JP2009197731A - Oil pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size and weight of an entire oil pump device by improving the arrangement configuration of a control valve. <P>SOLUTION: This oil pump device is provided with a first return flow passage 51 formed in recessed shape on an inner surface of a housing 7 on one end side in an axial direction of a drive shaft 25 and communicating to a pump chamber 35, a third return flow passage 55 formed in a recessed shape on the inner surface of the housing 7 on another end side in the axial direction of the drive shaft 25 and communicating to a suction port 41 formed on the housing 7, and a second return flow passage 53 formed inside of the drive shaft 25, communicating to the first return flow passage 51 at an upstream end and communicating to the third return flow passage 55 at an upstream end. A control valve 49 opening a second axial flow passage 63 by oil pressure when oil pressure in a pump chamber 35a reaches a set value or higher is provided at the second axial flow passage constructing the second return flow passage 53. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an oil pump device that is rotationally driven by an engine whose rotational speed changes.

  In general, an engine such as a vehicle is provided with an oil pump device, and oil in an oil pan attached below the engine body is sucked up by the oil pump device and is pumped to each part of the engine.

  In this type of oil pump device, as the engine speed increases, the amount of oil discharged from the oil pump increases accordingly, and the oil discharge pressure also increases, so the engine load (drive power) is reduced. There is a problem of increasing. On the other hand, Patent Document 1 discloses providing a control valve for returning a part of high-pressure oil discharged from the pump to the suction side of the pump.

  That is, in the housing, a large number of pump chambers are formed by external teeth and internal teeth, and a discharge channel and a suction channel communicating with the pump chamber are formed. Low pressure oil flows through the suction flow path, while high pressure oil discharged from the pump chamber flows through the discharge flow path. The control valve is provided in a housing outside the pump chamber and is opened to return a part of the high-pressure oil in the discharge passage to the suction passage.

Further, the control valve is configured to control the amount of oil recirculation according to the operating state of the actuator of the engine. As a result, the discharged oil is appropriately recirculated to reduce the load on the oil pump device.
Japanese Patent No. 3603536

  However, in the oil pump device disclosed in Patent Document 1, since the control valve is disposed outside the pump chamber in the housing, the size of the control valve itself inevitably increases the size of the oil pump device. There is a problem that it is difficult to reduce the size of the apparatus.

  The present invention has been made in view of such various points, and an object of the present invention is to reduce the overall size and weight of the oil pump device by improving the arrangement of control valves for recirculating oil. There is.

  In order to achieve the above object, the present invention is characterized in that a control valve is disposed inside a drive shaft.

  Specifically, the present invention includes an inner rotor that is integrally provided on a drive shaft that is rotated by an engine that changes in rotation speed and that has external teeth, an outer rotor that has internal teeth that mesh with the external teeth, and the inner And an oil pump device configured to pump oil in a pump chamber formed by the outer teeth and inner teeth to the engine by rotation of the inner rotor and outer rotor. The following solution was taken.

  That is, the invention according to claim 1 is formed in a concave shape on the inner surface of the housing on one end side in the axial direction of the drive shaft, and communicates with the pump chamber, and the other end side in the axial direction of the drive shaft. A recess formed on the inner surface of the housing and communicating with a suction port formed in the housing; and formed inside the drive shaft, with an upstream end communicating with the first reflux path, A second reflux path having an end communicating with the third reflux path, and the upstream end communicates with the first reflux path and extends across the drive shaft to a substantially axial center. A first axial flow path, a second axial flow path whose upstream end communicates with the downstream end of the first axial flow path, extending substantially the center of the drive shaft toward the other axial end, and an upstream end of the second axial flow path A third axial flow path communicating with the axial flow path and crossing the drive shaft and having a downstream end communicating with the third return path; And when the oil pressure in the pump chamber reaches a set value or more, the oil pressure opens the second shaft passage of the second return passage, and part of the oil in the pump chamber is on the suction port side. And a control valve that recirculates to the second axial flow path.

