of the rim. And a circular arc shape having a predetermined width between the opposite sides of the hub arm and the rim arm which are not adjacent to each other. A diaphragm including a plurality of flexure blades connecting the hub arm and the rim arm; a hub spacer having the same size and shape as the hub; A plurality of hub spacer arms formed in plural to have the same position and shape as the hub arms at an outer circumference thereof, and support protrusions formed at edges of the hub spacer arms corresponding to one edges of the hub arms connected to the flexure blades; An inner spacer fixed to the hub to match a shape; And a rim spacer having the same size and shape as the rim, a plurality of rim spacer arms formed at the inner circumference of the rim spacer to have the same position and shape as the rim arm, and a rim arm connected to the flexure blade. It is preferably composed of; an outer spacer comprising a support protrusion formed on the edge of the rim spacer arm corresponding to one side edge, and fixed to match the shape of the rim.

The invention will become more apparent through the preferred embodiments described below with reference to the accompanying drawings. Hereinafter will be described in detail to enable those skilled in the art to easily understand and reproduce through embodiments of the present invention.

Figure 1a is a cross-sectional configuration diagram of a non-contact volumetric fuel pump for LPG vehicle of the embodiment according to the present invention, Figure 1b is an operating state diagram of a non-contact volumetric fuel pump for LPG vehicle of the embodiment according to the present invention.

First, as shown in FIG. 1A, the present invention provides a non-contact type LPG vehicle in a non-contact structure that can pump LPG fuel in a non-contact manner so as to generate a constant pressure by eliminating frictional wear between the piston and the pump body, which is a problem of the LPG fuel pump. It relates to a volumetric fuel pump (1000).

The fuel pump 1000 is largely composed of four parts, which is a pump body 200, a piston 300 built in the pump body 200, and a linear motor reciprocating the piston 300. 400 and a bearing for supporting the piston 300.

Here, the fuel pump 1000 has a structure in which a single piston 300 is built in the pump body 200 to generate pressure. At this time, the piston 300 is in a non-contact manner with the pump body 200, it should be preceded to determine the outer diameter of the piston 300 so that the seal gap (G) is formed to minimize the loss of pressure.

In addition, one side of the pump body 200 has a structure in which a suction port 210 / discharge port 220 capable of sucking and discharging LPG fuel according to a suction stroke and a discharge stroke according to the reciprocating motion of the piston 300 is formed. In this case, check valves 211 and 221 are connected to the suction port 210 and the discharge port 220, respectively, and are intermittent according to the compression and suction of the piston 300.

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

Referring to this mounting structure in detail, as shown in Figure 1b, the stator 420 of the linear motor 400 is a structure fixed to the pump body 200, the mover 410 is a piston rod extending from the piston 300 It is a structure coupled to (320). At this time, the mover 410 interpolates the piston rod 320 so that the piston rod 320 also moves together when the mover 410 reciprocates by the magnetic field with the stator 420.

On the other hand, the bearing strongly supports the piston rod 320 in the radial direction so as to fix the piston 300 reciprocating in the pump body 200 at a constant radial position on both sides of the linear motor 400. It is a structure to be arranged.

The bearing has a high radial stiffness and low axial stiffness, and is a linear flexure bearing 100 that is less stressed by warping, thereby providing flexibility to the reciprocating piston.

That is, the linear flexure bearing 100 has a structure in which the piston 300 is reciprocated together with the piston rod 320 on the center of the coupling portion of the piston rod 320 as the piston reciprocates.

Therefore, even when the piston 300 is reciprocated through the linear flexure bearing 100, a structure in which the clearance gap G formed between the pump bodies 200 is stably maintained is provided.

Meanwhile, the piston 300 is a non-contact type in which the pump body 200 and the thread gap G are formed, and a plurality of LPG fuel introduced into the pump body 200 to the outer circumference thereof is prevented from leaking to the rear end. The sealing groove 310 is formed.

This structure is one of the non-contact sealing "Labyrinth" type, LPG fuel is introduced along the gap (G) through a plurality of sealing grooves 310, the pressure is gradually reduced by the pressure loss The pressure difference between the inside and the outside of the pump excluding volume is maintained, and the pressure difference is suppressed from the inflow from the outside in the intake stroke and fuel leakage from the outside in the discharge stroke.

In addition, the linear flexure bearing is the "linear flexure bearing" of the applicant No. 10-0462996, filed on August 25, 2002 and published on December 23, 2004, and specific components thereof will be described below. A brief description will be given with reference to the accompanying drawings.

