JP2019031932A - Oil pump - Google Patents

Abstract

To provide an oil pump capable of downsizing.SOLUTION: An oil pump comprises: a housing 11 having a suction port 54 for sucking in oil and a discharge port 55 for performing discharge; a driving source 14 supported rotatably on a housing 11 via a shaft 15; a pump rotor 31 rotated by the driving source 14; a working chamber 41 which is formed between the housing 11 and the pump rotor 31, is increased or reduced in volume with rotation of the pump rotor 31, sucks in oil from the suction port by increase of the volume and discharges the oil from the discharge by reduction of the volume; and a relief valve 42 which is disposed between the suction port 54 and the discharge port 55, abuts on the pump rotor 31 and opens to perform pressure adjustment with a valve element 61 moved when a predetermined pressure or more is reached in the discharge port 55.SELECTED DRAWING: Figure 3

Description

  The present invention relates to the structure of an oil pump.

Conventionally, a housing having a suction port and a discharge port and a pump rotor that is driven to rotate by a drive source via a shaft are provided, and oil is sucked from the suction port of the housing by rotating the pump rotor in the housing. An oil pump is known that supplies oil to an external device such as an engine by being discharged from a discharge port of a housing (Patent Document 1).
This oil pump is provided with a relief valve that can adjust the pressure of the discharge port as a protective structure when an excessive pressure acts on the discharge port. This relief valve is configured to include a passage formed between the discharge port and the suction port, and a valve body that switches between communication and blocking of the suction port and the discharge port by the passage. When an excessive pressure is applied to the discharge port, the valve body moves, whereby the suction port and the discharge port communicate with each other through the passage, and the oil is recirculated from the discharge port to the suction port. Thus, the pressure of the discharge port is adjusted.

JP 2008-151065 A

  However, in the oil pump configured as described above, since the valve body of the relief valve is disposed in the passage formed between the suction port and the discharge port, the relief valve is disposed at a position away from the pump rotor in the axial direction. As a result, the pump itself is increased in size.

  Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide an oil pump that can be reduced in size.

  An oil pump that solves the above problems includes a housing having a suction port for sucking oil and a discharge port for discharging, a drive source that is rotatably supported by the housing via a shaft, And a pump rotor that is rotated by the drive source, and is formed between the housing and the pump rotor, and the volume is increased or decreased by the rotation of the pump rotor, and oil is supplied from the suction port by the increase of the volume. The suction chamber is disposed between the suction port and the discharge port in contact with the pump rotor and the working chamber that discharges oil from the discharge port by reducing the volume, and the discharge port is a predetermined amount. And a relief valve having a valve body that adjusts the pressure by moving when the pressure becomes higher than the pressure.

  According to the above configuration, since the valve body of the relief valve operates in contact with the pump rotor, the relief valve can be provided at a position closer to that of the conventional one, and the oil pump can be downsized.

  In the above configuration, the suction port and the discharge port are configured by dividing the groove formed in the housing by the valve body, and the relief valve adjusts the pressure by moving the valve body through the groove. Preferably it is done.

  According to the above configuration, when the discharge port is equal to or higher than the predetermined pressure, the valve body moves in the groove, so that the oil compression process is limited when the working chamber due to the rotation of the pump rotor compresses the oil. As a result, the oil at the discharge port is prevented from exceeding a predetermined pressure. Therefore, since the pump rotor does not compress oil more than necessary, the load on the drive source when adjusting the pressure when the relief valve is opened is reduced. As a result, since the maximum load of the drive source is reduced, the drive source does not increase in size, and the oil pump can be reduced in size.

  In the above configuration, the relief valve opens when the valve body moves in the circumferential direction of the pump rotor, and when the valve body is closed, the working chamber has a maximum volume of the working chamber. When the valve body is opened, the working chamber is preferably shut off from the suction port in a state where the volume of the working chamber is smaller than the maximum volume.

  According to the above configuration, when the valve body moves in the circumferential direction and opens, the working chamber of the oil pump is in a state of being blocked from the suction port in a state where the volume is smaller than the maximum volume. After that, even if the volume of the working chamber increases and negative pressure is generated in the working chamber, no more oil can be sucked from the suction port. For this reason, the oil pump performs pump driving by limiting the oil discharge amount. Therefore, when the relief valve is opened and pressure adjustment is performed, the load of the driving source that drives the pump rotor can be reduced. The source can be downsized without increasing in size.

