CN102678541A - Fuel delivery pump with floated cycloid rotor - Google Patents

Abstract

The invention belongs to the technical field of auto parts, and relates to a suspended cycloidal rotor oil delivery pump. The cycloidal oil delivery pump is composed of an oil delivery pump body, an outer rotor, an inner rotor and a ten-byte. There is a transverse diversion groove on the bottom surface of the pump body cavity between the upper part of the right side wall of the cavity and the inner wall of the pump body cavity, and 7 axial through grooves on the outer wall of the outer rotor are distributed in the radially corresponding positions of the tooth lobe centers of the inner wall of each outer rotor. position, when the inner rotor and the outer rotor rotate, the fuel flows to the parts that need to be lubricated along the transverse guide groove and each axial through groove, and an oil film is formed between the outer wall of the outer rotor and the inner wall of the pump body cavity, and the surface tension of the liquid makes the outer rotor There is no direct contact with the oil delivery pump body, and the outer rotor is suspended in the oil delivery pump body, which avoids the friction between the outer rotor and the oil delivery pump body, and improves the service life of the oil delivery pump. The invention has the advantages of stable operation, small pulsation, low noise and high volumetric efficiency, and is suitable for the diesel engine fuel injection system of automobiles.

Description

Suspended Cycloidal Rotor Oil Transfer Pump

technical field

The invention belongs to the technical field of auto parts, in particular to a suspension type cycloidal rotor oil delivery pump.

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.

In the high-pressure common rail system of a diesel engine, in order to ensure that the fuel circulates in the low-pressure oil circuit system, and to deliver sufficient flow and a certain pressure of fuel to the high-pressure fuel supply system, the cycloidal rotor pump has been used in low-pressure and high-speed systems in recent years. The most widely respected type in the field of pumps. In the early days, it was difficult to be popularized 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 prior art cycloid rotor pumps are severely worn and have a short service life. The main reason is that since the inner rotor is assembled on the eccentric shaft of the pump body, and the outer rotor rotates under the drive of the inner rotor, the high-pressure oil is generated when the volume between the inner and outer rotors is reduced during the mutual rotation of the inner and outer rotors. Yes, and in this process, the high-pressure oil will produce a reaction force on the inner and outer rotors, making the inner rotor move inward relatively, while the outer rotor moves outward relatively, and the force acting on the outer rotor will be greater. Since the radial clearance between the outer rotor and the pump body is very small, it is not easy to produce an oil film, so the friction between the outer rotor and the pump body is very severe during high-speed rotation, and even burrs will be generated on the pump body, making the outer rotor and the pump body cling died, resulting in the failure of the fuel pump. Therefore need a kind of simple in structure, low in noise, volume ratio is big, the long-life cycloidal rotor oil delivery pump that avoids the direct contact friction between outer rotor and pump body.

Contents of the invention

The purpose of the present invention is to solve the problem of a cycloidal rotor oil delivery pump with simple structure, low noise, large volume ratio and long service life as described in the background technology, and provide a suspension type cycloidal rotor oil delivery pump, a suspension type cycloidal rotor oil delivery pump The oil delivery pump is composed of an oil delivery pump body 1, an outer rotor 2, an inner rotor 3 and a ten-byte 4. The outer rotor 2 is placed in the pump body cavity 101 of the oil delivery pump body 1, and the inner rotor 3 is in the outer rotor 2 and connected with the oil delivery pump body 1. The inner rotor shaft 102 is rotationally connected, and the ten-piece 4 is placed in the ten-piece installation groove 303 of the inner rotor 3. It is characterized in that the oil delivery pump body 1 has an integral structure, and in the circular pump body cavity 101, the inner rotor The 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 bottom surface of the pump body cavity 101 is O ₁ , and the circle center of the inner rotor shaft 102 on the bottom surface of the pump body cavity 101 is O ₂ . _2. The length of the radius O ₁ A of the bottom surface of the pump body cavity 101 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 symmetrically placed in the pump body. On the bottom surface of the body cavity 101, the groove on the left side of the radius O ₁ A is the high-pressure oil chamber 104, the groove on the right is the low-pressure oil chamber 103, and the oil inlet 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 joint part 110 is placed on the back of the oil delivery pump body 1, the inner cavity bottom of the oil inlet joint part 110 communicates with the oil inlet hole 105, and the oil inlet joint part The inner cavity wall of the component 110 is a threaded structure, and the annular sealing groove 109 is placed on the front surface of the oil delivery pump body 1, and the three fixing holes 108 are distributed on the oil delivery pump body 1 at equal intervals according to rotational symmetry. There is an annular groove 106 along the cylindrical inner wall of the pump body cavity 101 on the bottom surface. Between the upper part of the right side wall of the low pressure oil chamber 103 and the cylindrical surface inner wall of the pump body cavity 101, there is a transverse guide on the bottom surface of the pump body cavity 101. Launder 107;