FIG. 2A is a plan view showing a diaphragm of the linear flexure bearing of the embodiment extracted from FIG. 1A, FIG. 2B is a plan view showing inner and outer spacers of the linear flexure bearing of the embodiment extracted from FIG. 1A, and FIG. 2C is 2A is a plan view of the linear flexure bearing in which the diaphragm and the inner / outer spacers of FIG. 2A are assembled.

Referring first to FIG. 2A, the diaphragm 10 of the linear flexure bearing 100 is largely made by connecting the hub 12, the rim 16, and the flexure blades 21, 23, 25 to each other in the same plane. . The hub arm 14 is radially formed around the outer side of the hub 12 so that the flexure blades 21, 23, 25 can be connected to the hub 12 and the rim 16. 16, a rim arm 18 is formed radially around the inner circumference.

The hub 12 has a circular ring shape in which a circular hole is drilled in the center, and a plurality of rivet points 13 are formed on the hub 12 at regular intervals. Since the shaft supported by the bearing is inserted into the circular hole of the hub 12, the hole size of the hub 12 formed according to the thickness of the shaft to which the bearing is applied may vary.

The hub arms 14a, 14b, 14c are equal to each other with respect to the center of the hub 12, and a plurality of hub arms are formed radially around the outer circumference of the hub 12. In this embodiment, three hub arms 14a, 14b, 14c are integrally formed with the hub 12 such that they have a distance of 120 ° with respect to the center of the hub 12. At least one rivet point 15 is also formed in each of the hub arms 14a, 14b, 14c.

Outside the hub 12 and hub arms 14a, 14b, 14c, a circular ring shaped rim 16 is arranged to surround them all. These rims 16 are preferably sized such that their inner periphery is adjacent to the outer ends of the hub arms 14a, 14b, 14c at predetermined intervals. A plurality of rivet points 19 are formed on the rim 16 at regular intervals from each other.

Rim arms 18a, 18b, and 18c are perpendicular to each other with respect to the center of hub 12 and radially equal in number to the number of hub arms 14a, 14b, and 14c around the inner rim of rim 16. Is formed. These rim arms 18a, 18b, 18c are preferably arranged such that each of the rim arms 14a, 14b, 14c is adjacent to one edge of each of the hub arms 14a, 14b, 14c at predetermined intervals. In the present embodiment, the rim arms 18a, 18b, and 18c have three rims equal to the number of hub arms 14a, 14b, and 14c having a spacing of 120 ° with respect to the center of the hub 12. It is formed integrally with. At least one rivet point 17 is also formed in each of the rim arms 18a, 18b, 18c.

The flexure blades 21, 23, and 25 each have a predetermined width between the hub arms 14a, 14b, and 14c, which are not adjacent to each other, and opposite sides of the rim arms 18a, 18b, and 18c, respectively. Arcuately provided with the hub arms 14a, 14b, 14c and the rim arm 18a.

, 18b, 18c). In this embodiment, three flexure blades 21, 23, 25 are disposed adjacent to each other at predetermined intervals between the hub arms 14a, 14b, 14c and the rim arms 18a, 18b, 18c. Is connected.

The flexure blades 21, 23, 25 are formed to be narrower as they are located closer to the center of the hub 12.

Referring to FIG. 2B, the inner spacer 30 includes a hub spacer 32 and hub spacer arms 34a, 34b, and 34c, and the outer spacer 40 includes a rim spacer 41 and a rim spacer arm 43a, respectively. 43b, 43c).

The hub spacer 32 has the same size and shape as the hub 12 of the diaphragm 10.

A plurality of hub spacer arms 34a, 34b, 34c are formed around the outer circumference of the hub spacer 32 to have the same position and shape as the hub arms 14a, 14b, 14c.

In addition, a support protrusion 36 is formed at an edge of the hub spacer arms 34a, 34b, 34c corresponding to one edge of the hub arms 14a, 14b, 14c to which the flexure blades 21, 23, 25 are connected. Is formed.

The support protrusion 36 has a sawtooth shape and is formed to correspond to each of the flexure blades provided between the opposite sides of the hub arms 14a, 14b, 14c and the rim arms 18a, 18b, 18c that are not adjacent to each other. do. Each serrated support projection 36 has a long side 36a and a short side 36b, and the short side 36b is a flexure blade 21, 23, when the inner spacer 32 is engaged with the diaphragm 10. It is preferable to be made to overlap side by side with the outer edge of 25, the long side 36a is made to form a predetermined acute angle (α) with this short side (36b).