  The said structure WHEREIN: It is preferable that the said relief valve opens when the said valve body moves to radial direction, and when the said relief valve opens, the said suction inlet and the said discharge outlet are connected.

  According to the above configuration, when the valve element moves in the radial direction of the pump rotor, the discharge port and the suction port communicate with each other. Therefore, the working chamber has a negative pressure generated by the working chamber in which the volume of the oil at the discharge port increases. Therefore, oil compression is limited. Therefore, the oil pump can reduce the load of the drive source when the relief valve is opened and pressure adjustment is performed, and thus the drive source can be downsized without being enlarged.

  In the above configuration, when the relief valve maintains a closed state of the valve body by an urging force of an elastic body provided between the housing and the valve body, and the discharge port becomes a predetermined pressure or higher. In addition, it is preferable that the valve body is opened against the urging force of the elastic body.

  According to this, when the pressure at the discharge port becomes larger than the urging force of the elastic body, the valve body of the relief valve opens, and the elastic body provided between the housing and the valve body closes the valve with a simple configuration. The state can be maintained.

  The said structure WHEREIN: It is preferable that the said relief valve will be in a valve opening state, when the said valve body moves by the drive of a solenoid.

  According to this, the valve body can be moved with a simple configuration using the solenoid for driving the relief valve.

1 is a system configuration diagram of an oil pump system to which the present invention is applied. It is sectional drawing which shows the internal structure of the electric oil pump in 1st Embodiment shown in FIG. It is III-III sectional drawing (valve closed state) shown in FIG. It is IV-IV sectional drawing (valve closed state) shown in FIG. It is sectional drawing when the valve body shown in FIG. 3 transfers to a valve opening state from a valve closing state. It is a principal enlarged view which shows the internal structure of the 2nd housing member of 2nd Embodiment. It is sectional drawing (valve closed state) which shows the internal structure of the pump part shown in FIG. It is sectional drawing (valve open state) which shows the internal structure of the pump part shown in FIG. It is sectional drawing which shows the internal structure of the pump part of 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a conductive oil pump (electric O / P) 6 will be described as an example of an oil pump.

  FIG. 1 is a system configuration diagram of an oil pump system 7 to which an electric oil pump 6 of the present invention is applied.

  The oil pump system 7 shown below is applied to, for example, a vehicle equipped with an idle stop function for stopping the engine when the vehicle is stopped.

  The oil pump system 7 shown in FIG. 1 is represented by, for example, a clutch 1 that hydraulically cuts power from the engine between a vehicle engine and a transmission, and an engine E that reduces friction and cools by oil. A sliding part 2, a flow path 3 through which oil flows, an oil pan 4 for storing oil, a mechanical oil pump 5 driven by an engine E, an electric oil pump 6 driven by a motor, It was set as the structure provided with.

In the above system, when the engine E is driven, the mechanical oil pump 5 is driven to suck oil from the oil pan 4 and pump the oil to the clutch 1 and the sliding component 2. (Arrow W1 route)
When the engine E is stopped such as when the vehicle is idle due to a signal waiting or the like, it is necessary to supply oil to the clutch 1 and supply oil to the sliding component 2 in order to restart the engine E quickly. . However, since the mechanical oil pump 5 moves in synchronism with the engine E serving as power, when the engine E stops, the power stops and oil cannot be pumped. Therefore, in the present invention, the electric oil pump 6 is used so that oil can be pumped to the clutch 1 and the sliding component 2 even during idle stop. (Arrow W2 route)
Further, in the above system, the flow path 3 includes a strainer 8 for preventing foreign matter from being sucked in from the oil pan 4, a first check valve 9 for preventing backflow of oil, and a second check valve 10 as shown in FIG. And comprising.

  Here, the first check valve 9 causes the oil to flow along the W1 path, and does not flow in the opposite direction and does not flow backward. The second check valve 10 is configured so that oil flows along the W2 path and does not flow back.

Next, the electric oil pump 6 in this system will be described in detail with reference to FIGS.
(First embodiment)
FIG. 2 is a cross-sectional view showing an internal configuration of the electric oil pump 6 shown in FIG.

  As shown in FIG. 2, the electric oil pump 6 is integrated with a housing 11, a motor unit 14 (an example of a drive source) having a rotor 12 and a stator 13 on one side of the housing 11, and the rotor 12 of the motor unit 14. The rotating shaft 15 and the pump portion 16 rotated by the motor portion 14 on the other side of the housing 11 are provided.

