JP2020041522A - Variable displacement pump - Google Patents

Abstract

To provide a variable displacement pump which can inhibit reduction of oil pressure of an oil discharged from a discharge part.SOLUTION: A variable displacement pump includes: a pump mechanism which is rotationally driven to discharge an oil guided from a suction part from a discharge port 12; and a control ring 5 which houses the pump mechanism therein and moves to vary a discharge amount of the oil discharged from the pump mechanism. An interior of a discharge passage 61 which guides the oil discharged from the discharge port 12 includes a control ring support part 65 supporting a shaft member of the control ring 5. The control ring support part 65 is formed so as to become thinner in a direction away from a rotation axis of the pump mechanism.SELECTED DRAWING: Figure 7

Description

  The present invention relates to, for example, a variable displacement pump.

  For example, as a variable displacement pump applied to an internal combustion engine for an automobile, a pump described in Patent Literature 1 below is known.

  Patent Document 1 discloses a pump component that discharges oil guided from a suction portion from a discharge portion, a control ring that houses the pump component and changes the amount of oil discharged from the pump component, And a pin support portion provided in the discharge portion and into which a pin for rotatably supporting the control ring is inserted.

Japanese Patent No. 6130525

  However, in the technology described in Patent Literature 1, since the pin support portion is circular, a vortex is generated around the pin support portion, causing a pressure loss in the flow of the oil, and the oil discharged from the discharge portion. This could lead to a decrease in hydraulic pressure.

  An object of the present invention is to solve the above-mentioned problems and to provide a variable displacement pump capable of suppressing a decrease in oil pressure of oil discharged from a discharge unit.

  According to one aspect of the present invention, in one aspect, a pump mechanism that discharges oil guided from a suction unit by being driven to rotate from a discharge unit, and a pump mechanism that accommodates and moves the pump mechanism inside the pump mechanism and moves the pump mechanism A control ring that varies a discharge amount of the discharged oil, and a control ring support portion that supports a shaft member of the control ring in a discharge passage that guides the oil discharged from the discharge portion. Is formed so as to gradually become thinner in a direction away from the rotation axis of the pump mechanism.

  ADVANTAGE OF THE INVENTION According to this invention, the variable displacement pump which can suppress that the hydraulic pressure of the oil discharged from a discharge part falls can be provided.

FIG. 2 is an exploded perspective view of the variable displacement pump viewed from the control housing side according to the embodiment of the present invention. FIG. 2 is an exploded perspective view of the variable displacement pump viewed from the pump housing side according to the embodiment of the present invention. FIG. 2 is a side view of the variable displacement pump viewed from the control housing side according to the first embodiment of the present invention. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. FIG. 1 is a system configuration diagram of a variable displacement pump according to a first embodiment of the present invention. FIG. 2 is a side view of the variable displacement pump according to the first embodiment of the present invention as seen through. FIG. 2 is a side view of the variable displacement pump showing a state where the pump cover is attached to the control housing according to the first embodiment of the present invention. It is a side view of the variable displacement pump showing the state where the pump cover was attached to the control housing concerning a 2nd example of the present invention.

  Hereinafter, an embodiment of a variable displacement pump according to the present invention will be described in detail with reference to the drawings. In the present embodiment, a variable displacement for supplying oil (lubricating oil) to a sliding portion of an internal combustion engine for an automobile and supplying a hydraulic pressure as an operation source of a variable valve mechanism for varying valve timing of an engine valve. The figure shows an example applied to a pump.

  The variable displacement pump according to the present embodiment is applied to a vane type pump and is provided at a front end of a cylinder block of an internal combustion engine. FIG. 1 is an exploded perspective view of a variable displacement pump according to a first embodiment of the present invention as viewed from a control housing side, and FIG. 2 is an exploded perspective view of a variable displacement pump as viewed from a pump housing side according to the first embodiment of the present invention. FIG. 3 and FIG. 3 are side views of the variable displacement pump viewed from the control housing side according to the first embodiment of the present invention. 4 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a system configuration diagram of the variable displacement pump according to the embodiment of the present invention, and FIG. 6 is a side view of the variable displacement pump according to the first embodiment of the present invention. FIG. 7 is a side view of the variable displacement pump in a state where the pump cover is attached to the control housing according to the first embodiment of the present invention.