Here, in the inner spacer according to the first embodiment of the present invention, the acute angle α formed by the long side 36a and the short side 36b of the toothed support protrusion 36 is 52 °.

Rim spacer 41 has the same size and shape as rim 16 of diaphragm 10.

A plurality of rim spacer arms 43a, 43b, 43c are formed around the inner circumference of the rim spacer 41 to have the same position and shape as the rim arms 18a, 18b, 18c.

In addition, a support protrusion 45 is provided at an edge of the rim spacer arms 43a, 43b, 43c corresponding to one edge of the hub arms 14a, 14b, 14c to which the flexure blades 21, 23, 25 are connected. Is formed.

The support protrusion 45 has a sawtooth shape and is formed to correspond to each of the flexure blades provided between opposite sides of the hub arms 14a, 14b, 14c and the rim arms 18a, 18b, 18c that are not adjacent to each other. do. Each serrated support protrusion 45 has a long side 45a and a short side 45b and the short side 45b is a flexure, as shown in FIG. 2C, when the outer spacer 32 is engaged with the diaphragm 10. It is preferable to be made to overlap with the outer edge of the blades (21, 23, 25), and the long side (45a) is made to form a predetermined acute angle (β) with this short side (45b).

As shown in FIG. 2C, in the outer spacer, the acute angle β formed by the long side 45a and the short side 45b of the toothed support protrusion 45 is 50 °.

Each of the inner spacer 30 and the outer spacer 40 formed as described above has rivet points 31, 35, 42, 46 corresponding to the rivet points 13, 15, 17, and 19 formed on the diaphragm 10. ) Is formed to be used not only for coupling with the diaphragm 10 but also for fixing with the shaft or housing mounted on the inside and the outside of the bearing.

The linear flexure bearing 100 as described above has high radial stiffness and low axial stiffness as a result of measuring axial stiffness, radial stiffness and fatigue life according to the computer modeling analysis described. It was found to have less.

Therefore, while providing flexibility to the piston rod 320 through the linear flexure bearing 100 is provided a structure that can maintain a constant gap (G) between the piston 300 and the pump body 200.

Figure 3a is a cross-sectional view of a non-contact volumetric fuel pump for LPG vehicle of another embodiment according to the present invention, Figure 3b is an operating state diagram of a non-contact volumetric fuel pump for LPG vehicle of another embodiment according to the present invention.

First, as shown in Figure 3a, the structure of the non-contact volumetric fuel pump 1000 for the LPG vehicle of another embodiment has a structure having two pistons 300 on both sides of the pump body 200, unlike the embodiment to be.

Therefore, the suction port 210 and the discharge port 220 of the pump body 200 is a structure formed in the central region of the pump body 200. At this time, in order to smoothly pump the LPG fuel through the inlet port 210 and the outlet port 220, a certain space portion should be formed in the central region when the piston 300 is compressed.

Therefore, the fuel pump 1000 of another embodiment has a structure capable of suppressing vibration by left and right symmetry as well as double the pumping function by the two piston 300, as shown in FIG.

At this time, each of the piston 300 is a structure provided with a linear motor 400 and a pair of linear flexure bearing (100).

As described above, the non-contact volume fuel pump for LPG vehicles according to the present invention is not only limited to the fuel pump of the LPG vehicle, but can also be applied to DME (Dimethyl Ether), gasoline and diesel vehicles.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, various other modifications and variations may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover such modifications and variations as fall within the true scope of the invention.

Figure 1a is a cross-sectional view of a non-contact volume fuel pump for LPG vehicle of the embodiment according to the present invention,

Figure 1b is an operating state of the non-contact volume fuel pump for LPG vehicle of the embodiment according to the present invention,

Figure 2a is a plan view showing a diaphragm of the linear flexure bearing of the embodiment taken in Figure 1a,

Figure 2b is a plan view showing the inner / outer spacer of the linear flexure bearing of the embodiment taken in Figure 1a,

Figure 2c is a plan view of the linear flexure bearing assembled with the diaphragm and the inner / outer spacer of Figure 2a,

3A is a cross-sectional view of a non-contact volume fuel pump for an LPG vehicle according to another embodiment of the present invention;

Figure 3b is an operating state diagram of a non-contact volume fuel pump for LPG vehicle of another embodiment according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: linear flexure bearing 10: diaphragm