  According to a second aspect of the present invention, in the first aspect of the present invention, the first return path is configured to communicate with a pump chamber having a maximum volume among the pump chambers, and the control valve When the oil pressure in the volumetric pump chamber reaches a set value or more, the second shaft flow path is opened.

  According to the first aspect of the present invention, the second return path which is a part of the oil return path is formed inside the drive shaft provided integrally with the inner rotor, and a part of the second return path is formed. A control valve is disposed in the second shaft flow path. In other words, since the control valve is formed inside the drive shaft, the entire oil pump device is drastically reduced in size and weight compared to the case where the control valve is disposed outside the oil chamber as in Patent Document 1. Can be

  According to the second aspect of the present invention, the control valve opens the second shaft passage when the oil pressure in the pump chamber having the maximum volume reaches a set value or more, so that the oil is discharged from the pump chamber to the discharge port. Excess oil can be refluxed before being done. In other words, since wasteful oil is not discharged from the pump chamber, the load of the oil pump device is increased compared to the case where the oil after being excessively discharged from the pump chamber is recirculated as in Patent Document 1. Can significantly reduce the load of the engine driving the oil pump device, thereby improving the engine output and reducing fuel consumption.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

<< Embodiment of the Invention >>
1 to 5 show an embodiment of the present invention.

  FIG. 1 is a plan view showing the pump body with the cover part removed from the oil pump device of the present embodiment. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a plan view showing the pump body with the inner rotor and the outer rotor removed. FIG. 4 is a plan view of the inner surface of the cover portion in the oil pump device of the present embodiment.

  The oil pump device 1 is disposed in an engine (not shown). And it is comprised so that the oil which is the lubricating oil stored in the oil pan arrange | positioned by the engine lower part may be pumped to each sliding part in an engine.

  The oil pump device 1 includes an inner rotor 3 made of metal, an outer rotor 5, and a housing 7 that houses the inner rotor 3 and the outer rotor 5.

  As shown in FIG. 2, the housing 7 has a pump body 11 formed by opening a bottomed cylinder chamber 9 extending upward and downward and an upper portion of the pump body 11 to close the cylinder chamber 9. And a cover portion 13.

  For example, two positioning pins 15 project from the upper end of the pump body 11, and a positioning hole 17 into which the positioning pins 15 are inserted is formed in the cover portion 13. In addition, a plurality of bolt insertion holes 19 and 21 are formed in the pump body 11 and the cover part 13, respectively. Further, a first bearing 31 that rotatably supports the drive shaft 25 is formed in the bottom portion 12 of the cylinder chamber 9 of the pump body 11 so as to be rotatable, while the cover portion 13 rotates the drive shaft 25. A second bearing 33 that is freely supported is formed through.

  Thus, the drive shaft 25 is inserted into the second bearing 33 and the positioning pin 15 is inserted into the positioning hole 17 with respect to the pump body 11 in which the inner rotor 3 and the outer rotor 5 are accommodated in the cylinder chamber 9. The housing 7 is assembled by attaching the cover 13 to the bolts and inserting the bolts 23 into the bolt insertion holes 19 and 21 and fastening them.

  The inner rotor 3 is provided integrally with a drive shaft 25 rotated by the engine whose rotational speed changes, and has a plurality of external teeth 27 protruding outward in the radial direction of the drive shaft 25. It is integrally rotated with the drive shaft 25 in the clockwise direction in FIG.

  The outer rotor 5 is disposed in the cylinder chamber 9 with a predetermined amount of eccentricity from the axis of the drive shaft 25 and has inner teeth 29 that mesh with the outer teeth 27. It is configured to rotate in the same direction as the rotor 3.

  As for the internal tooth 29 and the said external tooth 27, the tooth surface which is a side surface which mutually mesh | engages is prescribed | regulated by the trochoid curve or the cycloid curve. 1 and 2, the outer teeth 27 of the inner rotor 3 and the inner teeth of the outer rotor 5 are provided between the bottom 12 of the cylinder chamber 9 and the inner surface 14 of the cover 13 in the pump body 11. 29, a plurality of pump chambers 35 are formed.

