JP2019196768A - Vane pump - Google Patents

Abstract

To suppress a pressure variation when a pump chamber communicates with a discharge port.SOLUTION: A vane pump 100 comprises: a rotationally-driven rotor 2; a plurality of vanes 3 reciprocally arranged in a radial direction with respect to the rotor 2; a cam ring 4 which accommodates the rotor 2, and in which tips of the vanes 3 slide-contact with an internal peripheral face 4a accompanied by the rotation of the rotor 2; a pump chamber 6 partitioned by the rotor 2, the cam ring 4 and a pair of the adjacent vanes 3; and a first side plate 10 as a side member which is arranged while abutting on one-side faces of the rotor 2 and the cam ring 4. The first side plate 10 has a discharge port 12 for discharging a working fluid of the pump chamber 6, a gradually-changeable notch 21 which is formed so as to be expanded in an opening area toward a rotation direction of the rotor 2, and communicates with an end part of the discharge port 12, and a constant notch 22 whose opening area is constantly formed along the rotation direction of the rotor 2, and communicates with the end part of the discharge port 12.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vane pump.

  Patent Document 1 discloses a vane pump that includes an outer notch 15 and an inner notch 16 that are provided on a side member and extend from the opening of the discharge port toward the rear in the rotational direction of the rotor. In this vane pump, since the high-pressure working fluid is guided to the pump chamber 6 at the rear side in the rotational direction through the outer notch 15, the pump chamber 6 at the rear side in the rotational direction gradually increases in pressure before communicating with the discharge port 11. Is done.

JP 2014-163307 A

  In the vane pump described in Patent Document 1, when the pump speed is high or the gas ratio in the working fluid is high, the pressure increase speed of the pump chamber 6 is slow, and the discharge port 11 is in a state where the pressure in the pump chamber 6 is insufficient. There is a risk of communication. In such a situation, pressure fluctuations occur when the pump chamber 6 communicates with the discharge port 11.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to suppress pressure fluctuation when a pump chamber communicates with a discharge port.

  1st invention is a vane pump, Comprising: The side member arrange | positioned in contact with one side of a rotor and a cam ring, A side member discharges the working fluid of a pump chamber, and rotation of a rotor The graduated notch is formed so that the opening area increases toward the direction and communicates with the end of the discharge port, and the opening area is formed constant along the rotation direction of the rotor and communicates with the end of the discharge port. And having a constant notch.

  In the first invention, in addition to the gradual change notch formed so that the opening area increases in the rotation direction of the rotor, the side member has a constant opening area formed along the rotation direction of the rotor. Since it has a notch, the high-pressure working fluid is easily guided to the pump chamber from the beginning when the pump chamber communicates with the fixed notch. Therefore, since the pressure increase speed of the pump chamber increases, the pressure of the pump chamber increases when the pump chamber communicates with the discharge port.

  The second invention is characterized in that the constant notch has an arc shape centered on the rotation center of the rotor.

  In the second invention, the opening defined by the constant notch and the vane has a constant rotational length of the rotor regardless of the rotational angle of the rotor, so that the pump chamber can be stably boosted.

  According to a third aspect of the present invention, the opening area of the constant notch is larger than the opening area of the gradually changing notch when it is less than a predetermined rotation angle of the rotor, and is larger than the opening area of the gradually changing notch when the opening angle is not less than the predetermined rotation angle. It is small.

  In the third invention, the high-pressure working fluid is easily guided to the pump chamber from the beginning when the pump chamber communicates with the constant notch.

  According to the present invention, pressure fluctuation when the pump chamber communicates with the discharge port can be suppressed.

It is sectional drawing of the vane pump which concerns on embodiment of this invention. It is a side view of the rotor, cam ring, and side plate of the vane pump which concerns on embodiment of this invention. It is a side view of the side plate of the vane pump concerning the embodiment of the present invention. It is a side view of the side plate of the vane pump concerning the comparative example of the embodiment of the present invention. The change of the opening area of the notch of this embodiment and a comparative example with respect to the rotation angle of a rotor is shown.

  Embodiments of the present invention will be described below with reference to the drawings.

  With reference to FIG. 1 and 2, the vane pump 100 which concerns on embodiment of this invention is demonstrated.

