Variable capacity pump

Abstract

The present invention provides a variable capacity pump that can suppress corrosion caused by cavitation of low-hardness materials. The variable capacity pump 120 of the present invention includes: a rotor 4 that is driven to rotate; a plurality of blades 15 for moving a liquid medium, which are arranged at intervals in the circumferential direction of the rotor 4 and can be moved in and out of the outer circumference of the rotor 4; and a housing that accommodates the rotor 4 and the plurality of blades 15, and uses the rotor 4 and the plurality of blades 15 to liquid-tightly define (liquid-tightly define around the rotor 4 with the plurality of blades 15 in the circumferential direction) a plurality of medium spaces for the liquid medium to flow in and out, and the blades 15 are opposite (sliding contact) to the inner wall of the housing that defines the medium space, and the inner wall has a Vickers hardness of less than 130, and a recess (15a to 15d) is formed to connect the adjacent medium spaces.

Description

Technical Field

[0001] The present invention relates to a variable capacity pump (also referred to as a variable displacement pump). Background Art

[0002] Conventionally, as a variable capacity pump applied to an internal combustion engine (hereinafter referred to as an engine) for a motor vehicle, a vane-type variable capacity pump (also referred to as a vane pump) is known in which a vane is accommodated in a gap of a rotor so that the vane can enter and exit, and the volume of a medium space (also referred to as a working oil chamber or a pump chamber) formed between the inner peripheral surface of a cam ring (also referred to as a control ring) and the outer peripheral surface of the rotor and the vane is changed. Patent Document 1 describes an example of the variable capacity pump described above.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-87777 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The variable capacity pump described above usually has flat blades, and the rotor is driven to rotate by the crankshaft of the engine. The blades rotate as the rotor rotates, thereby causing the working fluid (oil such as working oil or lubricating oil, also called liquid medium) to circulate (inhale and discharge) through the medium space. When the engine speed increases and the speed of the blades increases accordingly, the pressure reduction behind the blades becomes significant, and cavitation (also called cavitation or cavitation) occurs due to the pressure being lower than the saturated vapor pressure of the working fluid. When the cavitation is destroyed, there is a problem of corrosion (erosion) of the pump housing made of low-hardness materials such as aluminum alloy materials for lightweighting.

[0008] An object of the present invention is to provide a variable capacity pump capable of suppressing corrosion caused by cavitation of a low-hardness material.

[0009] Technical means for solving technical problems

[0010] In order to achieve the above-mentioned purpose, the variable capacity pump of the present invention includes: a rotor driven to rotate; a plurality of blades for moving a liquid medium, which are arranged at intervals in the circumferential direction of the rotor and can be arranged on the outer peripheral side of the rotor in an inward and outward manner; and a housing, which accommodates the rotor and the plurality of blades, and utilizes the rotor and the plurality of blades to liquid-tightly define (form) a plurality of medium spaces for the liquid medium to flow in and out, and the blades form a recess that connects adjacent medium spaces at a portion opposite to the inner wall of the housing that defines the medium space and has a Vickers hardness of less than 130.

[0011] Effects of the Invention

[0012] According to the present invention, by suppressing cavitation in the vicinity of a member having low hardness in a vane-type variable displacement pump, corrosion of the low-hardness material can be prevented.

[0013] Other structures, functions and effects of the present invention are described in detail in the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an exploded perspective view of the variable displacement pump according to the embodiment of the present invention when viewed from the control case side.

[0015] Figure 2 This is an exploded perspective view of a variable displacement pump according to an embodiment of the present invention when viewed from the pump housing side.

[0016] Figure 3 This is a side view (test view) of the variable displacement pump according to the embodiment of the present invention when viewed from the control case side.

[0017] Figure 4 yes Figure 3 Cross-sectional view along line IV-IV in FIG.

[0018] Figure 5 It is a system configuration diagram of a variable capacity pump according to an embodiment of the present invention.

[0019] Figure 6 yes Figure 5 Cross-sectional view along line VI-VI.

[0020] Figure 7 This is a side view of a variable displacement pump according to an embodiment of the present invention when viewed in perspective.

[0021] Figure 8 This is a side view of a variable displacement pump in a state where a pump cover is mounted on a control case, showing an embodiment of the present invention.

[0022] Fig. 9 This is an enlarged perspective view of a main part of the periphery of a blade of a variable displacement pump according to an embodiment (first embodiment of a blade) of the present invention.

[0023] Fig.10 It is an enlarged front view (front view) of a vane of a variable capacity pump according to an embodiment (first embodiment of a vane) of the present invention.

[0024] Fig.11 yes Fig.10 AA line cross-section diagram.

[0025] Fig.12The invention is used to explain the effects of the variable capacity pump according to the embodiment of the present invention. Fig.10 BB line cross section.

[0026] Fig.13 This is an enlarged front view of a vane of a variable displacement pump according to an embodiment (a second embodiment of a vane) of the present invention.

[0027] Fig.14 This is an enlarged front view of a vane of a variable displacement pump according to an embodiment (third embodiment of the vane) of the present invention.

[0028] Fig.15 yes Fig.14 AA line cross-section diagram.

[0029] Fig.16 This is an enlarged front view of a vane of a variable capacity pump according to an embodiment (fourth embodiment of the vane) of the present invention. DETAILED DESCRIPTION

[0030] The following is a detailed description of the embodiment of the variable capacity pump of the present invention based on the accompanying drawings. In addition, this embodiment shows an embodiment of a variable capacity pump that is applied to supply oil (working oil or lubricating oil) to a sliding part of an internal combustion engine for an automobile and supplies oil pressure as a working source of a variable valve mechanism that makes the valve timing of an engine valve variable.

[0031] The variable displacement pump in this embodiment is applied to a vane type and is provided at the front end of a cylinder block of an internal combustion engine or the like.

[0032] [Overall structure]

[0033] Figure 1 is an exploded perspective view of a variable capacity pump according to an embodiment of the present invention when viewed from the control housing side. Figure 2 is an exploded perspective view of a variable capacity pump according to an embodiment of the present invention when viewed from one side of a pump housing. Figure 3 This is a side view of the variable displacement pump according to the embodiment of the present invention when viewed from the control case side. Figure 4 yes Figure 3 The IV-IV cross-sectional view of Figure 5 is a system structure diagram of a variable capacity pump according to an embodiment of the present invention, Figure 6 yes Figure 5 Cross-sectional view along line VI-VI. Figure 7 This is a side view of a variable capacity pump according to an embodiment of the present invention. Figure 8 This is a side view of a variable displacement pump in a state where a pump cover is attached to a control case, showing an embodiment of the present invention.