  In addition, the bottom 12 of the cylinder chamber 9 in the pump body 11 is formed with a first recess 37 and a second recess 39 that are recessed in a concave shape. An oil suction port 41 is formed on the side surface of the first recess 37, and a suction flow path 43 communicating with the first recess 37 through the suction port 41 is formed in the pump body 11. Oil in the oil pan flows into the suction passage 43 via an oil conduit (not shown).

  On the other hand, the second recess 39 is formed with a discharge port 45 communicating with the second recess 39 on the bottom surface thereof, and communicates with an oil flow path (not shown) of the engine via the discharge port 45. Yes. As shown in FIG. 3, the discharge port 45 and the suction port 41 are spaced apart on the left and right sides of the first bearing 31.

  Then, the oil pump device 1 is moved from the oil pan to the first recess 37 through the oil conduit, the suction passage 43, the suction port 41, and the first recess 37 by the rotation of the inner rotor 3 and the outer rotor 5. The oil sucked into the corresponding pump chamber 35 is discharged from the pump chamber 35 corresponding to the second recess 39 to the second recess 39 and is pumped to the engine via the discharge port 45.

  The oil pump device 1 according to the present embodiment is formed in the housing 7 and the drive shaft 25 and is used for returning the oil in the pump chamber 35 having a high pressure to the first recess 37 on the suction side having a lower pressure. A reflux path 47 and a control valve 49 for controlling the oil flow in the reflux path 47 are provided. As shown in FIG. 2, the reflux path 47 includes a first reflux path 51, a second reflux path 53, and a third reflux path 55.

  The first reflux path 51 is formed in a concave shape on the inner surface of the housing 7 on the one end side in the axial direction of the drive shaft 25 (upper side in FIG. 2), that is, the inner surface of the cover portion 13, and communicates with the pump chamber 35. In particular, the first reflux path 51 is configured to communicate with the pump chamber 35 a having the maximum volume among the plurality of pump chambers 35. As shown in FIG. 1, the pump chamber 35 is located at an intermediate position between the first recess 37 and the second recess 39, that is, at a position where the pump chamber 35 does not communicate with any of the first recess 37 and the second recess 39. The pump chamber 35a has the maximum volume. The oil pressure in the pump chamber 35a communicates with the first recess 37 and is higher than the oil pressure in the pump chamber 35 on the side opposite to the rotation direction of the drive shaft 25 than the pump chamber 35a.

  Further, as shown in FIG. 4, the first reflux path 51 is formed in a concave groove shape extending in the radial direction of the drive shaft 25, and one end reaches the approximate center of the pump chamber 35 a having the maximum volume, while the other end Is formed so as to reach the inner peripheral surface of the second bearing 33.

  The third reflux path 55 is formed in a concave shape on the inner surface of the housing 7 on the other axial end of the drive shaft 25 (the lower side in FIG. 2), that is, on the bottom 12 of the cylinder chamber 9 of the pump body 11. Via the suction port 41. As shown in FIG. 3, the third reflux path 55 is formed in a groove shape extending in the radial direction of the drive shaft 25, and one end reaches the side surface of the first recess 37, while the other end is the first. It is formed so as to reach the inner peripheral surface of the bearing 31.

  A first circumferential groove 57 and a second circumferential groove 59 are formed on the outer circumferential surface of the drive shaft 25 so as to extend in a concave shape over the entire circumference. The first circumferential groove 57 communicates with the first reflux path 51, while the second circumferential groove 59 communicates with the third reflux path 55.

  The second return path 53 is formed inside the drive shaft 25 and has an upstream end communicating with the first return path 51 via the first circumferential groove 57, while a downstream end via the second circumferential groove 59. It communicates with the third reflux path 55. As shown in FIG. 2, the second reflux path 53 includes a first axial flow path 61, a second axial flow path 63, and a third axial flow path 65.

  The upstream end of the first shaft channel 61 communicates with the first reflux path 51 via the first circumferential groove 57 and extends substantially to the center of the shaft across the drive shaft 25 in the radial direction. The second shaft flow path 63 has an upstream end communicating with the downstream end of the first shaft flow path 61 and extends substantially the center of the drive shaft 25 toward the other end in the axial direction (lower side in FIG. 2).

