JP2018080586A - Oil pump, and balancer device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel oil pump: capable of making the length of the axial direction of an oil pump as short as possible, and reducing the radial size of the oil pump as much as possible; and a balancer device of an internal combustion engine integrated with the oil pump.SOLUTION: A pump cover 31, which is so fixed with a pump housing 30 as to be orthogonal to the axial direction of a rotation axis 37 of a pump body 36, is formed with a relief passage 38 extending in a direction perpendicular to the axial direction of a revolution shaft 37 of a pump body 36, and a spring 40 for biasing a relief valve 39 and a relief valve in closing directions are mounted in a portion of the relief passage 38.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an oil pump used in an internal combustion engine and a balancer device for an internal combustion engine including the oil pump.

  In a general internal combustion engine, a variable displacement oil pump driven by the internal combustion engine is used as a hydraulic pressure source for hydraulic equipment and a hydraulic pressure source used for lubrication of a mechanical sliding portion. (Hereinafter, oil for hydraulic equipment and oil for lubrication are expressed as hydraulic oil.) As this variable displacement oil pump, for example, a variable described in Japanese Patent Application Laid-Open No. 2011-111926 (Patent Document 1). Volumetric pumps are known.

  This variable displacement oil pump is a vane type oil pump, and the cam oil is eccentric with respect to the rotation center of the rotor by introducing hydraulic oil into a control oil chamber defined between the pump housing and the cam ring. The biasing force by the discharge pressure that acts to bias the cam ring in the direction of decreasing the amount (concentric direction) and the spring force by the spring that biases the cam ring in the direction of increasing the eccentric amount of the cam ring (eccentric direction) Based on this, by controlling the amount of eccentricity of the cam ring in accordance with the engine speed, it is possible to supply oil to a plurality of hydraulic devices having different required discharge pressures.

  The internal combustion engine is provided with a balancer device that rotatably accommodates a first balancer shaft driven by a crankshaft and a second balancer shaft driven by the first balancer shaft. The vibration generated in the internal combustion engine is reduced. The first balancer shaft and the second balancer shaft are provided with balance weights, and the first balancer shaft and the second balancer shaft are rotated at twice the number of rotations of the crankshaft, and are generated in the crankshaft. The vibration of the internal combustion engine is reduced by balancing the inertial force with the inertial force generated by the first balancer shaft and the second balancer shaft.

  Further, in this balancer device, as disclosed in Japanese Patent Application Laid-Open No. 2010-230129 (Patent Document 2), the balancer device is fastened to the lower portion of the internal combustion engine body and disposed in the oil pan. The first balancer shaft is rotationally driven by the crankshaft, the second balancer shaft is driven by the first balancer shaft via the gear transmission means for synchronization, and the variable capacity as disclosed in Patent Document 1 is provided by the second balancer shaft. It is also known to drive a mold oil pump.

JP 2011-111926 A JP 2010-230129 A

  In such an oil pump, for example, when the rotational speed is increased in a state where the temperature of the hydraulic oil is low, the discharge pressure rises rapidly due to the high viscosity of the hydraulic oil, and the discharge pressure exceeds the maximum set pressure. May be higher. For this reason, the components constituting the oil pump may be damaged or the oil pump may become inoperable. And in order to suppress that this discharge pressure becomes high pressure, the relief mechanism which is a safety valve is provided in the discharge side of the oil pump. This relief mechanism is composed of a relief valve that closes a relief passage connected to the discharge side, and a compression spring that urges the relief valve in a closing direction with a predetermined closing pressure, and the discharge pressure of the oil pump closes the compression spring. When the pressure is exceeded, the relief valve is opened to reduce the discharge pressure.

  The movement direction of the relief valve is set in the axial direction in which the rotating shaft that rotates the vane of the oil pump extends. Similarly, the compression spring is also arranged in the axial direction in which the rotating shaft extends. Thus, since this relief mechanism is configured to operate in the axial direction, the physique of the oil pump is increased in the axial direction by this amount. Further, the relief mechanism may be disposed adjacent to the pump chamber substantially parallel to the rotation shaft, and the pump housing that covers the pump chamber becomes larger outward in the radial direction. For this reason, in the area | region where the space volume where an oil pump is arrange | positioned is restrict | limited, the subject that an oil pump cannot be arrange | positioned occurred.

  In particular, in a configuration in which the oil pump is integrated with the balancer device, the balancer device is disposed at the axially central portion on the lower side of the internal combustion engine, and the oil pump is disposed at the rear end thereof. And since many auxiliary machines required for driving | running | working of a motor vehicle are arrange | positioned at the rear-end part side of a balancer apparatus, it is necessary to be able to arrange | position without interfering with these auxiliary machines. For this reason, it is required to shorten the axial length of the oil pump, and similarly, the size of the pump housing in the radial direction is set to a size necessary for the cam ring moving range and cam spring storage. It is also requested.

  An object of the present invention is to provide a novel oil pump capable of reducing the axial length of the oil pump and reducing the radial size of the pump housing, and an internal combustion engine in which the oil pump is integrated. It is to provide a balancer device.

