CN202579169U - Cycloidal fuel delivery pump of high-pressure common rail fuel injection system - Google Patents

Abstract

The utility model discloses a cycloidal fuel delivery pump in a high-pressure common rail fuel injection system, which belongs to the technical field of auto parts. The cycloidal fuel delivery pump is composed of a fuel delivery pump body, an outer rotor, an inner rotor and ten bytes. Integral structure, the inner rotor shaft and the eccentricity of the pump body cavity are placed vertically on the bottom surface of the pump body cavity, and the radius of the bottom surface of the pump body cavity passing through the center of the inner rotor shaft is the symmetry axis, and the low-pressure oil chamber and high-pressure oil chamber of the half-moon groove It is symmetrically placed on the bottom surface of the pump body cavity, the low-pressure oil chamber is on the right side, the oil inlet hole is connected to the oil inlet joint on the back of the oil delivery pump body at the bottom of the low-pressure oil chamber, and the inner rotor and the outer rotor of the tooth lobe structure form a pair of eccentric inner rotors. Engage the rotor. The utility model adopts an integral structure pump body and axial oil inlet, compact structure, small volume, not easy to produce cavitation; the teeth of the inner and outer rotors keep meshing with each other during the working cycle, stable operation, small pulsation, low noise, and high volumetric efficiency , suitable for automobile diesel engine fuel injection system.

Description

Cycloidal Fuel Delivery Pump in High Pressure Common Rail Fuel Injection System

technical field

The utility model belongs to the technical field of auto parts, in particular to a cycloid fuel pump in a high-pressure common rail fuel injection system.

Background technique

Automobile diesel engines generally have the problem of insufficient starting fuel supply at low temperature and low speed, which cannot meet the needs of high-pressure fuel systems. The fuel delivery pumps of the mechanical fuel injection system currently used, including vane pumps, gear pumps and plunger pumps, all have pressure and Large flow pulse, high noise, low volumetric efficiency, poor low-speed oil absorption and other defects lead to the emission of domestic automobile diesel engines not meeting the international requirements of Euro Ⅲ or even Euro Ⅳ and Euro Ⅴ standards.

The cycloidal rotor pump is a type that has been widely praised in the field of low-pressure high-speed pumps in recent years. It was difficult to be popularized in the early days because the internal and external rotors required expensive rotor grinding machines. However, with the development of domestic powder metallurgy technology, the manufacturing process has been solved, and the domestic oil pump industry has almost all adopted cycloid rotor pumps for single pumps. However, the existing cycloid rotor pumps use a split-structure pump body and The way of passing through the inside of the pump body, so the pump has a large volume, unstable operation, large pulsation, loud noise, easy to produce cavitation, and low volumetric efficiency. In order to solve the above problems, there is a need for a cycloid oil transfer pump with an integral structure of the pump body and axial oil inlet from the bottom surface of the pump body.

