JP5562170B2 - Internal gear type oil pump for vehicles - Google Patents

Description

  The present invention relates to a vehicular internal gear type oil pump having two discharge oil passages, and particularly to a technique for reducing pump driving torque.

  Around an eccentric shaft center that has an outer peripheral tooth and is eccentric from the single shaft center with a drive gear provided rotatably around a single shaft center and an inner peripheral tooth meshed with the outer peripheral tooth of the drive gear An annular driven gear rotatably provided and driven to rotate by the drive gear, a pump chamber in which the driven gear and the drive gear are accommodated, and a side surface of the pump chamber for discharging oil from the pump chamber And a plurality of hydraulic chambers formed in the circumferential direction by meshing gaps between the inner peripheral teeth and the outer peripheral teeth as the drive gear and the driven gear rotate. When the hydraulic chamber is moved in a predetermined rotational direction, the first discharge on the front side in the rotational direction is sequentially communicated with the hydraulic chamber in the process of reducing the volume of the hydraulic chamber. A housing having an oil passage and the second discharge passage of the rotation direction rear side, the vehicular internal gear type oil pump with are known. For example, those described in Patent Documents 1 to 5.

  In the oil pump as described above, in the hydraulic circuit provided on the discharge side, the consumption amount of the relatively high hydraulic fluid is one of the first discharge oil passage and the second discharge oil passage. When the amount of discharge from the other discharge oil passage is sufficient, the hydraulic oil in the other discharge oil passage is maintained at a low hydraulic pressure that is a predetermined pressure lower than the hydraulic oil in the one discharge oil passage. Used for. According to this, the hydraulic oil in the other discharge oil passage is maintained at the low hydraulic pressure, whereby the pump driving torque is reduced and the vehicle fuel efficiency is improved.

  Further, the oil pump disclosed in Patent Document 5 is configured so that the predetermined hydraulic chamber is positioned between the first discharge oil passage and the second discharge oil passage and is not in direct communication with the discharge oil passage. In order to communicate a predetermined hydraulic chamber and the other discharge oil passage, a pair of oil relief grooves formed on the side surface of the pump chamber is provided. These oil relief grooves comprise a pair of circumferential grooves respectively extending from a part of the opening edge of the other discharge oil passage formed on the side surface of the pump chamber to the one discharge oil passage. According to this, when the predetermined hydraulic chamber passes through the closed position between the first discharge oil passage and the second discharge oil passage, the hydraulic oil in the predetermined hydraulic chamber to be boosted is Since the oil is released to the other discharge oil passage through the escape groove, the pressure value of the hydraulic oil in the predetermined hydraulic chamber in the closed state is suppressed from increasing rapidly, and the pump driving torque is caused by the hydraulic pressure sudden increase. Can be prevented from increasing.

JP 2001-123967 A Japanese Utility Model Publication No. 7-42442 Japanese Patent Laid-Open No. 5-240166 JP-A-1-96485 JP 2009-127469 A

  By the way, in the conventional vehicle internal gear type oil pump having the oil relief groove, the hydraulic oil in the other discharge oil passage is maintained at a low hydraulic pressure that is a predetermined pressure lower than the hydraulic oil in the one discharge oil passage. If the oil relief groove is set longer due to eccentricity and deformation of the driven gear and the drive gear and processing variations of the oil relief groove, the predetermined hydraulic chamber is connected to the first discharge oil passage and the second discharge oil passage. When the predetermined hydraulic chamber is in direct communication with the one discharge oil passage, the predetermined hydraulic chamber and the other discharge oil passage pass through an oil relief groove. Communicated. Then, the hydraulic oil in the one discharge oil passage flows out to the other discharge oil passage through a predetermined hydraulic chamber and oil relief groove, and the volumetric efficiency on the one discharge oil passage side, that is, the high pressure discharge side is lowered. Therefore, in order to suppress the decrease in the volumetric efficiency, it is required by design not to set the oil relief groove longer than necessary on the one discharge oil passage side.