  As shown in FIG. 2, the second shaft channel 63 has a large diameter portion 67 whose inner diameter is locally increased at an intermediate portion thereof, and the control valve 49 is disposed in the large diameter portion 67. Thus, the downstream end portion of the drive shaft 25 of the large diameter portion 67 is closed by the plug 69.

  The control valve 49 includes a compression spring 71 placed on the upper end of the plug 69 and a valve body 73 that is supported by the upper end of the compression spring 71 and opens and closes the second shaft channel 63. Thus, the control valve 49 is configured to open the second shaft channel 63 by the oil pressure when the oil pressure in the pump chamber 35a having the maximum volume reaches a set value or more.

  The third shaft channel 65 communicates with the downstream end of the second shaft channel 63 at the upstream end, crosses the drive shaft 25 in the radial direction, and passes through the second circumferential groove 59 at the downstream end of the third return channel 55. Communicating with

  Therefore, according to the oil pump device 1 of the present embodiment, first, the drive shaft 25 is driven to rotate clockwise in FIG. 1 by the rotation of the engine. By rotating the inner rotor 3 integrally with the drive shaft 25, the outer teeth 27 of the inner rotor 3 rotate around the drive shaft 25. The outer rotor 5 rotates following the inner rotor 3 in a state of being eccentric from the axis of the drive shaft 25 by the inner teeth 29 meshing with the outer teeth 27 and rotating.

  The oil in the oil pan passes through the suction passage 43, the suction port 41, and the first recess 37 in order through the oil conduit (not shown) by the rotation of the inner rotor 3 and the outer rotor 5, and the outer teeth. The air is sucked into a pump chamber 35 formed by 27 and internal teeth 29. The oil sucked into the pump chamber 35 passes through the engine oil flow path (not shown) from the discharge port 45 of the second recess 39 by the rotation of the rotors 3 and 5, and the sliding parts of the engine, the cooling part, etc. To be pumped.

  When the pressure of the oil in the pump chamber 35a having the maximum volume reaches a set value or more, the control valve 49 is opened, and the oil in the pump chamber 35a passes through the reflux path 47 and the oil pressure is higher than that in the pump chamber 35a. Is returned to the first concave portion 37 on the suction side having a low level.

  That is, the control valve 49 opens the second axial flow path 63 of the second reflux path 53 when the valve body 73 descends against the urging force of the compression spring 71. As a result, part of the oil in the pump chamber 35a flows into the first return path 51 and passes through the first circumferential groove 57, the first axial flow path 61, the second axial flow path 63, and the second axial flow path 53. It flows through the third shaft channel 65 to the third reflux path 55 via the second circumferential groove 59. Thereafter, the oil flows out from the third reflux path 55 to the first recess 37 on the suction side and is refluxed.

  Here, FIG. 5 is a graph showing the relationship between the engine speed and the oil pressure (oil discharge amount). When the reflux path 47 and the control valve 49 in the present embodiment are not provided in the oil pump device, as shown by a two-dot chain line a in FIG. 5, the oil pressure, that is, the oil discharge amount is proportional to the increase in the engine speed. Then increase. Therefore, an excessive amount of oil exceeding the required amount is discharged.

  On the other hand, in the present embodiment, the above-described reflux path 47 and the control valve 49 are provided, so that the control is performed when the oil pressure in the maximum volume pump chamber 35a reaches or exceeds the set value, that is, at the point P shown in FIG. By opening the valve 49, a part of the oil in the pump chamber 35a (shown by hatching in FIG. 5) can be recirculated to the suction side via the recirculation path 47. As a result, the amount of oil in the pump chamber 35a is appropriately reduced. Therefore, as shown by the solid line b in FIG. 5, the optimum oil discharge amount (the discharge amount in the region below the solid line b in FIG. 5) is supplied to the engine. In addition to being able to perform pressure feeding, it is possible to reduce an excessive load on the oil pump device 1 and thus an excessive load on the engine driving the oil pump device 1.