  The first feature of the present invention is that the pump cover fixed to the pump housing is orthogonal to the axial direction of the rotation axis of the pump body, and extends in the direction orthogonal to the axial direction of the rotation axis that rotates the pump body. A relief passage is formed, and a relief valve is provided in a part of the relief passage to open when the discharge pressure on the discharge side exceeds a predetermined pressure.

  The second feature of the present invention is that the pump cover fixed to the pump housing so as to be orthogonal to the axial direction of the rotation axis of the pump body is directed in a direction orthogonal to the axial direction of the rotation axis rotating the pump body. And a relief valve that is opened when the discharge pressure on the discharge side exceeds a predetermined pressure is provided in a part of the relief passage, and this pump cover is adjacent to the end face of the housing constituting the balancer device. And it's fixed.

  According to the first feature of the present invention, the relief passage provided with the relief valve and the spring for urging the relief valve in the closing direction is formed in the pump cover orthogonal to the axis of the rotating shaft that rotates the pump body. The axial length can be shortened, and the pump housing can be reduced in the radial direction.

  According to the second feature of the present invention, in addition to the above-described configuration, the pump cover provided with the relief passage is fixed adjacent to the end surface of the housing of the balancer device. The size of the housing in the radial direction can be reduced, and the oil pump can be installed without interfering with surrounding auxiliary equipment.

It is sectional drawing which shows the cross section of the internal combustion engine provided with the balancer apparatus. 1 is an overall perspective view of a balancer device to which an oil pump according to an embodiment of the present invention is attached. FIG. 3 is a cross-sectional view in which the balancer device shown in FIG. 2 is cut in the axial direction. FIG. 4 is an exploded perspective view of the balancer device shown in FIG. 3. It is sectional drawing of the state which removed the upper side housing with the balancer apparatus shown in FIG. It is sectional drawing which shows the cross section containing a relief channel | path and a pump main body. It is a disassembled perspective view of the oil pump shown in FIG. It is sectional drawing which shows the cross section by the side of the pump housing of an oil pump. It is the front view seen from the oil housing side of the oil pump. It is the front view which looked at the pump cover from the outside. It is the rear view which looked at the pump cover shown in FIG. 10 from the inner side.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and application examples are included in the technical concept of the present invention. Is also included in the range.

  Before explaining the embodiment of the present invention, first, the installation state of the internal combustion engine and the balancer device will be explained based on FIG. FIG. 1 shows a longitudinal section of the internal combustion engine 01. The internal combustion engine 01 is, for example, an in-line 4-cylinder reciprocating internal combustion engine. A cylinder block 03 is provided below the cylinder head 02, and a ladder frame 04 is fixed to the lower surface of the cylinder block 03. A crankshaft (not shown) is rotatably supported on the ladder frame 04, and the crankshaft is disposed along the axial direction of the internal combustion engine.

  The internal combustion engine 01 is mounted on a vehicle such that the crankshaft is in a lateral direction with respect to the longitudinal direction of the vehicle body, and an unillustrated engine-side gear is fixed to a part of the crankshaft in the axial direction. The engine side gear is a drive gear for driving a balancer device described later. Further, an oil pan 05 in which hydraulic oil (lubricating oil) is stored is attached to the lower portion of the ladder frame 04, and secondary vibration of the internal combustion engine 01 is suppressed in the oil pan 05. A balancer device 10 is accommodated.

  The balancer device 10 includes an upper housing, a lower housing, a balancer body, and an oil pump 11, which will be described in detail later. The upper housing and the lower housing are fixed to the lower surface of the cylinder block 03 or the ladder frame 04 by a plurality of fixing bolts (balancer fastening bolts) 06 so as to overlap in the vertical direction. The oil pump 11 is connected to and integrated with the balancer device 10 by a plurality of fixing bolts (oil pump fastening bolts) 07. The oil pump 11 is a variable displacement oil pump that changes the volume change amount of the pump chamber in accordance with a predetermined operation state.

  The variable displacement oil pump used in the present embodiment is a vane pump having a mechanism for reducing the volume change amount of the pump chamber at the time of high pump rotation, and is described in, for example, the above-described Japanese Patent Application Laid-Open No. 2011-111926. Known ones are used. The oil pump 11 is fixed to the axial end surface side of the lower housing 12 by a plurality of fixing bolts 07.

  In such an oil pump 11, a relief mechanism is provided on the discharge side of the oil pump 11. As described above, in the relief mechanism provided in the conventional oil pump, the movement direction of the relief valve constituting the relief mechanism is set to the axial direction in which the rotating shaft that rotates the vane of the oil pump extends. Further, the compression spring is also arranged in the axial direction in which the rotation shaft extends. For this reason, the physique of the oil pump tends to increase in the axial direction. Further, when the relief mechanism is disposed adjacent to the pump chamber substantially parallel to the rotation shaft, the pump housing tends to increase outward in the radial direction. For this reason, there exists a subject that an oil pump cannot be arrange | positioned in the area | region where the space volume where an oil pump is arrange | positioned is restrict | limited.

  When the oil pump is integrated with the balancer device, the balancer device is disposed at the axially central portion on the lower side of the internal combustion engine, and the oil pump is disposed at the rear end thereof. And since many auxiliary machines required for driving | running | working of a motor vehicle are arrange | positioned at the rear-end part side of a balancer apparatus, it is necessary to be able to arrange | position without interfering with these auxiliary machines.