  On the other hand, the driven gear and the drive gear are provided with a small gap in the radial direction with respect to the pump chamber or the drive shaft, and are closed by eccentricity or deformation during rotation. When the predetermined hydraulic chamber located in the retracted position moves relatively to the side away from the oil relief groove, the oil relief groove is blocked by the driven gear or the drive gear when the predetermined hydraulic chamber is located in the closed position. There is. In addition, there is a possibility that the processing reference position for processing the oil release groove may vary for each oil release groove, and as a result, the oil release groove is shortened to the side away from the predetermined hydraulic chamber located at the closed position. Then, when the predetermined hydraulic chamber is located at the closed position, the oil drain groove that has been shortened may be blocked by the driven gear or the drive gear. Therefore, when the hydraulic chamber passes through the closed position between the first discharge oil passage and the second discharge oil passage, the hydraulic oil in the hydraulic chamber is not released to the other discharge oil passage through the oil release groove. In some cases, there has been a problem that the pump driving torque increases due to a sudden increase in the pressure value of the hydraulic oil in the hydraulic chamber that is closed in that case.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicle internal gear that can reduce pump drive torque while suppressing a decrease in volumetric efficiency on the high-pressure discharge side. Is to provide a mold oil pump.

  The gist of the invention according to claim 1 for achieving the above object is as follows: (a-1) a drive gear having outer peripheral teeth and rotatably provided around one axis; ) An annular driven gear that has an inner peripheral tooth meshed with an outer peripheral tooth of the drive gear and is rotatably provided around an eccentric shaft center that is eccentric from the single shaft center, and is driven to rotate by the drive gear; (a-3) a pump chamber in which the driven gear and the drive gear are housed, and (a-4) a predetermined circumferential interval on the side of the pump chamber in order to discharge oil from the pump chamber. When a plurality of hydraulic chambers that are respectively opened and formed in the circumferential direction by the meshing gaps between the inner peripheral teeth and the outer peripheral teeth are moved in a predetermined rotational direction as the drive gear and the driven gear rotate. The oil A vehicle interior having a housing having a first discharge oil passage on the rear side in the rotation direction and a second discharge oil passage on the front side in the rotation direction, which are sequentially communicated with the hydraulic chamber in the process of reducing the volume of the chamber. (B) a predetermined hydraulic chamber of the plurality of hydraulic chambers is positioned between the opening of the first discharge oil passage and the opening of the second discharge oil passage; and (B-1) A first discharge formed on a side surface of the pump chamber in order to connect the predetermined hydraulic chamber and the first discharge oil passage when not in direct communication with the discharge oil passage. A first oil relief oil passage extending in a circumferential direction from a part of an opening edge of the oil passage toward the second discharge oil passage on the front side in the rotation direction; and (b-2) the predetermined hydraulic chamber. And an opening edge of the second discharge oil passage formed on the side surface of the pump chamber to communicate the second discharge oil passage with the second discharge oil passage And a second oil relief oil passage from a portion extending in the said direction of rotation of the first circumferential direction toward the discharge passage of the rear side is to contain.

  The gist of the invention according to claim 2 is that, in the invention according to claim 1, (a) the first oil relief oil path is the inner circumference of the opening edge of the first discharge oil path. (B) the second oil relief oil, comprising an outer circumferential groove extending in a circumferential direction from a portion radially outward from a locus of the closest contact between the tooth and the outer peripheral tooth to the front side in the rotational direction. The path extends in a circumferential direction from a part radially inward of a locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the second discharge oil path to the rear side in the rotational direction. In the inner circumferential groove.

  A gist of the invention according to claim 3 is that, in the invention according to claim 1, (a) the first oil relief oil path is the inner circumference of the opening edge of the first discharge oil path. An inner circumferential groove extending in a circumferential direction from a portion radially inward of a locus of closest contact between the tooth and the outer peripheral tooth to the front side in the rotational direction, and (b) the second oil relief oil The path extends in the circumferential direction from a part radially outside the locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the second discharge oil path to the rear side in the rotational direction. In the outer circumferential groove.