Utility model content

The purpose of the utility model is to solve the problems of large volume, unstable operation, large pulsation, high noise, easy cavitation and low volumetric efficiency of the pump described in the background technology, and provide a cycloid pump in a high-pressure common rail fuel injection system. Fuel delivery pump, the cycloid fuel delivery pump in the high-pressure common rail fuel injection system is composed of a fuel delivery pump body 1, an outer rotor 2, an inner rotor 3 and a ten-byte 4, and the outer rotor 2 is placed in the pump body cavity 101 of the fuel delivery pump body 1 , the inner rotor 3 is rotationally connected with the inner rotor shaft 102 of the oil delivery pump body 1 in the outer rotor 2, and the ten-byte 4 is placed in the ten-byte installation groove 303 of the inner rotor 3. It is characterized in that the oil delivery pump body 1 includes a pump The body cavity 101, the inner rotor shaft 102, the low-pressure oil cavity 103, the high-pressure oil cavity 104, the oil inlet hole 105, the oil inlet joint 106, the fixing hole 107 and the seal groove 108 are integrated in the circular pump body cavity 101, The inner rotor shaft 102 is eccentric to the pump body cavity 101 and is placed vertically on the bottom surface of the pump body cavity 101. The center of the circle of the bottom surface of the pump body cavity 101 is _O1 , and the circle center of the inner rotor shaft 102 on the bottom surface of the pump body cavity 101 is _O2 . The length of the radius O ₁ A of the bottom surface of the pump body cavity 101 passing through O 2 is r, _and the distance between O ₂ and O ₁ is d. Taking the radius O ₁ A of the bottom surface of the pump body cavity 101 as the axis of symmetry, two half-moon grooves are placed symmetrically. On the bottom surface of the pump body cavity 101, the groove on the left side of the radius O ₁ A is the high-pressure oil chamber 104, and the groove on the right is the low-pressure oil chamber 103, and the oil inlet hole 105 is built in the low-pressure oil chamber 103 on the bottom surface of the low-pressure oil chamber 103 The lower end of the oil inlet hole 105 is a round hole penetrating the bottom of the oil delivery pump body 1, the oil inlet connector 106 is placed on the back of the oil delivery pump body 1, the bottom of the inner cavity of the oil inlet connector 106 communicates with the oil inlet hole 105, and the oil inlet connector The inner cavity wall of 106 is a threaded structure, the annular sealing groove 108 is placed on the front surface of the oil delivery pump body 1, and the three fixing holes 107 are distributed on the oil delivery pump body 1 at equal intervals according to rotational symmetry;

The distance d between the O ₂ and O ₁ is 8-10% of the radius r of the bottom surface of the pump body cavity 101;

The oil delivery pump body 1 is processed by powder metallurgy technology;

The structure of the outer rotor 2 is that the outer rotor outer wall 201 is a cylindrical surface, the outer rotor outer wall 201 and the inner wall of the pump body cavity 101 are clearance fit, the outer rotor inner wall 202 is a rotationally symmetrical seven-lobed tooth-shaped cylindrical surface; The structure of the rotor 3 is that the outer wall 301 of the inner rotor is a rotationally symmetrical six-lobe tooth-shaped cylindrical surface, the center of the inner rotor 3 is a circular inner rotor shaft hole 302, and the drum-shaped ten-byte installation groove 303 is connected to the inner rotor shaft hole. 302 is concentrically placed on the front of the inner rotor 3; the drum-shaped ten-byte 4 is placed in the ten-byte installation groove 303 of the inner rotor 3, and the ten-byte 4 is connected to the camshaft 5 of the common rail pump through the central camshaft connection hole 401 Connection, in the outer rotor 2, the inner rotor 3 is rotationally connected with the inner rotor shaft 102 of the oil delivery pump body 1 through the inner rotor shaft hole 302, and the outer rotor 2 and the inner rotor 3 are eccentrically formed in the inner cavity 101 of the oil delivery pump body 1 A pair of eccentric inner meshing rotors are used as working elements for generating oil pressure; the front surfaces of the outer rotor 2 and the inner rotor 3 are 0.03mm-0.07mm lower than the front surface of the oil delivery pump body 1, and when the oil delivery pump is working, the camshaft 5 Driven, the inner rotor 3 is the active rotor, and the outer rotor 2 is the driven rotor. The inner rotor 3 and the outer rotor 2 rotate clockwise in the same direction, and the outer wall 301 of the inner rotor and the inner wall 202 of the outer rotor are eccentrically engaged with each other through the teeth.

Both the outer rotor 2 and the inner rotor 3 are processed by powder metallurgy technology.

