JP2015117638A - Oil pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil pump device capable of minimizing loads applied to a pump, an engine and the like by changing an oil pressure and an amount of discharge corresponding to values required by the engine and hydraulic equipment.SOLUTION: An oil pump device is composed of an oil circulation flow channel S, a drive gear unit 5, a gear pump portion B having a driven gear unit 4, a first branched flow channel 31 branched from the oil circulation flow channel S and communicated to the gear pump portion B, a hydraulic control valve C driving the driven gear unit 4, a second branched flow channel 33 branched from the oil circulation flow channel S and communicated to a second small-diameter passage portion 24, a solenoid valve D having a drainage discharge port 73c, an orifice 36 disposed between the second small-diameter passage portion 24 and the solenoid valve D, and a spring 81 for elastically biasing the driven gear unit 4. The solenoid valve D is controlled to communicate or not to communicate the second branched flow channel 33 and the second small-diameter passage portion 24, and communicate the drainage discharge port 73c and the second small-diameter passage portion 24 in the non-communicated state.

Description

  The present invention relates to an oil pump device capable of changing a hydraulic pressure and a discharge amount in accordance with values required by an engine and hydraulic equipment in a variable displacement pump and minimizing a load on the pump and the engine.

  In general, the theoretical discharge amount of a gear pump (external gear pump) is determined by the tooth height, the tooth width, and the like, and the discharge amount per unit time is determined by the theoretical discharge amount and the rotational speed of the gear (pump rotation speed). When this gear pump is used, for example, as an oil pump that supplies lubricating oil inside a vehicle engine, the theoretical discharge amount of this oil pump is necessary for lubrication even if the output of the engine as a drive source is low and the pump speed is low. It is set so that an appropriate amount of oil can be supplied.

  On the other hand, when the engine output increases and the pump rotation speed increases, an excessive amount or hydraulic oil is supplied into the engine, and a high driving force is consumed by the oil pump. Risk of loss. As a gear pump that solves this problem, as the pump speed increases, either or both of the drive gear and driven gear are moved in the axial direction to shorten the meshing width in the axial direction and reduce the theoretical discharge amount. Capacity type gear pumps are known.

JP 2012-215169 A

  The problem with conventional external gear pumps is that the amount of discharge required by the engine and hydraulic equipment, the amount of discharge corresponding to the oil pressure, and the oil pressure do not become the oil pressure in each rotation speed region. This is an inefficient variable that generates hydraulic pressure. In addition, there was a variable variable responsiveness.

  For the purpose of solving such problems, Patent Document 1 has been developed to solve many conventional problems. However, in Patent Document 1, no consideration is given to the function of discharging oil in the oil circulation passage. Therefore, when a relief valve is separately provided, there is a problem that the cost and space increase due to that. Accordingly, an object (technical problem to be solved) of the present invention is to realize a variable displacement pump having a relief function by utilizing a part of a device to be configured.

  In view of the above, the inventor has intensively and intensively studied to solve the above-described problems, and as a result, the invention of claim 1 is replaced with an oil circulation passage, an axially stationary drive gear unit, and an axially driven gear that reciprocates. A unit, a gear pump unit having a second small-diameter passage portion on which a second small-diameter shaft portion of the driven gear unit slides, and a first branch passage branched from the oil circulation passage and communicating with the gear pump portion A hydraulic control valve provided in the first branch flow path and driving the driven gear unit in the axial direction; a second branch flow path branched from the oil circulation flow path and communicating with the second small diameter passage portion; A solenoid valve provided in the second branch flow path and having a drain discharge port, an orifice provided between the second small diameter passage portion and the solenoid valve, and a second small diameter passage portion. The driven gear unit includes a spring that elastically biases the driven gear unit in a direction in which the meshing area increases, and the solenoid valve connects or disconnects the second branch flow path and the second small-diameter passage portion, In the non-communication state, the above problem has been solved by providing an oil pump device that performs control for communication between the drain discharge port and the second small-diameter passage portion.

  According to a second aspect of the invention, in the first aspect, the orifice is an oil pump device that is mounted from the inside to the outside of the second small-diameter passage portion, thereby solving the above-described problem. According to a third aspect of the present invention, in the first or second aspect, the hydraulic control valve is controlled so that the first branch flow path is in communication or non-communication by movement of an internal spool. By using an oil pump device, the above problems have been solved.