  A gist of the invention according to claim 4 is that, in the invention according to claim 1, (a) the first oil release oil passage is formed on one side surface of the pump chamber. Out of the opening edge of the oil passage, from the part of the radially outer side and the part of the radially inner side from the locus of the closest point between the inner peripheral tooth and the outer peripheral tooth, respectively, in the circumferential direction toward the front side in the rotational direction. (B) the second oil relief oil passage is formed of an opening edge of the second discharge oil passage formed on the other side surface of the pump chamber. The outer circumferential direction extending in the circumferential direction from the part of the radially outer side and the part of the radially inner side than the locus of the closest contact between the inner peripheral tooth and the outer peripheral tooth to the rear side in the rotational direction, respectively. Consisting of grooves and inner circumferential grooves

  Further, the gist of the invention according to claim 5 is that, in the invention according to any one of claims 1 to 3, the first oil relief oil passage and the second oil relief oil passage have a common processing position. Each groove is machined using a reference.

  According to the vehicle internal gear type oil pump of the first aspect of the present invention, the predetermined hydraulic chamber of the plurality of hydraulic chambers is between the opening of the first discharge oil passage and the opening of the second discharge oil passage. A first discharge oil formed on a side surface of the pump chamber to communicate the predetermined hydraulic chamber and the first discharge oil passage when positioned and not in direct communication with the discharge oil passage A first oil relief oil passage extending in a circumferential direction from a part of an opening edge of the passage toward a second discharge oil passage on a front side in a predetermined rotation direction; the predetermined hydraulic chamber; and the second discharge oil. In order to communicate with the passage, it extends in the circumferential direction from a part of the opening edge of the second discharge oil passage formed on the side surface of the pump chamber toward the first discharge oil passage on the rear side in the rotation direction. Since the second oil relief oil passage is included, the driven gear and the drive gear are eccentric or deformed during rotation. Thus, even if the predetermined hydraulic chamber located at the closed position moves to the side away from one of the oil release oil passages, the predetermined hydraulic chamber moves to the side closer to the other oil release oil passage. When the one oil relief oil passage is blocked by the driven gear or the drive gear, the predetermined hydraulic chamber is discharged from the discharge oil passage without being closed by the other oil relief oil passage. Communicated with. Also, the processing reference position for processing each oil release oil passage varies for each oil release groove, and as a result, one of the oil release oil passages moves away from a predetermined hydraulic chamber located at the closed position. Even if it is processed to be short, the other oil relief oil passage provided facing the one oil relief oil passage in the circumferential direction is not processed to the side away from the predetermined hydraulic chamber located in the closed position. Therefore, when the predetermined hydraulic chamber is located at the closed position, even if one of the oil relief oil passages that has been shortened is blocked by the driven gear or the drive gear, the other oil relief oil passage is blocked. Instead, the predetermined hydraulic chamber communicates with the discharge oil passage. Therefore, it is a case where each oil relief oil passage is set as short as possible while it is required not to set the oil escape oil passage longer than necessary in order to suppress a decrease in volumetric efficiency on the high pressure discharge side, Even when the driven gear and the drive gear are decentered or deformed during rotation, or when variations occur in the processing of the oil relief oil passages, the predetermined hydraulic chambers are provided with the first discharge oil passage and the second discharge oil passage. When passing through the closed position between the two, the hydraulic oil in the predetermined hydraulic chamber is released to the discharge oil passage through at least one of the plurality of oil release oil passages. A sudden increase in the pressure value of the hydraulic oil in the hydraulic chamber can be suppressed, and an increase in pump drive torque due to an increase in the hydraulic pressure in the hydraulic chamber can be suppressed. That is, the pump driving torque can be reduced while suppressing a decrease in volumetric efficiency on the high pressure discharge side. Even if the oil relief groove is set longer due to eccentricity or deformation of the driven gear and drive gear, or due to variations in processing of the oil relief groove, the predetermined hydraulic chamber located at the closed position can communicate directly with the discharge oil passage. In addition, since the communication is made through the oil relief groove having a sufficiently small flow cross-sectional area as compared with the discharge oil passage, there is little influence on the volumetric efficiency reduction.

