JP6490975B2 - Oil pump - Google Patents

Description

  The present invention relates to, for example, an oil pump that lubricates a sliding portion of an internal combustion engine and supplies oil serving as a drive source for auxiliary components of the internal combustion engine.

  Various types of conventional oil pumps are provided. For example, a variable displacement pump disclosed in the following Patent Document 1 previously filed by the present applicant is known.

  In this variable displacement pump, a pump housing is fixed to a balancer housing of a balancer device via a mounting surface by a plurality of bolts, and from a main oil gallery formed in an internal combustion engine downstream of a pump discharge passage. The hydraulic pressure is supplied to the two first and second control oil chambers via a plurality of intake and discharge oil passages and a control oil passage, or the cam ring is discharged through the drain passage. The amount of pump discharge is changed by changing the amount of eccentricity with respect to the shaft center.

  The oil passage is partly formed in a groove shape on the mounting surface of the pump housing so that the oil passage is sealed by the axial force of the bolt between the mounting surface and the mounted surface of the balancer housing. It has become.

  Then, by controlling the hydraulic pressure on the main oil gallery side to the second control oil chamber according to the pump rotational speed and increasing / decreasing the eccentric amount of the cam ring, the pump discharge pressure has a multi-stage characteristic from low pressure to high pressure. It comes to control.

JP 2014-105622 A

  However, in the variable displacement pump described in the above publication, a seal between the mounting surface of the balancer housing with respect to a part of each oil passage formed on the mounting surface of the pump housing is used as the shaft of the bolt. It is to be done only by force.

  For this reason, for example, the pump housing is deformed by the tension or rotational driving force of the chain that transmits the rotational force from the driving shaft or driven shaft of the balancer device to the pump shaft, and the mating surface of the mounting surface and the mounting surface becomes It may open slightly and a minute clearance may be formed.

  As a result, the hydraulic oil flowing through the oil passage may leak from the minute clearance to the outside, and the control accuracy of the eccentric amount of the cam ring, for example, by the hydraulic oil may be reduced.

  The present invention has been devised in view of the above-described conventional technical problem, and sufficiently suppresses the occurrence of a minute clearance between the mounting surface of the pump housing and the mounting surface of the counterpart housing, It aims at providing the oil pump which can reduce a leak.

The present invention is a pump housing, comprising a housing main body and a cover member, wherein the housing main body is open at one end of the housing main body, and is provided with a pump housing portion on the inner side. A housing attachment surface attached to one end of the housing main body so as to close the pump housing portion, an attachment surface on an outer end surface side provided on an outer end surface opposite to the housing attachment surface, and an outer end surface side The pump housing having a plurality of oil passage grooves provided on the mounting surface, and a bearing hole penetrating between the housing mounting surface and the mounting surface on the outer end surface side ;
A pump shaft that is inserted into the bearing hole of the cover member of the pump housing and rotatably supported;
A rotor housed in the pump housing portion, fixed to the pump shaft, and in contact with the housing mounting surface ;
A driven helical gear fixed to the pump shaft;
A balancer device, comprising a balancer housing, a balancer shaft, and a drive-side helical gear, wherein the balancer housing includes the cover member between the balancer housing and the housing body in the rotational axis direction of the pump shaft. It is arranged so as to be sandwiched, and one end is open, and has a gear accommodating portion that accommodates the driven helical gear inside,
At one end of the balancer housing, a mounting surface that comes into contact with the mounting surface on the outer end surface side provided with the plurality of oil passage grooves is provided,
The drive side helical gear is provided in the gear housing portion and meshes with the driven side helical gear;
The balancer shaft is rotatably supported by the balancer housing and has the drive side helical gear.
The balancer device ,
Thrust force generated when transmitting the rotational force of the driving side helical gear to the driven side helical gear acts via the rotor from the housing mounting surface of the cover member toward the mounting surface of the balancer housing . It is characterized and Turkey.

  According to the present invention, it is possible to sufficiently suppress the occurrence of a minute clearance between the mounting surface of the pump housing and the mounting surface of the counterpart housing.

1 is an exploded perspective view showing an oil pump and a balancer device as variable displacement pumps according to an embodiment of the present invention. It is a perspective view which decomposes | disassembles and shows a part of oil pump and balancer apparatus which are provided to this embodiment. It is a perspective view which shows the state which attached the oil pump of this embodiment to the balancer apparatus. It is a hydraulic circuit diagram of the oil pump of this embodiment. It is a disassembled perspective view of the oil pump provided to this embodiment. It is sectional drawing which shows the state which attached the oil pump of this embodiment to the balancer apparatus. It is a rear view of the cover member provided for this embodiment. It is a front view of the cover member provided for this embodiment. It is operation | movement explanatory drawing of the variable displacement pump of this embodiment. It is operation | movement explanatory drawing of the variable displacement pump. It is operation | movement explanatory drawing of the variable displacement pump. It is operation | movement explanatory drawing of the variable displacement pump. It is a characteristic view which shows the relationship between the discharge pressure of the variable displacement pump and the engine speed.

  Hereinafter, an embodiment of an oil pump according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 to 3, the oil pump 1 according to the present embodiment is attached to a balancer device 2 that is a drive side member provided at a lower portion of a cylinder block of an internal combustion engine (not shown). This is applied to a so-called variable displacement pump that is rotationally driven by the device 2.

  First, the internal combustion engine and the balancer device 2 will be described briefly. In the internal combustion engine, a plurality of bearing caps each having a bearing for supporting a crankshaft are fixed to a lower portion of a cylinder block made of an aluminum alloy material by fixing bolts. Yes. The balancer device 2 is fixedly attached to a lower position of the bearing caps below the cylinder block by a plurality of mounting bolts (not shown).