The beneficial effect of the utility model is that the oil delivery pump body has an integral structure, the oil inlet hole is placed on the bottom surface of the pump body, and the oil enters axially, the structure is compact, the volume is small, and cavitation is not easy to occur; the outer rotor and the inner rotor are in the shape of seven petals The eccentric internal meshing structure of the cylindrical surface and the six-lobed toothed cylindrical surface, the deviation between the center of the inner rotor and the center of the outer rotor is small, the inner and outer rotors rotate in the same direction, and an independent oil chamber is formed between the teeth. During the working cycle, the teeth of the inner rotor and the outer rotor They keep meshing with each other, so the operation is smooth, the pulsation is small, the noise is low, and the volumetric efficiency is high.

Description of drawings

Figure 1 is a schematic structural diagram of the cycloidal fuel delivery pump in the high-pressure common rail fuel injection system;

Fig. 2 is a schematic diagram of the three-dimensional structure of the oil delivery pump body;

Fig. 3 is a left view of the oil delivery pump body;

Fig. 4 is a sectional view at B-B place among Fig. 3;

Figure 5 is a front view of the outer rotor;

Figure 6 is a front view of the inner rotor;

Fig. 7 is the front view of ten bytes;

Fig. 8 is a schematic diagram of the installation of the cycloid fuel delivery pump used in the high-pressure common rail fuel injection system.

In the figure, 1--oil pump body, 2--outer rotor, 3--inner rotor, 4--ten bytes, 5--camshaft, 6--common rail pump body, 7--oil pump fastening Screw, 8--low-pressure oil pipe tee joint, 9--O-ring, 101--pump body cavity, 102--inner rotor shaft, 103--low-pressure oil chamber, 104--high-pressure oil chamber, 105--inlet Oil hole, 106--oil inlet joint, 107--fixing hole, 108--seal groove, 201--outer wall of outer rotor, 202--inner wall of outer rotor, 301--outer wall of inner rotor, 302--shaft hole of inner rotor , 303--ten word installation groove, 401--camshaft connecting hole.

Detailed ways

Below in conjunction with embodiment and accompanying drawing, the utility model is further described.

Fig. 1 is a schematic structural diagram of an embodiment of a cycloidal fuel delivery pump in a high-pressure common rail fuel injection system. The cycloidal fuel delivery pump in a high-pressure common rail fuel injection system consists of a fuel delivery pump body 1, an outer rotor 2, an inner rotor 3 and a ten-section 4 Composition, the outer rotor 2 is placed in the pump body cavity 101 of the oil delivery pump body 1, the inner rotor 3 is rotationally connected with the inner rotor shaft 102 of the oil delivery pump body 1 in the outer rotor 2, and ten characters 4 are placed in the cross of the inner rotor 3 section installation groove 303.

As shown in Fig. 2, Fig. 3 and Fig. 4, the oil delivery pump body structure diagram, the oil delivery pump body 1 includes a pump body cavity 101, an inner rotor shaft 102, a low pressure oil chamber 103, a high pressure oil chamber 104, an oil inlet hole 105, an oil inlet The joint 106, the fixing hole 107, the sealing groove 108, and the oil delivery pump body 1 are an integral structure processed by powder metallurgy technology. In the circular pump body cavity 101, the inner rotor shaft 102 and the pump body cavity 101 are _{eccentrically} placed on the bottom surface of the pump body cavity 101. The center of the circle on the bottom surface of 101 is O ₂ , the length of the radius O ₁ A of the bottom surface of pump body cavity 101 passing through O ₂ is r, and the distance between O ₂ and O ₁ is d. In this embodiment, r is 22.5 mm, and d is 2.2 mm. . Taking the radius O ₁ A of the bottom surface of the pump body cavity 101 as the axis of symmetry, two half-moon grooves are placed symmetrically on the bottom surface of the pump body cavity 101 . The groove on the left side of the radius O ₁ A is the high-pressure oil chamber 104 , and the groove on the right side is the low-pressure oil chamber 103 . The oil inlet hole 105 is built in the lower end of the bottom surface of the low pressure oil chamber 103 . The oil inlet hole 105 is a round hole penetrating the bottom of the oil delivery pump body 1. The oil inlet connector 106 is placed on the back of the oil delivery pump body 1. The bottom of the inner cavity of the oil inlet connector 106 communicates with the oil inlet hole 105. The oil inlet connector 106 The wall of the inner cavity is a threaded structure. An annular sealing groove 108 is placed on the front surface of the oil delivery pump body 1, and three fixing holes 107 are distributed on the oil delivery pump body 1 at equal intervals according to rotational symmetry.