  According to a fourth aspect of the present invention, in the third aspect, the hydraulic control valve is provided with a relief discharge port, and the second small-diameter passage portion and the relief discharge port are communicated with each other via a relief flow path. The hydraulic control valve is configured such that the relief channel is blocked when the first branch channel is not in communication, and the relief channel and the relief discharge port are open when the first branch channel is in communication. By using an oil pump device, the above problems have been solved. According to a fifth aspect of the present invention, in the first, second, third or fourth aspect of the present invention, the second small diameter passage portion and the second small diameter passage portion are interposed via the solenoid valve in the low engine speed range and the medium engine speed range. The oil pump device is configured to communicate with the drain flow path, and in communication with the second branch flow path and the orifice via the solenoid valve in a high engine speed range, thereby solving the above problem. did.

  According to the first aspect of the present invention, the second branch passage branched from the oil circulation passage for supplying oil for lubrication to the engine communicates with the second small-diameter passage portion of the gear pump portion, and the second branch passage is The oil can be sent to the second small-diameter passage portion. Furthermore, the solenoid valve provided in the second branch flow path is controlled so as to communicate or not communicate oil in the second branch flow path.

  An orifice is provided in the second small diameter passage portion. The orifice can maintain the proper hydraulic pressure by only slightly reducing the hydraulic pressure of the oil that has flowed into the second small-diameter passage portion by controlling the direction of the solenoid valve, and a small amount of oil can continue to be discharged from the orifice. Therefore, it also has a function as a relief. This relief function is constituted by a housing of a solenoid valve and a gear pump part, and does not separately provide a new relief valve. Therefore, space saving and cost saving of the entire apparatus can be realized.

  In the invention of claim 2, since the orifice is configured to be mounted from the inside of the second small diameter passage portion to the outside, the oil in the second small diameter passage portion can be discharged to the outside through the orifice as it is, By configuring the oil pan or the like to receive oil as it is, a very simple relief device can be realized.

  According to a third aspect of the present invention, the hydraulic control valve is configured so that the first branch flow path is controlled to be either one of communication or non-communication by movement of an internal spool. The movement of the driven gear in the axial direction can be controlled according to the increase or decrease of the oil pressure of the oil, and the hydraulic control valve is less likely to cause problems due to the failure of the electrical system as seen in the case of the electric control valve. Can be used in a stable state.

  In the invention of claim 4, the hydraulic control valve is provided with a relief discharge port, the second small-diameter passage portion and the relief discharge port communicate with each other via the relief flow path, and the hydraulic control valve has the first branch. The relief flow path is blocked when the flow path is in a non-communication state, and the relief flow path and the relief discharge port are open when the first branch flow path is in a communication state. It is possible to control the axial movement of the driven gear in accordance with the change in pressure.

  In addition, when the first branch flow path is in the non-communication state at the low oil pressure level in the low engine speed range, the relief flow path is also blocked, so that the oil in the second small diameter passage portion is discharged. This makes it possible to reliably suppress the movement of the driven gear unit in the axial direction, which reduces the meshing range with respect to the drive gear unit, and realize more stable oil circulation in the low rotation speed range.

  Further, since the relief passage and the relief outlet are opened when the first branch passage is in communication, the oil inside the second small-diameter passage portion is, for example, in the high rotation speed region of the engine. And the oil can be discharged to the outside through the relief discharge port of the hydraulic control valve, and the driven gear moves according to the change of the hydraulic pressure due to the change of the rotation speed, and the oil discharge amount is made appropriate. be able to. Further, since oil is relieved (discharged) from the hydraulic control valve, the hydraulic control valve also functions as a relief valve, and a separate relief valve can be dispensed with.

  According to a fifth aspect of the present invention, the second small diameter passage portion and the drain passage are communicated with each other through the solenoid valve in a low engine speed range and an intermediate engine speed range, and the solenoid is operated in a high engine speed range. With the configuration in which the second branch flow path and the orifice are communicated with each other through a valve, the most appropriate oil discharge amount can be obtained in each rotation speed range.