  As shown in FIGS. 1 to 4, the variable displacement pump passes through a pump housing 1 having a bottomed cylindrical shape whose one end is closed by a pump cover 2, and a substantially central portion of the pump housing 1. A drive shaft 3 rotatably driven by a crankshaft of an external engine, a rotor 4 rotatably housed inside the pump housing 1 and having a central portion coupled to the drive shaft 3, and swinging around the outer periphery of the rotor 4. A control ring, which is a movable member arbitrarily disposed, and a control housing 6, which is disposed and fixed to the outer surface of the pump cover 2, controls switching of hydraulic pressure supply to swing the control ring 5. It is mainly composed of a pilot valve 7 which is a mechanism. The variable displacement pump is connected to a solenoid valve 100 which is a switching mechanism described later.

  As shown in FIGS. 1 and 3, the pump housing 1, the pump cover 2 and the control housing 6 are integrally connected by a plurality of bolts 9, each of which is connected to the pump housing 1, the control housing 6 and the control housing 6. The bolts are inserted into bolt insertion holes formed in the pump cover 2 and fastened together.

  The pump housing 1 is integrally formed of an aluminum alloy material, and the bottom surface of the concave pump housing portion 1s has a high precision such as flatness and surface roughness because one axial side of the control ring 5 slides. It is machined 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 serving as a housing of a variable displacement pump, and a pump housing portion is formed inside the housing.

  As shown in FIGS. 1, 2 and 4, the pump housing 1 has a bearing hole 1d for bearing one end of the drive shaft 3 formed therethrough substantially at the center of the bottom surface of the pump accommodating portion 1s which is the working chamber. In addition, a bottomed pin hole 1c into which a pivot pin 10 (shaft member), which is a pivot pin serving as a pivot point of the control ring 5, is inserted at a predetermined position on the inner peripheral surface. .

  Further, a first seal surface 1a formed in an arc-shaped concave shape is formed on the inner peripheral side at a position above the pump housing portion 1s in the vertical direction. On the other hand, an arc-shaped concave second seal surface 1b is formed on the inner peripheral side at a vertically lower position of the pump housing portion 1s.

  The first sealing surface 1a seals a first control oil chamber 16 described later so that a first seal member 13 fitted in a first seal groove 5b described later formed in the control ring 5 always slides and seals. Has become. The first seal surface 1a and the first seal member 13 constitute a first seal mechanism.

  The second seal surface 1b is configured such that a second seal member 14 described below, which is fitted in a second seal groove 5c formed in the control ring 5, constantly slides and seals a second control oil chamber 17 described later. ing. A second seal mechanism is configured by the second seal surface 1b and the second seal member 14.

  As shown in FIG. 5, the first seal surface 1a and the second seal surface 1b are formed in a circular arc shape having a predetermined length around the pivot pin 10, and the control ring 5 eccentrically swings. In the range, the first seal member 13 and the second seal member 14 are set to a length that can always be in sliding contact.

  As shown in FIGS. 1 and 2, the pump cover 2 is formed with a suction port 11 (suction part), which is a substantially crescent notch-shaped suction part. Discharge ports 12 (discharge parts), which are discharge parts substantially in the shape of a crescent, are formed substantially opposite to each other at positions on the opposite side. The specific configuration of the suction port 11 and the discharge port 12 will be described later.

  As shown in FIGS. 1 and 2, the pump cover 2 is formed in a substantially plate shape from an aluminum alloy material, and has a bearing hole 2 a formed at a substantially central position thereof to rotatably support the other end of the drive shaft 3. In addition, a plurality of bosses forming the bolt insertion holes are formed integrally on the outer peripheral portion. The pump cover 2 is coupled to the pump housing 1 by a plurality of bolts 9 while being positioned in the circumferential direction of the pump housing 1 via a plurality of positioning pins (not shown).