  The housing 11 roughly includes a motor housing 17 in which the motor unit 14 is disposed and a pump housing 18 in which the pump unit 16 is disposed.

  The motor portion 14 is formed with a motor chamber 21 having a concave shape on the side of the motor housing 17 that contacts the pump housing 18 (downward in FIG. 2), and a coil 22 is wound inside the motor housing 17 having an outer diameter of the motor chamber 21. The stator 13 is fixed in the state where it is held, and the rotor 12 is rotatably held in the motor chamber 21 via the shaft 15 while being kept at a predetermined distance from the stator 13. Therefore, the motor unit 14 is rotatably supported by the housing 11 via the shaft 15. The rotor 12 is configured by laminating a plurality of disk-shaped magnetic members 23, and a magnet insertion hole 24 and a shaft hole 25 are formed. Further, a permanent magnet 26 is inserted into the magnet insertion hole 24. In addition, the rotor 12 is arranged on the inner diameter of the stator 13 in a state where a predetermined interval is maintained, and the rotor 12 can be rotationally driven by energizing the coil 22 wound around the stator 13. Further, the shaft 15 formed in a columnar shape is inserted into the shaft hole 25, so that the shaft 15 can rotate integrally with the rotor 12 and transmits the rotation of the motor unit 14 to the pump unit 16.

  Next, the pump unit 16 will be described below.

  As shown in FIG. 2, the pump unit 16 includes a pump housing 18 and a pump rotor 31 disposed in the pump housing 18.

  The pump housing 18 includes a first housing member 32 that is connected to the motor housing 17 in the axial direction, and a second housing member 33 that is connected to the first housing member 32 in the axial direction.

  The first housing member 32 has a boss 34 that protrudes toward the motor housing 17 in the axial direction, a pump chamber 35 that presents a cylindrical recess space on the surface that contacts the second housing member 33, and the shaft 15. And a bearing portion 36 that is pivotally supported on the shaft. The first housing member 32 is connected to the motor housing 17 by inserting the boss portion 34 into the motor chamber 21. The boss portion 34 is provided with a ring-shaped oil seal 37 that blocks oil from leaking into the motor chamber 21.

  As shown in FIG. 2, the pump rotor 31 is disposed in the pump chamber 35 of the first housing member 32, is rotated by the motor unit 14 via the shaft 15, and is between the pump chamber 35 of the first housing member 32. The working chamber 41 is formed.

  3 is a cross-sectional view taken along the line III-III shown in FIG.

  As shown in FIG. 3, the pump rotor 31 has an outer rotor 44 in which an outer peripheral portion is rotatably in close contact with the inner peripheral surface of the pump chamber 35 and a plurality of inner teeth 43 are formed on the inner peripheral portion, and an outer rotor on the outer peripheral portion. The outer teeth 45, which are fewer than the inner teeth 43 of 44, are formed so as to mesh with the inner teeth 43, and have an inner rotor 46 that rotates integrally with the shaft 15.

  The outer rotor 44 is eccentrically arranged with respect to the rotation axis of the inner rotor 46, and a plurality of working chambers 41 are formed in the pump chamber 35 between the outer teeth 45 and the inner teeth 43. Here, the volume of the working chamber 41 increases / decreases due to the rotation of the inner rotor 46 due to the rotation of the shaft 15, becomes the minimum volume (41 Rmin in the drawing) when closest to the rotation center C of the inner rotor 46, and moves away from the rotation center C of the inner rotor 46. As the volume increases, the maximum volume (41Rmax in the drawing) is reached when it is farthest from the rotation center C of the inner rotor 46.

  4 is a cross-sectional view taken along the line IV-IV shown in FIG.

  As shown in FIG. 4, on the surface of the second housing member 33 on the first housing member 32 side, a region closest to the rotation center C of the inner rotor 46 along the circumferential direction of the pump rotor 31 is divided to form a C-shaped concave shape. The groove part 51 formed in is formed. The first inner circumferential surface 52 on the radially inner side of the groove 51 is formed along the root circle of the inner rotor 46, and the second inner circumferential surface 53 on the radially outer side of the groove 51 is formed on the bottom circle of the outer rotor 44. Formed along. Since the outer rotor 44 is eccentrically arranged with respect to the rotation axis of the inner rotor 46, the width of the groove 51 varies depending on the distance from the rotation center C of the inner rotor 46. Specifically, the width of the groove 51 is the widest when it is farthest from the rotation center C of the inner rotor 46, and becomes narrower as it approaches the rotation center C of the inner rotor 46. It becomes the narrowest when it is closest to the rotation center C of the inner rotor 46.