It is sectional drawing which shows the structure in 1st Embodiment of this invention, and the oil circulation flow path of an engine. (A) is a schematic cross-sectional view in which the axial engagement range between the drive gear and the driven gear of the gear pump unit is maximum, (B) is a cross-sectional view taken along the line X1-X1 in (A), and (C) is a gear pump. FIG. 6 is a schematic cross-sectional view in which the axial engagement range between the drive gear and the driven gear of the portion is in the minimum state, and (D) is a cross-sectional view taken along the line X 2 -X 2 in FIG. FIG. 3 is an overall configuration diagram showing the operation of the engine in a low speed range in the present invention. It is a whole block diagram which shows the operation | movement in the engine rotation speed area in this invention. FIG. 3 is an overall configuration diagram showing the operation of the engine in a high speed range in the present invention. It is a block diagram of the principal part in 2nd Embodiment of this invention. It is a graph which shows the relationship between an engine speed and oil_pressure | hydraulic which shows the process which transfers to the high speed area from the low speed area in this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configuration of the present invention is mainly composed of an oil circulation flow path S, a housing A, a gear pump unit B, a hydraulic control valve C, a solenoid valve D, an orifice 36, and the like, as shown in FIGS. Yes. In the housing A, main components such as a gear pump part B, a hydraulic control valve C, a solenoid valve D and the like are integrated.

  In addition, the gear pump B, the hydraulic control valve C, and the solenoid valve D are provided with independent housings A, and these are connected in a block shape to be integrated, or each housing is appropriately In some cases, the oil circulation path S may be arranged at an appropriate position.

  The gear pump portion B includes a pump chamber 2, a driven gear unit 4, and a drive gear unit 5 formed in the housing A. The pump chamber 2 is formed of a driven gear unit chamber 2a and a drive gear unit chamber 2b. The driven gear unit chamber 2a includes a first small-diameter passage portion 21, a large-diameter passage portion 22, a stepped surface portion 23, and a second small-diameter passage portion 24, and these are arranged in a straight line (see FIG. 1). ). The step surface portion 23 is formed as a flat surface that is perpendicular to the axial direction of the first small diameter passage portion 21.

  The drive gear unit chamber 2b is formed adjacent to the driven gear unit chamber 2a. The drive gear unit chamber 2 b includes a drive gear storage portion 25 and shaft support hole portions 26 formed on both upper and lower sides of the drive gear storage portion 25.

  Here, in the present invention, for the sake of convenience, the vertical direction of the housing A is set for the sake of convenience. This does not limit the actual vehicle mounting direction. The passage direction of the driven gear unit chamber 2a is set to the vertical direction, the large diameter passage portion 22 is set to be higher than the first small diameter passage portion 21, the large diameter passage portion 22 side is set to the upper side, and the first small diameter passage portion 21 is set. The side is the lower side (see FIGS. 1, 2A and 2C). This vertical positional relationship is similarly applied to the gear pump unit B, the hydraulic control valve C, and the solenoid valve D.

  The driven gear unit 4 includes a valve piston 4a, a driven gear 44, and a partition piston 45 (see FIGS. 2A and 2C). In the valve piston 4a, a first small-diameter shaft portion 41, a large-diameter portion 42, and a second small-diameter shaft portion 43 are integrally formed in the axial direction. The first small-diameter shaft portion 41 and the second small-diameter shaft portion 43 are formed in a cylindrical shape, and the large-diameter portion 42 is formed with a substantially half-moon-shaped or concave arc-shaped relief portion 42b in a part of the outer peripheral side surface. Yes.

  The escape portion 42b is a portion where the outer peripheral portion of the drive gear 52 bites in when the driven gear 44 moves in the axial direction with respect to the drive gear 52 (see FIGS. 2C and 2D). The drive gear 52 and the valve piston 4a serve to prevent mutual interference.

  The valve piston 4a is used in a state in which the first small-diameter shaft portion 41 is downward and the second small-diameter shaft portion 43 is upward and the axial direction is vertical. The lower end of the first small-diameter shaft portion 41 is a shaft end surface 41a, and a step portion formed at the boundary between the first small-diameter shaft portion 41 and the large-diameter portion 42 becomes the pressure receiving surface 42a. The lower surface portion (step portion) of the second small diameter shaft portion 43 is used as a return pressure receiving surface 43a [see FIGS. 2A and 2C].