  According to the vehicle internal gear type oil pump of the invention according to claim 2, the first oil relief oil passage includes the inner peripheral tooth and the outer peripheral tooth of the opening edge of the first discharge oil passage. The outer circumferential groove extending in the circumferential direction from a portion radially outward from the locus of the closest contact point to the front side in the rotational direction, and the second oil relief oil passage includes the second discharge oil It comprises an inner circumferential groove extending in the circumferential direction from a part radially inward from a locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the road. Therefore, the circumference of the first oil relief oil passage is shorter than that in the case where the first oil relief oil passage is formed on the radially inner side of the locus of the nearest contact point, and the second oil relief oil passage is connected to the latest oil passage. Since the circumference of the second oil relief oil passage is shorter than the case where it is formed on the radially outer side of the contact locus, Life of the relief processing tools used in the conjunction with the processing time for forming the oil passage is reduced becomes longer.

  According to the vehicle internal gear type oil pump of the invention according to claim 3, the first oil relief oil passage includes the inner peripheral tooth and the outer peripheral tooth of the opening edge of the first discharge oil passage. The inner circumferential direction groove extending in the circumferential direction from a part radially inward of the locus of the closest contact point to the front side in the rotational direction, and the second oil relief oil path is the second discharged oil It comprises an outer circumferential groove extending in a circumferential direction from a part radially outside the locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the road to the rear side in the rotational direction. Therefore, even when the driven gear and the drive gear are decentered or deformed during rotation, or when the processing of each oil relief oil passage varies, the hydraulic oil in the predetermined hydraulic chamber located at the closed position remains inside. Through at least one of the circumferential groove and the outer circumferential groove Since the oil is released to the discharge oil passage, the pressure value of the hydraulic oil in the predetermined hydraulic chamber that is closed is prevented from rapidly increasing, and the pump driving torque increases due to the increase in the hydraulic pressure in the hydraulic chamber. This can be suppressed.

  According to the vehicle internal gear type oil pump of the invention according to claim 4, the first oil relief oil passage is an opening edge of the first discharge oil passage formed on one side surface of the pump chamber. Outwardly extending from the part of the radially outer side and the part of the radially inner side with respect to the locus of the closest contact between the inner peripheral tooth and the outer peripheral tooth, respectively, to the front side in the rotational direction. The second oil escaping oil passage is composed of a circumferential groove and an inner circumferential groove, and the inner peripheral tooth and the outer periphery of the opening edge of the second discharge oil passage formed on the other side surface of the pump chamber. An outer circumferential groove and an inner circumferential groove extending in a circumferential direction from a part radially outside and a part radially inward of a locus of the closest contact with the tooth to the rear side in the rotational direction, respectively. Therefore, the two circumferential grooves formed on one side face are opened on the side face. Since the processing for a single discharge oil passage which is is formed is subjected, there is an advantage that the processing time of the oil relief oil passage is relatively short. Moreover, there is an advantage that there is robustness against the eccentricity and deformation of the driven gear and the drive gear. Incidentally, for example, one first oil relief oil passage and one second oil relief oil passage are formed on one side surface of the pump chamber, and the first oil relief oil passage and second oil relief oil are formed on the other side surface of the pump chamber. In the case of forming a path one by one, the two circumferential grooves formed on one side face must be formed by processing each of the two discharge oil paths opened on the side face, There is a drawback that the processing time of each oil relief groove is relatively long.