  The vane pump 100 is used as a fluid pressure supply source for a fluid pressure device mounted on a vehicle or an industrial machine, such as a power steering device or a continuously variable transmission. In the present embodiment, a fixed displacement vane pump 100 using hydraulic oil as a working fluid will be described. The vane pump 100 may be a variable displacement vane pump.

  In the vane pump 100, the power of an engine (not shown) is transmitted to the end of the drive shaft 1, and the rotor 2 connected to the drive shaft 1 rotates. The rotor 2 rotates clockwise in FIG. The power source of the vane pump 100 may be an electric motor instead of the engine.

  As shown in FIGS. 1 and 2, the vane pump 100 includes a plurality of vanes 3 provided so as to freely reciprocate in the radial direction with respect to the rotor 2 and the rotor 2. A cam ring 4 in which the tip of the vane 3 is in sliding contact with the cam surface 4a, and a housing 5 for housing the rotor 2 and the cam ring 4 are provided.

  A plurality of pump chambers 6 are defined by the rotor 2, the cam ring 4, and the pair of adjacent vanes 3.

  The rotor 2 is an annular member and is connected to the tip of the drive shaft 1 by spline coupling. In the rotor 2, slits 2a that open to the outer peripheral surface are formed radially, and the vanes 3 are slidably inserted into the slits 2a. A back pressure chamber 2b is defined by the bottom surface of the vane 3 at the bottom of the slit 2a.

  The cam ring 4 is an annular member having a substantially elliptical shape in which the cam surface 4a has a short diameter and a long diameter. The cam ring 4 has two suction regions that expand the volume of the pump chamber 6 as the rotor 2 rotates, and two discharge regions that contract the volume of the pump chamber 6 as the rotor 2 rotates. That is, the vane 3 reciprocates twice while the rotor 2 makes one rotation, and the pump chamber 6 repeats contraction and expansion twice. The suction area and the discharge area are defined by the shape of the cam surface 4a.

  A first side plate 10 is disposed in contact with one side surface of the rotor 2 and the cam ring 4.

  The rotor 2, the cam ring 4, and the first side plate 10 are accommodated in a pump accommodating portion 5 a formed in a concave shape in the housing 5. The pump housing part 5 a is sealed by the pump cover 7. The pump cover 7 is disposed in contact with the other side surfaces of the rotor 2 and the cam ring 4. The first side plate 10 and the pump cover 7 are disposed with both side surfaces of the rotor 2 and the cam ring 4 sandwiched therebetween, and seal the pump chamber 6. The first side plate 10 and the pump cover 7 function as side members that are disposed in contact with one side surface of the rotor 2 and the cam ring 4.

  A high pressure chamber 8 into which hydraulic oil discharged from the pump chamber 6 is guided is formed in an annular shape on the bottom surface 5b of the pump housing portion 5a. The high pressure chamber 8 is partitioned by the first side plate 10 disposed on the bottom surface 5b. The high pressure chamber 8 communicates with a discharge passage (not shown) formed in the outer surface of the housing 5.

  Two arc-shaped suction ports (not shown) that open corresponding to the two suction areas of the cam ring 4 and guide the hydraulic oil to the pump chamber 6 are formed on the end surface 7a of the pump cover 7 on which the rotor 2 slides. Is done. Further, two arc-shaped discharge ports 7 b that open corresponding to the discharge region of the cam ring 4 are formed in the end surface 7 a of the pump cover 7 in a groove shape. Further, the pump cover 7 is formed with a suction passage (not shown) that guides the hydraulic oil of the tank to the pump chamber 6 through the suction port.

  FIG. 3 is a plan view of the end surface 10 a on which the rotor 2 in the first side plate 10 slides. As shown in FIG. 3, the first side plate 10 is a disk-shaped member and has two suction ports 11 and two discharge ports 12.

  The suction port 11 is opened corresponding to the two suction areas of the cam ring 4 and is formed in a groove shape on the end surface 10 a of the first side plate 10 so as to guide the hydraulic oil to the pump chamber 6. The suction port 11 communicates with the suction port of the pump cover 7 through a passage (not shown) formed on the inner peripheral surface of the pump housing portion 5a. Therefore, the hydraulic oil from the suction passage is guided to the pump chamber 6 through the suction port of the pump cover 7 and the suction port 11 of the first side plate 10.