  The drive shaft 3 rotates the rotor 4 in the direction indicated by the arrow (clockwise) in FIG. 5 by the rotational force transmitted from the crankshaft via a gear or the like to the distal end protruding from the pump housing 1. The left half in the figure with the drive shaft 3 as the center is the suction area, and the right half is the discharge area.

  As shown in FIGS. 1 and 2, the rotor 4 has nine vanes 15 slidably held therein so as to be able to advance and retreat (appear and retract) in nine slits 4a formed radially outward from the inner center side. At the base end of each slit 4a, a back pressure chamber 24 having a substantially circular cross section for introducing the discharge hydraulic pressure discharged to the discharge port 12 is formed. The vanes 15 are pushed outward by the pressure in each of the back pressure chambers 24 and the centrifugal force caused by the rotation of the rotor 4.

  Each of the vanes 15 has an inner base edge that is in sliding contact with the outer peripheral surface of the pair of front and rear vane rings 18, and a distal edge that is slidably in contact with the inner peripheral surface 5 a of the control ring 5. . A plurality of pump chambers 19, which are a plurality of hydraulic oil chambers, are provided between adjacent vanes 15 and the inner peripheral surface 5a of the control ring 5, the inner peripheral surface of the rotor 4, the pump housing 1s, and the inner surface of the pump cover 2. Are liquid-tightly separated. Each vane ring 18 pushes each vane 15 to the radial outside with the rotation, so that even when the engine speed is low and the centrifugal force and the pressure in the back pressure chamber 24 are small, each vane 15 Are in sliding contact with the inner peripheral surface of the control ring 5, so that the pump chambers 19 are liquid-tightly separated.

  The control ring 5 is integrally formed in a substantially cylindrical shape by a sintered metal which is easy to process. As shown in FIGS. 1, 2 and 5, a pivot recess 5d is formed at the position of the pivot pin 10 on the outer peripheral surface. The pivot pin 10 inserted and positioned in the pivot concave portion 5d is inserted and forms an eccentric swing fulcrum.

  A communication port 25 communicating with the discharge port 12 is formed through the control ring 5 at a position below the pivot recess 5d, and the control ring 5 holds the second seal member 14 through the second seal groove 5c. A substantially triangular second protrusion 5g is provided. Further, at a position above the control ring 5, the substantially triangular first protrusion 5h that holds the first seal member 13 via the first seal groove 5b is provided.

  A pump mechanism is formed by the drive shaft 3, the rotor 4, the control ring 5, the vanes 15, and the vane rings 18. The pump mechanism is housed inside the pump housing part, and discharges oil guided from the suction port 11 (suction part) from the discharge port 12 (discharge part) by being rotationally driven.

  The first control oil chamber 16 is formed between the outer peripheral surface of the control ring 5 on the side of the first protrusion 5h and the second protrusion 5g and the pump housing 1 above the control ring 5 as a center. At the same time, a second control oil chamber 17 is formed on the lower side.

  The first control oil chamber 16 presses the control ring 5 in a direction in which the amount of eccentricity decreases against the spring force of a coil spring 28 described later by the hydraulic pressure supplied to the inside. That is, the first control oil chamber 16 is a reduction side control chamber.

  The oil discharged from the discharge port is guided to the first control oil chamber 16 through the discharge hole 12a, the main oil gallery 31, the second oil gallery 33, and the first control groove 35, and the discharge amount of the oil is reduced. The pump chamber is configured to increase in volume when the control ring moves in the decreasing direction. The first control oil chamber 16 communicates with or is cut off from the discharge port 12 via the pilot valve 7, and the first seal mechanism also allows the control ring 5 to swing when it swings. It is always liquid-tightly sealed.

  The second control oil chamber 17 presses the control ring 5 in a direction in which the amount of eccentricity increases by assisting the control ring 5 with the spring force of a coil spring 28 described later by the hydraulic pressure supplied to the inside. The hydraulic pressure is supplied or discharged via the pilot valve 7. That is, the second control oil chamber 17 is an increase control chamber.