  Therefore, in the present embodiment, an oil pump configuration is proposed in which the axial length of the oil pump 11 can be made as short as possible and the radial size of the pump housing can be made as small as possible. Hereinafter, the oil pump and the balancer installation of the internal combustion engine according to the present embodiment will be described in detail with reference to FIGS.

  FIG. 2 shows an overall configuration of the balancer device 10 to which the oil pump 11 is attached as viewed from an oblique direction, and FIG. 3 shows an axial cross section of the balancer device 10. 2 is the front side (front side) of the vehicle, and the left side of FIG. 2 and the right side of FIG. 3 are the rear side (rear side) of the vehicle. The balancer device 10 is fixed to the cylinder block 03 or the ladder frame 04 as shown in FIG.

  2 and 3, an oil pump 11 is fixed to the rear side of the balancer device 10, and is driven to rotate by a second balancer shaft built in the balancer device 10. In the balancer device 10, the balancer body is housed in a housing space formed by the lower housing 12 and the upper housing 13.

  In FIG. 3, the first balancer shaft 14 side is sectioned along the axial direction, and a balancer drive gear 15 is fixed to the end surface of the first balancer shaft 14 on the oil pump 11 side. The balancer drive gear 15 is rotated and driven by an engine side gear rotated by a crankshaft.

  A first gear 16 constituting a gear transmission mechanism is fixed to the other end of the first balancer shaft 14, and is configured to mesh with a second gear fixed to a second balancer shaft (not shown). Further, a first balance weight 17 is provided on the first balancer shaft 14 between the balancer drive gear 15 and the first gear 16. Between the first balance weight 17 and the first gear 16 is pivotally supported by the front side first bearing 18, and between the first balance weight 17 and the balancer drive gear 15 is pivotally supported by the rear side first bearing 19.

  A pump drive gear 20 is fixed to the rotation shaft of the oil pump 11 and is rotated by a reduction gear fixed to an end face of a second balancer shaft (not shown). The pump drive gear 20 is integrated with the oil pump 11 and is engaged with the reduction gear by being assembled to the balancer device 10. Accordingly, the pump drive gear 20 is arranged between the end face of the lower housing 12 and the upper housing 13 on the oil pump 11 side and the pump cover of the oil pump 11.

  An exposure opening 21 is formed in a region of the upper housing 13 where the balancer drive gear 15 is disposed, and a part of the balancer drive gear 15 protrudes upward from the exposure opening 21 and is exposed. This makes it possible to mesh with the engine side gear. In addition, an oil barrier 22 formed on the upper housing 13 and covering the pump drive gear 20 from above is formed on the oil pump 11 side from the exposed opening 21.

  Returning to FIG. 2, the oil pump 11 includes a pump housing 30 in which a pump body is accommodated, and a pump cover 31 that covers the pump housing 30 so as to be sealed. The pump housing 30 and the pump cover 31 are integrally fixed to each other with fixing bolts 32, and both the pump housing 30 and the pump cover 31 are fixed to the lower housing 12 with fixing bolts 07. The fixing bolt 07C fixes the pump cover 31 and the lower housing 12. Therefore, the pump cover 31 is disposed adjacent to the end surfaces of the lower housing 12 and the upper housing 13 that constitute the balancer device 10.

  The pump housing 30 and the pump cover 31 are overlapped, and a relief mechanism 34 is formed in the non-polymerization region 33 other than the polymerization region. The relief mechanism 34 includes a relief passage formed in the pump cover 31, a relief valve built in a part of the relief passage, and a compression spring urged in a direction to close the relief valve. Details of the relief mechanism 34 will be described with reference to the drawings described later.

  The relief passage of the relief mechanism 34 is opened to the outside through a discharge port 35 opened on the surface of the pump cover 31, and discharges high-pressure hydraulic oil to the outside with the relief valve opened. . The discharge port 35 is open toward the side opposite to the end surfaces of the lower housing 12 and the upper housing 13 of the balancer device 10, and high-pressure hydraulic oil is fixed to the second balancer shaft of the balancer device 10. It is made not to get down to the meshing surface of the reduction gear and the pump drive gear 20. This is because if more hydraulic oil than necessary is supplied to the meshing surface of the reduction gear and the pump drive gear 20, the rotational resistance increases at this portion, which is not preferable from the viewpoint of fuel consumption.

  FIG. 4 is an exploded view of the balancer device 10 shown in FIG. A storage space formed by the lower housing 12 and the upper housing 13 stores a balancer body that suppresses vibration of the internal combustion engine, and an oil pump 11 is fixed to the rear side on the left side of the drawing. Yes.

  The balancer body is composed of a first rotation system having a balance weight and a second rotation system also having a balance weight, and the second rotation system is rotated by reversing the rotation of the first rotation system by a gear transmission mechanism. It has become. Then, by rotating the first rotating system and the second rotating system, an exciting force is generated, and an exciting force having a phase opposite to the secondary component of the exciting force of the internal combustion engine caused by the reciprocating motion of the piston is generated. Therefore, the vibration of the internal combustion engine is reduced.