  According to the vehicle internal gear type oil pump of the invention according to claim 5, the first oil relief oil passage and the second oil relief oil passage are each grooved using a common machining position reference. Therefore, even if the processing reference position varies from individual to individual, the circumferential interval between the tips of the first oil relief oil passage and the second oil relief oil passage is kept substantially constant, which is caused by the variation. Thus, even if one of the oil release oil passages is shortened to the side away from the predetermined hydraulic chamber located at the closed position, the other oil release oil passage is processed longer to the side approaching the predetermined hydraulic chamber. The Therefore, it is a case where each oil relief oil passage is set as short as possible while it is required not to set the oil relief oil passage longer than necessary in order to suppress the decrease in volumetric efficiency on the high pressure discharge side. Even when the processing position reference of each oil relief oil passage varies from individual to individual, when the hydraulic chamber passes through the confined position between the first discharge oil passage and the second discharge oil passage. The hydraulic oil in the hydraulic chamber is surely released to the discharge oil passage through at least one of the plurality of oil escape oil passages. Therefore, even if one oil relief groove is machined longer due to processing variations in the oil relief groove, the other oil relief groove is shortened, and the tip interval between the one and other oil relief grooves is maintained with high accuracy. An increase in pump driving torque and a decrease in volumetric efficiency of the high-pressure discharge oil passage due to the variation in the groove processing are further suppressed.

It is sectional drawing which shows the internal gear type oil pump for vehicles of one Example of this invention. It is sectional drawing which shows the II-II arrow part cross section of FIG. It is sectional drawing which shows the III-III arrow part cross section of FIG. It is a figure which shows the relationship between the rotation angle around the axial center of a hydraulic chamber, and the volume of the hydraulic chamber. It is a figure which shows only the pump body of FIG. 2, Comprising: It is a figure for demonstrating the process of each circumferential groove | channel. It is a figure which shows typically an example of a structure of the hydraulic control circuit to which hydraulic pressure is supplied from each discharge oil path of an oil pump. It is a figure which shows the relationship between the rotational speed of a drive gear, the hydraulic pressure value of each discharge oil path, and discharge amount. FIG. 3 is an enlarged view showing a portion corresponding to a portion indicated by an arrow A in FIG. 2, wherein the first inner circumferential groove is shortened by about 1 degree in a circumferential direction away from a predetermined hydraulic chamber located at a closed position. It is a figure which shows the case where it forms. It is a figure which expands and shows the part corresponded to the A arrow view part of FIG. 2, Comprising: It is a figure which shows the case where the drive gear and the driven gear are decentered upwards during rotation. It is sectional drawing of the oil pump of the other Example of this invention, Comprising: It is a figure corresponded in FIG. It is sectional drawing of the oil pump of the other Example of this invention, Comprising: It is a figure equivalent to FIG. It is a figure which shows only the pump cover of FIG. 11, Comprising: It is a figure for demonstrating the process of each circumferential groove | channel. It is a figure which expands and shows the part corresponded to the B arrow view part of FIG. 10, Comprising: Each circumferential direction groove | channel of a 2nd oil relief oil path is the circumferential direction which leaves | separates from the predetermined | prescribed hydraulic chamber located in the closed position It is a figure which shows the case where it forms short about 1 degree. It is a figure which expands and shows the part corresponded to the C arrow view part of FIG. 11, Comprising: Each circumferential groove | channel of a 2nd oil relief oil path is the circumferential direction away from the predetermined | prescribed hydraulic chamber located in the closed position It is a figure which shows the case where it forms short about 1 degree. It is a figure which expands and shows the part corresponded to the B arrow part of FIG. 10, Comprising: It is a figure which shows the case where a drive gear and a driven gear are decentered upwards during rotation. It is a figure which expands and shows the part corresponded to the C arrow part of FIG. 11, Comprising: It is a figure which shows the case where a drive gear and a driven gear are decentered upwards during rotation. It is sectional drawing of the conventional oil pump, Comprising: It is a figure corresponded in FIG. It is a figure which shows only the pump body of FIG. 17, Comprising: It is a figure for demonstrating the process of each circumferential groove | channel. It is a figure which expands and shows the part corresponded to the arrow D part of FIG. 17, Comprising: The circumferential direction which each circumferential direction groove | channel of a 1st low pressure discharge oil path moves away from the predetermined | prescribed hydraulic chamber located in the closed position It is a figure which shows the case where it forms short about 1 degree. It is a figure which expands and shows the part corresponded to the arrow D part of FIG. 17, Comprising: It is a figure which shows the case where a drive gear and a driven gear are decentered upwards during rotation.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a cross-sectional view showing a vehicular internal gear type oil pump (hereinafter referred to as an oil pump) 10 according to an embodiment of the present invention. An oil pump 10 shown in FIG. 1 includes, for example, a well-known torque converter, and is included in an automatic transmission that is suitably used for an FF (front engine / front drive) type vehicle. Specifically, it is provided between a transaxle housing 12 that mainly accommodates the torque converter and the like, and a transaxle case 14 that mainly accommodates a transmission mechanism and the like.