  Further, since the distance from the eccentric oscillating fulcrum to the second seal member 14 is set to be larger than the distance to the first seal member 13, the control ring 5 has an outer surface on the second control oil chamber 17 side. The area of a certain second pressure receiving surface 20 is larger than the area of the second pressure receiving surface 21 which is the outer surface on the first control oil chamber 16 side.

  Accordingly, the pressing force of the hydraulic pressure in the second control oil chamber 17 on the control ring 5 is slightly offset by the opposite hydraulic pressure in the first control oil chamber 16, and as a result, the control ring 5 is pivoted by the discharge oil pressure. The force for reducing the amount of eccentricity by swinging the pin 10 in the counterclockwise direction with the fulcrum as the fulcrum is reduced, and the spring force of the coil spring 28 described later, which urges the control ring 5 clockwise in opposition thereto, is reduced. Can be set smaller.

  The first seal member 13 and the second seal member 14 are formed elongate in the axial direction of the control ring 5 by, for example, a synthetic resin material having low abrasion. A rubber seal held in the first seal groove 5b and the second seal groove 5c formed on the outer peripheral surface of the protrusion 5g and fixed to the bottom side of the first seal groove 5b and the second seal groove 5c. The elastic members 13a and 14a are pressed forward, that is, pressed against the sealing surfaces 1a and 1b. This ensures that the first control oil chamber 16 and the second control oil chamber 17 always have good liquid tightness.

  As shown in FIGS. 5 and 6, the suction port 11 is opened in a region where the volume of each pump chamber 19 is increased, and is almost at the center by a negative pressure generated by a pumping action of the pump component. The oil in the oil pan 55 is introduced through the formed suction port 11a.

  A spring housing chamber 27 for housing a coil spring 28 is formed in the pump housing 1 and communicates with the suction port 11a. The suction port 11a communicates with the low pressure chamber 22 together with the spring accommodating chamber 27, and the oil sucked up from the oil pan 55 via the suction passage by the negative pressure generated by the pumping action of the pump structure. 11 and is supplied to each of the pump chambers 19 whose volume has been increased. Therefore, the entirety of the suction port 11, the suction port 11a, the spring accommodating chamber 27, and the low-pressure chamber 22 are configured as a low-pressure section.

  On the other hand, the discharge port 12 is opened to a region where the volume of each pump chamber 19 is reduced due to the pumping action of the pump component, and is discharged from the discharge hole 12 a formed in the pump housing 1 through the main oil gallery 31. Each of the sliding parts of the engine and a variable valve operating device such as a valve timing control device are communicated with each other. In the middle of the main oil gallery 31, a filter 34 for removing oil impurities is attached.

  As shown in FIG. 5, the control ring 5 is integrally provided with an arm 26 which is an extended portion projecting radially outward at a position opposite to the pivot recess 5d on the outer peripheral surface of the tubular main body. The arm 26 is urged by a coil spring 28 to swing the control ring 5.

  Further, a spring housing chamber 27 is formed at a position below the arm 26 of the pump housing 1.

  The spring housing chamber 27 is formed in a substantially planar rectangular shape extending along the axial direction of the pump housing 1, and internally biases the control ring 5 via the arm 26 in the clockwise direction in FIG. A coil spring 28, which is an urging member for urging the control ring 5 in a direction in which the amount of eccentricity between the rotation center of the rotor 4 and the center of the inner peripheral surface of the control ring 5 increases, is accommodated. The spring housing chamber 27 communicates with the low-pressure chamber 22 via the suction port 11.

  The coil spring 28 has a lower end elastically contacting the bottom surface of the spring accommodating chamber 27, while an upper end elastically elastically contacting the arm 26, and a predetermined spring load W is applied in the spring accommodating chamber 27. The edge is constantly in contact with the arm 26 and is urged in a direction in which the amount of eccentricity between the rotation center of the rotor 4 in the control ring 5 and the center of the inner peripheral surface of the control ring 5 increases.