  In the second housing member 33, a relief valve 42 that performs pressure adjustment is disposed so as to partition the groove 51 in a region farthest from the rotation center C of the inner rotor 46 and to contact the pump rotor 31. The relief valve 42 defines the groove 51 in the groove 51 of the second housing member 33, so that the suction port 54 that sucks oil into the working chamber 41 and the discharge port 55 that discharges oil from the working chamber 41 are provided. Is configured. Therefore, the relief valve 42 is disposed between the suction port 54 and the discharge port 55.

  As shown in FIG. 4, the relief valve 42 includes a valve body 61 that moves due to a pressure difference between the suction port 54 and the discharge port 55, and a spring 56 that biases the valve body 61 to maintain a closed state in which the valve body 61 does not move. FIG. 4 shows the valve body 61 in a closed state.

  The valve body 61 has an axial length that is substantially the same as the depth of the groove 51 of the second housing member 33, and a radially outer first outer peripheral surface 62 that contacts the first inner peripheral surface 52 of the groove 51. A radially outer second outer peripheral surface 63 that contacts the second inner peripheral surface 53 of the groove 51 is formed. The first outer peripheral surface 62 has substantially the same arc shape as the first inner peripheral surface 52 in the region where the working chamber 41 has the maximum volume, and the length is equal to or longer than the length between the tooth tips of the inner rotor 46. Further, the second outer peripheral surface 63 has substantially the same arc shape as the second inner peripheral surface 53 in the region where the working chamber 41 has the maximum volume, and the length is equal to or longer than the length between the tooth tips of the outer rotor 44. Furthermore, a spring recess 64 in a cylindrical space is formed on the outer peripheral surface of the valve body 61 on the inlet 54 side.

  Therefore, when the valve body 61 is disposed in a region farthest from the rotation center C of the inner rotor 46 of the groove 51, the first inner peripheral surface 52 and the first outer peripheral surface 62 come into contact with each other, and the second inner peripheral surface 53 and the second outer peripheral surface are brought into contact. The groove 63 is partitioned by the contact of the 63, and oil is prevented from moving through the groove 51 and through the suction port 54 and the discharge port 55.

  The second inner peripheral surface 53 on the suction port 54 side has a spring insertion hole 57 for locking the spring 56, and the valve body 61 has substantially the same width as the widest region of the groove 51. A circumferential guide recess 58 is further formed so that the groove 51 having a narrow width does not restrict the movement of the valve body 61.

  One end of the spring 56 is inserted into the spring recess 64 of the valve body 61, is locked to the bottom surface of the spring recess 64, and the other end is formed in the second inner peripheral surface 53 of the second housing member 33. And is locked to the bottom surface of the spring insertion hole 57. Therefore, the relief valve 42 maintains the valve closed state (see FIG. 4) because the valve body 61 is biased to the region where the width of the groove 51 is narrowed by the biasing force of the spring 56.

  Further, a suction port 65 for supplying oil to the suction port 54 and a discharge port 66 for discharging oil from the discharge port 55 are formed in the second housing member 33 so as to communicate with each other. The suction port 65 is disposed so as not to overlap the relief valve 42 in the axial direction so as not to interfere with the relief valve 42. Specifically, the suction port 65 is moved in the circumferential direction. The suction port 65 is connected to the flow path 3 to suck oil from the oil pan 4, and the discharge port 66 is connected to the flow path 3 to pump oil to the clutch 1 and the sliding component 2.

  Next, the operation of the relief valve 42 of this embodiment will be described in detail.

  As shown in FIG. 2, when the inner rotor 46 and the outer rotor 44 rotate clockwise as indicated by the arrows in the drawing, the working chamber 41 on the suction port 54 side moves along with the rotation of the inner rotor 46 and the outer rotor 44. As a result, the volume of the working chamber 41 increases and negative pressure is generated. The volume of the working chamber 41 is maximized at a position farthest from the rotation center C of the inner rotor 46. Further, the working chamber 41 on the discharge port 55 side decreases in volume and generates positive pressure as the inner rotor 46 and the outer rotor 44 rotate.