  The discharge port 12 is formed through the first side plate 10 in an arc shape. The discharge port 12 is formed corresponding to the discharge region of the cam ring 4 and discharges the hydraulic oil in the pump chamber 6 to the high-pressure chamber 8. On the end surface 10a of the first side plate 10, a notch 20 communicating with the end of the discharge port 12 is formed in a groove shape. The notch 20 will be described in detail later.

  The first side plate 10 is formed with two back pressure passages 15 that lead the working oil from the high pressure chamber 8 to the back pressure chamber 2b of the rotor 2 (see FIG. 2). Further, four arc grooves 16 that communicate with the back pressure chamber 2 b are formed on the end surface 10 a of the first side plate 10.

  The relative rotation of the cam ring 4, the first side plate 10, and the pump cover 7 is restricted by two positioning pins (not shown). Thereby, the suction port 11 and the discharge port 12 of the first side plate 10 with respect to the suction region and the discharge region of the cam ring 4 and the suction port and the discharge port 7b of the pump cover 7 are positioned.

  When the drive shaft 1 is rotated by driving the engine, the rotor 2 connected to the drive shaft 1 is rotated. Accordingly, each pump chamber 6 in the cam ring 4 is connected to the suction port of the pump cover 7 and the first side plate 10. The working oil is sucked through the suction port 11, and the working oil is discharged to the high pressure chamber 8 through the discharge port 7 b of the pump cover 7 and the discharge port 12 of the first side plate 10. The hydraulic oil in the high pressure chamber 8 is supplied to the fluid pressure device through the discharge passage. Thus, each pump chamber 6 in the cam ring 4 supplies and discharges hydraulic oil by expansion and contraction accompanying the rotation of the rotor 2.

  Next, the notch 20 formed in the end surface 10a of the first side plate 10 will be described in detail with reference to FIGS.

  The notch 20 is formed in each of the two discharge ports 12. The notch 20 includes two notches, a gradually changing notch 21 and a constant notch 22.

  The gradually changing notch 21 is formed in a groove shape so that the opening area gradually increases in the rotation direction of the rotor 2. Here, the opening area of the gradual change notch 21 is a cross-sectional area of the gradual change notch 21 on the surface along the radial direction of the rotor 2. The shape of the gradually changing notch 21 will be specifically described. The gradual change notch 21 is formed on the end surface 10a of the first side plate 10 in a triangular shape having two straight lines 21b and 21c extending linearly from the top 21a to the discharge port 12. The gradually changing notch 21 has a V-shaped cross section on the surface along the radial direction of the rotor 2. Further, the groove depth of the gradual change notch 21 is formed so as to gradually increase toward the rotation direction of the rotor 2. The shape of the gradually changing notch 21 is not limited to the above shape, and may be any shape as long as the opening area gradually increases in the rotation direction of the rotor 2.

  The constant notch 22 is formed in a groove shape with a constant opening area along the rotation direction of the rotor 2. Here, the opening area of the constant notch 22 is a cross-sectional area of the constant notch 22 on the surface along the radial direction of the rotor 2. The shape of the constant notch 22 will be specifically described. The constant notch 22 is formed in an arc shape on the end surface 10 a of the first side plate 10. The constant notch 22 has two arcs 22a and 22b centering on the rotation center of the rotor 2, and a curved portion 22c connecting both ends of the two arcs 22a and 22b. Thus, the constant notch 22 is formed in an arc shape centered on the rotation center of the rotor 2. The constant notch 22 has a U-shaped cross section on the surface along the radial direction of the rotor 2. Further, the groove depth of the constant notch 22 is formed constant along the rotation direction of the rotor 2. The shape of the constant notch 22 is not limited to the above shape, and may be any shape as long as the opening area is constant along the rotation direction of the rotor 2. Note that the opening area of the curved portion 22 c of the constant notch 22 is not constant along the rotation direction of the rotor 2. However, since the curved portion 22 c prevents the vane 3 and the tip of the constant notch 22 from being caught, the opening area of the tip of the constant notch 22 may not be constant along the rotation direction of the rotor 2.