  In other words, the coil spring 28 constantly urges the control ring 5 upward through the arm 26 in a direction in which the spring load W is applied, that is, in a direction in which the volume of each pump chamber 19 increases. The spring load W is a load that is introduced into only the first control oil chamber 16 and the control ring 5 starts to move when the hydraulic pressure is the required hydraulic pressure P1 of the valve timing control device.

  Further, at a position facing the spring housing chamber 27 of the pump housing 1 from the axial direction, a regulating portion 29 for regulating the maximum clockwise rotation position of the arm 26 by contacting the upper surface of the arm 26 is formed.

  As shown in FIG. 5, the pump housing 1 has a discharge pressure introduction hole 30 formed therein, and a first control groove 35 communicating with the first control oil chamber 16 and the second control oil chamber 17. Two control grooves 36 are respectively formed.

  The discharge pressure introduction hole 30 communicates with a later-described hydraulic pressure introduction port 45 of the pilot valve 7.

  The first control groove 35 is connected to the second oil gallery 33 via a control groove 35b (FIGS. 6 and 7) whose one end is also open to the pump cover 2.

  On the other hand, the second control groove 36 branches off from the first control groove 35 and communicates with the second control oil chamber 17.

  The oil discharged from the discharge port 12 formed in the pump cover 2 is guided from the discharge opening 60 formed in the control housing 6 to the discharge passage 61, and flows toward the discharge hole 12a. The discharge port 12 and the discharge passage 61 are connected. The configuration of the discharge passage 61 will be described later.

  As shown in FIGS. 1 and 5, the pilot valve 7 is provided integrally on one side of the outer surface of the control housing 6 in a vertical direction, and has a cylindrical valve body 40 whose upper part is closed and an inner part of the valve body 40. A spool valve 42 slidable in the up-down direction in a valve housing 41 formed in the valve housing 41, a plug 43 for closing a lower end opening of the valve housing 41, and a spring mounted between the spool valve 42 and the plug 43. A valve spring 44 for urging the spool valve 42 upward. The spool valve 42 controls supply and discharge of hydraulic pressure to and from the second control oil chamber 17 by using a pair of large-diameter portions, a first land portion 42a and a second land portion 42b.

  In the valve body 40, an introduction port 46, which is an introduction passage opening connected to the solenoid valve 100, is formed. Further, the peripheral wall of the valve accommodating portion 41 is connected at an intermediate position in the axial direction to the second control oil chamber 17 with one end connected to the second control oil chamber 17 and the other end connected to a relay chamber 47 described later. A hydraulic introduction port 45, which is a control oil chamber opening for supplying and discharging hydraulic pressure to and from the chamber 17, is formed with an opening, and one end is directly opened to the outside or connected to the suction side at a position at the other end in the axial direction. A first drain port 48, which is a control drain opening for discharging the hydraulic pressure in the second control oil chamber 17 via the relay chamber 47 by switching the connection with the relay chamber 47 described later, is formed. As in the case of the first drain port 48, the valve body 40 is directly opened to the outside or connected to the suction side at the axial position where the one end side peripheral wall of the valve body 40 overlaps the back pressure chamber 52 described later in the radial direction. The second drain port 49 is formed with an opening. The first drain port 48 and the second drain port 49 communicate with an oil pan 55, and the oil discharged from the first drain port 48 and the second drain port 49 is stored in the oil pan 55.

  In addition, a communication oil passage 50 that connects the introduction port 46 and a relay chamber 47 described below is formed on the peripheral wall portion of the valve body 40 in a state where the spool valve 42 is located at the upper end side in FIG. 5. ing.