The structure of the outer rotor 2 is that the outer wall 201 of the outer rotor is a cylindrical surface, the outer wall 201 of the outer rotor is in clearance fit with the inner wall of the inner cavity 101 of the pump body, and the outer wall 301 of the inner rotor is a rotationally symmetrical seven-lobe tooth-shaped cylindrical surface, as shown in Figure 5 . The structure of the inner rotor 3 is that the outer wall 301 of the inner rotor is a rotationally symmetrical six-lobe tooth-shaped cylinder, the center of the inner rotor 3 is a circular inner rotor shaft hole 302, and the drum-shaped ten-byte installation groove 303 is aligned with the inner rotor shaft. The hole 302 is concentrically placed on the front of the inner rotor 3, as shown in FIG. 6 . The drum-shaped ten-piece 4 shown in FIG. 7 is placed in the ten-piece installation groove 303 of the inner rotor 3 , and the ten-piece 4 is connected to the camshaft 5 of the common rail pump through the central camshaft connecting hole 401 .

In the outer rotor 2, the inner rotor 3 is rotationally connected with the inner rotor shaft 102 of the oil delivery pump body 1 through the inner rotor shaft hole 302. The eccentric inner meshing rotor is used as the working element to generate oil pressure; when the oil delivery pump is working, driven by the camshaft 5, the inner rotor 3 is the active rotor, the outer rotor 2 is the driven rotor, and the inner rotor 3 and the outer rotor 2 are the same Rotating clockwise, the outer wall 301 of the inner rotor and the inner wall 202 of the outer rotor are eccentrically engaged with each other through the teeth

Fig. 8 is a schematic diagram of the installation of the cycloid fuel delivery pump used in the high-pressure common rail fuel injection system. The cycloid oil delivery pump is assembled with the outer rotor 2, the inner rotor 3 and the ten-piece 4 in the oil delivery pump body 1, and then the cycloid oil delivery pump is fastened to the common rail pump body 6 with the oil delivery pump fastening screw 7, and the inner cavity of the pump body 101 Cover the oil inlet hole of the common rail pump on the common rail pump body 6, the front surface of the outer rotor 2 and the inner rotor 3 is 0.05mm lower than the front surface of the oil delivery pump body 1, and the O-ring 9 is placed on the seal of the oil delivery pump body 1 The groove 108 acts as a seal to ensure that the fuel does not leak out. The camshaft 5 of the common rail pump is connected to the ten-piece 4 through the camshaft connection hole 401 in the center. The low-pressure oil pipe tee joint 8 is fixedly connected on the oil inlet joint 106 by threaded connection, so that the cycloid oil delivery pump is communicated with the fuel tank.