  In addition, according to the present embodiment, since the control valve 49 is arranged inside the drive shaft 25, the control valve is arranged outside the pump chamber 35 in the housing 7 as described in Patent Document 1 above. Compared with the case where it installs, the whole oil pump apparatus 1 can be remarkably reduced in size and weight.

<< Other Embodiments >>
In the above embodiment, the first reflux path is formed so as to communicate with the maximum volume pump chamber 35a, and the control valve 49 is operated when the oil pressure in the maximum volume pump chamber 35a reaches a set value or more. Although the biaxial channel 63 is configured to open, the present invention is not limited to this.

  That is, the first return path is communicated with the pump chamber 35 having a volume smaller than that of the pump chamber 35a, that is, the pump chamber 35 on the opposite side of the drive shaft 25 to the pump chamber 35a. The control valve 49 may be opened to open the second shaft channel 63 when the oil pressure reaches a set value or more. This also makes it possible to reduce the size and weight of the entire apparatus, and a part of oil having a pressure smaller than the discharge pressure can be recirculated from the pump chamber 35 to the suction side. The load of can be reduced suitably.

  In the above embodiment, for example, the vertical direction in FIG. 2, that is, the axial direction of the drive shaft 25 is described as “vertical direction”, but the present invention is not limited to this. For example, the present invention can be similarly applied to the case of the horizontal direction, that is, when the oil pump device 1 is disposed in the engine in the lateral direction or in the oblique direction.

  As described above, the present invention is useful for an oil pump device that is rotationally driven by an engine whose rotational speed changes.

FIG. 1 is a plan view showing the pump body with the cover part removed from the oil pump device of the present embodiment. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a plan view showing the pump body with the inner rotor and the outer rotor removed. FIG. 4 is a plan view of the inner surface of the cover portion in the oil pump device of the present embodiment. FIG. 5 is a graph showing the relationship between engine speed and oil pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oil pump apparatus 3 Inner rotor 5 Outer rotor 7 Housing 11 Pump main body 13 Cover part 25 Drive shaft 27 External tooth 29 Internal tooth 35 Pump chamber 35a Maximum capacity pump chamber 41 Suction port 43 Suction channel 45 Ejection port 47 Recirculation channel 49 Control valve 51 1st return path 53 2nd return path 55 3rd return path 61 1st axis flow path 63 2nd axis flow path 65 3rd axis flow path 71 Compression spring 73 Valve body

Claims (2)

An inner rotor integrally provided on a drive shaft rotated by an engine whose rotational speed changes and having external teeth, an outer rotor having internal teeth that mesh with the external teeth, and a housing that houses the inner rotor and the outer rotor An oil pump device configured to pump oil in a pump chamber formed by the outer teeth and inner teeth to the engine by rotation of the inner rotor and outer rotor,
A recess formed on the inner surface of the housing on one axial end side of the drive shaft, and a recess formed on the inner surface of the housing on the other axial end side of the drive shaft; A third reflux path communicating with the suction port formed in the housing and a first reflux path formed inside the drive shaft, the upstream end communicating with the first reflux path, and the downstream end communicating with the third reflux path. 2 reflux paths,
The second reflux path has a first shaft flow path that communicates with the first reflux path at an upstream end and extends substantially to the center of the shaft across the drive shaft, and an upstream end downstream of the first shaft flow path. A second shaft channel extending to the other end side in the axial direction, an upstream end communicating with the second shaft channel, a downstream end crossing the drive shaft and the downstream end A third axial flow path communicating with the third reflux path,
When the oil pressure in the pump chamber reaches a set value or higher, the oil pressure opens the second shaft passage of the second return passage, and returns a part of the oil in the pump chamber to the suction port side. An oil pump device characterized in that a valve is disposed in the second shaft flow path. The oil pump device according to claim 1,
The first reflux path is configured to communicate with a pump chamber having a maximum volume among the pump chambers,
The oil pump device, wherein the control valve opens the second shaft passage when the oil pressure in the pump chamber having the maximum volume reaches a set value or more.

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