  Here, the working chamber 41 is in communication with only the suction port 54, so that negative pressure is generated so that oil can be sucked from the suction port 54, and the entire working chamber 41 comes into contact with the valve body 61. In this state, the communication between the suction port 54 and the discharge port 55 is blocked, so that suction and discharge are not performed, and the oil is discharged from the discharge port 55 when a positive pressure is generated while only communicating with the discharge port 55. be able to.

  In the configuration shown in FIG. 2, when the pressure at the discharge port 55 is equal to or lower than a predetermined pressure, the biasing force of the spring 56 is set to be larger than the pressure at the discharge port 55. For this reason, the valve body 61 urged toward the discharge port 55 by the spring 56 is formed to be substantially the same as the region with the longest width of the groove 51 in the radial direction, and thus proceeds to the discharge port 55 side. As a result, it comes into contact with the groove portion 51 whose width becomes narrower. Therefore, the relief valve 42 is closed (see FIG. 3) without the valve body 61 moving from the region farthest from the rotation center C of the inner rotor 46. In the valve-closed state, the working chamber 41 on the suction port 54 side comes into contact with the valve body 61 when the volume becomes maximum, so that the working chamber 41 is blocked from the suction port 54 in the state where the maximum volume is reached. . For this reason, oil can be sucked from the suction port 54 until the maximum volume is reached. Therefore, one working chamber 41 can discharge a maximum volume of oil while the pump rotor 31 makes a round.

  FIG. 5 is a diagram of a state in which the valve body 61 of the relief valve 42 has shifted from the closed state shown in FIG. 3 to the opened state.

  As shown in FIG. 5, when the pressure at the discharge port 55 is equal to or higher than a predetermined pressure, the relief valve 42 has a pressure difference between the discharge port 55 and the suction port 54 against the biasing force of the spring 56, The valve is opened by moving toward the suction port 54 along the circumferential direction while coming into contact with the circumferential guide recess 58. In the valve open state, the working chamber 41 on the side of the suction port 54 contacts the valve body 61 before reaching the maximum volume, and the communication with the suction port 54 is blocked. Oil is sucked in by volume, and oil cannot be sucked from the suction port 54 even if the volume increases. Therefore, the working chamber 41 can discharge oil only in a volume smaller than the maximum volume while the pump rotor 31 makes a round, and the discharge amount is limited. In other words, the relief valve 42 adjusts the pressure as the valve body 61 moves in the groove 51.

According to the above configuration, the following effects can be obtained.
(1) Since the valve body 61 abuts against the pump rotor 31, the relief valve 42 can be provided at a position closer than before, and the electric oil pump 6 can be reduced in size.
(2) When the discharge port 55 is at a predetermined pressure or higher, the valve body 61 moves in the groove portion 51, so that the oil compression process is limited when the working chamber 41 compresses oil due to rotation of the pump rotor 31. Therefore, the oil pressure at the discharge port 55 is suppressed from exceeding a predetermined pressure. Therefore, since the pump rotor 31 does not compress oil more than necessary, the load on the motor unit 14 when adjusting the pressure when the relief valve 42 is opened is reduced. As a result, since the maximum load of the motor unit 14 is reduced, the motor unit 14 does not increase in size, and the oil pump can be reduced in size.
(3) Since the valve body 61 is in contact with the pump rotor 31, the relief valve 42 has a good response of oil pressure adjustment when the pressure at the discharge port 55 becomes equal to or higher than a predetermined pressure.
(4) When the valve body 61 moves in the circumferential direction due to a pressure difference between the suction port 54 and the discharge port 55 and opens, the working chamber 41 of the electric oil pump 6 sucks in a state where the volume is smaller than the maximum volume. Since it is shut off from the port 54, no further oil can be sucked from the suction port 54 even if the volume of the working chamber 41 increases and negative pressure is generated. Therefore, the electric oil pump 6 performs pump driving with the oil discharge amount limited, so that the load on the motor unit 14 can be reduced when the relief valve 42 is opened.
(5) When the pressure at the discharge port 55 becomes equal to or higher than the predetermined pressure, the valve body 61 starts to open and the pressure at the discharge port 55 is prevented from becoming higher than the predetermined pressure.
(6) When the pressure of the discharge port 55 becomes larger than the urging force of the spring 56, the valve body 61 moves to open the relief valve 42.
(7) Since the suction port 54 and the discharge port 55 are formed by dividing one groove 51 formed in the housing 11 by the relief valve 42, the relief valve 42 is provided between the suction port 54 and the discharge port 55. Since it is disposed, the electric oil pump 6 can be downsized with a simple configuration.
(Second Embodiment)
In the above description of the first embodiment, the configuration in which the valve body 61 of the relief valve 42 moves in the circumferential direction has been described, but in the second embodiment, the valve body 61 has a diameter with reference to FIGS. The relief valve 42a that moves in the direction and opens will be described. In the second embodiment, the configurations of the relief valve 42a and the second housing member 33a are different when compared to the first embodiment. For this reason, about the member structure which is common in 1st Embodiment, the same code | symbol is attached | subjected and description shall be abbreviate | omitted or simplified.