12: hub 14a, 14b, 14c: hub arm

13,15,17,19,31,35,42,46: Rivet Point 16: Rim

18a, 18b, 18c: Rim Arm 21, 23, 25: Flexure Blade

30: inner spacer 32: hub spacer

34a, 34b, 34c: hub spacer arms 36, 45: support protrusion

40: outer spacer 41: rim spacer

43a, 43b, 43c: Rim spacer arm

200: pump body 210: suction port

211: check valve 220: discharge port

221: check valve

300: piston 310: sealing groove

320: piston rod

400: linear motor 410: mover

420: stator

1000: Non-contact volumetric fuel pump for LPG cars

G: Clearance

Claims (5)

In the LPG automobile fuel pump, A pump body 200 equipped with a suction port 210 / discharge port 220 at one side; A piston 300 built in the pump body 200 to generate pressure to the pump body 200; A linear motor 400 coupled to the piston rod 320 to reciprocate the piston 300; And Bearings disposed on both sides of the linear motor 400 to strongly support the piston rod 320 in a radial direction to fix the piston 300 reciprocating in the pump body 200 at a predetermined radial position; Non-contact volumetric fuel pump for LPG vehicles, characterized in that comprises a. In the LPG automobile fuel pump, A pump body 200 equipped with a suction port 210 / discharge port 220 at a central portion thereof; A piston 300 which is arranged on both sides of the pump body 200 to generate pressure to the pump body 200; A linear motor 400 coupled to each piston rod 320 to reciprocate the respective pistons 300; And Strongly supporting each of the piston rod 320 in the radial direction on both sides of each linear motor 400 to fix the piston 300 reciprocating to both sides of the pump body 200 in a constant radial position. Non-contact volumetric fuel pump for LPG vehicle, characterized in that it comprises a bearing disposed. The method according to claim 1 or 2, The piston 300 is a non-contact type is formed in the pump body 200 and the seal gap (G), a plurality of sealing to prevent the LPG fuel flowing into the pump body 200 to leak to the rear end to the outer peripheral surface Non-contact volumetric fuel pump for LPG vehicle, characterized in that the groove 310 is formed The method according to claim 1 or 2, The piston rod 320 is a non-contact type fuel pump for LPG motor vehicle, characterized in that is installed in the mover (410) of the linear motor (400). The method according to claim 1 or 2, The bearing is made of a linear flexure bearing 100 to provide flexibility to the reciprocating piston rod 320, The linear flexure bearing 100 has a circular ring-shaped hub 12 in which a circular hole is formed in the center thereof, and is perpendicular to each other with respect to the center of the hub 12. Hub arms 14a, 14b and 14c, each of which has a plurality of radially formed outer peripheries, and adjacent to the outer ends of the hub arms 14a, 14b and 14c, the hub 12 and the hub arms 14a, Circular ring-shaped rims 16 formed to surround 14b and 14c, and with respect to the center of the hub 12 to be adjacent to one edge of each of the hub arms 14a, 14b, 14c. Rim arms 18a, 18b 18c conformal and radially formed with the same number of hub arms 14a, 14b, 14c around the inner rim of the rim 16, and hub arms 14a, 14b not adjacent to each other , 14c) and an arcuate shape each having a predetermined width between opposite sides of the rim arms 18a, 18b and 18c. A diaphragm (10) comprising a plurality of flexure blades (21, 23, 25) connecting hub arms (14a, 14b, 14c) and the rim arms (18a, 18b 18c); A hub spacer 32 having the same size and shape as the hub 12 and a plurality of hub spacers 32 having the same position and shape as the hub arms 14a, 14b, 14c on the outer circumference of the hub spacer 32. Hub spacer arms 34a, 34b, 34c in which dogs are formed, and the hub spacer arms 34a corresponding to one edges of hub arms 14a, 14b, 14c connected to the flexure blades 21, 23, 25. And an inner spacer 30 including support protrusions 36 and 45 formed at edges of the edges 34b and 34c and fixed to match the shape of the hub 12. And A rim spacer 41 having the same size and shape as the rim 16, and a plurality of rims formed in the inner circumference of the rim spacer 41 to have the same position and shape as the rim arms 18a, 18b 18c. Spacer arms 43a, 43b, 43c and the rim spacer arms 43a, 43b, 43c corresponding to one edges of the rim arms 18a, 18b 18c connected to the flexure blades 21, 23, 25. Non-contact volumetric fuel pump for an LPG vehicle, comprising a support protrusion (36, 45) formed at the edge of the outer spacer is fixed to match the shape of the rim (16); (40).

Images