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 is a rotationally symmetrical seven-lobed tooth-shaped cylindrical surface, and the outer rotor inner wall There are 7 inwardly protruding outer rotor inner wall tooth lobes 203, and there are 7 axial through grooves 202 on the outer rotor outer wall 201. Location;

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 in contact with the inner rotor. The rotor shaft hole 302 is concentrically placed on the front of the inner rotor 3; the drum-shaped ten-piece 4 is placed in the ten-piece installation groove 303 of the inner rotor 3, and the ten-piece 4 is connected to the common rail pump through the central camshaft connection hole 401. Camshaft 5 connection;

In the outer rotor 2, the inner rotor 3 and the outer rotor 2 are eccentric to each other. In the inner cavity 101 of the pump body 1, the outer rotor 2 and the inner rotor 3 constitute a pair of eccentric inner meshing rotors 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;

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, 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 of the outer rotor Mesh with each other through tooth lobe.

The width of the annular groove 106 is 0.8-1.2 mm, and the depth is 0.4-0.6 mm;

The width of the lateral guide groove 107 is 0.7-1.2 mm, and the depth is 0.4-0.6 mm;

The axial through groove 202 has a width of 0.7-1.2 mm and a depth of 0.1-0.3 mm;

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, outer rotor 2 and inner rotor 3 are all processed by powder metallurgy technology.

The feature of the present invention is that there is a transverse guide groove 107 on the bottom surface of the pump body cavity 101 between the top of the right side wall of the low-pressure oil chamber 103 and the pump body cavity 101 inner wall, and on the outer rotor outer wall 201 and each outer rotor inner wall At the radial position corresponding to the center of the tooth lobe 203, there is an axial through groove 202 on the outer wall 201 of the outer rotor. The fuel entering the low-pressure oil chamber 102 of the fuel delivery pump body 1 smoothly flows to the parts requiring lubrication along the transverse guide groove 107 and each axial through groove 202 . Within the scope of the width and depth of the transverse diversion groove 107 and the axial through groove 202 defined in the present invention, an oil film is formed between the outer wall 201 of the outer rotor and the inner wall of the inner cavity 101 of the pump, and due to the surface tension of the liquid, the outer rotor 2 and the The oil delivery pump body 1 will not be in direct contact, and the outer rotor 2 is in a suspended state in the oil delivery pump body 1, which avoids direct contact between the two to generate friction, and improves the service life of the oil delivery pump.

The beneficial effect of the present invention is that the oil delivery pump body has an integrated structure, the oil inlet hole is placed on the bottom surface of the pump body, and the oil enters axially, and the outer rotor and the inner rotor are in the eccentricity of the seven-lobe tooth-shaped cylinder and the six-lobe tooth-shaped cylinder The meshing structure, 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, and the teeth of the inner rotor and the outer rotor keep meshing with each other during the working cycle, realizing the structure of the oil pump Requirements of simplicity, low noise and large volume ratio; the horizontal diversion groove set on the oil delivery pump body and the axial through groove set on the outer wall of the outer rotor avoid the friction caused by the direct contact between the outer rotor and the oil delivery pump body, so that the delivery The service life of the oil pump can be increased from about 500 hours in the prior art to about 1000 hours, and the service life is doubled without increasing the cost. According to the unit price of each oil delivery pump being 178 yuan and 20,000 units needed per year, the oil delivery pump of the present invention only needs 10,000 units, which can save 1,780,000 yuan of funds and will produce huge economic benefits.

Description of drawings

Figure 1 is a schematic structural diagram of a suspended cycloidal rotor oil delivery pump;

Fig. 2 is the front view of the oil delivery pump body;

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

Figure 4 is a front view of the outer rotor;

Fig. 5 is a sectional view at C-C place among Fig. 4;

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 a suspended cycloidal rotor fuel pump used in a 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--oil inlet joint part, 9--O-ring, 101--pump body cavity, 102--inner rotor shaft, 103--low pressure oil chamber, 104--high pressure oil chamber, 105--oil inlet Hole, 106--annular groove, 107--transverse guide groove, 108--fixing hole, 109--seal groove, 110--oil inlet joint part, 201--outer rotor wall, 202--axial through groove , 203--outer rotor inner wall tooth lobe, 301--inner rotor outer wall, 302--inner rotor shaft hole, 303--ten byte installation groove, 401--camshaft connecting hole.

Detailed ways

The present invention will be further described below in conjunction with the embodiments and the accompanying drawings.

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 slot 303.