  The drive gear unit 5 includes a drive shaft 51 and a drive gear 52 [see FIGS. 1, 2A and 2C]. In the drive gear unit 5, the drive gear 52 is housed in the drive gear housing portion 25, and the drive shaft 51 is pivotally supported by the shaft support hole portion 26 and is housed in the drive gear unit chamber 2b. The drive shaft 51 is rotated by power from an engine crankshaft (not shown), and the drive gear 52 that rotates together with the drive shaft 51 transmits rotation to the driven gear 44 and operates as an external gear pump.

  A spring 81 is mounted in the second small-diameter passage portion 24, and the spring 81 always serves to elastically bias the driven gear unit 4 in the discharge increasing direction [FIGS. 1, 2A, (C). )reference〕. The spring 81 is a coil spring and is elastically biased so that the engagement width between the driven gear 44 and the drive gear 52 is maximized.

  A first branch passage 31 is provided at a position upstream of the engine in the oil circulation passage S, and the first branch passage 31 communicates with a lower side of the large-diameter passage portion 22 of the driven gear unit chamber 2a. It is formed to do. In the oil circulation flow path S, a part of the oil flowing toward the engine flows into the first branch flow path 31 and the oil is sent to the large diameter passage portion 22.

  And the oil which flows through the large diameter passage part 22 is controlled by the hydraulic control valve C mentioned later, and it is comprised so that the pressure receiving surface 42a of the said valve piston 4a can receive the pressure of oil. The oil pressure is hereinafter referred to as oil pressure. The first branch flow path 31 communicates with the large diameter passage portion 22 of the driven gear unit chamber 2a. Further, a hydraulic control valve C is provided at an intermediate position of the first branch flow path 31. In the first branch flow path 31, the flow path between the hydraulic control valve C and the large diameter passage portion 22 is referred to as a first branch connection flow path 311 and belongs to the first branch flow path 31. The oil flowing through the first branch connection flow path 311 is communicated or blocked by the hydraulic control valve C.

  The hydraulic control valve C includes a spool 61, a spool chamber 62 in which the spool 61 is accommodated, and a spring 82. The spool 61 includes two large-diameter portions 61a and 61b and one small-diameter portion 61c, and the small-diameter portions 61c are arranged in a straight line between the two large-diameter portions 61a and 61b. ing. The periphery of the narrow diameter portion 61c of the spool 61 is a groove portion 61d. The spool chamber 62 is formed with a first outlet port 62a, a second outlet port 62b, a relief opening / closing port 62c, and a relief outlet port 62d. The spring 82 always closes the first outlet port 62a and the second outlet port 62b by the large diameter portion 61a of the spool 61 by the elastic biasing force, and the relief opening / closing port 62c and the relief discharge port by the large diameter portion 61b. 62d is closed.

  The hydraulic control valve C performs switching control between communication and blocking between the first branch flow path 31 and the large diameter passage portion 22. Specifically, the oil in the first branch flow path 31 flows in from the first outlet / inlet 62a, and the hydraulic pressure is applied to the end surface of the large-diameter portion 61a of the spool 61. To do. When the large-diameter portion 61a that has blocked the second outflow inlet 62b moves upward, the second outflow inlet 62b opens, oil flows into the first branch connection flow path 311, and oil flows into the large-diameter passage section 22. Flows in and presses the pressure receiving surface 42a of the driven gear unit 4 upward.

  Next, the solenoid valve D will be described. The solenoid valve D is composed of a direction control valve 71, a solenoid portion 72, and a direction control valve chamber 73. The directional control valve 71 is formed with an in-valve control channel 71a, and the directional control valve chamber 73 is formed with a directional control inlet 73a, a directional control outlet 73b, and a drain outlet 73c.

  The direction control valve 71 is controlled by a solenoid unit 72, and an in-valve control flow path 71a of the direction control valve 71 is provided between the direction control inlet 73a and the direction control outlet 73b, or between the direction control inlet 73a and the drain outlet 73c. Either one is selected and controlled. At this time, if one is selected so as to communicate, the other is blocked and the communication is disconnected.