  As described above, the first rotation system includes the balancer drive gear 15 fixed to both ends of the first balancer shaft 14, the first gear 16, the rear-side first bearing 18 that supports the first balancer shaft 14, and the front-side first shaft. 1 bearing 19 and the 1st balance weight 17 provided in the 1st balancer shaft 14 are comprised. The rear side first bearing 18 and the front side first bearing 19 are fixed and supported between the lower housing 12 and the upper housing 13, thereby rotating and supporting the first balancer shaft 14. The balancer drive gear 15 and the first gear 16 are housed rotatably in a housing space between the lower housing 12 and the upper housing 13.

  On the other hand, the second rotation system includes a reduction gear 24, a second gear 25, a rear-side second bearing 26 that pivotally supports the second balancer shaft 23, and a front-side second bearing that are fixed to both ends of the second balancer shaft 23. 27 and a second balance weight 28 provided on the second balancer shaft 23. Here, the reduction gear 24 is engaged with the pump drive gear 20 fixed to the rotation shaft of the oil pump 11 to rotate the pump drive gear 20.

  The rear side second bearing 26 and the front side second bearing 27 are fixed and supported between the lower housing 12 and the upper housing 12, thereby rotating and supporting the second balancer shaft 23. The reduction gear 24 and the second gear 25 are rotatably housed in a housing space between the lower housing 12 and the upper housing 13. Here, since the pump drive gear 20 is integrally fixed to the oil pump 11, it cannot be hidden in the drawing of FIG.

  An oil receiving portion 29 formed integrally with the lower housing 12 is provided on the end surface of the lower housing 12 on the oil pump 11 side, and the reduction gear 24 and the pump drive gear 20 are disposed on the upper side. It is. Similarly, an oil barrier wall 22 formed integrally with the upper housing 13 is provided on the end face of the upper housing 13 on the oil pump 11 side, and the reduction gear 24 and the pump drive gear 20 are provided below this. Is to be placed. Therefore, the reduction gear 24 and the pump drive gear 20 are sandwiched from above and below by the oil receiving portion 29 and the oil barrier 22.

  Except for the opening 21 of the upper housing 13, the pump housing 20 including the oil pump 11 is covered with an upper housing 13 that integrally forms an oil barrier 22. For this reason, hydraulic oil falling from the internal combustion engine 01 is less likely to fall on the pump drive gear 20 that drives the oil pump 11, and an increase in rotational resistance at the meshing portion of the reduction gear 24 and the pump drive gear 20 is suppressed. can do.

  When the engine side gear fixed to the crankshaft disposed above the balancer device 10 rotates, the balancer drive gear 15 rotates at a rotational speed twice that of the engine side gear. The first balancer shaft 14 to which the drive gear 15 is fixed is also rotated. In addition, the second gear 25 meshed with the first gear 16 fixed to the first balancer shaft 14 rotates, thereby rotating the second balancer shaft 23 phase-adjusted with the first balancer shaft 14, thereby generating the balancer vibration. Generating power. This balancer device 10 generates an excitation force having a phase opposite to that of the secondary component of the excitation force of the internal combustion engine caused by the reciprocating motion of the piston, thereby reducing the vibration of the internal combustion engine. Such a balancer device 10 is well known.

  FIG. 5 shows a state in which the balancer device 10 with the oil pump 11 assembled is sectioned between the upper housing 13 and the lower housing 12.

  A balancer drive gear 15 and a first gear 16 are fixed to both ends of the first balancer shaft 14, and the first balancer shaft 14 is pivotally supported by a rear first bearing 18 and a front first bearing 19. A first balance weight 17 is provided on the first balancer shaft 14 between the rear first bearing 18 and the front first bearing 19.

  Similarly, a second gear 25 and a reduction gear 24 are fixed to both ends of a second balancer shaft 23 arranged in parallel with the first balancer shaft 14, and the second balancer shaft 23 is connected to the rear side second bearing 26 and the front side. It is supported by the side second bearing 27. A second balance weight 28 is provided in the second balancer shaft 23 between the rear side second bearing 26 and the front side second bearing 27. The second gear 25 is rotated by the first gear 16, whereby the second balancer shaft 23 is rotated and the reduction gear 24 is further rotated.

  Between the balancer drive gear 15 fixed to the first balancer shaft 14 and the oil pump 11, a pump drive gear 20 fixed to the end of the rotating shaft 37 of the oil pump 11 is provided. The balancer drive gear 15 is disposed adjacent to the balancer drive gear 15. Further, the pump drive gear 20 is meshed with the reduction gear 24, and the pump drive gear 20 and the reduction gear 24 are arranged so as to be located on the same plane in the radial direction.

  The pump cover 31 is fixed to the end face of the balancer device 10 on the balancer drive gear 15 side with fixing bolts 07 (see FIG. 4). A pump housing 30 that houses a pump body 36 is fixed to the pump cover 31. A rotation shaft 37 of the oil pump 11 is fixed near the center of the pump drive gear 20, and the rotation shaft 37 is pivotally supported by the pump housing 30 through the pump cover 31. Therefore, the rotary shaft 37 is rotated by the rotation of the pump drive gear 20, and the rotation of the rotary shaft 37 is transmitted to the pump body 36 to perform a pump action.