[0034] like Figures 1 to 4As shown, the variable capacity pump 120 mainly includes: a bottomed cylindrical pump housing 1 whose one end opening is closed by a pump cover 2; a rotor 4 rotatably accommodated in the pump housing 1 and connected by inserting a crankshaft 3 into a central opening 4b; a control ring 5 as a movable part swingably arranged on the outer peripheral side of the rotor 4 and into which the crankshaft 3 is inserted; and a pilot valve 7 provided in a control housing 6 fixed to the outer side of the pump cover 2 as a control mechanism for controlling the oil pressure supply switching in order to swing the control ring 5. The crankshaft 3 passes through the approximate center of the pump housing 1. In addition, a solenoid valve 100 as a switching mechanism described later is connected to the variable capacity pump 120.

[0035] The pump housing 1, pump cover 2 and control housing 6 are as shown in FIG. Figure 1 and Figure 3 As shown, the pump housing 1, the control housing 6 and the pump cover 2 are integrally connected by a plurality of bolts 9, and the bolts 9 are inserted into bolt insertion holes respectively formed in the pump housing 1, the control housing 6 and the pump cover 2 to fasten them.

[0036] The pump housing 1 is integrally formed of a material containing aluminum such as an aluminum alloy, and the bottom surface of the concave pump housing portion 1s is processed to have high precision in terms of flatness and surface roughness because one axial side surface of the control ring 5 slides thereon, and the sliding range is formed by machining. In this embodiment, the pump housing 1, the pump cover 2, and the control housing 6 constitute a housing of the variable capacity pump 120, and the pump housing portion is formed inside the housing.

[0037] In addition, the pump housing 1, such as Figure 1 , Figure 2 , Figure 4 As shown, a bearing hole 1d for supporting one end of the crankshaft 3 is formed through the bottom surface of the pump storage portion 1s serving as the working chamber at a substantially central position, and a bottomed pin hole 1c is provided at a specified position on the inner circumferential surface, and a pivot support pin 10 (shaft component) serving as a pivot support point of the control ring 5 is inserted into the pin hole 1c.

[0038] A first arcuate concave sealing surface 1a is formed on the inner circumference of the vertically upper portion of the pump housing portion 1s, and a second arcuate concave sealing surface 1b is formed on the inner circumference of the vertically lower portion of the pump housing portion 1s.

[0039] The first seal member 13 fitted into the first seal groove 5b formed in the control ring 5 is in normal (constant) sliding contact with the first seal surface 1a to seal the first control oil chamber 16. The first seal surface 1a and the first seal member 13 constitute a first seal mechanism.

[0040] The second seal member 14, which is fitted into the second seal groove 5c formed in the control ring 5, normally slides in contact with the second seal surface 1b to seal the second control oil chamber 17, which is described below. The second seal surface 1b and the second seal member 14 constitute a second seal mechanism.

[0041] In addition, the first sealing surface 1a and the second sealing surface 1b are as follows Figure 5 As shown, the pivot pin 10 is formed into an arcuate surface of a predetermined length centered thereon, and the length is set to allow the first seal member 13 and the second seal member 14 to be in sliding contact with each other at all times within the range of eccentric swing of the control ring 5 .

[0042] In addition, in the pump housing 2, as Figure 1 and Figure 2 As shown, a roughly crescent-shaped inlet suction portion, namely, a suction port portion 11 (suction portion) is formed, and a roughly crescent-shaped inlet discharge portion, namely, a discharge port portion 12 (discharge portion) is formed roughly opposite to the suction port portion 11 in the radial direction. In addition, the specific structures of the suction port portion 11 and the discharge port portion 12 will be described later.

[0043] In addition, an opening 62 constituting a discharge passage 61 is formed through the pump cover 2 on the outer peripheral side of the discharge port portion 12 (a formation position of a discharge passage 61 described later).

[0044] Pump cover 2 Figure 1 and Figure 2 As shown, the pump cover 2 is formed of an aluminum alloy material into a roughly plate-like shape, and a bearing hole 2a is formed through the substantially central position to rotatably support the other end of the crankshaft 3, and a plurality of convex portions for forming the above-mentioned bolt insertion holes are integrally formed on the outer periphery. In addition, the pump cover 2 is positioned in the circumferential direction on the pump housing 1 by a plurality of positioning pins outside the figure, and is connected to the pump housing 1 by a plurality of bolts 9.

[0045] The rotational force transmitted from the crankshaft 3 is transmitted to the rotor 4, causing the rotor 4 to rotate Figure 5 The crankshaft 3 rotates in the direction of the arrow (clockwise), and the left half of the figure centered on the crankshaft 3 becomes the suction area, and the right half becomes the discharge area.

[0046] The rotor 4 (outer periphery), such as Figure 1 and Figure 2 As shown in FIG. 1 , the gaps 4a formed by a plurality of (nine in this example) notches spaced apart in the circumferential direction are formed radially (along the radial direction). Figure 1 and Figure 2As shown, nine blades 15 are slidably held in nine slits 4a formed radially from one side of the inner center to the outside, and back pressure chambers 24 having a substantially circular cross section are formed at the root end of each slit 4a for introducing the discharge oil pressure discharged to the discharge port 12. The blades 15 are pushed outward by the pressure in each back pressure chamber 24 and the centrifugal force generated by the rotation of the rotor 4.