  Further, an oil pan 14 (see FIG. 4), which will be described later, is fixed to the lower end portion of the cylinder block so as to cover the balancer device 2 from below.

  As shown in FIGS. 1 and 2, the balancer device 2 is a general one, and is an upper housing made of an aluminum alloy material fixed to the lower part of the cylinder block via the plurality of mounting bolts. 3, a lower housing 4 made of the same aluminum alloy material coupled to the lower portion of the upper housing 3 by a plurality of fastening bolts, and rotatably supported inside the housings 3, 4, in the longitudinal direction of the engine The drive shaft 5 that is a balancer shaft and the driven shaft 6 that is a drive shaft, which are arranged in parallel to each other, and an axial intermediate position of the drive shaft 5 and a front end side 6b of the driven shaft 6 are fixed to each tooth. Includes a helical gear type drive gear 7 and a driven gear 8 that mesh with each other.

  The lower housing 4 is formed in a rectangular box shape that is substantially the same shape as the upper housing 3, and a mounting surface 9 to which the oil pump 1 is mounted is formed on the front end surface.

  The attached surface 9 is formed in a flat shape as a whole, the outer shape is bent in a substantially arc shape, and four female screw holes 10 are formed on both sides. Further, an opening end 11a of a main oil gallery 11 for supplying hydraulic oil discharged from the oil pump 1 to the inside of the engine is provided on the attached surface 9 and an outer surface of the lower housing 4 of the balancer device 2 is provided. An opening end 24a of a control passage 24 (described later) for supplying control hydraulic pressure (pilot pressure) to a pilot valve 22 (control mechanism on the oil pump 1 side) from an electromagnetic switching valve 21 side (which will be described later) attached to the cylinder is provided. ing.

  As shown in FIG. 1, the drive shaft 5 has a front end portion 5b in the axial direction supported by a lower portion of the upper housing 3 and a bearing cap 01 fixed to the lower portion by bolts 02, and is attached to the front end portion 5b. When the rotational force of the crankshaft is transmitted through a drive chain (not shown), the drive shaft 5 and the driven shaft 6 are rotated in opposite directions via the drive gear 7 and the driven gear 8. It has become so.

  Further, as shown in FIG. 2, the drive shaft 5 includes two front and rear plain bearings in which large-diameter journal portions 5a formed at two locations in the axial direction are provided between the upper housing 3 and the lower housing 4. It is bearing.

  The drive shaft 5 is integrally provided with a counterweight (not shown) between the pair of large-diameter journal portions 5a and rotates at twice the speed of the crankshaft. ing.

  The driven shaft 6 has a large-diameter journal portion 6 a formed in two axial directions, like the drive shaft 5, and is supported by two front and rear plain bearings provided between the upper housing 3 and the lower housing 4. In addition, a counterweight (not shown) is integrally provided between the pair of large diameter journal portions 6a in the axial direction.

  Further, the driven shaft 6 has a small-diameter drive side helical gear 13 for driving the oil pump 1 fixed to the front end portion.

  The oil pump 1 is rotated by the rotational driving force transmitted from the driven shaft 6 of the balancer device 2 and sucks oil stored in the oil pan 14 through a strainer 15 as shown in FIG. The air is sucked from the passage 16 and discharged from the discharge passage 17 as a discharge portion to the main oil gallery 11 formed inside the engine.

  The main oil gallery 11 supplies oil to an oil jet, a valve timing control device (VTC), and a crankshaft bearing that injects cooling oil to a sliding portion of the engine, for example, a piston.

  On the downstream side of the discharge passage 17, an oil filter 18 that collects foreign matters in the flowing oil and sends them to the main oil gallery 11 is provided, and when the discharge pressure becomes excessive, A pressure control valve 19 that suppresses breakage of the oil filter 18 is provided.

  The main oil gallery 11 has a supply passage 20 that is always in communication with a first control oil chamber 45 to be described later, and a second supply passage 23 that is connected to the electromagnetic switching valve 21. ing.

  The electromagnetic switching valve 21 includes a control passage 24 that supplies a pilot pressure from the second supply passage 23 to a pilot valve 22 that is a control mechanism, and the second control oil chamber 46 through the pilot valve 22. A supply / discharge passage 25 for supplying hydraulic pressure via a branch passage 28 branched from the control passage 24 or discharging the internal hydraulic pressure to the outside is connected.

  The downstream end of the second supply passage 23 is opened or shut off by the electromagnetic switching valve 21, while the supply / discharge passage 25 is controlled by the hydraulic pressure of the main oil gallery 11 acting on the pilot valve 22. The supply and discharge of hydraulic pressure to the second control oil chamber 46 are controlled.

  The oil pump 1 is attached to the front end portion of the balancer device 2 with four bolts 26 screwed into the respective female screw holes 10 as shown in FIGS. A pump housing. The pump housing includes a housing main body 31 having a U-shaped cross section having an opening at one end and having a pump housing chamber 30 therein, and a cover member 32 attached to close the front end opening of the housing main body 31. It is configured.