  The second branch flow path 33 communicates with the second small diameter passage portion 24 of the pump chamber 2. In the second branch flow path 33, the flow path between the solenoid valve 7 and the second small diameter passage portion 24 is referred to as a second connection flow path 331. The second connection flow path 331 belongs to the second branch flow path 33 and is a part of the second branch flow path 33. Further, the drain discharge port 73c is provided with a drain flow path 35, which is discharged to the outside of the oil circulation flow path S or communicates with an oil pan.

  In the second branch channel 33, an orifice 36 is attached to the second connection channel 331. The orifice 36 serves to flow oil into and out of the second small-diameter passage portion 24 little by little.

  At a position above the second small-diameter passage portion 24 in the driven gear unit chamber 2a, a relief inlet 24a communicating with the second connection channel 331 of the second branch channel 33 is formed above. A relief outlet 24b is formed at the same position as or below the relief inlet 24a.

  That is, the orifice 36 discharges oil from the second small diameter passage portion 24 little by little while maintaining a substantially constant pressure when the second small diameter passage portion 24 is filled with oil having pressure. Is to be able to.

  The orifice 36 is a separate member from the relief inlet 24a, or the relief inlet 24a and the orifice 36 are integrally formed. In the case where the relief inlet 24a and the orifice 36 are integrally formed, the relief inlet 24a is a small-diameter pipe or a pipe having a small inner diameter so that the relief inlet 24a can be used as the orifice 36. Sometimes.

  The relief outlet port 24 b of the second small diameter passage portion 24 and the relief opening / closing port 62 c of the hydraulic control valve C communicate with each other through a relief channel 37. Then, the movement of the spool 61 of the hydraulic control valve C moves the large diameter portion 61b upward, and the groove portion 61d formed by the small diameter portion 61c connects the relief opening / closing port 62c and the relief discharge port 62d with the spool chamber 62. The relief outlet 24b and the relief outlet 62d communicate with each other by allowing the oil to be discharged from the second small-diameter passage portion 24.

  Next, the direction control action of the hydraulic control valve C will be described. The oil pump device of the present invention is incorporated in the oil circulation passage S of the engine 100. Oil flows from the oil circulation passage S into the first branch passage 31 of the housing A.

  Further, the oil flowing into the first branch flow path 31 is brought into a state where the first outflow inlet 62a and the large-diameter passage portion 22 are in communication or non-communication (blocked) by the operation of the spool 61 of the hydraulic control valve C. In the communication state, hydraulic pressure is applied to the pressure receiving surface 42a of the driven gear unit 4, the driven gear unit 4 is moved upward in the axial direction, the meshing range between the driven gear 44 and the drive gear 52 is narrowed, and the oil discharge amount is reduced ( (See FIG. 4).

  Next, the direction control action of the solenoid valve D will be described. When the solenoid valve D is in an ON state, the direction control valve 71 is not in communication between the second branch passage 33 and the relief inlet 24a of the second small diameter passage portion 24 by the control operation of the solenoid portion 72. The oil flowing from the oil circulation passage S through the second branch passage 33 cannot flow into the second small diameter passage portion 24 (see FIGS. 3 and 4). At this time, the drain discharge port 73c and the relief inlet 24a of the second small diameter passage portion 24 communicate with each other, and the oil in the second small diameter passage portion 24 is discharged from the drain discharge port 73c.

  When the solenoid valve D is in the OFF state, the valve portion 71a of the directional control valve 71 is switched by the solenoid portion 72, and the second branch passage 33 is the second small diameter passage of the gear pump portion B. The hydraulic pressure and the biasing force of the spring 81 are applied to the return pressure receiving surface 43 a of the driven gear unit 4, communicating with the portion 24 and flowing into the second small diameter passage portion 24.

  When the force by the hydraulic pressure applied to the return pressure receiving surface 43a on the second small diameter passage portion 24 side and the biasing force of the force by the spring 81 are larger than the force by the pressure receiving surface 42a on the first branch flow path 31 side, The driven gear unit 4 stays on the first small diameter passage portion 21 side, the engagement width between the drive gear 52 and the driven gear 44 is in the maximum state, and the discharge amount is normal.