[0047] Each blade 15 has a rectangular flat plate shape and is inserted into each gap 4a along the radial direction. Each blade 15 is configured so that each root end edge on the inner side is in sliding contact with the outer peripheral surface of a pair of front and rear blade rings 18, 18, and each front end edge on the outer side can be in sliding contact with the inner peripheral surface 5a of the control ring 5. In addition, each blade 15 is configured so that each side end edge in the direction of the rotation axis of the rotor 4, etc. can be in sliding contact with the pump housing portion 1s of the pump housing 1 and the inner side surface of the pump cover 2. In addition, between each circumferentially adjacent blade 15 and the inner peripheral surface 5a of the control ring 5, the outer peripheral surface of the rotor 4, the pump housing portion 1s of the pump housing 1, and the inner side surface of the pump cover 2, a plurality of pump chambers 19 as a plurality of working oil chambers are formed in a liquid-tight manner. As described later, the plurality of pump chambers 19 are a plurality of medium spaces for the liquid medium (oil such as working oil or lubricating oil) moved by the blades 15 to flow in and out, and are spaces defined in a circumferential direction liquid-tightly by the nine blades 15 around the rotor 4 (between the inner peripheral surface 5a of the control ring 5 and the outer peripheral surface of the rotor 4) in the housing. Each blade ring 18 pushes each blade 15 radially outward as it rotates, and even when the internal combustion engine speed is low and the centrifugal force and the pressure of the back pressure chamber 24 are small, each front end of each blade 15 is in sliding contact with the inner peripheral surface 5a of the control ring 5, and each pump chamber 19 is formed by being partitioned liquid-tightly.

[0048] Therefore, when the rotational force transmitted from the crankshaft 3 is transmitted to the rotor 4, the volume of the pump chamber 19 increases from the minimum volume state, and after reaching the maximum volume, the volume decreases. In this way, the area where the volume of the pump chamber 19 increases becomes the suction area, and the area where the volume decreases becomes the discharge area.

[0049] In the present embodiment, the vanes 15 , the control ring 5 , the rotor 4 , and the vane ring 18 constituting the pump chamber 19 accommodated in the pump accommodation portion 1 s constitute a pump structure.

[0050] The control ring 5 constituting a part of the pump structure is integrally formed into a substantially cylindrical shape by sintered metal of an easily processable iron-based material. Figure 1 , Figure 2 and Figure 5 As shown, a pivot recess 5d is formed at the position of the pivot pin 10 on the outer peripheral surface, and the inserted and positioned pivot pin 10 is embedded in the pivot recess 5d to form an eccentric swing fulcrum.

[0051] In addition, a hole portion 25 (holes 25a, 25b) communicating with the discharge port 12 is formed through the control ring 5 at a position below the pivot recess 5d, and a second protrusion 5g of a substantially triangular shape is provided to hold the second sealing member 14 via the second sealing groove 5c. The hole portion 25 is provided on a side close to the pump chamber 19 with the smallest volume among the plurality of pump chambers 19 in the interval where the volume of the plurality of pump chambers 19 decreases with the rotational drive of the pump structure. That is, the hole portion 25 is provided between the middle position of the interval where the volume of the pump chamber decreases in the circumferential direction with the rotational drive of the pump structure and the terminal portion of the discharge port 12 close to the pump chamber with the smallest volume.

[0052] Furthermore, at a position on the upper side of the control ring 5, the above-mentioned first protrusion 5h of a roughly triangular shape is provided for holding the first sealing member 13 via the first sealing groove 5b. The hole portion 25 is rectangular, is provided along the rotation axis of the rotor 4 which is a part of the pump structure, and is connected to the discharge port portion 12 for the oil discharged from the pump structure to flow. The hole portion 25 is divided into a plurality of holes 25a, 25b by a dividing member 37 (partitioning member). The dividing member 37 divides the hole portion 25 into two holes 25a, 25b in the radial direction with respect to the rotation axis of the rotor 4 which is a part of the pump structure. The structure of the hole portion 25 will be described later. In addition, the dividing member 37 may also divide the hole portion 25 into a plurality of holes of more than two.

[0053] like Figure 6 As shown by the arrow, the oil is discharged from the discharge port 12 and is directed to the side ( Figure 6 A portion of the oil on the lower side of the discharge passage 61 passes through multiple holes 25a, 25b.

[0054] The pump structure is housed in the pump housing portion 1s, and is rotationally driven to discharge oil introduced from the suction port 11 (suction portion) from the discharge port 12 (discharge portion).

[0055] In addition, in the present embodiment, the rotor 4, the blades 15, the blade ring 18, and the control ring 5 are formed of iron-based materials.

[0056] Between the outer peripheral surface of the control ring 5 on the first protrusion 5h and the second protrusion 5g side and the pump housing 1, the first control oil chamber 16 is formed on the upper side centered on the control ring 5, and the second control oil chamber 17 is formed on the lower side.

[0057] The first control oil chamber 16 pushes the control ring 5 in a decreasing direction (a direction in which the amount of oil discharged from the pump structure decreases), which is one of the directions in which the eccentricity changes, against the elastic force of the coil spring 28 described later, by the oil pressure supplied thereto. That is, the first control oil chamber 16 becomes a decreasing-side control chamber.

[0058] The oil discharged from the discharge port is introduced into the first control oil chamber 16 via the discharge hole 12a, the main oil passage 31, the second oil passage 33, and the first control groove 35, and the volume of the pump chamber 19 increases when the control ring 5 moves in the direction in which the discharge amount of the oil decreases. In addition, the first control oil chamber 16 is connected to or blocked from the discharge port 12 via the pilot valve 7, and is always sealed liquid-tightly by the first sealing mechanism when the control ring 5 swings.

[0059] In the second control oil chamber 17, the oil pressure supplied thereto urges the control ring 5 in the direction of increasing the eccentricity in cooperation with the elastic force of the coil spring 28 described later, and the oil pressure is supplied or discharged via the solenoid valve 100 and the pilot valve 7. That is, the second control oil chamber 17 becomes an increasing side control chamber.

[0060] In addition, since the distance from the eccentric swing fulcrum to the second sealing component 14 is set to be larger than the distance to the first sealing component 13, the area of ​​the second pressure-bearing surface 20 which is the outer surface on the second control oil chamber 17 side of the control ring 5 is larger than the area of ​​the first pressure-bearing surface 21 which is the outer surface on the first control oil chamber 16 side.

[0061] Therefore, the pushing force applied to the control ring 5 by the oil pressure in the second control oil chamber 17 is slightly offset by the opposite oil pressure in the first control oil chamber 16. As a result, the force that causes the control ring 5 to swing counterclockwise around the pivot pin 10 to reduce the eccentricity due to the pressure of the discharged oil becomes smaller, and the elastic force of the coil spring 28 described later that applies force to the control ring 5 in the clockwise direction relative to it can be set to be smaller.