  The oil pump 1 is disposed substantially at the center of the pump housing chamber 30, and both axial ends of the pump shaft 33 are rotatably supported through the housing body 31 and the cover member 32; A rotor 34 that is rotatably accommodated in the pump accommodating chamber 30 and has a central portion coupled to the pump shaft 33, and a plurality of slits 34a that are radially cut out on the outer periphery of the rotor 34 are accommodated in a freely retractable manner. A plurality of vanes 35 arranged on the outer peripheral side of each vane 35 so as to be eccentrically swingable (movable eccentrically) with respect to the rotation center of the rotor 34, and a plurality of the vanes 35 together with the rotor 34 and adjacent vanes 35, 35. A cam ring 37 that defines a pump chamber 36 and a cam ring 3 that is accommodated in the housing body 31 and increases in the amount of eccentricity of the cam ring 37 with respect to the rotation center of the rotor 34. A coil spring 38, which is a biasing mechanism that constantly biases the rotor 34, and a pair of ring members 39, 39 having a smaller diameter than the rotor 34, which are slidably disposed on both inner peripheral sides of the rotor 34. I have. The pump shaft 33, the rotor 34, and each vane 35 constitute a pump element.

  The housing body 31 is integrally formed of an aluminum alloy material, and as shown in FIG. 6, a bearing hole 31 a that rotatably supports one end portion of the pump shaft 33 at a substantially central position of the bottom surface 30 a of the pump housing chamber 30. Is formed through. An arc-shaped support groove 31b into which a pivot pin 40 for swingably supporting the cam ring 37 is inserted is formed at a predetermined position on the inner peripheral wall of the pump housing chamber 30 which is the inner side surface of the housing body 31. Yes.

  Further, as shown in FIGS. 5 and 9 and the like, the inner circumferential wall of the pump housing chamber 30 is a straight line (hereinafter referred to as “cam ring reference line”) connecting the axis of the pump shaft 33 and the axis of the pivot pin 40. ) On both sides of M, first and second seal slidable contact surfaces 31c and 31d are formed in which two seal members 27 and 27, which will be described later, disposed on the outer periphery of the cam ring 37 are slidably contacted.

  The housing body 31 is formed with an annular flat mounting surface 31 e on the outer peripheral side of the front end opening of the pump storage chamber 30. Further, three female screw holes 31f are formed on the upper side of the outer peripheral portion of the mounting surface 31e of the housing body 31 via a boss portion, and the bolts through which the four bolts 26 are inserted on the lower side. An insertion hole 31g is formed through. In addition, two positioning holes 31h through which two positioning pins 55 and 56 for positioning together with the cover member 32 with respect to the balancer device 2 are inserted are formed in one side of the lower portion.

  As shown in FIGS. 2 and 5 to 8, the cover member 32 is formed in a substantially flat plate shape by an aluminum alloy material like the housing main body 31, and is located at a position corresponding to the bearing hole 31 a of the housing main body 31. A bearing hole 32a for rotatably supporting the other end side of the pump shaft 33 is formed therethrough, a housing mounting surface 32b as a mounting surface to be mounted on the housing main body 31 side, and a mounted surface 9 of the balancer device 2. And an attachment surface 32c on the outer end surface side which is attached in contact with.

  Further, as shown in FIG. 5, three bolts 29 through which three second bolts 29 screwed into the female screw holes 31 f of the housing main body 31 and fastened together are inserted, as shown in FIG. 5, on the upper side of the outer peripheral portion of the cover member 32. An insertion hole 32d is formed through, and a bolt insertion hole 32e through which the four bolts 26 are inserted is formed through the lower side. Further, two positioning holes 32f through which the two positioning pins 55 and 56 are inserted are formed through the housing body 31 at positions corresponding to the two positioning holes 31h.

  As shown in FIG. 7, the housing mounting surface 32 b is formed in a flat shape as a whole, and an outer peripheral portion is disposed in contact with the flat mounting surface 31 e of the housing body 31.

  In addition, at a substantially central position of the housing mounting surface 32b, an arcuate concave suction port 41 which is a suction portion that opens to a region (suction region) where the internal volume of the pump chamber 36 increases with the pumping action of the pump element. And an arc concave discharge port 42 that is a discharge portion that opens to a region (discharge region) in which the internal volume of the pump chamber 36 decreases in accordance with the pumping action of the pump element, is approximately above and below the bearing hole 32a. Notches are formed so as to face each other.

  On one end portion side of the suction port 41, a suction hole 41 a extending toward the spring accommodating chamber 44, which will be described later, is formed to open to the outside through the bottom wall of the housing body 31. Accordingly, the lubricating oil stored in the oil pan 14 is supplied to each pump in the suction region via the suction passage 16, the suction hole 41 a and the suction port 41 based on the negative pressure generated by the pump action of the pump component. Inhaled into the chamber 36.

  The discharge port 42 is formed with an unillustrated discharge hole that passes through the bottom wall of the cover member 32 and communicates with the main oil gallery 11 through the discharge passage 17 and communicates with the bearing hole 32a. One end of the passage groove 32g is connected, and oil is supplied between the bearing hole 32a and the pump shaft 33 through the passage groove 32g.

  In the pump shaft 33, a driven helical gear 43 that meshes with the driving helical gear 13 of the driven shaft 6 of the balancer device 2 is press-fitted and fixed to a tip 33 a protruding from the bearing hole 32 a of the cover member 32. The rotational force of the driven shaft 6 is transmitted to the pump shaft 33 through both the helical gears 13 and 43, and the rotor 34 is rotated counterclockwise in FIG.

  In the rotor 34, the seven slits 34a formed radially from the inner center side to the outer side in the radial direction are notched, and discharged to the discharge port 42 at the inner base end of each slit 34a. Back pressure chambers 34b each having a substantially circular cross section for introducing the discharged oil are formed. Thereby, each vane 35 is pushed outward by the centrifugal force accompanying the rotation of the rotor 34 and the hydraulic pressure of the back pressure chamber 34b.