As shown in Fig. 2 and Fig. 3, the oil delivery pump body 1 is an integrated 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 joint part 110 is placed on the back side of the oil delivery pump body 1. The bottom of the inner cavity of the oil inlet joint part 110 communicates with the oil inlet hole 105. The oil inlet joint part The lumen wall of the component 110 is a threaded structure. The annular sealing groove 109 is placed on the front surface of the oil delivery pump body 1, and the three fixing holes 108 are distributed on the oil delivery pump body 1 at equal intervals according to rotational symmetry. An annular groove 106 is formed on the bottom surface of the pump body cavity 101 along the cylindrical inner wall of the pump body cavity 101, the width of the ring groove 106 is 1mm, and the depth is 0.5mm. There is a transverse diversion groove 107 on the bottom surface of the pump body cavity 101 between the top of the right side wall of the low pressure oil chamber 103 and the cylindrical inner wall of the pump body cavity 101. The width of the transverse diversion groove 107 is 1 mm and the depth is 0.5 mm. mm.

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, the inner wall of the outer rotor is a rotationally symmetrical seven-lobe tooth-shaped cylindrical surface, and there are 7 teeth on the inner wall of the outer rotor. There are 7 axial through-slots 202 on the outer rotor outer wall 201, and the 7 axial through-slots 202 are distributed in the positions radially corresponding to the centers of the outer rotor inner wall tooth lobes 203. The axial through groove 202 has a width of 1 mm and a depth of 0.15 mm, as shown in FIG. 4 and FIG. 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 connection hole 401 .

In the outer rotor 2, the inner rotor 3 and the outer rotor 2 are eccentric to each other. In the inner cavity 101 of the oil pump body 1, the outer rotor 2 and the inner rotor 3 constitute a pair of eccentric inner meshing rotors as working elements for generating oil pressure. Both the inner rotor 3 and the outer rotor 2 are processed by powder metallurgy technology. 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, 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 of the outer rotor 202 are meshed with each other through tooth lobe.

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. After the outer rotor 2, inner rotor 3 and ten-piece 4 are assembled in the oil delivery pump body 1 of the cycloid oil delivery pump, the cycloid oil delivery pump is fastened on the common rail pump body 6 with the oil delivery pump fastening screw 7, and the pump The internal cavity 101 covers the common rail pump oil inlet hole 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 oil delivery pump body 1 The sealing groove 109 of the pump 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 part 110 through threaded connection, so that the cycloid oil delivery pump is communicated with the fuel tank.

The working principle of the present invention 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 petals of the inner rotor 3 and the outer rotor 2 are mutually eccentric Mesh, rotate clockwise in the same direction, suck fuel from the fuel tank into the low-pressure oil pipe tee joint 8 and fill 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 chambers during the meshing rotation process , with the meshing rotation of the inner and outer rotors, 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, and the fuel is sucked in, and the volume of the oil chamber corresponding to the position of the high-pressure oil chamber 104 is the smallest. The fuel with a certain pressure is discharged, and the cyclic engagement of the teeth of the inner and outer rotors forms an oil suction and discharge process to provide fuel to the common rail pump. During the working cycle, the teeth of the inner rotor and the outer rotor keep meshing with each other, so the operation is stable, the pulsation is small, the noise is low, and the volumetric efficiency is high. Different from the prior art cycloidal oil delivery pump, there is a transverse diversion groove 107 on the bottom surface of the pump body cavity 101 between the upper part of the right side wall of the low pressure oil chamber 103 and the inner wall of the pump body cavity 101 and a horizontal flow guide groove 107 on the outer wall of the outer rotor. 201 corresponds to the radial position of the center of each outer rotor inner wall tooth lobe 203. There is an axial through groove 202 on the outer wall 201 of the outer rotor. When the inner rotor 3 and the outer rotor 2 rotate, they enter the low-pressure oil chamber of the oil delivery pump body 1 103 The fuel flows smoothly along the transverse guide groove 107 and each axial through groove 202 to the parts that need to be lubricated. An oil film is formed between the outer wall of the rotor 201 and the inner wall of the pump body cavity 101. Due to the surface tension of the liquid, the outer rotor 2 and the oil delivery pump body 1 will not be in direct contact. The outer rotor 2 is suspended in the oil delivery pump body 1 to avoid friction. The service life of the oil delivery pump is improved.