[0062] The first sealing member 13 and the second sealing member 14 are formed of, for example, a synthetic resin material with low wear resistance to be elongated along the axial direction of the control ring 5, and are retained in the first sealing groove 5b and the second sealing groove 5c formed on the outer peripheral surface of the first protrusion 5h and the second protrusion 5g of the control ring 5. Furthermore, the first sealing member 13 and the second sealing member 14 are pushed forward, that is, pushed against the respective sealing surfaces 1a and 1b, by the elastic force of a rubber elastic member (not shown) fixed to the bottom side of the first sealing groove 5b and the second sealing groove 5c. As a result, the first control oil chamber 16 and the second control oil chamber 17 can be made to have good liquid tightness at ordinary times.

[0063] The suction port 11 is as Figure 5 and Figure 7 As shown, each pump chamber 19 is opened in a region where the volume increases, and the oil in the oil pan 55 is introduced through the suction port 11 a formed substantially in the center due to negative pressure generated by the pumping action of the pump structure.

[0064] The pump housing 1 is provided with a spring housing chamber 27 for housing a coil spring 28, which is communicated with the suction port 11a. The suction port 11a is communicated with the low-pressure chamber 22 together with the spring housing chamber 27, and the oil sucked from the oil pan 55 through the suction passage by the negative pressure generated by the pumping action (pumping action) of the pump structure is supplied to the suction port 11, and to each pump chamber 19 after the volume is increased. Therefore, the suction port 11 and the suction port 11a, the spring housing chamber 27 and the low-pressure chamber 22 constitute a low-pressure portion as a whole.

[0065] On the other hand, the discharge port 12 opens in a region where the volume of each pump chamber 19 is reduced by the pumping action of the pump structure, and communicates with each sliding part of the engine and a variable valve device such as a valve timing control device via a main oil gallery 31 from a discharge hole 12a formed in the pump housing 1. A filter 34 for removing impurities in the oil is installed in the middle of the main oil gallery 31.

[0066] Control loop 5, such as Figure 5 As shown in FIG. 1 , an arm 26 is integrally provided on the outer peripheral surface of the cylindrical body at a position opposite to the pivot recess 5d. The arm 26 is biased by a coil spring 28 to cause the control ring 5 to swing.

[0067] Furthermore, a spring accommodation chamber 27 is formed at a position below the arm 26 of the pump housing 1 .

[0068] The spring housing chamber 27 is formed in a substantially rectangular shape extending in the axial direction of the pump housing 1, and a coil spring 28 as a biasing member is housed and arranged in the spring housing chamber 27. The coil spring 28 is arranged along the axis of the pump housing 1 via the arm 26. Figure 5 The control ring 5 is forced in the clockwise direction of the control ring 5, that is, in the increasing direction (the direction in which the amount of oil discharged from the pump structure increases), which is one of the directions in which the eccentricity between the rotation center of the rotor 4 and the center of the inner peripheral surface of the control ring 5 changes. In addition, the spring storage chamber 27 is connected to the low-pressure chamber 22 via the suction port 11.

[0069] The coil spring 28 is constructed so that its lower end edge is in elastic contact with the bottom surface of the spring storage chamber 27, and on the other hand, its upper end edge is in elastic contact with the arm 26. A specified spring load W is applied in the spring storage chamber 27, and the upper end edge and the arm 26 are always in contact and apply force in the direction of increasing the eccentricity between the rotation center of the rotor 4 at the control ring 5 and the center of the inner circumferential surface of the control ring 5.

[0070] That is, the coil spring 28 always applies force to the control ring 5 via the arm 26 in a direction that makes the control ring 5 eccentric upward, that is, in a direction that increases the volume of each pump chamber 19, in a state where the spring load W is applied. The spring load W is a load that is introduced only into the first control oil chamber 16 and the control ring 5 starts to move when the oil pressure is the necessary oil pressure P1 of the valve timing control device.

[0071] Furthermore, a restricting portion 29 is formed at a position of the pump housing 1 that is opposed to the spring accommodation chamber 27 in the axial direction and against which the upper surface of the arm 26 abuts to restrict the maximum rotation position of the arm 26 in the clockwise direction.

[0072] Furthermore, in the pump housing 1, as Figure 5 As shown, a discharge pressure introduction hole 30 is formed, and a first control groove 35 and a second control groove 36 communicating with the first control oil chamber 16 and the second control oil chamber 17 are formed respectively.

[0073] The discharge pressure introduction hole 30 communicates with a hydraulic pressure introduction port portion 45 of the pilot valve 7 , which will be described later.

[0074] One end of the first control groove 35 is connected to a control groove 35b ( Figure 7 , Figure 8 ) is connected to the second oil passage 33.

[0075] On the other hand, the second control groove 36 branches (forks) from the first control groove 35 and communicates with the second control oil chamber 17 .

[0076] The oil discharged from the discharge port 12 formed in the pump cover 2 is guided to the discharge passage 61 from the discharge opening 60 formed in the control case 6 and flows to the discharge hole 12a. The discharge port 12 is connected to the discharge passage 61. The structure of the discharge passage 61 will be described later.

[0077] Pilot valve 7 Figure 1 , Figure 2 and Figure 5 As shown, the control housing 6 is integrally provided on one side of the outer surface in the vertical direction, and includes: a cylindrical valve body 40 with a closed upper portion; a slide valve 42 that can slide in the vertical direction in a valve receiving portion 41 formed inside the valve body 40; a plug 43 that closes the lower end opening of the valve receiving portion 41; and a valve spring 44 that is elastically installed between the slide valve 42 and the plug 43 and urges the slide valve 42 upward. The slide valve 42 controls the supply and discharge of oil pressure to the second control oil chamber 17 by a pair of large-diameter portions, namely, a first land portion 42a and a second land portion 42b.