  Each vane 35 has a distal end surface in sliding contact with the inner peripheral surface of the cam ring 37, and an inner end surface of each base end portion in sliding contact with the outer peripheral surface of each ring member 39, 39. As a result, even when the engine speed is low and the centrifugal force or the hydraulic pressure in the back pressure chamber 34b is small, the outer peripheral surface of the rotor 34, the inner surfaces of the adjacent vanes 35 and 35, and the inner peripheral surface of the cam ring 37 The pump chambers 36 are defined in a liquid-tight manner by the bottom surface 30a of the pump housing chamber 30 of the housing body 31 and the inner surface of the cover member 32, which are side walls.

  As shown in FIGS. 5 and 9, the cam ring 37 is integrally formed of a sintered metal in a cylindrical shape, and the pivot pin 40 is fitted and supported at a predetermined position on the outer peripheral portion in cooperation with the support groove 31 b. A pivot groove 37a having a substantially arcuate concave shape constituting an eccentric oscillating fulcrum is projected along the axial direction, and the coil is disposed at a position opposite to the pivot groove 37a across the center of the cam ring 37. An arm portion 37b that is linked to the spring 38 protrudes along the radial direction.

  Here, a spring accommodating chamber 44 is provided in the housing main body 31 so as to communicate with the pump accommodating chamber 30 via a suction hole 41a formed at a position opposite to the support groove 31b. The coil spring 38 is accommodated in the spring accommodating chamber 44.

  The coil spring 38 is elastically held with a predetermined set load W between the lower surface of the distal end portion of the arm portion 37b extending into the spring accommodating chamber 44 through the suction hole 41a and the bottom surface of the spring accommodating chamber 44. ing.

  Therefore, the coil spring 38 always urges the cam ring 37 in the direction in which the amount of eccentricity increases (counterclockwise in FIG. 1) via the arm portion 37b with an elastic force based on the spring load W. It is like that. As a result, when the cam ring 37 is not in operation, the outer surface of the arm portion 37b is pressed against the stopper surface 44a formed on the lower surface of the upper wall of the spring accommodating chamber 44 by the spring force of the coil spring 38. It is held at a position where the amount of eccentricity with respect to the center is maximized.

  Further, as shown in FIG. 9, the outer periphery of the cam ring 37 has a cross section having first and second seal surfaces formed so as to face the first and second seal sliding contact surfaces 31c and 31d. Two substantially triangular first and second seal holding portions 37c and 37d are provided so as to protrude. Further, the seal sliding contact surfaces 31c when the cam ring 37 is eccentrically swung in the first and second seal holding grooves having a substantially U-shaped cross section formed in the cutouts on the seal surfaces of the seal holding portions 37c and 37d, respectively. Each of the sealing members 27 made of a rubber material slidably contacting 31d is accommodated and held.

  The two seal members 27 are, for example, elongated in a straight line along the axial direction of the cam ring 37 by using a fluorine-based resin material having low friction characteristics, and are made of rubber elastic disposed at the bottom of each seal holding groove. The seal sliding contact surfaces 31c and 31d are pressed against each other by the elastic force of the member so that good liquid tightness of first and second control hydraulic pressures 45 and 46 to be described later is always secured. It has become.

  As shown in FIG. 2, the outer peripheral surface of the cam ring 37, the pivot groove 37 a, and the inner peripheral surface of the housing body 31, as shown in FIG. The first control oil chamber 45 and the second control oil chamber 46 described above are separated from both sides of the pivot groove 37a by the seal members 27 and the inner surface of the housing body 31, respectively.

  In FIG. 9, the first control oil chamber 45 on the right side from the pivot groove 37 a is always in communication with the main oil gallery 11 through the supply passage 20, and is slightly lower than the discharge pressure from the main oil gallery 11. Hydraulic pressure is supplied.

  A first pressure receiving surface 37e constituted by the outer peripheral surface of the cam ring 37 facing the first control oil chamber 45 resists the urging force of the coil spring 38 to provide the hydraulic pressure from the main oil gallery 11 and the supply passage 20. In response, a swinging force (moving force) is applied in a direction that reduces the amount of eccentricity of the cam ring 37 (clockwise in FIG. 9).

  That is, the first control oil chamber 45 always acts on the cam ring 37 in the direction in which the center of the cam ring 37 approaches the center of rotation of the rotor 34 via the first pressure receiving surface 37e, that is, in the direction in which the amount of eccentricity decreases. Therefore, the cam ring 37 is used for controlling the amount of movement in the concentric direction.

  The second control oil chamber 46 on the left side of the pivot groove 37 a is appropriately supplied with the hydraulic pressure of the main oil gallery 11 through the pilot valve 22 via the branch passage 28 branched from the control passage 24. It has become.

  Further, a second pressure receiving surface 37f is formed on the outer peripheral surface of the cam ring 37 facing the second control oil chamber 46, and by applying a discharge pressure to the second pressure receiving surface 37f, the biasing force of the coil spring 38 is increased. This is a force acting in the assisting direction, whereby a swinging force (moving force) is applied to the cam ring 37 in the direction of increasing the amount of eccentricity (counterclockwise in FIG. 9).

  Here, as shown in FIG. 9, the pressure receiving area of the first pressure receiving surface 37e is formed larger than the pressure receiving area of the second pressure receiving surface 37f, and the urging force and coil based on the internal pressure of the second control oil chamber 46 are formed. The urging force in the eccentric direction of the cam ring 37 due to the urging force of the spring 38 and the urging force based on the internal pressure of the first control oil chamber 45 are balanced with a predetermined force relationship. As described above, the hydraulic pressure assists the biasing force of the coil spring 38.