  The constant notch 22 is formed outside the gradually changing notch 21. The top portion 21 a of the gradually changing notch 21 and the rotation direction end portion of the rotor 2 in the curved portion 22 c of the constant notch 22 are located on the same radial direction of the rotor 2. Therefore, the pump chamber 6 communicates with the gradual change notch 21 and the constant notch 22 simultaneously with the rotation of the rotor 2. When the pump chamber 6 communicates with the gradual change notch 21 and the constant notch 22 as the rotor 2 rotates, the adjacent pump chamber 6A and pump chamber 6B (see FIG. 2) are connected to the gradual change notch 21, the constant notch 22 and the vane 3. It communicates through the opening defined by Thereby, the high-pressure hydraulic fluid from the discharge port 12 is guided from the pump chamber 6A on the front side in the rotational direction to the pump chamber 6B on the rear side in the rotational direction. Accordingly, the pressure in the pump chamber 6B on the rear side in the rotational direction gradually increases before communicating with the discharge port 12, so that rapid pressure fluctuations when communicating with the discharge port 12 are suppressed.

  The length of the rotor 2 in the rotational direction of the gradual change notch 21 and the constant notch 22 is such that the pump chamber 6 sucks when the pump chamber 6 communicates with the gradual change notch 21 and the constant notch 22 as the rotor 2 rotates. It is formed in a length that does not communicate with the port 11. That is, the gradually changing notch 21 and the constant notch 22 are formed so that the hydraulic oil does not flow backward from the discharge port 12 to the suction port 11 through the gradually changing notch 21 and the constant notch 22.

  Here, with reference to FIG. 4, the notch 40 in the vane pump which concerns on a comparative example is demonstrated. FIG. 4 is a side view of the first side plate 10 in the vane pump according to the comparative example, and corresponds to FIG. 3. In FIG. 4, the same components as those in the present embodiment are denoted by the same reference numerals.

  The notch 40 includes a gradual change notch 21 and a gradual change notch 21 formed outside the gradual change notch 21 and having a shorter length than the gradual change notch 21. The comparative example is different from the present embodiment in that a gradually changing small notch 41 is formed instead of the constant notch 22. The gradually changing small notch 41 is formed in a groove shape so that the opening area gradually increases in the rotation direction of the rotor 2 and is different from the gradually changing notch 21 only in that the length is short.

  FIG. 5 shows changes in the opening areas of the notches 20 and 40 of the present embodiment and the comparative example with respect to the rotation angle of the rotor 2. The horizontal axis in FIG. 5 is the rotation angle of the rotor 2. The vertical axis represents the opening area of the notches 20 and 40, which is the opening area defined by the notches 20 and 40 and the vane 3, and is the cross-sectional area of the opening communicating with the adjacent pump chamber 6.

  As can be seen from FIG. 5, in the comparative example, the opening area of both the gradually changing notch 21 and the gradually changing small notch 41 increases in a quadratic curve toward the rotation direction of the rotor 2. As the rotor 2 rotates, the pump chamber 6 communicates with the gradually changing notch 21 and then with the gradually changing small notch 41. Therefore, in the comparative example, the opening area of the notch 40 (the combined opening area of the gradually changing notch 21 and the gradually changing small notch 41) is small at the initial stage when the pump chamber 6 communicates with the gradually changing notch 21, and the pump chamber 6 gradually changes. After communicating with the small notch 41, the opening area of the notch 40 is increased. That is, in the comparative example, when the pump chamber 6 approaches the discharge port 12, the opening area of the notch 40 is increased.

  In such a comparative example, when the rotational speed of the rotor 2 is high or the gas ratio in the hydraulic oil is high, the opening area of the notch 40 is small at the initial stage when the pump chamber 6 communicates with the gradual change notch 21. The high pressure hydraulic oil from the discharge port 12 is led from the pump chamber 6A on the front side in the rotation direction to the pump chamber 6B on the rear side in the rotation direction through the notch 40, so that the pump chamber 6B has insufficient pressure increase speed. The discharge port 12 communicates with the pressure not sufficiently increased. Thereby, when the pump chamber 6B communicates with the discharge port 12, a rapid pressure fluctuation occurs.