  Here, the rotary shaft 37 is pivotally supported by the pump cover 31 and the pump housing 30, and a sliding bearing is used as the bearing of this portion. In addition, the mounting surface of the pump cover 31 that is orthogonal to the axis of the rotary shaft 37 is fixed to the opening surface of the pump housing 30 that houses the pump body 36, and the pump body 36 is fixed to the pump cover 31 as will be described later. A suction port and a suction port, which are suction systems for sucking hydraulic oil, and a discharge port and a discharge port, which are discharge systems for discharging hydraulic oil, are formed.

  The pump cover 31 pivotally supports the rotary shaft 37 in a form orthogonal to the axis of the rotary shaft 37, and is placed in the pump cover 31 in the non-polymerization region 33 other than the polymerization region where the pump cover 31 and the pump housing 30 are overlapped. A relief mechanism 34 is provided.

  As shown in FIG. 6, the relief mechanism 34 is connected to a discharge port 50 (see FIG. 11) formed in the pump cover 31, and is disposed in the relief passage 38 formed in the pump cover 31 and the relief passage 38. The relief valve (here, a ball valve is used) 39 and a spring 40 that urges the relief valve 39 in the closing direction. The open end of the relief passage 38 is sealed with a sealing plug 53.

  The relief passage 38 is perforated from the side end surface 31S side of the pump cover 31 along the outer surface of the pump cover 31 so as to approach the rotary shaft 37, and thereby the discharge port 35 is opened from the non-polymerization region 33 side to the relief passage 38. Can be easily connected to.

  The relief passage 38 is fluidly connected to the discharge side of the pump main body 36, and the relief valve 39 is separated from the valve seat formed in the relief passage 38 and opened, whereby high-pressure hydraulic oil is discharged from the discharge port 35. To be discharged. The spring 40 is a compression spring, and a closing pressure is set so that the relief valve 39 is opened when the discharge pressure becomes higher than a predetermined pressure, for example, higher than the maximum set pressure.

  The pump cover 31 requires a region having a thickness that allows the relief mechanism 34 to be provided, but at least the non-polymerized region 33 has this thickness. Of course, the entire thickness of the pump cover 31 can be increased uniformly, but considering the increase in the weight of the oil pump 11, at least the bearing portion that supports the rotary shaft 37 and the non-polymerized region 33 only. If the thickness of the oil pump 11 is increased, the other regions can be reduced, so that an increase in weight of the oil pump 11 can be suppressed.

  In addition, since the relief mechanism 34 is provided in the non-polymerization region 33, it is not involved in the total axial length of the oil pump 11 determined by the axial length of the sliding bearing portion of the pump cover 31 and the axial length of the pump housing 30. The relief mechanism 34 can be designed to an arbitrary physique. Of course, the thickness of the non-polymerized region 33 where the relief mechanism 34 is disposed can be equal to or thinner than the axial length (= thickness) of the sliding bearing portion of the pump cover 31. In this case, an increase in the weight of the oil pump 11 can be further suppressed.

  FIG. 7 is an exploded view of the oil pump 11 shown in FIG. 4 for each component and is viewed obliquely. FIG. 8 is a cross-sectional view in a direction perpendicular to the axis of the oil pump 11.

  7 and 8, the pump main body 36 is accommodated in a concave pump accommodating portion 41 formed in the pump housing 30. In the pump housing portion 41, a rotor 42 fitted with the rotary shaft 37 is arranged at substantially the center, and a cam ring 43 is arranged with its inner diameter center being eccentric from the rotary shaft 37. The cam ring 43 can swing about the pivot 44 as a fulcrum. In the initial state, the cam ring 43 is pushed rightward in FIG. The amount is at the maximum setting.

  A plurality of slits provided in the rotor 42 are provided with vanes 47, and when the rotor 42 rotates, the tip slides on the inner peripheral surface of the cam ring 43 while protruding and retracting from the outer peripheral surface of the rotor 42. The vane 47 is supported by the vane ring 48 so that all of the vanes 47 do not retract inward even when stopped.

  A space (= pump chamber) formed by the outer peripheral surface of the rotor 42, the inner peripheral surface of the cam ring 43, and the two vanes 47 is increased in volume as the rotor 42 rotates counterclockwise as shown in FIG. Increases or decreases. A suction port 49 is provided on the side surfaces of the pump housing 30 and the pump cover 31 in the range where the volume of the pump chamber increases, and a discharge port 50 is provided on the side surfaces of the pump housing 30 and the pump cover 31 in a range where the volume decreases. . The suction port 49 is connected to a suction port 51 (here, disposed in the pump cover 31) provided in the pump cover 31 or the pump housing 30, and the discharge port 50 is connected to a discharge port 52 (provided in the pump cover 31 or the pump housing 30). Here, it is connected to the pump housing 30 (see FIG. 9) and further connected to the outside of the pump. The oil pump 11 sucks up the hydraulic oil from the oil pan through the suction port 51 and discharges the hydraulic oil to the main gallery of the internal combustion engine through the discharge port 52 to perform a pump action. Since the configuration and operation of the pump main body 36 are well known as described in Patent Document 1, further description thereof is omitted.