  As shown in FIG. 7, a part of a control passage 24 that supplies pilot pressure (control pressure) to the pilot valve 22 is formed on one side of the housing mounting surface 32 b of the cover member 32. One control passage groove 50 is formed in a straight line along the vertical direction, and a supply / discharge passage groove 51 constituting a part of the supply / discharge passage 25 (including the branch passage 28) is formed at an inward position thereof. It is substantially L-shaped. Further, a drain passage groove 52 for discharging the hydraulic pressure in the second control oil chamber 46 to the oil pan 14 through the pilot valve 22 is formed below the supply / discharge passage groove 51.

  The first control passage groove 50 has a control communication hole 50a penetratingly formed at a lower end portion thereof and communicating with a second control passage groove 54 described later formed on the mounting surface 32c of the cover member 32. In the supply / discharge passage groove 51, two communication holes 51a and 51b communicating with a second supply / discharge port 78 (described later) of the pilot valve 22 and a second control oil chamber 46 are formed through both ends.

  These passage grooves 50, 51, 52 are formed when the cover member 32 comes into contact with the mounting surface 31e of the housing body 31 through the housing mounting surface 32b in a metal contact state and is fastened together by the bolts 26. Further, it is sealed by the surface pressure due to the bolt axial force.

  On the other hand, as shown in FIG. 8, the attachment surface 32c of the cover member 32 is formed in a flat arc shape in accordance with the shape of the attachment surface 9 of the balancer device 2, and on the right side in the figure. A supply passage groove 53 that is a square-shaped oil passage groove that forms part of the supply passage 20 that supplies hydraulic pressure from the main oil gallery 11 to the first control oil chamber 45 is formed. In the supply passage groove 53, a communication hole 53a communicating with the first control oil chamber 45 is formed in a bent position.

  Further, a second control passage groove 54, which is an oil passage groove formed in a circular arc shape, is formed on the left side of the attachment surface 32c in the drawing from a substantially central position, and the second control passage groove 54 has one end. The portion communicates with the control communication hole 50a via the control communication groove 54a, and the other end portion communicates with a pilot pressure introduction port 76 (to be described later) of the pilot valve 22 via the control communication hole 54b.

  Each of the passage grooves 53 and 54, when the cover member 32 comes into contact with the attachment surface 9 of the balancer device 2 through the attachment surface 32c in a metal contact state and is fastened together by the bolts 26, It is sealed by the surface pressure due to this bolt axial force.

  As shown in FIGS. 9 to 12, the pilot valve 22 slides in a cylindrical valve body 71 attached to the cover member 32 and a sliding hole 72 formed in the valve body 71. A spool valve 73 provided freely, and a valve spring 74 that is elastically mounted below the sliding hole 72 and biases the spool valve 73 upward. A plug 75 for sealing the opening is press-fitted and fixed.

  The valve body 71 is formed with a pilot pressure introduction port 76 communicating with the control passage 24 at an upper end portion, a first supply / exhaust port 77 communicating with the branch passage 28 in order from the upper side on the peripheral wall, A second supply / discharge port 78 communicating with the second control oil chamber 46 and the first supply / discharge port 77 as appropriate, a drain port 79 communicating with the drain passage groove 52, and good slidability of the spool valve 73 are ensured. Air vent hole 71b for carrying out.

  If the spool valve 73 is described in order from the upper end side, a first small-diameter shaft portion 73a that receives the hydraulic pressure of the pilot pressure introduction port 76 at the upper end surface, a first land portion 73b that functions as a valve portion, and an outer periphery It has a second small-diameter shaft portion 73c having an annular groove, a second land portion 73d that functions as a valve portion, and a lowermost third small-diameter shaft portion 73e that supports the upper end side of the valve spring 74. .

  The spool valve 73 moves downward or upward by the relative pressure between the control hydraulic pressure received from the pilot pressure introduction port 76 and the spring force of the valve spring 74 on the upper end surface of the first small diameter shaft portion 73a. The ports 77, 78, 79 are appropriately opened / closed (communication).

  The electromagnetic switching valve 21 is a three-port two-position valve that opens and closes the second supply passage 23 and communicates the control passage 24 (branch passage 28) with the outside, or shuts off the communication. Based on the on / off signal (control current) from the control unit to be controlled, the on / off operation is performed according to the operating state of the engine.

  That is, as shown in FIGS. 9 to 12, the electromagnetic switching valve 21 includes a cylindrical valve body 61 inserted and fixed in a valve hole formed in a cylinder block, and a base end portion of the valve body 61. A cylindrical solenoid unit 62 which is coupled and accommodates a coil, a fixed plunger, a movable plunger, and the like inside, and a push rod which is coupled to the distal end side of the movable plunger and is supported so as to be movable forward and backward. 63, and a ball valve body 64 that opens and closes the opening port of the valve seat 65 provided in the distal end portion of the valve body 61 by the push rod 63.

  In the valve body 61, a passage hole 61a in which the push rod 63 slides is formed along the axial direction, and the valve seat 65 on which the ball valve body 64 is seated and separated is disposed in the distal end portion. The fitting is fixed. The opening port of the valve seat 65 is configured such that the downstream portion of the second supply passage 23 and one end portion of the control passage 24 are communicated or blocked by the seating (opening / closing operation) of the ball valve body 64.

  Further, the valve body 61 has a supply / discharge hole 61b communicating with the opening port and one end side of the control passage 24 in the side portion of the ball valve body 64 in the peripheral wall, which is formed through the radial direction. A drain hole 61c that communicates with the passage hole 61a through the ball valve body 64 is formed through the unit 62 along the radial direction.

  The coil is energized or interrupted on and off from the engine control unit.