  On the other hand, in the present embodiment, the constant notch 22 has a constant opening area along the rotation direction of the rotor 2. Specifically, as shown in FIG. 5, the opening area of the constant notch 22 is larger than the opening area of the gradual change notch 21 below the predetermined rotation angle α of the rotor 2 and gradually changes above the predetermined rotation angle α. The opening area of the notch 21 is smaller. As the rotor 2 rotates, the pump chamber 6 communicates with the gradual change notch 21 and the constant notch 22 simultaneously. For this reason, in this embodiment, the opening area of the notch 20 (the combined opening area of the gradually changing notch 21 and the constant notch 22) is large from the initial stage when the pump chamber 6 communicates with the gradually changing notch 21 and the constant notch 22, and the secondary The curve increases smoothly.

  Therefore, in the present embodiment, even when the rotation speed of the rotor 2 is high or the gas ratio in the hydraulic oil is high, the pump chamber 6 communicates with the gradual change notch 21 and the constant notch 22 from the initial stage of the notch 20. Since the opening area is large, the high pressure hydraulic fluid from the discharge port 12 is guided through the notch 20 from the pump chamber 6A on the front side in the rotational direction to the pump chamber 6B on the rear side in the rotational direction, so that the pump chamber 6B is pressurized. Then, the pump chamber 6B communicates with the discharge port 12 in a state where the pressure is sufficiently increased. Thereby, pressure fluctuation when the pump chamber 6B communicates with the discharge port 12 is suppressed.

  In addition, since the constant notch 22 has an arc shape centered on the rotation center of the rotor 2, the opening defined by the constant notch 22 and the vane 3 has a rotation direction length of the rotor 2 at a rotation angle of the rotor 2. It is constant without approaching. That is, the length of the diaphragm, which is an opening defined by the constant notch 22 and the vane 3, is constant regardless of the rotation angle of the rotor 2. Therefore, the pump chamber 6 can be stably boosted.

  According to the above embodiment, there exists an effect shown below.

  The first side plate 10 has a constant opening area formed along the rotation direction of the rotor 2 in addition to the gradual change notch 21 formed so that the opening area increases toward the rotation direction of the rotor 2. Since the notch 22 is provided, high-pressure hydraulic oil is easily guided to the pump chamber 6 from the beginning when the pump chamber 6 communicates with the constant notch 22. Accordingly, the pressure increase speed of the pump chamber 6 increases, and the pressure of the pump chamber 6 when the pump chamber 6 communicates with the discharge port 12 increases. Therefore, pressure fluctuation when the pump chamber 6 communicates with the discharge port 12 can be suppressed.

  Below, the modification of this embodiment is demonstrated.

  (1) The gradual change notch 21 and the constant notch 22 may be formed in communication with the discharge port 7b (see FIG. 1) of the pump cover 7. Thus, the gradual change notch 21 and the constant notch 22 may be formed in communication with at least one of the discharge port 12 of the first side plate 10 and the discharge port 7b of the pump cover 7.

  (2) In addition to the first side plate 10 as a side member disposed in contact with one side surface of the rotor 2 and the cam ring 4, the second side plate as a side member is also provided on the other side surface of the rotor 2 and the cam ring 4. May be disposed in contact with each other. That is, the pump chamber 6 may be partitioned by sandwiching the rotor 2 and the cam ring 4 from both sides by two side plates (side members). In this case, the second side plate is disposed between the rotor 2 and the pump cover 7. In this embodiment, instead of the discharge port 7b of the pump cover 7, a discharge port is formed on the surface of the second side plate that contacts the rotor 2 and the cam ring 4. The gradually changing notch 21 and the constant notch 22 may be formed in communication with the discharge port of the second side plate. In this embodiment, the gradual change notch 21 and the constant notch 22 may be formed in communication with at least one of the discharge port 12 of the first side plate 10 and the discharge port of the second side plate.

  (3) In the above embodiment, the constant notch 22 is formed outside the gradually changing notch 21. Instead of this, the constant notch 22 may be formed inside the gradually changing notch 21.