  The feature of this embodiment is that the pump cover 31 arranged so as to be orthogonal to the axial direction of the rotary shaft 37 is provided with a relief mechanism 34 that extends so as to be orthogonal to the axial direction of the rotary shaft 37. is there.

  As shown in FIG. 7, a relief mechanism 34 is provided in the non-polymerization region 33 of the pump cover 31, and a relief passage 38 constituting the relief mechanism 34 extends in a direction perpendicular to the axial direction of the rotation shaft 37. The tip is connected to the discharge port 50. As shown in FIGS. 5 and 6, the relief passage 38 accommodates a relief valve 39 and a compression spring 40, and is sealed by a sealing plug 53 from the rear side.

  FIG. 9 shows the oil pump 11 as viewed from the outside in the axial direction of the pump housing 30, and the pump cover 31 and the pump housing 30 are integrally fixed by three fixing bolts 32. Further, the pump cover 31 and the pump housing 30 are formed with bolt insertion holes 08 for fixing to the lower housing 12 of the balancer device 10, and three fixing bolts 07 (not shown) are inserted into the lower part. It is fastened together with the side housing 12. Further, the bolt insertion hole 08C formed in the pump cover 31 is formed on the outer side in the radial direction of the rotation shaft 37 of the relief mechanism 34 in the non-overlapping region 33, and the fixing bolt 07C shown in FIG. 12 is fixed.

  A relief mechanism 34 is formed in a non-polymerization region 33 other than the polymerization region where the pump cover 31 and the pump housing 30 are overlapped, and a relief valve 39 is provided on the surface of the balancer device 10 opposite to the housings 12 and 13. A discharge port 35 is formed through which hydraulic oil is released when opened. As described above, since the hydraulic oil is released from the discharge port 35 on the opposite side of the balancer device 10 from the housings 12 and 13, the hydraulic oil falls on the reduction gear 24 and the pump drive gear 20 accommodated between the housings 12 and 13. Therefore, it is possible to suppress supply of unnecessary hydraulic oil to the reduction gear 24 and the pump drive gear 20.

  10 shows the pump cover 31 as seen from the outside, and FIG. 11 shows the pump cover 31 as seen from the inside. The surface shown in FIG. 10 is a surface facing the housings 12 and 13 of the balancer device 10.

  10 and 11, the pump cover 31 has a rotation shaft 37 inserted therethrough and an insertion hole 54 that also serves as a bearing. A suction port 49, a suction port 51, and a discharge port 50 that are formed in cooperation with the pump housing 30 are provided on the inner surface of the pump cover 31. Further, the relief passage 38 of the relief mechanism 34 is connected to the discharge port 50, and when the discharge pressure becomes higher than the maximum set pressure, the hydraulic oil is released from the relief passage 38 toward the discharge port 35 to reduce the discharge pressure. To function. The structure of the relief mechanism 34 is as shown in FIG.

  In this way, the relief passage 38 provided with the relief valve 39 and the compression spring 40 that urges the relief valve 39 in the closing direction is formed in the pump cover 31 orthogonal to the axis of the rotary shaft 37 that rotates the pump body 36. Therefore, the axial length of the oil pump can be shortened, and the relief mechanism 34 is not disposed adjacent to the radial direction of the pump housing 30, so that the pump housing 30 can be reduced in the radial direction. It becomes like this.

  Further, in addition to the above-described configuration, the pump cover 31 including the relief mechanism 34 is fixed adjacent to the end faces of the housings 12 and 13 of the balancer device 10, so that the axial length of the oil pump 11 and the pump housing 30 The oil pump 11 can be installed without reducing the size in the radial direction and without interfering with surrounding accessories.

  Furthermore, since the relief passage 38 is formed along the surface of the pump cover 31 in the radial direction, the stroke of the relief valve 39 can be increased and a sufficient pressure reducing effect can be obtained. If the relief passage 38 is formed in the axial direction, there is a problem that the axial length of the relief passage 38 becomes long if an attempt is made to obtain a stroke having the same length as in the present embodiment. For this reason, when the relief passage 38 is formed so as to shorten the axial length, a new problem arises that the stroke of the relief valve 39 is insufficient and a sufficient pressure reducing effect cannot be obtained.

  In the oil pump-integrated balancer device in which the oil pump 11 is integrally arranged in the housing of the balancer device 10 that is divided vertically, the oil pump is provided on one side of the lower housing 12 or the upper housing 13 divided vertically. 11 is fixed on the outer peripheral side of the non-polymerization region 33, the limited fixing position of the oil pump 11 to the lower housing 12 can be secured, and the discharge of the pump storage portion 41 can be secured. Since the bolt hole 09 into which the fixing bolt 32 is screwed can be disposed so as to surround the vicinity of the port 50, when the pump housing 30 and the pump cover 31 are fixed by the fixing bolt 32, the contact surface around the discharge port 50 can be changed. It can adhere firmly.

  Furthermore, since the bolt insertion hole 08C is formed on the outer peripheral side of the non-polymerized region 33, the fixing position of the fixing bolt 07C to the housing can be arranged near the boundary line of the lower housing 12 or the upper housing 13, so that the balancer device 10 and the oil pump 11 can be firmly adhered to each other.