  That is, when an ON signal (energization) is output from the control unit to the coil, the movable plunger moves forward against the spring force of a return spring, and the ball valve body 64 is moved toward the valve seat 65 by the push rod 63. Press to. Accordingly, the ball valve body 64 closes the opening port and allows the supply / discharge hole 61b and the passage hole 61a to communicate with each other.

  Therefore, the hydraulic pressure in the second control oil chamber 46 is discharged from the branch passage 28 to the oil pan 14 through the supply / discharge hole 61b, the passage hole 61a, and the drain hole 61c via the pilot valve 22. (See FIGS. 9 and 10).

  On the other hand, when an off signal (non-energized) is output to the coil, the movable plunger moves backward by the spring force of the return spring, thereby separating the ball valve body 64 from the valve seat 65 via the push rod 63. Thus, the opening port is opened, and the one end portion of the control passage 24 (branch passage 28) and the second supply passage 23 are communicated (see FIGS. 11 and 12).

The control unit detects the current engine operating state from the oil temperature and water temperature of the engine, the engine speed, the load, and the like. When it is higher than a predetermined value, an off signal (non-energized) is output.
[Operation of Variable Displacement Pump of Embodiment]
Hereinafter, the operation of the variable displacement pump according to the present embodiment will be briefly described with reference to FIGS.

  When the engine is in a low-speed operation state such as an idling operation from the start of the engine, the drive shaft 5 of the balancer device 2 receives the rotational force of the crankshaft and is driven via the drive gear 7 and the driven gear 8. The shaft 6 is driven to rotate. As a result, the oil pump 1 causes the pump shaft 33 to rotationally drive from the drive-side helical gear 13 of the driven shaft 6 through the driven-side helical gear 43 of the pump shaft 33 to perform pumping action by the pump element. On the first side, the operating states shown in FIGS. 9 and 10 are obtained. In this state, an ON signal is output from the control unit to the coil of the electromagnetic switching valve 21, and the ball valve body 64 is pushed up by the movable plunger and the push rod 63 to close the opening port of the valve seat 65. To do. For this reason, the communication between the second supply passage 23 and the control passage 24 is blocked, the supply of the control hydraulic pressure to the pilot valve 22 is stopped, and the supply / discharge hole 61b and the drain hole 61c are communicated.

  On the other hand, in the pilot valve 22, since the control oil pressure does not act on the spool valve 73 from the pilot pressure introduction port 76, the spool valve 73 is urged to the maximum raised position by the spring force of the valve spring 74, and the first land portion. 73b is seated on the seating surface.

  Therefore, the first and second supply / exhaust ports 77 and 78 communicate with each other so that the hydraulic pressure in the second control oil chamber 46 is equal to the branch passage 28, one end of the control passage 24 and The second control oil chamber 46 is in a low pressure state by being discharged into the oil pan 14 through the electromagnetic switching valve 21. The first control oil chamber 45 is always supplied with hydraulic pressure downstream of the main oil gallery 11.

  In this first state, the discharge pressure supplied to the discharge passage 17 rises as the engine speed increases, and the cam ring 37 via the first pressure receiving surface 37e is supplied by the discharge pressure supplied to the first control oil chamber 45. The force in the direction of decreasing the amount of eccentricity increases. When the discharge pressure P shown in FIG. 13 reaches P1, the force acting on the cam ring 37 overcomes the spring force of the coil spring 38, and the amount of eccentricity of the cam ring 37 is reduced to control the increase of the discharge pressure. That is, in the state where the engine speed shown in FIG. 13 is (1) and (2), the discharge pressure characteristic P of the pump is in a low pressure state where the engine speed slightly rises as the engine speed increases as shown by P1 in FIG. Is maintained and controlled.

  Next, when the engine speed rises into the region of (3) in FIG. 13, the load and oil temperature increase, and the operation state that requires the operation of the oil jet for injecting oil to the piston is reached, the oil pump 1 The second state shown in FIG. That is, the control unit outputs an off signal (non-energized) to the electromagnetic switching valve 21. As a result, as shown in FIG. 11, the electromagnetic switching valve 21 opens the opening port by separating the ball valve body 64 from the valve seat 65 with the backward movement of the push rod 63, and the one end portion of the control passage 24. The second supply passage 23 is connected, and the upper end opening of the passage hole 61a is closed to block the communication of the drain hole 61c.

  For this reason, the hydraulic pressure of the main oil gallery 11 acts on the upper end surface of the first small-diameter shaft portion 73a of the spool valve 73 through the control passage 24 as indicated by an arrow in the figure. As a result, the spool valve 73 slightly moves downward against the spring force of the valve spring 74, but the first supply / discharge port 77 and the second supply / discharge port 78 maintain the communication state.

  Accordingly, the hydraulic pressure of the main oil gallery 11 is supplied to the second control oil chamber 46 via the second supply passage 23, the control passage 24 and the branch passage 28 to assist the spring force of the coil spring 38. The cam ring 37 is slightly swung counterclockwise to balance the reaction force of the cam ring 37. For this reason, the discharge pressure of the pump is largely controlled in a stepwise manner from P1 to P2, as shown in FIG.

  Next, when the engine enters the high rotation range shown in (4) of FIG. 13 and enters an operation state where higher oil pressure is required due to high oil temperature or the like, the oil pump 1 is in the third state shown in FIG. Become. That is, an OFF signal (non-energized) is maintained in the electromagnetic switching valve 21 by the control unit. Thereby, the ball valve body 64 is separated from the valve seat 65 as the push rod 63 moves backward, so that the opening port is opened and the communication state between the one end portion of the control passage 24 and the second supply passage 23 is maintained. .