  2 is a cross-sectional view showing a cross section taken along the line II-II in FIG. 1, and FIG. 3 is a cross-sectional view showing a cross section taken along the line III-III in FIG. As shown in FIG. 1, the oil pump 10 includes a housing 18 fixed to the transaxle housing 12 with a plurality of bolts 16, and a plurality of oil pumps 10 (9 in this embodiment) as shown in FIGS. As shown in FIG. 1, the tip of a cylindrical pump shaft 22 that protrudes from the inner peripheral end of the pump impeller of the torque converter in the direction of the axial center (uniaxial center) C1. The drive gear 24 that is engaged with a plurality of (two in this embodiment) claw portions 22 a and is rotatable about the axis C 1 together with the pump shaft 22 and the outer peripheral teeth 20. A plurality of (10 in this embodiment) inner peripheral teeth 26 engaged with each other are housed in the housing 18 so as to be rotatable around an eccentric shaft center C2 eccentric from the shaft center C1. Rotated circle And Jo of the driven gear 28, is of the so-called internal gear where provided. The driven gear 28 is provided with a small gap in the radial direction with respect to the inner peripheral surface of the gear housing portion of the housing 18, and the drive gear 24 is provided with respect to the outer peripheral surface of the pump shaft 22. Although it is very small, it is provided with a predetermined gap in the radial direction.

  As shown in FIG. 2, the drive gear 24 and the driven gear 28 have the outer peripheral teeth 20 and the inner peripheral teeth 26 meshed with each other below. The drive gear 24 is rotationally driven by the pump shaft 22 in a predetermined rotation direction indicated by an arrow a in FIG. 2 around the axis C1, and the driven gear 28 is driven by the drive gear 24 in FIG. 2 around the eccentric axis C2. It is driven to rotate in a predetermined rotation direction indicated by an arrow a.

As shown in FIG. 2, a plurality of (9 in this embodiment) hydraulic chambers 30 formed in the circumferential direction by the meshing gaps between the outer peripheral teeth 20 and the inner peripheral teeth 26 are used to rotate the drive gear 24 and the driven gear 28. Accordingly, the volume V [cm ³ ] is moved in the rotation direction while being changed. FIG. 4 is a diagram showing the relationship between the rotation angle θ [degree] around the axis C1 of the hydraulic chamber 30 and the volume V of the hydraulic chamber 30. As shown in FIG. In FIG. 4, 0 ° (360 °) of the rotation angle θ of the hydraulic chamber 30 shown on the horizontal axis represents a circumferential position where the outer peripheral teeth 20 and the inner peripheral teeth 26 are located below in FIG. As shown in FIG. 4, the hydraulic chamber volume V is increased as the hydraulic chamber 30 is moved in the rotational direction from the circumferential position where the rotational angle θ = 0 °, and the hydraulic chamber 30 has a rotational angle θ = 180 °. It is made the maximum when it is located at the circumferential position. The hydraulic chamber volume V is decreased as the hydraulic chamber 30 is moved in the rotational direction from the circumferential position at the rotational angle θ = 180 °, and the hydraulic chamber 30 is moved to the circumferential position at the rotational angle θ = 360 °. Minimized when positioned.