  In addition, since the bolt insertion hole 08C is provided outside the relief mechanism 34 provided in the non-polymerization region 33, the housings 12 and 13 of the balancer device 10 can be used in a wide range in cooperation with the other bolt insertion holes 08. Since it can be fixed, the fixing strength can be increased.

  In addition, a relief mechanism 34 is formed in the non-polymerization region 33 of the pump cover 31 other than the polymerization region where the pump housing 30 and the pump cover 31 are overlapped. For this reason, the thickness of the relief mechanism 34 does not affect the axial length of the oil pump 11 determined by the pump housing 30 and the pump cover 31, so that the axial length of the oil pump 11 can be shortened. become. Further, since the relief mechanism 34 is not disposed adjacent to the radial direction of the pump housing 30, the radial size of the pump housing 30 can be set as much as possible without affecting the radial size of the pump housing 30. Can be small.

  Further, since the relief mechanism 34 is provided in the non-polymerized region 33 where the thickness is ensured, the thickness of the pump cover 31 other than this can be reduced, and this also increases the length of the oil pump 11 in the axial direction. In addition to being shortened, an increase in the weight of the oil pump 11 can be suppressed.

  Here, the pump cover 31 is enlarged in the radial direction by the amount provided with the relief mechanism 34. However, when the oil pump 11 is fixed to the housings 12 and 13 of the balancer device 10, the area of the end surfaces of the housings 12 and 13 is large. It will not be. Furthermore, since the pump cover 31 including the relief mechanism 34 is located between the oil pump 11 and the balancer device 10, there is less possibility of interference with other auxiliary machines, and the installation of the oil pump 11 can be improved. it can.

  As described above, according to the present invention, the pump cover fixed to the pump housing so as to be orthogonal to the axis of the rotation axis of the pump body is directed to the direction orthogonal to the axis direction of the rotation axis of rotating the pump body. An extending relief passage is formed, and a relief valve and a spring that biases the relief valve in a closing direction are provided in a part of the relief passage. As a result, a relief passage provided with a relief valve and a spring that urges the relief valve in the closing direction is formed in the pump cover orthogonal to the axis of the rotary shaft that rotates the pump body, so the axial length is shortened. In addition, the pump housing can be reduced in the radial direction.

  In addition to the above-described configuration, the pump cover provided with the relief mechanism is fixed adjacent to the end face of the balancer device housing, so that the axial length of the oil pump and the radial size of the pump housing can be reduced. In addition, an oil pump can be installed without interfering with surrounding accessories.

  In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 10 ... Balancer device, 11 ... Oil pump, 12 ... Lower housing, 13 ... Upper housing, 14 ... First balancer shaft, 15 ... Balancer drive gear, 16 ... First gear, 17 ... First balance weight, 18 ... Front side first bearing, 19 ... rear side first bearing, 20 ... pump drive gear, 21 ... exposure opening, 22 ... oil barrier, 23 ... second balancer shaft, 24 ... reduction gear, 25 ... second gear, 26 ... 2nd bearing on the front side, 27 ... 2nd bearing on the rear side, 28 ... 2nd balance weight, 29 ... Oil receiving part, 30 ... Pump housing, 31 ... Pump cover, 32 ... Fixing bolt, 33 ... Non-polymerized area, 34 ... Relief mechanism 35 ... Discharge port 36 ... Pump body 37 ... Rotating shaft 38 ... Relief passage 39 ... Relief valve 40 ... Compression spring 41 ... Pump housing part 42 ... , 43 ... cam ring, 44 ... pivot, 45 ... arm part, 46 ... control spring, 47 ... vane, 48 ... vane ring, 49 ... suction port, 50 ... discharge port, 51 ... suction port, 52 ... discharge port, 53 ... Sealing plug, 54 ... Insertion hole.

Claims (13)