  The electric oil pump 6 of the second embodiment includes a relief valve 42a and a second housing member 33a as member configurations different from those of the first embodiment.

  FIG. 6 is a schematic view showing the internal configuration of the contact surface of the second housing member 33a that contacts the first housing member 32. As shown in FIG.

  As shown in FIG. 6, on the contact surface of the second housing member 33 a that is in contact with the first housing member 32, a region far from the rotation center C of the inner rotor 46 along the circumferential direction of the pump rotor 31 is divided. A groove 51a formed in a concave shape is formed.

  In the second housing member 33 a, a relief valve 42 a that adjusts the pressure is disposed so as to partition the groove 51 a in a region closest to the rotation center C of the inner rotor 46 and to contact the pump rotor 31. In the groove 51a, the relief valve 42a defines the groove 51a, whereby a suction port 54 for sucking oil into the working chamber 41 and a discharge port 55 for discharging oil from the working chamber 41 are configured. Therefore, the relief valve 42 a is disposed between the suction port 54 and the discharge port 55.

  Further, a suction port 65 for supplying oil to the suction port 54 and a discharge port 66 for discharging oil from the discharge port 55 are formed in the second housing member 33a so as to communicate with each other. The suction port 65 is connected to the flow path 3 to suck oil from the oil pan 4, and the discharge port 66 is connected to the flow path 3 to pump oil to the clutch 1.

  FIG. 7 is a cross-sectional view showing the internal configuration of the pump unit 16 in the opened state of the relief valve 42a.

  As shown in FIG. 7, the first inner peripheral surface 52 is formed with a concave guide hole 71 that guides the relief valve 42 a in a region closest to the rotation center C of the inner rotor 46. The guide hole 71 is formed with a concave portion 72 in contact with the relief valve 42a at the center, and a communication hole 73 is formed to communicate the concave portion 72 of the guide hole 71 with the discharge port 55.

  Further, in order to dispose the relief valve 42a on the second housing member 33a, the outer periphery of the second housing member 33a is directed radially outward from the region closest to the rotation center C of the inner rotor 46 of the second inner peripheral surface 53. A through hole 74 penetrating to the surface is formed.

  The relief valve 42a includes a valve body 61 that moves due to a pressure difference between the suction port 54 and the discharge port 55, a spring 56 (an example of an elastic body) that is biased to maintain a closed state in which the valve body 61 does not move, Have

  The valve body 61 a is a substantially rectangular parallelepiped, has a tip 75 for contacting the recess 72 of the guide hole 71 formed in the first inner peripheral surface 52, and a spring recess 64 for locking the spring 56. A convex portion 76 that is formed on the opposite surface and is in contact with the pump rotor 31 is formed on the surface on the pump rotor 31 side.

  The through hole 74 is formed with a valve body moving chamber 81 on the radially inner side and a screw portion 83 for screwing the bolt 82 from the outer peripheral surface of the second housing member 33a. The valve body moving chamber 81 is formed with a guide member 84 that moves the valve body 61 in the axial direction by contacting the convex portion 76 of the valve body 61. Further, the bolt 82 screwed into the threaded portion 83 is formed with a spring insertion hole 57 for inserting the spring 56 at the tip 75 in the axial direction. When the bolt 82 is screwed into the threaded portion 83, oil is prevented from leaking from the through hole 74 by inserting an annular seal member 85 between the bolt 82 and the threaded portion 83.

  One end of the spring 56 is inserted into the spring recess 64 of the valve body 61 and is inserted into the bottom surface of the spring recess 64, and the other end is inserted into the spring insertion hole 57 of the bolt 82. It is locked to the bottom of the.

  Next, the operation of the relief valve 42b will be described in detail.