  Next, the operation of the present invention in each rotation speed region of engine 100 will be described. In the oil pump device of the present invention, the discharge amount of the gear pump unit B is made appropriate in accordance with the engine speed Ne of the engine 100. The speed Ne is low, medium, and high. The discharge amount changes in the rotation speed range.

  First, the operation when the engine speed Ne is low is described (see FIG. 3). Here, the low rotational speed range specifically refers to a range where the rotational speed Ne is about 1000 rpm from the rotational speed during idling. The solenoid valve D is in an on state (ON), and the direction control valve 71 blocks communication between the second branch flow path 33 and the second small diameter passage portion 24 and makes it non-communication. Further, the in-valve control flow path 71a of the direction control valve 71 communicates the second small diameter passage portion 24 and the drain discharge port 73c. Therefore, the second small diameter passage portion 24 is opened in communication with the atmosphere, and only the force of the spring 81 acts on the driven gear unit 4 on the return pressure receiving surface 43 a of the second small diameter passage portion 24.

  The hydraulic control valve C controls so that the hydraulic pressure by the oil flowing through the first branch flow path 31 is applied or not applied to the pressure receiving surface 42 a of the driven gear unit 4. Since the hydraulic pressure generated by the external gear pump is low in the spool 61 of the hydraulic control valve C in the low rotation speed range, the urging force of the spring 81 is superior to the hydraulic pressure, and the driven gear unit 4 does not move. Therefore, since the driven gear 44 and the drive gear 52 are all meshed in the axial direction, the pump discharge amount per rotation speed is the maximum. Note that in this rotational speed region, the hydraulic pressure is substantially proportional to the engine rotational speed.

  Next, the operation in the middle speed range of the engine 100 will be described (see FIG. 4). Specifically, the medium rotational speed range is a range where the rotational speed Ne is about 1000 rpm to about 3500 rpm. First, when the engine speed reaches a predetermined value Ne1 (about 1000 rpm), the force of the hydraulic pressure received by the spool 61 of the hydraulic control valve C surpasses the elastic biasing force of the spring 82, and the spool 61 moves upward in the axial direction. The first outflow inlet 62a and the second outflow inlet 62b communicate with each other in the spool chamber 62, and the first branch flow path 31 and the large diameter passage portion 22 communicate with each other. Then, a hydraulic force is applied to the pressure receiving surface 42a.

  Further, in the middle rotation speed range, the solenoid valve D is in an ON state, and the directional control valve 71 includes the second branch flow path 33, the second small diameter passage portion 24, and the like, as in the low rotation speed range. The communication will be cut off and will not be communicated. Further, the in-valve control flow path 71a of the direction control valve 71 communicates with the second small diameter passage portion 24 through the drain discharge port 73c.

  Therefore, the second small-diameter passage portion 24 is opened in communication with the atmosphere, and the second small-diameter passage portion 24 is in a state where only the force of the spring 81 is applied to the return pressure receiving surface 43 a of the driven gear unit 4. Therefore, the force applied to the pressure receiving surface 42a of the valve piston 4a is greater than the force applied to the return pressure receiving surface 43a, and the driven gear unit 4 moves to the second small diameter passage portion 24 side.

  As a result, the meshing width between the drive gear 52 and the driven gear 44 is reduced, and the theoretical discharge amount is gradually reduced. Therefore, in the middle rotation speed range, by maintaining the low hydraulic pressure almost constant over a wide rotation speed, the work of the pump itself and the power loss of the engine can be reduced, thereby improving the fuel consumption.

  Next, a relief operation when the rotational speed Ne of the engine 100 is in a high rotational speed range will be described (see FIG. 5). Specifically, in the high rotation speed range, the rotation speed Ne is about 3500 rpm or more. In the high rotation speed range, the discharge amount from the gear pump part B increases. The solenoid valve D is in an OFF state, and the second branch flow path 33 and the direction control valve 71 are switched and communicated with each other by the solenoid portion 72, and the second branch flow path 33 is connected via the in-valve control flow path 71a. And the second small diameter passage portion 24 communicate with each other.