A pump housing in which a pump housing portion for housing the pump body is formed, covers the pump housing portion, and the rotation shaft of the pump body is inserted through the pump housing so as to be orthogonal to the axial direction of the rotation shaft. With a fixed pump cover,
The pump cover is provided with a suction system for sucking hydraulic oil into the pump main body and a discharge system for discharging hydraulic oil from the pump main body. Further, the pump cover has an axis of the rotary shaft of the pump main body. A relief passage that extends in a direction perpendicular to the direction and connected to the discharge system is formed, and a relief valve that opens when a discharge pressure of the discharge system exceeds a predetermined pressure is provided in a part of the relief passage. An oil pump characterized by that. A pump housing provided with a pump housing portion in which the pump body is housed;
A rotor that rotates by rotation of a rotation shaft of the pump body;
A plurality of vanes provided on the outer peripheral side of the rotor so as to be able to appear and disappear;
The rotor and the plurality of vanes are accommodated, and a plurality of hydraulic oil chambers are formed by the outer peripheral surface of the rotor and the plurality of vanes, and are eccentric with respect to the rotation center of the rotor, and the amount of eccentricity is controlled. A cam ring that is swingably disposed in the pump housing portion;
A pump cover that covers the pump housing portion and through which the rotating shaft is inserted and is fixed to the pump housing so as to be orthogonal to the axial direction of the rotating shaft;
The pump cover includes a suction system that sucks hydraulic oil into the pump body, and a discharge system that discharges hydraulic oil from the pump body, and further toward a direction orthogonal to the axial direction of the rotation shaft of the pump body. An oil pump characterized in that a relief passage extending and connected to the discharge system is formed, and a relief valve is provided in a part of the relief passage and opens when a discharge pressure of the discharge system exceeds a predetermined pressure. In the oil pump according to claim 1 or 2,
The oil is characterized in that the relief passage containing the relief valve is formed in a non-polymerization region formed in the pump cover other than the polymerization region where the pump cover and the pump housing are fixed and overlapped. pump. In the oil pump according to claim 3,
The relief passage is perforated so as to approach the rotating shaft from a side end face of the non-polymerization region of the pump cover, and a discharge port for releasing hydraulic oil to the outside when the relief valve is opened has the non-polymerization An oil pump connected to the relief passage from an outer surface of the region. The oil pump according to claim 4, wherein
A ball valve as a relief valve and a compression spring that urges the ball valve in a direction to close the ball valve with a predetermined closing pressure are disposed in the relief passage, and the relief is drilled in the side end surface of the pump cover. An oil pump characterized in that a side of the passage opposite to the ball valve is sealed with a sealing plug. In the oil pump according to claim 3,
The axial thickness of the non-overlapping region provided with the relief passage is equal to or thinner than the axial thickness of the bearing that pivotally supports the rotary shaft inserted through the pump cover. Oil pump characterized by that. A balancer drive gear that meshes with an engine-side gear rotated by the internal combustion engine is fixed at one end, and a first gear is fixed at the other end, and a first balance provided between the balancer drive gear and the first gear. A first balancer shaft having a weight;
A second gear that meshes with the first gear is fixed at one end, and a reduction gear that meshes with a pump drive gear of the oil pump is fixed at the other end, and a second gear provided between the second gear and the reduction gear. A second balancer shaft having a balance weight;
The balancer driving gear, the first balancer shaft including the first balance weight, the first gear, the second gear, the second balancer shaft including the second balance weight, and the lower portion on which the reduction gear is mounted. A side housing;
The balancer drive gear, the first balancer shaft including the first balance weight, the first gear, the second gear, the second balancer shaft including the second balance weight, the reduction gear, and the pump drive gear An upper housing that is formed in a shape that covers the upper housing and is assembled to the lower housing;
An oil pump fixed to one or both of the lower housing and the upper housing, and the oil pump,
A pump housing in which a pump housing portion for housing the pump body is formed;
The pump housing portion is covered, the rotation shaft of the pump body is inserted, and is fixed to the pump housing so as to be orthogonal to the axial direction of the rotation shaft, and one of the lower housing and the upper housing or A pump cover fixed to both end faces;
A pump drive gear disposed between the pump cover and the lower housing, and the end face of the upper housing, fixed to the rotary shaft and meshed with the reduction gear;
Further, the pump cover is provided with an intake system for sucking hydraulic oil into the pump body and a discharge system for discharging hydraulic oil from the pump body, and the pump cover further includes the rotating shaft of the pump body. A relief passage that extends in a direction perpendicular to the axial direction of the discharge system and is connected to the discharge system is formed, and a relief valve that opens when a discharge pressure of the discharge system exceeds a predetermined pressure is provided in a part of the relief passage. A balancer device for an internal combustion engine. The balancer device for an internal combustion engine according to claim 7,
An internal combustion engine characterized in that the relief passage accommodating the relief valve is formed in a non-polymerization region formed in the pump cover other than a polymerization region in which the pump cover and the pump housing are fixed and overlapped. Engine balancer equipment. The balancer device for an internal combustion engine according to claim 8,
The relief passage is perforated so as to approach the rotation shaft from the side end surface of the non-polymerization region of the pump cover, and a discharge port for allowing hydraulic oil to escape to the outside when the relief valve is opened is provided in the non-polymerization region. A balancer device for an internal combustion engine, which is connected to the relief passage from an outer surface of the internal combustion engine. The balancer device for an internal combustion engine according to claim 9,
A ball valve as a relief valve and a compression spring that urges the ball valve in a direction to close the ball valve with a predetermined closing pressure are disposed in the relief passage, and the relief is drilled in the side end surface of the pump cover. A balancer device for an internal combustion engine, wherein a side of the passage opposite to the ball valve is sealed with a sealing plug. The balancer device for an internal combustion engine according to claim 10,
The balancer device for an internal combustion engine, wherein the discharge port is formed in the lower housing and the non-polymerization region opposite to the upper housing. The balancer device for an internal combustion engine according to claim 8,
The axial thickness of the non-overlapping region provided with the relief passage is equal to or thinner than the axial thickness of the bearing that pivotally supports the rotary shaft inserted through the pump cover. A balancer device for an internal combustion engine. The balancer device for an internal combustion engine according to claim 8,
A balancer device for an internal combustion engine, wherein a bolt insertion hole for fixing an oil pump to a balancer housing is formed in the non-polymerization region.

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