  As in the first embodiment, when the inner rotor 46 and the outer rotor 44 rotate in the clockwise direction, the working chamber 41 on the suction port 54 side increases in volume with the rotation of the inner rotor 46 and the outer rotor 44 and becomes negative. Pressure is generated. Then, the volume becomes maximum at a place farthest from the rotation center C of the inner rotor 46. Further, the working chamber 41 on the discharge port 55 side decreases in volume and generates positive pressure as the inner rotor 46 and the outer rotor 44 rotate.

  As shown in FIG. 7, when the pressure at the discharge port 55 is equal to or lower than the predetermined pressure, the relief valve 42a moves the valve element 61 because the urging force of the spring 56 is larger than the pressure at the discharge port 55 applied from the communication hole 73. In this state, the suction port 54 and the discharge port 55 are partitioned. In the valve-closed state, the pump rotor 31 sucks oil from the suction port 54 when negative pressure is generated in the working chamber 41 by the rotation of the inner rotor 46 and discharges it to the discharge port 55 when positive pressure is generated.

As shown in FIG. 8, when the pressure of the discharge port 55 is equal to or higher than a predetermined pressure, the relief valve 42 a has a valve body 61 because the pressure of the discharge port 55 transmitted through the communication hole 73 is larger than the urging force of the spring 56. The valve is opened by moving radially outward.
Since the suction port 54 and the discharge port 55 of the second housing member 33 communicate with each other in the valve open state, the oil in the discharge port 55 is sucked by the negative pressure generated by the increase in the volume of the working chamber 41. To return to the inlet 54. Therefore, the pump rotor 31 cannot compress and discharge the oil at the discharge port 55.

In addition to the effects (1), (2), (3), (5), (6), and (7) of the first embodiment, the following effects can be obtained.
(8) According to the above configuration, when the valve body 61 moves in the radial direction of the pump rotor 31, the discharge port 55 and the suction port 54 communicate with each other. Since the negative pressure generated by the working chamber 41 sucks into the suction port 54, oil compression is limited. Therefore, the electric oil pump 6 can reduce the load on the motor unit 14 when the relief valve 42a is opened and adjusts the pressure, so the motor unit 14 is not enlarged and the electric oil pump 6 is reduced in size. Is possible.
(Third embodiment)
Next, with reference to FIG. 9, a third embodiment in which a relief valve 42 b in which the valve body 61 moves in the radial direction by the solenoid 91 is applied to the electric oil pump 6 will be described. The third embodiment differs from the second embodiment in the configuration of the relief valve 42b. For this reason, about the member structure which is common in 2nd Embodiment, the same code | symbol is attached | subjected and description shall be abbreviate | omitted or simplified.

  The electric oil pump 6 of the third embodiment includes a relief valve 42b as a member configuration different from that of the second embodiment.

  In the second housing member 33 a, a relief valve 42 b that adjusts the pressure is disposed so as to partition the groove 51 a in a region closest to the rotation center C of the inner rotor 46 and to contact the pump rotor 31. In the groove 51a, the relief valve 42b defines the groove 51a, whereby a suction port 54 for sucking oil into the working chamber 41 and a discharge port 55 for discharging oil from the working chamber 41 are configured. Therefore, the relief valve 42 b is disposed between the suction port 54 and the discharge port 55.

  FIG. 9 is a cross-sectional view showing the internal configuration of the pump unit 16.

  As shown in FIG. 9, the relief valve 42 b includes a sensor (not shown) that detects the pressure of the discharge port 55, a valve body 61 that moves in the radial direction, and a solenoid 91 that drives the valve body 61.

  The solenoid 91 includes a movable iron core 92 that is integrally driven with the valve body 61, a fixed iron core 93 that is a magnetic core, and a solenoid coil 94 that is energized when a copper wire is wound and the sensor detects a pressure higher than a predetermined pressure, A spring 56 disposed between the movable iron core 92 and the fixed iron core 93 and energized to maintain a valve closing state in which the valve body 61 does not move.

  Next, the operation of this embodiment will be described in detail.

  As in the second embodiment, when the inner rotor 46 and the outer rotor 44 rotate in the clockwise direction, the working chamber 41 on the suction port 54 side increases in volume with the rotation of the inner rotor 46 and the outer rotor 44 and becomes negative. Pressure is generated. Then, the volume becomes maximum at a place farthest from the rotation center C of the inner rotor 46. Further, the working chamber 41 on the discharge port 55 side decreases in volume and generates positive pressure as the inner rotor 46 and the outer rotor 44 rotate.