[0078] The valve body 40 is provided with an inlet port 46 as an opening of an inlet passage connected to the solenoid valve 100. Furthermore, the peripheral wall of the valve housing 41 is provided with an oil pressure inlet port 45 as an opening of the control oil chamber at an axial middle position, and a first discharge port 48 as a control discharge opening is provided at the other axial end side thereof. One end side of the oil pressure inlet port 45 is connected to the second control oil chamber 17, and the other end side of the oil pressure inlet port 45 is always connected to the relay chamber 47 described later, thereby supplying and discharging the oil pressure to the second control oil chamber 17. One end side of the first discharge port 48 is directly opened to the outside or connected to the suction side, and the oil pressure in the second control oil chamber 17 is discharged through the relay chamber 47 by switching the connection with the relay chamber 47 described later. In addition, a second discharge port 49 is formed at an axial position that radially overlaps with a back pressure chamber 52 described later on the peripheral wall of one end side of the valve body 40, and is opened to directly open to the outside or connected to the suction side in the same manner as the first discharge port 48. The first discharge port 48 and the second discharge port 49 are connected to the oil pan 55, and the oil discharged from the first discharge port 48 and the second discharge port 49 is stored in the oil pan 55.

[0079] In addition, a peripheral wall portion of the valve body 40 is formed so that the slide valve 42 is located at Figure 5 A communication oil passage 50 is formed to connect the introduction port 46 with a relay chamber 47 to be described later in a state where the introduction port 46 is located at the upper end side of the middle portion.

[0080] The slide valve 42 is provided with a first land portion 42a and a second land portion 42b at both ends in the axial direction, and a shaft portion 42c as a small diameter portion is provided between the first land portion 42a and the second land portion 42b. By housing the slide valve 42 in the valve housing portion 41, the following are divided and formed in the valve body 40: a pressure chamber 51 provided between the first land portion 42a and one end of the valve body 40 on the axial outer side thereof, for guiding the discharge pressure from the inlet 46; a relay chamber 47 provided between the first land portion 42a and the second land portion 42b, for relaying between the oil pressure inlet portion 45 and the inlet portion 46 (the oil passage 50) or the first discharge port portion 48 according to the axial position of the slide valve 42; and a back pressure chamber 52 provided between the second land portion 42b and the plug 43 on the axial outer side thereof, for discharging the oil leaked from the relay chamber 47 through the outer peripheral side (small gap) of the second land portion 42b.

[0081] With such a structure, the pilot valve 7 is configured such that when the discharge pressure guided from the inlet portion 46 to the pressure chamber 51 is below a predetermined pressure, the spool valve 42 is located in a predetermined area, i.e., a first area, on the upper end side of the valve housing portion 41 due to the biasing force (acting force) of the valve spring 44 (see Figure 5That is, by positioning the slide valve 42 in the first region, the inlet portion 46 is connected to the relay chamber 47 via the oil communication passage 50, and the connection between the first outlet portion 48 and the relay chamber 47 is cut off by the second stage 42 b, and the second control oil chamber 17 is connected to the relay chamber 47 via the oil pressure inlet portion 45. As a result, the oil pressure guided from the inlet portion 46 through the oil communication passage 50 is supplied to the second control oil chamber 17 via the relay chamber 47.

[0082] When the discharge pressure of the pilot pressure chamber 51 exceeds a predetermined pressure, the spool valve 42 moves from the first region to the lower end side of the valve housing portion 41 against the force of the valve spring 44, and the second region (not shown) is a predetermined region located at the lower end side of the valve housing portion 41. That is, by positioning the spool valve 42 in the second region, the connection between the second control oil chamber 17 and the relay chamber 47 via the oil pressure introduction port 45 is maintained, while the connection between the communication oil passage 50 and the relay chamber 47 is cut off by the first stage 42a, and the relay chamber 47 is connected to the oil pan 55 via the first discharge port 48, and as a result, the oil in the second control oil chamber 17 is discharged to the oil pan 55 via the relay chamber 47 via the first discharge port 48.

[0083] The pilot valve 7 is actuated (operated) by the solenoid 56 , and an exciting current is supplied to the solenoid 56 from an ECU (not shown) mounted on the vehicle via a connector portion 57 .

[0084] Solenoid valve 100 Figure 5 As shown, located in the middle of the first oil passage 32, it mainly includes: a roughly cylindrical valve body 101 formed by penetrating along the internal axial direction to form an oil passage 102; a seat component 105 that is pressed and fixed to the outer end of a valve body housing 103 formed at one end (the left end in the figure) of the valve body 101 to increase the diameter of the oil passage 102, and has an upstream side opening portion, namely an inlet portion 104, connected to the passage 32a on the upstream side of the first oil passage 32 (hereinafter referred to as the "upstream side passage") in the center; a ball valve body 106 that is arranged to be able to leave and sit on a valve seat 105a formed at the inner end opening edge of the seat component 105, and is used to open and close the inlet portion 104; and a solenoid 107 arranged at the other end (the right end in the figure) of the valve body 101.

[0085] The valve body 101 is configured such that, at the inner peripheral portion of one end side thereof, the valve body housing portion 103 housing the ball valve body 106 is provided to increase in a stepped manner relative to the diameter of the oil passage 102. A downstream opening portion, i.e., a supply and discharge port portion 108, which is connected to the downstream passage 32b and used for supplying and discharging the oil pressure of the pilot valve 7, is formed through the outer peripheral portion of the valve body housing portion 103 at one end side of the peripheral wall of the valve body 101 in the radial direction, and a switching discharge opening portion, i.e., a discharge port portion 109, which is connected to the oil pan 55, is formed through the outer peripheral portion of the oil passage 102 at the other end side in the radial direction.

[0086] The solenoid 107 is configured to use electromagnetic force generated by energizing a coil (not shown) housed in a housing 107a to move an armature (not shown) disposed on the inner circumference of the coil and a rod 107b fixed thereto. Figure 3 In addition, based on the engine operating state detected or calculated based on the prescribed parameters such as the oil temperature, water temperature, and engine speed of the internal combustion engine, an excitation current is passed through the solenoid 107 from the vehicle-mounted ECU (not shown).

[0087] With such a structure, when the solenoid 107 is energized, the rod 107b is moved, and the ball valve body 106 disposed at the front end of the rod 107b is pressed against the valve seat 105a on the seat member 105 side, so that the communication between the introduction port 104 and the supply and discharge port 108 is blocked, and the supply and discharge port 108 and the discharge port 109 are connected through the oil passage 102. On the other hand, when the solenoid 107 is not energized, the ball valve body 106 moves backward based on the discharge pressure introduced from the introduction port 104, thereby the ball valve body 106 is pushed to the valve body 101 side, the introduction port 104 and the oil pressure introduction port 45 are connected, and the communication between the oil pressure introduction port 45 and the discharge port 109 is blocked.