  As a result, the oil from the second branch flow path 33 flows into the second small diameter passage portion 24, and hydraulic pressure is applied to the return pressure receiving surface 43 a of the driven gear unit 4. As a result, the driven gear unit 4 moves in the direction in which the amount of meshing with the drive gear 52 increases, and the discharge amount and discharge pressure of the pump increase.

  As the pump discharge pressure increases, the spool 61 moves upward, and the second small-diameter passage portion 24 communicates with the relief opening / closing port 62 c by the hydraulic control valve C and the relief flow path 37. The spool 61 moves upward in the spool chamber 62 by the hydraulic pressure from the first branch flow path 31. The large-diameter portion 61b of the spool 61 opens the relief opening / closing port 62c and the relief discharge port 62d, and the groove portion 61d connects the relief opening / closing port 62c and the relief discharge port 62d.

  The oil in the second small-diameter passage portion 24 is oil outside the oil circulation passage S by the relief passage 37 and the return passage 38 connected to the relief outlet 62d of the hydraulic control valve C. Relief is done back to the bread. As a result, the increase in hydraulic pressure due to the increase in engine speed is small (see FIG. 7).

  Furthermore, the hydraulic pressure of the second small diameter passage portion 24 is lowered by the orifice 36 provided in the second connection flow path 331. As a result, the force due to the oil pressure applied to the pressure receiving surface 42a is superior to the force due to the pressure of the oil in the spring 81 and the second small-diameter passage 24, and the driven gear unit 4 moves in a direction in which the amount of meshing with the drive gear unit 5 decreases. Even when the rotational speed increases, the hydraulic pressure can be kept constant at all times.

  FIG. 6 shows a second embodiment of the present invention, in which the relief outlet 24b is not provided in the second small-diameter passage portion 24, and the relief is performed from the drain discharge port 73c via the solenoid valve D.

S ... Oil circulation passage, B ... Gear pump part, 21 ... First small diameter passage part,
24 ... 2nd small diameter passage part, 31 ... 1st branch flow path, 33 ... 2nd branch flow path, 36 ... Orifice,
4 ... driven gear unit, 41 ... first small diameter shaft portion, 43 ... second small diameter shaft portion,
5 ... Drive gear unit, C ... Hydraulic control valve, 61 ... Spool,
D ... Solenoid valve, 71 ... Direction control valve, 72 ... Solenoid part, 73 ... Direction control valve chamber,
73c ... Drain discharge port, 81 ... Spring.

Claims (5)

  An oil circulation channel, a drive gear unit stationary in the axial direction, a driven gear unit reciprocating in the axial direction, and a gear pump portion having a second small diameter passage portion on which a second small diameter shaft portion of the driven gear unit slides; A first branch passage branched from the oil circulation passage and communicating with the gear pump unit; a hydraulic control valve provided in the first branch passage and driving the driven gear unit in the axial direction; and the oil A second branch flow path branched from the circulation flow path and communicating with the second small diameter passage section; a solenoid valve provided in the second branch flow path and having a drain discharge port; the second small diameter passage section; An orifice provided between the solenoid valve and a spring disposed in the second small-diameter passage portion and elastically biasing the driven gear unit in a direction in which the meshing area increases. The solenoid valve controls the communication between the drain outlet and the second small-diameter passage portion in a non-communication state while the second branch flow channel and the second small-diameter passage portion are in communication or non-communication. An oil pump device characterized by performing.   2. The oil pump device according to claim 1, wherein the orifice is mounted from the inside to the outside of the second small diameter passage portion.   3. The oil pump according to claim 1, wherein the hydraulic control valve is controlled so that the first branch flow path is in communication or non-communication by movement of an internal spool. apparatus.   The hydraulic control valve according to claim 3, wherein the hydraulic control valve is provided with a relief discharge port, the second small-diameter passage portion and the relief discharge port communicate with each other via a relief flow path, and the hydraulic control valve includes An oil pump characterized in that the relief channel is blocked when the first branch channel is not in communication, and the relief channel and the relief outlet are open when the first branch channel is in communication. apparatus.   5. The method according to claim 1, wherein the second small-diameter passage portion and the drain passage are communicated with each other through the solenoid valve in a low engine speed range and a medium engine speed range. An oil pump device characterized in that the second branch flow path and the orifice communicate with each other through the solenoid valve in a high engine speed range.

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