  As shown in FIG. 8, when the pressure at the discharge port 55 is equal to or lower than the predetermined pressure, the relief valve 42b does not move the valve body 61 because the pressure at the discharge port 55 detected by the sensor is equal to or lower than the predetermined pressure. This is a closed valve state in which the outlet 55 is partitioned. In the valve-closed state, the pump rotor 31 sucks oil from the suction port 54 when negative pressure is generated in the working chamber 41 by the rotation of the inner rotor 46 and discharges it to the discharge port 55 when positive pressure is generated.

  When the pressure at the discharge port 55 is equal to or higher than the predetermined pressure, the movable core 92 detects that the pressure at the discharge port 55 is equal to or higher than the predetermined pressure, and energizes the solenoid coil 94 to thereby move the movable core 92 and the fixed core. 93 is magnetized, and the movable iron core 92 is attracted to the fixed iron core 93 against the urging force of the spring 56. Therefore, the relief valve 42b is opened when the valve element 61 moves radially outward by driving the movable iron core 92 of the solenoid 91. In the opened state, the suction port 54 and the discharge port 55 of the second housing member 33 communicate with each other. Therefore, even if the volume of the working chamber 41 is reduced, the oil in the discharge port 55 only returns to the suction port 54, so that the pump rotor 31 cannot compress and discharge the oil.

In addition to the same effects as those of the second embodiment, the following effects can be obtained.
(9) According to the above configuration, since the solenoid 91 is used to drive the relief valve 42b, the valve body 61 can be moved with a simple structure.
(Modification)
In the second embodiment, the valve body 61 moves in the radial direction. However, the relief valve 42 that causes the suction port 54 and the discharge port 55 to communicate with each other when the valve body 61 moves in a direction other than the radial direction, such as the tangential direction of the pump rotor 31. May be provided.

  In the first embodiment and the second embodiment, the suction port 54, the discharge port 55, and the relief valve 42 are disposed in the second housing member 33, but may be disposed in the first housing member 32.

6 Electric oil pump (Electric O / P)
11 Housing 14 Motor portion 15 Shaft 16 Pump portion 31 Pump rotor 32 First housing member 33 Second housing member 41 Working chamber 42 Relief valve 44 Outer rotor 46 Inner rotor 51 Groove portion 52 First inner peripheral surface 53 Second inner peripheral surface 54 Suction port 55 Discharge port 56 Spring 61 Valve body 91 Solenoid 92 Movable iron core 93 Fixed iron core 94 Solenoid coil

Claims (6)

A housing having a suction port for sucking oil and a discharge port for discharging;
A drive source rotatably supported by the housing via a shaft;
A pump rotor disposed in the housing and rotated by the drive source;
Formed between the housing and the pump rotor, the volume is increased or decreased by the rotation of the pump rotor, the oil is sucked from the suction port by the increase of the volume, and the oil is discharged from the discharge port by the decrease of the volume. A working chamber;
Relief having a valve body that is disposed between the suction port and the discharge port in contact with the pump rotor and adjusts the pressure by moving when the discharge port becomes a predetermined pressure or higher. And an oil pump having a valve. By partitioning the groove formed in the housing with the valve body, the suction port and the discharge port are configured,
The oil pump according to claim 1, wherein the relief valve performs pressure adjustment as the valve body moves in the groove. The relief valve opens when the valve body moves in the circumferential direction of the pump rotor,
When the valve body is closed, the working chamber shuts off from the suction port in a state where the volume of the working chamber reaches a maximum volume,
3. The oil pump according to claim 1, wherein when the valve element is opened, the working chamber is blocked from the suction port in a state where the volume of the working chamber is smaller than a maximum volume. The relief valve opens when the valve body moves in the radial direction,
The oil pump according to claim 1 or 2, wherein the suction port and the discharge port communicate with each other when the relief valve is opened.   The relief valve maintains a closed state of the valve body by an urging force of an elastic body provided between the housing and the valve body, and when the pressure of the discharge port becomes a predetermined value or more, The oil pump according to any one of claims 1 to 4, wherein the valve body opens against an urging force of the elastic body.   The oil pump according to any one of claims 1 to 4, wherein the relief valve is opened when the valve element is moved by driving of a solenoid.

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