The working principle of the utility model is that the camshaft 5 rotates, and the inner rotor 3 is driven to rotate through the ten-point 4, the inner rotor 3 is the active rotor, the outer rotor 2 is the driven rotor, and the tooth lobes of the inner rotor 3 and the outer rotor 2 interact with each other. Eccentric meshing, rotating clockwise in the same direction, sucking fuel from the fuel tank into the low-pressure oil pipe tee joint 8 and filling the low-pressure oil chamber 103 through the oil inlet hole 105, and the inner rotor 3 and the outer rotor 2 form several independent oil tanks during the meshing rotation process. As the internal and external rotors mesh and rotate, the volume of each oil chamber will change. The volume of the oil chamber corresponding to the position of the low-pressure oil chamber 103 is the largest to absorb fuel, and the volume of the oil chamber corresponding to the position of the high-pressure oil chamber 104 is the smallest. , to discharge fuel with a certain pressure, the cyclic meshing of the teeth of the inner and outer rotors forms the oil suction and discharge process, and provides fuel to the common rail pump. Different from the cycloid oil delivery pump in the prior art, the utility model adopts an integrated structure oil delivery pump body processed by powder metallurgy technology, and the oil inlet method is axially from the oil inlet hole on the bottom surface of the low pressure oil chamber of the oil delivery pump body. Oil, the entire oil delivery pump is compact in structure, small in size, and not prone to cavitation; the teeth of the inner rotor and outer rotor keep meshing with each other during the working cycle, so the operation is stable, the pulsation is small, the noise is low, and the volumetric efficiency is high.

The utility model ensures that the fuel oil circulates in the low-pressure oil circuit system, and supplies fuel oil with sufficient flow and certain pressure to the high-pressure fuel injection pump, and can improve the energy-saving emission reduction and comprehensive performance level of domestic diesel engines in my country. The utility model is suitable for the fuel injection system of the diesel engine of the automobile.

Claims (3)

1. A cycloid fuel delivery pump in a high-pressure common rail fuel injection system. The cycloid fuel delivery pump in a high-pressure common rail fuel injection system consists of a fuel delivery pump body (1), an outer rotor (2), an inner rotor (3) and ten byte (4), the outer rotor (2) is placed in the inner cavity (101) of the oil delivery pump body (1), the inner rotor (3) is in the outer rotor (2) and the inner rotor of the oil delivery pump body (1) The shaft (102) is rotatably connected, and the ten-piece (4) is placed in the ten-piece installation groove (303) of the inner rotor (3). The integrated structure of the inner rotor shaft (102), low pressure oil chamber (103), high pressure oil chamber (104), oil inlet hole (105), oil inlet joint (106), fixing hole (107) and sealing groove (108), In the circular pump body cavity (101), the inner rotor shaft (102) is eccentric to the pump body cavity (101) and placed vertically on the bottom surface of the pump body cavity (101). The center of the bottom surface of the pump body cavity (101) is O ₁ , the center of the inner rotor shaft (102) on the bottom surface of the pump body cavity (101) is O ₂ , the length of the radius O ₁ A of the bottom surface of the pump body cavity (101) passing through O ₂ is r, and O ₂ deviates from O ₁ The distance is d, taking the radius O ₁ A of the bottom surface of the pump body cavity (101) as the axis of symmetry, two half-moon grooves are symmetrically placed on the bottom surface of the pump body cavity (101), and the groove on the left side of the radius O ₁ A is the high pressure oil cavity (104), the groove on the right is the low pressure oil cavity (103), the oil inlet hole (105) is built in the lower end of the bottom surface of the low pressure oil cavity (103) in the low pressure oil cavity (103), and the oil inlet hole (105) is Through the round hole at the bottom of the oil delivery pump body (1), the oil inlet connector (106) is placed on the back of the oil delivery pump body (1), and the bottom of the inner cavity of the oil inlet connector (106) communicates with the oil inlet hole (105). The inner cavity wall of the oil joint (106) is a threaded structure, the circular sealing groove (108) is placed on the front surface of the oil delivery pump body (1), and the three fixing holes (107) are distributed in the oil delivery pump at equal intervals according to rotational symmetry. body (1). 2. The cycloid fuel delivery pump in a high-pressure common rail fuel injection system according to claim 1, characterized in that the distance d between the O ₂ and O ₁ is 8 times the radius r of the bottom surface of the inner cavity (101) of the pump body ~10%. 3. The cycloid fuel delivery pump in a high pressure common rail fuel injection system according to claim 1, characterized in that the fuel delivery pump body (1) is processed by powder metallurgy technology.

Images