The spool valve 42 has a first land portion 42a and a second land portion 42b provided at both ends in the axial direction, and a small-diameter shaft portion 42c between the first land portion 42a and the second land portion 42b. Is provided. When the spool valve 42 is accommodated in the valve accommodating portion 41, the spool valve 42 is provided in the valve body 40 between the first land portion 42 a and the one end of the valve body 40 in the axial direction outside. The hydraulic pressure introduction port 45 and the introduction port 46 (communication oil passage) are provided between the first land portion 42 a and the second land portion 42 b, depending on the axial position of the spool valve 42. 50) or a relay chamber 47 for relaying to the first drain port 48, and a plug 43 provided axially outside the second land portion 42b between the plug 43 and relaying through the outer peripheral side (small gap) of the second land portion 42b. The back pressure chamber 52 for discharging the oil leaked from the chamber 47 is separated from each other.
With such a configuration, when the discharge pressure guided from the introduction port 46 to the pressure chamber 51 is equal to or lower than the predetermined pressure, the spool valve 42 is biased by the valve spring 44 to move the spool valve 42 to the upper end side of the valve housing 41. (Refer to FIG. 5). That is, when the spool valve 42 is located in the first region, the introduction port 46 and the relay chamber 47 are connected via the communication oil passage 50, while the first drain port 48 and the relay chamber 47 are connected by the second land portion 42b. Is disconnected, and the second control oil chamber 17 and the relay chamber 47 are connected via the hydraulic pressure introduction port 45. As a result, the hydraulic pressure guided from the introduction port 46 through the communication oil path 50 is 2 is supplied to the control oil chamber 17.

  When the discharge pressure guided to the 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 41 against the urging force of the valve spring 44, and It will be located in the second area, which is a predetermined area on the lower end side of the storage section 41 (not shown). That is, when the spool valve 42 is located in the second region, the connection of the second control oil chamber 17 to the relay chamber 47 via the hydraulic pressure introduction port 45 is maintained, while the communication oil passage is formed by the first land portion 42a. The connection between the relay chamber 50 and the relay chamber 47 is cut off, and the relay chamber 47 and the oil pan 55 are connected via the first drain port 48. As a result, the oil in the second control oil chamber 17 flows through the relay chamber 47 to the first drain. The oil is discharged to the oil pan 55 via the port 48.

  The pilot valve 7 is operated by a solenoid 56, and an excitation current is supplied to the solenoid 56 from a vehicle-mounted ECU (not shown) via a connector 57.

  As shown in FIG. 5, the solenoid valve 100 is provided in the middle of the first oil gallery 32, and has a substantially cylindrical valve body 101 having an oil passage 102 formed therethrough along the internal axial direction. At one end of the valve body 101 (the left end in the figure), the oil passage 102 is press-fitted and fixed to the outer end of a valve body accommodating portion 103 having an enlarged diameter. A sheet member 105 having an introduction port 104 that is an upstream opening connected to an upstream passage (hereinafter, simply referred to as an “upstream passage”) 32a, and an inner end opening edge of the sheet member 105 is formed. A ball valve body 106 is provided so as to be detachable from and seated on a valve seat 105a for opening and closing the introduction port 104, and is provided at the other end (the right end in the figure) of the valve body 101. And a solenoid 107 is mainly comprised.

  In the valve body 101, a valve housing 103 for housing a ball valve 106 is provided on an inner peripheral portion on one end side so as to have a step-increased diameter with respect to the oil passage 102. Of the peripheral wall of the valve body 101, a supply / discharge port which is a downstream opening connected to the downstream passage 32b and used for supplying and discharging hydraulic pressure to and from the pilot valve 7 at an outer peripheral portion of the valve body accommodating portion 103 at one end thereof. 108 is formed in the radial direction, and a drain port 109 as a switching drain opening connected to the oil pan 55 is formed in the outer peripheral portion of the oil passage 102 on the other end side in the radial direction. Is formed.