[0088] As described above, in this embodiment, the oil discharged from the discharge port 12 formed in the pump cover 2 is guided to the discharge passage 61 from the discharge opening 60 formed in the control housing 6, and flows to the discharge hole 12a. The discharge hole 12a is formed in the discharge passage 61 at a distance from the control ring support portion 65. Regarding the structure of the discharge passage 61, the discharge hole 12a is formed in the discharge passage 61. Figure 7 and Figure 8 Provide explanation.

[0089] like Figure 7 and Figure 8 As shown in FIG. 1 , a control ring support portion 65 for supporting the pivot pin 10 of the control ring 5 is provided in the discharge passage 61. The control ring support portion 65 is formed so as to gradually become thinner in a direction away from the rotation axis of the rotor 4 as a part of the pump structure when viewed from the direction of the rotation axis of the rotor 4 as a part of the pump structure. In other words, the control ring support portion 65 is formed in a teardrop shape.

[0090] The oil discharged from the discharge opening 60 to the discharge passage 61 is divided into two flow paths by the control ring support portion 65, and after converging in the discharge passage 61, is guided to the discharge hole 12a. The discharge passage 61 includes: a first discharge passage 61a formed between the peripheral wall of the control ring support portion 65 and the peripheral wall of the discharge passage 61 in the rotation direction of the rotor 4 as a part of the pump structure; and a second discharge passage 61b formed between the peripheral wall of the control ring support portion 65 and the peripheral wall of the discharge passage 61 in the direction opposite to the rotation direction of the rotor 4 as a part of the pump structure. The peripheral wall of the control ring support portion 65 forming the first discharge passage 61a and the peripheral wall of the discharge passage 61 are formed to be substantially parallel to the flow direction of the oil. As a result, the oil can flow smoothly to the downstream side.

[0091] The control ring support portion 65 of the present embodiment is characterized in that, as described above, it is formed in a so-called teardrop shape that gradually becomes thinner in a direction away from the rotation axis of the rotor 4 as a part of the pump structure when viewed from the rotation axis of the rotor 4 as a part of the pump structure.

[0092] Generally speaking, when a fluid collides with an object, the pressure at the collision site increases. On the other hand, the pressure on the downstream side of the collision site drops sharply, and separation occurs (vortex is generated). In the portion where separation occurs, the flow becomes turbulent, and this turbulence causes pressure loss, which reduces the efficiency of the pump. For example, when the control ring support portion 65 is formed into a cylindrical shape, the oil collides with the control ring support portion 65 and the upstream end 65a, and separates at the downstream end 65b where the first discharge passage 61a and the second discharge passage 61b merge, causing pressure loss. In order to suppress the separation of the fluid, it is effective to move the separation position to the downstream side and reduce the portion where the pressure drops sharply. Therefore, in this embodiment, the downstream end 65b of the control ring support portion 65 is located at a position that stretches (extends) to the downstream side. That is, the distance between the center of the connecting pivot pin 10 and the downstream end 65b is made longer than the distance between the center of the connecting pivot pin 10 and the upstream end 65a. The oil that collides with the upstream end 65a at the control ring support 65 is divided into the first discharge passage 61a and the second discharge passage 61b, and converges at a position passing through the downstream end 65b. In this embodiment, the control ring support 65 is teardrop-shaped, so that the oil flowing through the peripheral wall of the control ring support 65 flows smoothly to the downstream side.

[0093] According to the present embodiment, the control ring support portion 65 is formed in a so-called teardrop shape that gradually tapers away from the rotation axis of the pump mechanism when viewed from the rotation axis of the pump mechanism, thereby making it possible to smooth the flow of oil and reduce the pressure loss of the pump.

[0094] [Detailed structure of the blade]

[0095] The variable capacity pump 120 of the present embodiment of the above-mentioned structure has a flat blade 15, and the blade 15 rotates with the rotation of the rotor 4 driven by the crankshaft 3 of the engine, thereby causing the working fluid (oil) to circulate (inhale and discharge) through the medium space (pump chamber 19). When the engine speed increases, the speed of the blade 15 increases accordingly, and the pressure reduction behind the blade 15 becomes significant, and cavitation is generated due to the pressure being lower than the saturated vapor pressure of the working fluid (oil). There is a problem that when the cavitation is destroyed, corrosion (erosion) occurs in the pump housing 1 made of a low-hardness material such as an aluminum alloy for lightweighting.

[0096] Regarding the structure of the blade 15 for solving the technical problem, use Figures 9 to 16 The enlarged figure is used for explanation.

[0097] [First Embodiment of Blade]

[0098] Figure 5 , Figure 7 and Fig. 9 The blade 15 shown has a rectangular flat plate shape as described above, including: a root end edge 154 that can be slidably inserted into the gap 4a formed radially (along the radial direction) in the rotor 4 and is in sliding contact with the outer peripheral surfaces of a pair of front and rear blade rings 18, 18; a front end edge 155 that protrudes outward from the gap 4a and can be in sliding contact with the inner peripheral surface 5a of the control ring 5 (in other words, is always pressed against the inner peripheral surface 5a); a side end edge 151 that connects the end portions of the root end edge 154 and the front end edge 155 on the pump casing 1 side to each other and is in relative sliding contact with the pump housing portion 1s (inner side surface) of the pump casing 1; and a side end edge 152 that connects the end portions of the root end edge 154 and the front end edge 155 on the pump cover 2 side to each other and is in relative sliding contact with the inner side surface of the pump cover 2.

[0099] The blades 15 are configured to be able to enter and exit (appear and disappear) in the gap 4a of the rotor 4. By causing a portion of the blades 15 to protrude outward (peripherally) from the gap 4a, a plurality of medium spaces (pump chambers 19) for allowing the liquid medium (oil) to flow in and out are formed in a circumferentially liquid-tight manner around the rotor 4 (between the inner peripheral surface 5a of the control ring 5 and the outer peripheral surface of the rotor 4) within a housing composed of the pump housing 1, the pump cover 2, etc., and the liquid medium (oil) in the medium space (pump chamber 19) is moved in accordance with the rotation.