  (4) In the above embodiment, the top portion 21 a of the gradual change notch 21 and the rotation direction end portion of the rotor 2 in the curved portion 22 c of the constant notch 22 are located on the same radial direction of the rotor 2. Instead, the top portion 21 a of the gradual change notch 21 and the rotation direction end portion of the rotor 2 in the curved portion 22 c of the constant notch 22 may be shifted in the rotation direction of the rotor 2. In this embodiment, either the gradual change notch 21 or the constant notch 22 may communicate with the pump chamber 6 in advance as the rotor 2 rotates. However, from the viewpoint of securing the opening area from the initial stage, it is desirable that the pump chamber 6 communicates with the constant notch 22 before the gradual change notch 21 as the rotor 2 rotates.

  Hereinafter, the configuration, operation, and effect of the embodiment of the present invention will be described together.

  The vane pump 100 includes a rotor 2 that is driven to rotate, a plurality of vanes 3 that are reciprocally movable in the radial direction with respect to the rotor 2, and a rotor 2 that houses the rotor 2 and an inner peripheral surface 4 a as the rotor 2 rotates. The cam ring 4 slidably contacting the tip of the vane 3, the pump chamber 6 defined by the rotor 2, the cam ring 4, and a pair of adjacent vanes 3, and one side surface of the rotor 2 and the cam ring 4 are disposed in contact with each other. A first side plate 10 as a side member, and the first side plate 10 has a discharge port 12 that discharges the hydraulic oil in the pump chamber 6 and an opening area that increases in the rotational direction of the rotor 2. The gradual change notch 21 that is formed and communicates with the end of the discharge port 12, and has a constant opening area along the rotation direction of the rotor 2, and communicates with the end of the discharge port 12. It has a notch 22, a.

  In this configuration, the first side plate 10 has a constant opening area along the rotation direction of the rotor 2 in addition to the gradually changing notch 21 formed so that the opening area increases toward the rotation direction of the rotor 2. Since the fixed notch 22 is formed, high-pressure hydraulic oil is easily guided to the pump chamber 6 from the beginning when the pump chamber 6 communicates with the fixed notch 22. Accordingly, the pressure increase speed of the pump chamber 6 increases, and the pressure of the pump chamber 6 when the pump chamber 6 communicates with the discharge port 12 increases. Therefore, pressure fluctuation when the pump chamber 6 communicates with the discharge port 12 can be suppressed.

  The constant notch 22 has an arc shape centered on the rotation center of the rotor 2.

  In this configuration, since the opening defined by the constant notch 22 and the vane 3 has a constant rotational length of the rotor regardless of the rotational angle of the rotor 2, the pump chamber 6 can be stably boosted. .

Further, the opening area of the constant notch 22 is larger than the opening area of the gradually changing notch 21 when it is less than the predetermined rotation angle α of the rotor 2, and smaller than the opening area of the gradually changing notch 21 when it is equal to or larger than the predetermined rotation angle α. Then, high-pressure hydraulic oil is easily guided to the pump chamber 6 from the beginning when the pump chamber 6 communicates with the constant notch 22.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

DESCRIPTION OF SYMBOLS 100 ... Vane pump, 2 ... Rotor, 3 ... Vane, 4 ... Cam ring, 6 ... Pump chamber, 7 ... Pump cover (side member), 7b ... Discharge port, 10 ... 1st side plate (side member), 12 ... Discharge port, 20 ... Notch, 21 ... Gradual change notch, 22 ... Constant notch

Claims (3)

A rotor that is driven to rotate;
A plurality of vanes provided so as to freely reciprocate in the radial direction with respect to the rotor;
A cam ring that houses the rotor and has the vane tip slidably contact the inner peripheral surface as the rotor rotates;
A pump chamber defined by the rotor, the cam ring, and a pair of adjacent vanes;
A side member disposed in contact with one side surface of the rotor and the cam ring, and
The side member is
A discharge port for discharging the working fluid in the pump chamber;
A gradual change notch formed so that the opening area increases in the rotational direction of the rotor, and communicates with the end of the discharge port;
A vane pump having a constant notch that is formed with a constant opening area along a rotation direction of the rotor and communicates with an end of the discharge port. The vane pump according to claim 1,
The vane pump according to claim 1, wherein the constant notch has an arc shape centering on a rotation center of the rotor. The vane pump according to claim 1 or 2,
The opening area of the constant notch is larger than the opening area of the gradually changing notch when it is less than a predetermined rotation angle of the rotor, and smaller than the opening area of the gradually changing notch when it is equal to or more than the predetermined rotation angle. Vane pump.

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