  The solenoid 107 is provided with an armature (not shown) disposed on the inner peripheral side of the coil and a rod fixed thereto, with an electromagnetic force generated by energizing a coil (not shown) housed inside the casing 107a. 107b is configured to move forward in the left direction in FIG. The solenoid 107 is supplied with an exciting current from an on-board ECU (not shown) based on an engine operating state detected or calculated by predetermined parameters such as an oil temperature and a water temperature of the internal combustion engine and an engine speed. Becomes

  With such a configuration, when the solenoid 107 is energized, the rod 107b advances and moves to push the ball valve element 106 disposed at the distal end of the rod 107b against the valve seat 105a on the seat member 105 side, The communication between the introduction port 104 and the supply / discharge port 108 is cut off, and the supply / discharge port 108 and the drain port 109 communicate with each other 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 guided from the introduction port 104, so that the ball valve body 106 is pressed toward the valve body 101, and the introduction port 104 The communication between the hydraulic pressure introduction port 45 and the drain port 109 is cut off while the hydraulic pressure introduction port 45 is in communication.

  As described above, in this embodiment, the oil discharged from the discharge port 12 formed in the pump cover 2 is guided from the discharge opening 60 formed in the control housing 6 to the discharge passage 61, and is discharged to the discharge hole 12a. Flowing towards. The discharge hole 12 a is formed in the discharge passage 61 at a position away from the control ring support 65. The configuration of the discharge passage 61 will be described with reference to FIGS.

  As shown in FIGS. 6 and 7, the discharge passage 61 is provided with a control ring support portion 65 that supports the pivot pin 10 of the control ring 5. The control ring support 65 is formed to be gradually narrower in a direction away from the rotation axis of the pump mechanism when viewed from the direction of the rotation axis of the pump mechanism. In other words, the control ring support 65 is formed in a teardrop shape.

  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, merges in the discharge passage 61, and is guided to the discharge hole 12a. The discharge passage 61 has a first discharge passage 61a formed between the peripheral wall of the control ring support 65 and the peripheral wall of the discharge passage 61 in the rotation direction of the pump assembly, and a direction opposite to the rotation direction of the pump assembly. A second discharge passage 61b is formed between the peripheral wall of the control ring support 65 and the peripheral wall of the discharge passage 61. 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 substantially in parallel along the oil flow direction. This allows the oil to flow smoothly downstream.

  As described above, the control ring support portion 65 of the present embodiment has a so-called teardrop shape that is gradually narrowed in a direction away from the rotation axis of the pump mechanism when viewed from the direction of the rotation axis of the pump mechanism. It is characterized by:

  Generally, when a flow collides with an object, the pressure increases at the collision site. On the other hand, the pressure drops abruptly downstream of the collision site, and separation occurs (vortex is generated). In the area where the separation occurs, the flow is disturbed, and the disturbance becomes a pressure loss, and the efficiency of the pump is reduced. For example, when the control ring support 65 is formed in a cylindrical shape, the oil collides with the control ring support 65 at the upstream end 65a, and separates at the downstream end 65b where the first discharge passage 61a and the second discharge passage 61b join. Occurs, resulting in pressure loss. In order to suppress the separation of the flow, it is effective to move the separation position to the downstream side and to reduce the portion where the pressure sharply decreases. Therefore, in the present embodiment, the downstream end 65b of the control ring support 65 is set to a position extending to the downstream side. That is, the distance between the center of the pivot pin 10 and the downstream end 65b is longer than the distance between the center of the pivot pin 10 and the upstream end 65a. Then, the oil that has collided with the control ring support 65 at the upstream end 65a is divided into the first discharge passage 61a and the second discharge passage 61b, and joins at a position where the oil has passed through the downstream end 65b. In the present embodiment, the control ring support 65 is of a teardrop type, so that the oil flowing on the peripheral wall of the control ring support 65 flows smoothly downstream.

  According to the present embodiment, the control ring support 65 is formed in a so-called teardrop shape that is gradually narrowed in a direction away from the rotation axis of the pump mechanism when viewed from the direction of the rotation axis of the pump mechanism. Thus, the oil flow can be made smooth and the pressure loss of the pump can be reduced.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a side view of a variable displacement pump showing a state where a pump cover is attached to a control housing according to a second embodiment of the present invention. The same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The second embodiment differs from the first embodiment in the shape of the control ring support 66. In the first embodiment, the control ring support 65 is of a teardrop type. However, the distance between the center of the pivot pin 10 and the downstream end 66b is different from that of the control ring support 65 in the second embodiment. It is formed shorter than the distance connecting the center of the pin 10 and the downstream end 65b. The control ring support 66 has a distal end (downstream end 65b) that is gradually narrowed toward the discharge hole 12a. Then, the oil that has collided with the control ring support portion 66 at the upstream end 66a is split into the first discharge passage 61a and the second discharge passage 61b, and joins at a position where the oil has passed through the downstream end 66b. In this embodiment, the control ring support 66 is gradually tapered toward the discharge hole 12a so that the oil flowing on the peripheral wall of the control ring support 65 flows smoothly downstream.