[0100] In addition, in blade 15, as Figures 9 to 12As shown, in the portion of the side edge 151 on the pump housing 1s side formed of an aluminum alloy material as a low-hardness component that protrudes outward from the slit 4a, a recess 15a is formed through the side edge 151 that connects the adjacent pump chambers 19 (fluid communication). In this embodiment, the pump housing 1s of the pump housing 1 constitutes the inner wall with the lowest Vickers hardness among the inner walls of the housing that define the pump chamber 19 (the pump housing 1s, the inner side surface of the pump cover 2, etc.), and the recess 15a is formed only in the portion of the blade 15 that is opposite (in sliding contact with) the inner wall with the lowest Vickers hardness among the inner walls of the housing that define the pump chamber 19 (the portion of the side edge 151 on the pump housing 1s side of the pump housing 1 that protrudes outward from the slit 4a).

[0101] exist Figures 9 to 12 In the example shown, the recess 15a is formed in a substantially rectangular shape when viewed in the circumferential direction (rotational direction) near the center of the portion of the side edge 151 protruding from the gap 4a. In addition, the position, size, shape (semicircular, semi-elliptical, triangular, trapezoidal or other polygonal shapes), number, etc. of the recess 15a are not limited thereto, and for example, the recess 15a may be formed by dividing it into a plurality of parts. In addition, the recess 15a may also be formed on the side edge 152 of the inner side surface of the pump cover 2 constituting the inner wall of the housing defining the pump chamber 19, and the front end edge 155 of the inner peripheral surface 5a side of the control ring 5.

[0102] In addition, the recess 15a is preferably formed into a cone shape, such as Figures 10 to 12 As shown, it is preferable that the opening end on the front side (upstream side) of the rotation direction of the rotor 4 is larger, and the opening end on the rear side (downstream side) of the rotation direction is smaller. In other words, it is preferable that the opening of the recessed portion 15a has a tapered shape that becomes smaller as it goes from the front side to the rear side of the rotation direction of the rotor 4.

[0103] According to the structure of the first embodiment, cavities are generated behind the blades 15 as the blades 15 rotate at high speed. However, by providing a conical recess 15a at a portion (side edge 151 on the pump housing 1s side of the pump housing 1) opposite to the inner wall with the lowest Vickers hardness in the inner wall of the medium space (the pump housing 1s of the pump housing 1), the pressure of the working fluid in the conical recess 15a rises due to the wedge effect, and the reduction in discharge efficiency can be suppressed as much as possible. In addition, by supplying a jet from the recess 15a to the rear of the blades 15, cavities that may contact the inner wall of the medium space can be eliminated (in other words, the cavities are separated from the inner wall of the medium space), and corrosion of low-hardness parts can be suppressed (refer to Fig.12 ).

[0104] In addition, the inventors of the present invention have conducted intensive research using computer simulation, and as a result, have confirmed that, assuming normal use environments and conditions, corrosion caused by cavitation may occur at the inner wall (low hardness component) with a Vickers hardness of less than 130 in the inner wall of the casing that defines the pump chamber 19, but by providing the recess 15a described above (preferably a conical recess 15a) in the portion of the blade 15 that is opposite to (in sliding contact with) the inner wall (low hardness component) with a Vickers hardness of less than 130, corrosion caused by cavitation at the inner wall (low hardness component) can be effectively suppressed.

[0105] [Second Embodiment of Blade]

[0106] Fig.13 Another embodiment (second embodiment) of the concave portion formed in the blade is shown. This embodiment is effective when the degree of corrosion caused by cavitation in a low-hardness member is different in the radial direction.

[0107] The concave portion 15b of the blade 15 of this embodiment is as follows Fig.13 As shown, the opening area is changed in the radial direction of the variable capacity pump 120. In other words, the opening of the recess 15b has a tapered shape that changes as it goes from the radial inside to the outside. In the illustrated embodiment, the recess 15b is formed so that the opening end on the radial inside of the rotor 4 is smaller and the opening end on the radial outside is larger (it becomes larger as it goes from the radial inside to the outside), but it can also be formed so that the opening end on the radial inside of the rotor 4 is larger and the opening end on the radial outside is smaller (it can also be formed so that it becomes smaller as it goes from the radial inside to the outside).

[0108] The structure of the second embodiment can achieve the same effects as those of the first embodiment of the blade 15 , and by changing the opening area of ​​the recess 15 b of the blade 15 , corrosion of a portion where cavitation corrosion occurs significantly can be effectively suppressed.

[0109] [Third Embodiment of Blade]

[0110] Fig.14 and Fig.15 Another embodiment (third embodiment) of the concave portion formed in the blade is shown. This embodiment is effective in controlling the pressure of the working fluid and adjusting the discharge efficiency.

[0111] The conical recess 15a of the blade 15 of the first embodiment is a straight line shape, that is, the opening of the recess 15a changes linearly from the front side to the rear side in the rotation direction of the rotor 4, and the degree of change (slope) of the opening (opening area) of the recess 15a in the rotation direction is fixed.

[0112] The conical recess 15c of the blade 15 of the third embodiment is a curved shape, that is, the opening of the recess 15c changes in a curved line from the front side to the rear side in the rotation direction of the rotor 4, and the degree of change (slope) of the opening (opening area) of the recess 15c in the rotation direction changes. In the illustrated embodiment, the degree of change of the opening (opening area) of the recess 15c in the rotation direction gradually decreases (the slope becomes gentle) as it goes from the front side to the rear side in the rotation direction of the rotor 4, but it may also be that it gradually increases (the slope becomes steeper) as it goes from the front side to the rear side in the rotation direction of the rotor 4.

[0113] The structure of the third embodiment can achieve the same effects as the first and second embodiments of the blade 15, and even with recesses of the same size (opening area), the pressure of the working fluid can be controlled by the wedge effect, effectively regulating the reduction in discharge efficiency.

[0114] [Fourth Embodiment of Blade]

[0115] Fig.16 Another form (fourth embodiment) of the recessed portion formed in the blade is shown.

[0116] The tapered recess 15b of the blade 15 of the second embodiment is linear, that is, the opening of the recess 15b changes linearly from the radial inside to the radial outside, and the degree of change (gradient) of the opening of the recess 15b in the radial direction is constant.