  On the other hand, on the pilot valve 22 side, as shown in FIG. 12, the first small diameter shaft of the spool valve 73 passes from the main oil gallery 11 through the second supply passage 23 and the control passage 24 as the discharge pressure increases. Since the control hydraulic pressure acting on the upper end surface of the portion 73a also increases, the spool valve 73 further moves downward slightly, the first land portion 73b closes the first supply / discharge port 77, and the second small diameter shaft portion. The second supply / discharge port 78 and the drain port 79 are communicated with each other through an annular groove 73c.

  For this reason, the supply of the hydraulic pressure of the main oil gallery 11 to the second control oil chamber 46 is stopped, and the hydraulic pressure in the second control oil chamber 46 is discharged to the outside as indicated by an arrow. On the other hand, since a large discharge pressure is continuously supplied also to the first control oil chamber 45, the cam ring 37 is slightly swung in the clockwise direction against the spring force of the coil spring 38 to reduce the eccentric amount. Control in the direction

  Accordingly, although the pump discharge pressure temporarily decreases, the control hydraulic pressure acting on the spool valve 73 also decreases along with this decrease, and therefore the spool valve 73 moves up again to reduce the discharge pressure to the second control oil chamber 46. Supply. In other words, when the pump discharge pressure is in the state of P2, the discharge pressure is adjusted to a constant pressure while repeatedly increasing and decreasing as the spool valve 73 moves up and down.

  Thus, in this embodiment, by controlling the operation of the pilot valve 22 via the electromagnetic switching valve 21, the pump discharge pressure can be controlled in two stages P1 and P2.

  In the present embodiment, the rotational force is efficiently transmitted to the pump shaft 33 of the oil pump 1 during driving by the meshing of the driven side helical gear 43 and the driven side helical gear 13 of the driven shaft 6. Due to the meshing characteristics of the helical gears 13 and 43, a thrust load in the direction of the balancer device 2 acts on the pump shaft 33 as shown by the arrow in FIG.

  For this reason, the mounting surface 32c of the cover member 32 of the pump housing is connected to the mounting surface 9 of the lower housing 4 of the balancer device 2 via the rotor 34 fixed to the pump shaft 33 in the axial direction, that is, in the direction of the arrow ( The pressing force from the thrust direction) acts, and the entire mounting surface 32c is strongly pressed against the entire mounting surface 9.

  Therefore, the pump housing is deformed due to the drive gear 7 that transmits the rotational force from the driven shaft 6 of the balancer device 2 to the pump shaft 33, the rotational drive force of the driven gear 8, and the like, and the attachment surface 32c and the attachment surface are attached. Without opening the mating surface with the surface 9, a strong and liquid-tight contact state is maintained at all times, and the sealing performance between the both 9 and 32c is improved.

  As a result, leakage of hydraulic fluid (hydraulic pressure) flowing through the passage grooves 53 and 54 to the outside can be sufficiently suppressed, and good control accuracy of the eccentric amount of the cam ring 37 by the hydraulic fluid can be achieved. can get. Therefore, the stepwise pump discharge pressure characteristics described above can be accurately controlled.

Further, the housing body 31 is also pulled in the direction of the balancer device 2, that is, in the direction of the cover member 32 through the pump shaft 33 and the like by the force in the thrust direction of the pump shaft 33, so that the mounting surface 31 e of the housing body 31 is covered. The member 32 is pressed strongly against the housing mounting surface 32b. As a result, the sealing performance between the mounting surface 31e and the housing mounting surface 32b is also improved, and leakage of hydraulic fluid flowing through the passage grooves 50, 51, 52 to the outside can be effectively suppressed. The electromagnetic switching valve 21 is energized from the control unit in the engine low rotation range (discharge pressure P1), but is not energized at high rotation (discharge pressure P2). Even when the coil or harness of the valve 21 is disconnected, it is possible to perform pump discharge pressure control at the time of high rotation (P2). However, it is also possible to reversely set energization and non-energization in consideration of power saving.

  The present invention is not limited to the configuration of the embodiment described above, and can be applied to other variable displacement oil pumps having different specifications.

  Further, the counterpart side to which the oil pump 1 is attached is not limited to the balancer device 2 but may be, for example, an internal combustion engine.

  Furthermore, in the above-described embodiment, the attachment surface 32c of the cover member 32 is used as the contact target with respect to the attached surface 9, but when the cover member is not provided, the attachment surface 31e of the housing body 31 can be the target. .

DESCRIPTION OF SYMBOLS 1 ... Oil pump 2 ... Balancer apparatus (drive side member)
3 ... Upper housing 4 ... Lower housing (drive side member)
5 ... Drive shaft 6 ... Driven shaft (drive shaft)
9 ... Mounted surface 11 ... Main oil gallery 13 ... Drive-side helical gear 20 ... Supply passage 21 ... Electromagnetic switching valve (switching mechanism)
22 ... Pilot valve (control mechanism)
23 ... Second supply passage 24 ... Control passage 25 ... Supply / discharge passage 30 ... Pump housing chamber 31 ... Housing body 32 ... Cover member 32c ... Mounting surface 33 ... Pump shaft 34 ... Rotor 35 ... Vane 36 ... Pump chamber 37 ... Cam ring 38 ... Coil spring (biasing mechanism)
41 ... Suction port (suction part)
42: Discharge port (discharge part)
43 ... driven helical gear 45 ... first control oil chamber 46 ... second control oil chamber 50 ... first control passage groove 51 ... supply / discharge passage groove 52 ... drain passage groove 53 ... supply passage groove (oil passage groove)
54 ... Second control passage groove (oil passage groove)

Claims (8)