  According to the present embodiment, the control ring support 65 is formed so that the control ring support 66 is gradually narrowed toward the discharge hole 12a when viewed from the direction of the rotation axis of the pump mechanism. And the pressure loss of the pump can be reduced.

  Note that the present invention is not limited to the above-described embodiment, and includes various modifications. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the described configurations.

  DESCRIPTION OF SYMBOLS 1 ... Pump housing, 1c ... Pin hole, 1s ... Pump housing part, 2 ... Pump cover, 3 ... Drive shaft, 4 ... Rotor, 5 ... Control ring, 6 ... Control housing, 7 ... Pilot valve, 10 ... Pivot pin, 11 suction port, 12 discharge port, 12a discharge hole, 13 first seal member, 14 second seal member, 15 vane, 16 first control oil chamber, 17 second control oil chamber, 18 ... Vane ring, 19 ... Pump chamber, 30 ... Discharge pressure introduction hole, 31 ... Main oil gallery, 32 ... First oil gallery, 32a ... Upstream passage, 32b ... Downstream passage, 33 ... Second oil gallery, 35 ... 1st control groove, 36 ... 2nd control groove, 60 ... discharge opening, 61 ... discharge passage, 61a ... 1st discharge passage, 61b ... 2nd discharge passage, 65 ... control ring support part, 65a ... upstream end, 65b ... under End, 66 ... control ring support portion, 66a ... upstream end, 66b ... downstream end

Claims (6)

A housing having a pump housing formed therein,
A pump mechanism that is housed inside the pump housing part and discharges oil guided from the suction part by being driven to rotate from the discharge part,
A control ring that accommodates the pump mechanism therein and varies a discharge amount of oil discharged from the pump mechanism by moving;
A discharge passage connected to the discharge unit and guiding oil discharged from the discharge unit;
Oil discharged from the discharge unit is guided, and a reduction-side control chamber whose volume increases when the control ring moves in a direction in which the discharge amount of the oil decreases,
A shaft member that is disposed in the discharge passage and movably supports the control ring is supported, and gradually becomes thinner in a direction away from the rotation axis of the pump mechanism when viewed from the direction of the rotation axis of the pump mechanism. A formed control ring support,
A variable displacement pump comprising: The variable displacement pump according to claim 1,
The said control ring support part is a teardrop type, The variable displacement pump characterized by the above-mentioned. The variable displacement pump according to claim 1,
The discharge passage has a discharge hole at a position away from the control ring support,
The control ring support portion has a tip portion gradually narrowed toward the discharge hole,
A variable displacement pump characterized by comprising: The variable displacement pump according to claim 1,
The discharge passage has a first discharge passage formed between a peripheral wall of the control ring support portion and a peripheral wall of the discharge passage in a rotation direction of the pump mechanism, and a first discharge passage formed in a direction opposite to a rotation direction of the pump mechanism. A variable displacement pump comprising: a second discharge passage formed between a peripheral wall of a control ring support and a peripheral wall of the discharge passage. The variable displacement pump according to claim 1,
The variable displacement pump according to claim 1, wherein the pump mechanism includes a rotor that is driven to rotate, and a plurality of vanes provided to be able to protrude and retract on an outer peripheral side of the rotor. The variable displacement pump according to claim 4,
A variable displacement pump, wherein a peripheral wall of the control ring supporting portion forming the first discharge passage and a peripheral wall of the discharge passage are formed in parallel along a flow direction of the oil.

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