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

Claims (6)

1. floated cycloid rotor oil transfer pump; Floated cycloid rotor oil transfer pump is made up of fuel supply pump housing (1), external rotor (2), internal rotor (3) and cross joint (4); External rotor (2) places in the pump housing inner chamber (101) of fuel supply pump housing (1); Internal rotor (3) is rotationally connected with the inner rotor shaft (102) of fuel supply pump housing (1) in external rotor (2), and cross joint (4) places in the cross joint mounting groove (303) of internal rotor (3), it is characterized in that; Said fuel supply pump housing (1) is structure as a whole; In the pump housing inner chamber (101) of circle, inner rotor shaft (102) and pump housing inner chamber (101) be eccentric and vertical to be placed on the bottom surface of pump housing inner chamber (101), and the center of circle of pump housing inner chamber (101) bottom surface is O ₁, the center of circle of inner rotor shaft (102) on pump housing inner chamber (101) bottom surface is O ₂, through O ₂Pump housing inner chamber (101) bottom surface radius O ₁The length of A is r, O ₂Depart from O ₁Distance be d, with pump housing inner chamber (101) bottom surface radius O ₁A is a symmetry axis, and 2 half-moon-shaped grooves are symmetrically placed on pump housing inner chamber (101) bottom surface radius O ₁The groove in A left side is high-voltage oil cavity (104); The groove on right side is low pressure oil pocket (103); Oil inlet hole (105) is built in the lower end of low pressure oil pocket (103) bottom surface at low pressure oil pocket (103); Oil inlet hole (105) is for penetrating the circular hole bottom the fuel supply pump housing (1), and fuel inlet fitting parts (110) place the back side of fuel supply pump housing (1), and the intracavity bottom of fuel inlet fitting parts (110) is communicated with oil inlet hole (105); The internal chamber wall of fuel inlet fitting parts (110) is a worm structure; The seal groove of ring (109) places on fuel supply pump housing (1) front surface, and 3 fixed holes (108) are spacedly distributed on fuel supply pump housing (1) by the rotation symmetry, at the cylndrical surface inwall of pump housing inner chamber (101) upper edge, bottom surface pump housing inner chamber (101) circular groove (106) are arranged; Between the cylndrical surface inwall of the top of low pressure oil pocket (103) right side wall and pump housing inner chamber (101), a transverse channels (107) is arranged on the bottom surface of pump housing inner chamber (101);

The structure of said external rotor (2) does; External rotor outer wall (201) is the cylndrical surface; External rotor outer wall (201) is a Spielpassung with the inwall of pump housing inner chamber (101), and the external rotor inwall is rotational symmetric seven lobe profile of tooth cylinders, and 7 parietal tooth lobes (203) in projecting inward external rotor are arranged on the external rotor inwall; 7 axial through slots (202) are arranged on the external rotor outer wall (201), and 7 axial through slots (202) are distributed in radially corresponding position, parietal tooth lobe (203) center in each external rotor;

The structure of said internal rotor (3) does; Internal rotor outer wall (301) is rotational symmetric six lobe profile of tooth cylinders; The center of internal rotor (3) is circular internal rotor axis hole (302), the cross joint mounting groove (303) and the concentric front that places internal rotor (3) of internal rotor axis hole (302) of cydariform; The cross joint (4) of cydariform places in the cross joint mounting groove (303) of internal rotor (3), and cross joint (4) is through camshaft attachment hole (401) camshaft of rail pump (5) connection together at center;

In external rotor (2); Internal rotor (3) and external rotor (2) are eccentric mutually; In the pump housing inner chamber (101) of fuel supply pump housing (1); External rotor (2) and internal rotor (3) constitute the internally meshed rotor of a pair of off-centre as the operation element that produces oil pressure, and the front surface of external rotor (2) and internal rotor (3) is lower than fuel supply pump housing (1) front surface 0.03mm～0.07mm;

Oil transfer pump is when work; Under the driving of camshaft (5), internal rotor (3) is a power rotor, and external rotor (2) is a driven rotor; Internal rotor (3) and external rotor (2) turn clockwise in the same way, intermesh through the tooth lobe between internal rotor outer wall (301) and the external rotor inwall.

2. floated cycloid rotor oil transfer pump according to claim 1 is characterized in that the width of said circular groove (106) is 0.8～1.2mm, and the degree of depth is 0.4～0.6mm.

3. floated cycloid rotor oil transfer pump according to claim 1 is characterized in that the width of said transverse channels (107) is 0.7～1.2mm, and the degree of depth is 0.4～0.6mm.

4. floated cycloid rotor oil transfer pump according to claim 1 is characterized in that the width of said axial through slot (202) is 0.7～1.2mm, and the degree of depth is 0.1～0.3mm.

5. floated cycloid rotor oil transfer pump according to claim 1 is characterized in that said O ₂Depart from O ₁Be 8～10% of pump housing inner chamber (101) bottom surface radius r apart from d.

6. floated cycloid rotor oil transfer pump according to claim 1 is characterized in that, said fuel supply pump housing (1), external rotor (2) and internal rotor (3) all adopt means of a powder metallurgy technique processing.

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