A pump housing having a housing body and a cover member;
One end of the housing body is open at the housing body, and a pump housing portion is provided inside,
The cover member includes a housing attachment surface attached to one end of the housing body so as to close the pump housing portion, and an attachment surface on the outer end surface side provided on the outer end surface opposite to the housing attachment surface, The pump housing having a plurality of oil passage grooves provided in the mounting surface on the outer end surface side, and a bearing hole penetrating between the housing mounting surface and the mounting surface on the outer end surface side ;
A pump shaft that is inserted into the bearing hole of the cover member of the pump housing and rotatably supported;
A rotor housed in the pump housing portion, fixed to the pump shaft, and in contact with the housing mounting surface ;
A driven helical gear fixed to the pump shaft;
A balancer device, comprising a balancer housing, a balancer shaft, and a drive-side helical gear,
The balancer housing is disposed so that the cover member is sandwiched between the balancer housing and the housing body in the rotation axis direction of the pump shaft, and one end is open, and a gear housing portion that houses the driven helical gear inside. Have
At one end of the balancer housing, a mounting surface that comes into contact with the mounting surface on the outer end surface side provided with the plurality of oil passage grooves is provided,
The drive side helical gear is provided in the gear housing portion and meshes with the driven side helical gear;
The balancer shaft is rotatably supported by the balancer housing and has the drive side helical gear.
The balancer device ,
Thrust force generated when transmitting the rotational force of the driving side helical gear to the driven side helical gear acts via the rotor from the housing mounting surface of the cover member toward the mounting surface of the balancer housing . oil pump, wherein the Turkey. The oil pump according to claim 1, wherein
The pump element provided inside the pump accommodating portion is
A plurality of vanes provided on the outer periphery of the rotor so as to be freely movable; and
The center of the inner diameter is eccentrically arranged with respect to the rotation center of the rotor arranged on the inner side, and a plurality of pump chambers are separated in cooperation with the rotor and the vane, and the eccentric amount is obtained by moving. A cam ring that changes and changes the volume change of the pump chamber;
A suction portion that opens to the plurality of pump chambers, the volume of which is increased by rotation of the rotor;
A discharge portion that opens to the plurality of pump chambers, the volume of which is reduced by rotation of the rotor;
Have
An urging mechanism that is provided in a state in which a set load is applied and urges the cam ring in a direction in which the amount of eccentricity increases;
A first control oil chamber that applies a force in a direction in which the volume change amount of the plurality of pump chambers is reduced by supplying hydraulic oil to the cam ring;
A second control oil chamber that applies a force to the cam ring in a direction in which a volume change amount of the plurality of pump chambers is increased by supplying hydraulic oil;
A switching mechanism that switches between supplying and discharging hydraulic oil to the second control oil chamber;
An oil pump comprising: The oil pump according to claim 2,
The oil pump, wherein the oil passage groove includes a supply passage groove and a discharge passage groove for supplying and discharging hydraulic oil to and from the second control oil chamber via the switching mechanism. In the oil pump according to claim 3,
The first control oil is controlled to be in a state in which hydraulic oil whose pressure is lower than the discharge pressure from the discharge unit is supplied to the second control oil chamber and in a state in which the hydraulic oil in the second control oil chamber is discharged. A control mechanism is provided for adjusting the pressure in the second control oil chamber by discharging the hydraulic oil in the second control oil chamber as the discharge pressure increases when the hydraulic oil is supplied to the chamber; Features oil pump. The oil pump according to claim 4, wherein
The oil passage groove has a second supply passage provided for supplying hydraulic oil to the second control oil chamber via the control mechanism, and a second discharge passage provided for discharge. pump. The oil pump according to claim 1, wherein
Before Kiyu passage groove, an oil pump, characterized in that is also formed on the inner end face opposite to the mounting surface. A pump housing in which the pump element is housed in an internal housing chamber, and an oil passage groove is formed on the mounting surface of the outer end surface;
A pump shaft inserted through the pump housing and rotatably supported;
A rotor driven to rotate by the pump shaft;
A drive side member having a mounting surface of the pump housing and a mounting surface formed to face the mounting surface;
A drive-side helical gear provided at the tip of the drive shaft protruding outward from the inside of the drive-side member;
A balancer device provided at a tip of the pump shaft protruding from the inside of the pump housing, having a driven helical gear meshing with the driving helical gear, and transmitting a rotational force from a crankshaft to the pump shaft;
With
The pump housing is attached to the balancer device via the attachment surface, and a thrust force generated when transmitting the rotational force of the drive side helical gear to the driven side helical gear is the attachment surface of the pump housing. An oil pump characterized in that it is arranged so as to act from the side toward the surface to which the balancer device is attached. A pump housing in which the pump element is housed in an internal housing chamber, and an oil passage groove is formed on the mounting surface of the outer end surface;
A pump shaft inserted through the pump housing and rotatably supported;
A rotor driven to rotate by the pump shaft;
A balancer housing of the balancer device formed to face the mounting surface of the pump housing and having a mounted surface that contacts the mounting surface;
A drive-side helical gear provided at the tip of the driven-side balancer shaft that protrudes outward from the inside of the balancer housing;
A driven helical gear provided at a tip portion of the pump shaft protruding from the inside of the pump housing and meshing with the driving helical gear;
A drive-side balancer shaft that is rotatably provided in the balancer housing and transmits a rotational force transmitted from a crankshaft to the driven-side balancer shaft;
With
The pump housing is attached to the balancer housing via the attachment surface and the attachment surface, and a thrust force generated when the rotational force of the driving helical gear is transmitted to the driven helical gear is the pump housing. An oil pump characterized in that the oil pump is arranged to act from a mounting surface side of the housing toward a mounting surface of the balancer housing.

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