[0117] In contrast, the tapered recess 15d of the blade 15 of the fourth embodiment is in a curved shape, that is, the opening of the recess 15d changes in a curved shape from the radial inside to the radial outside, and the degree of change (gradient) of the opening of the recess 15d in the radial direction changes.

[0118] According to the structure of the fourth embodiment, the same effects as those of the first, second, and third embodiments of the blade 15 can be obtained.

[0119] [Effects]

[0120] As described above, the variable capacity pump 120 of the present embodiment includes: a rotor 4 that is driven to rotate; a plurality of blades 15 that are arranged at intervals in the circumferential direction of the rotor 4 and are arranged on the outer circumferential side of the rotor 4 so as to be able to move in and out, and a housing that accommodates the rotor 4 and the plurality of blades 15 and that defines a plurality of medium spaces that are used for the liquid medium to flow in and out by the rotor 4 and the plurality of blades 15 (circumferentially defined by the plurality of blades 15 around the rotor 4), wherein the blades 15 form recessed portions (15a to 15d) that connect adjacent medium spaces at portions that are opposite (in sliding contact with) the inner wall of the housing that defines the medium spaces and has a Vickers hardness of less than 130.

[0121] Furthermore, the recessed portions (15a to 15d) are formed only in the portion of the vane 15 that faces (is in sliding contact with) the inner wall having the lowest Vickers hardness among the inner walls of the housing that define the medium space.

[0122] Furthermore, the recessed portion ( 15 a to 15 d ) is formed only on one of the two side edge portions of the blade 15 in the direction of the rotation axis of the rotor 4 .

[0123] In addition, the openings of the recessed portions (15a to 15d) have a tapered shape that becomes smaller from the front side (upstream side) to the rear side (downstream side) in the rotation direction.

[0124] That is, the variable capacity pump 120 of this embodiment provides a recess (preferably a conical recess) (15a to 15d) in the portion of the blade 15 that is opposite to the wall surface having a Vickers hardness lower than 130 (or the wall surface having the lowest Vickers hardness) in the inner wall of the medium space, and utilizes the wedge effect in the conical recess (15a to 15d) to suppress the reduction in the discharge efficiency of the blade 15 as much as possible, and supplies fluid to the rear of the blade 15 from the recess (15a to 15d) to suppress cavitation.

[0125] According to this embodiment, by supplying and ejecting fuel from the recessed portion (15a to 15d) provided in the blade 15 toward the rear of the blade 15 as the blade 15 rotates, cavitation near components with lower hardness can be suppressed in the blade-type variable capacity pump 120, thereby preventing corrosion (cavitation) of low-hardness materials.

[0126] In addition, by forming a recess (15a~15d) only in the portion opposite to (in sliding contact with) the inner wall of the casing having the lowest Vickers hardness, or only in one of the two side edges in the direction of the rotation axis of the rotor 4, it is possible to minimize the reduction in the discharge efficiency of the blade 15 with a simple structure and effectively suppress cavitation near the parts with lower hardness.

[0127] Furthermore, by making the recesses (15a-15d) tapered, the wedge effect in the tapered recesses (15a-15d) can be used to minimize the reduction in discharge efficiency of the blade 15 and prevent corrosion caused by cavitation of low-hardness parts.

[0128] The present invention is not limited to the above-described embodiments, and includes various modifications. The above-described embodiments are described in detail to facilitate understanding of the present invention, and are not limited to having all the described configurations.

[0129] In addition, the present invention is described mainly around an embodiment in which the control ring 5 swings with the pivot pin 10 as a reference, but can also be applied to a variable capacity pump in which the eccentricity between the center of the inner circumferential surface of the control ring 5 and the rotation center of the rotor 4 changes due to linear sliding of the control ring 5.

[0130] Description of Reference Numerals

[0131] 1 ... pump housing, 1c ... pin hole, 1s ... pump housing, 2 ... pump cover, 3 ... crankshaft, 4 ... rotor, 4a ... gap, 4b ... opening, 5 ... control ring, 6 ... control housing, 7 ... pilot valve, 10 ... pivot pin, 11 ... suction port, 12 ... discharge port, 12a ... discharge hole, 13 ... first sealing member, 14 ... second sealing member, 15 ... vane, 15a to 15d ... recessed portion (first to fourth embodiments), 16 ... first control oil chamber, 17 ... second control oil chamber, 18 ... vane ring, 19 ... Pump chamber (medium space), 25…hole portion, 25a, 25b…hole, 30…discharge pressure introduction hole, 31…main oil passage, 32…first oil passage, 32a…upstream side passage, 32b…downstream side passage, 33…second oil passage, 35…first control groove, 36…second control groove, 37…dividing component, 60…discharge opening, 61…discharge passage, 61a…first discharge passage, 61b…second discharge passage, 65…control ring support portion, 65a…upstream end, 65b…downstream end, 120…variable capacity pump.

Claims

1. A variable capacity pump, characterized in that: include: a rotor driven in rotation; a plurality of blades for moving the liquid medium, the plurality of blades being arranged at intervals in the circumferential direction of the rotor and being arranged on the outer circumferential side of the rotor so as to be able to move in and out; and a housing that accommodates the rotor and the plurality of blades, and that defines a plurality of medium spaces for the liquid medium to flow in and out in a liquid-tight manner using the rotor and the plurality of blades, The blade forms a recessed portion connecting adjacent medium spaces at a portion thereof facing an inner wall of the housing defining the medium space and having a Vickers hardness lower than 130. The opening of the recess has a tapered shape that becomes smaller from the front side to the rear side in the rotation direction.

2. The variable capacity pump according to claim 1, characterized in that: The recessed portion is formed only at a portion of the blade that is opposite to an inner wall having the lowest Vickers hardness among inner walls of the housing defining the medium space.

3. The variable capacity pump according to claim 1, characterized in that: The recessed portion is formed only on one of two side end edges of the blade in the rotation axis direction of the rotor.

4. The variable capacity pump according to claim 1, characterized in that: The opening of the recessed portion changes in a straight line or a curve from the front side to the rear side in the rotation direction.

5. The variable capacity pump according to claim 1, characterized in that: The opening of the recess has a tapered shape that changes from the radial inner side to the radial outer side.

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