  As shown in FIG. 1, the housing 18 includes a pump cover 32 fastened by a plurality of bolts 16 while being fitted to a cylindrical inner peripheral surface of the transaxle case 14, and a transaxle of the pump cover 32. The pump body 36 is fastened by a plurality of bolts 34 while being disposed adjacent to the housing 12 side. On the inner peripheral surface of the pump cover 32, the other end portion of a cylindrical stator shaft 38 whose one end portion is connected to a stator impeller of the torque converter (not shown) is integrally fitted.

  The housing 18 includes a space on the inner peripheral side of a bottomed cylindrical hole formed on the wall surface of the pump body 36 on the pump cover 32 side, and a pump chamber 40 in which the driven gear 28 and the drive gear 24 are accommodated, and In order to suck oil into the pump chamber 40, a first suction oil passage 46 and a second suction oil passage 48 opened on the side surface 42 on the pump body 36 side and the side surface 44 on the pump cover 32 side of the pump chamber 40, respectively. As shown in FIG. 2, in order to discharge oil from the pump chamber 40, the first high-pressure discharge oil passage 50 and the first high-pressure discharge oil passage 50 opened to the side surface 42 of the pump chamber 40 at predetermined intervals in the circumferential direction, respectively. As shown in FIG. 3, the low pressure discharge oil passage 52 and the side surface 44 of the pump chamber 40 are opened at predetermined intervals in the circumferential direction in order to discharge oil from the pump chamber 40. And a second high pressure discharge passage 54 and the second low-pressure discharge passage 56 includes. In FIG. 2 and FIG. 3, the opening edges of these oil passages are indicated by broken lines. The first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 of the present embodiment correspond to the first discharge oil passage in the present invention, and the first low-pressure discharge oil passage 52 and the second high-pressure discharge oil passage 52 of the present embodiment. The second low pressure discharge oil passage 56 corresponds to the second discharge oil passage in the present invention.

  The first suction oil passage 46 and the second suction oil passage 48 have a circumferential range in which the volume V of the hydraulic chamber 30 increases as the hydraulic chamber 30 is moved in the rotational direction, that is, as shown in FIG. Of the suction section where the rotation angle θ of the hydraulic chamber 30 is 0 ° to 180 °, the pump chamber 40 is opened in a predetermined suction section where the rotation angle θ is 12 ° to 178 °, for example. As a result, when the hydraulic chamber 30 is moved in the rotation direction as the drive gear 24 and the driven gear 28 rotate, the hydraulic chamber 30 is moved to the first intake oil passage in the process of increasing the volume V of the hydraulic chamber 30. 46 and the second intake oil passage 48 are communicated with each other.

  The first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 are shown in FIG. 4 as a circumferential range in which the volume V of the hydraulic chamber 30 decreases as the hydraulic chamber 30 is moved in the rotational direction. As described above, among the discharge sections in which the rotation angle θ of the hydraulic chamber 30 is 180 ° to 360 °, for example, the first discharge section in which the rotation angle θ is 212 ° to 250 ° is opened in the pump chamber 40. As a result, when the hydraulic chamber 30 is moved in the rotation direction as the drive gear 24 and the driven gear 28 rotate, the hydraulic chamber 30 becomes the first high pressure in the first half of the process in which the volume V of the hydraulic chamber 30 is reduced. The discharge oil passage 50 and the second high-pressure discharge oil passage 54 are communicated with each other.

  The first low-pressure discharge oil passage 52 and the second low-pressure discharge oil passage 56 are shown in FIG. 4 as a circumferential range in which the volume V of the hydraulic chamber 30 decreases as the hydraulic chamber 30 is moved in the rotational direction. Thus, among the discharge sections where the rotation angle θ of the hydraulic chamber 30 is 180 ° to 360 °, for example, the second discharge section whose rotation angle θ is 289 ° to 351 ° is opened to the pump chamber 40. As a result, when the hydraulic chamber 30 is moved in the rotational direction as the drive gear 24 and the driven gear 28 rotate, the hydraulic chamber 30 is moved to the first low pressure in the latter half of the process in which the volume V of the hydraulic chamber 30 is reduced. The discharge oil passage 52 and the second low-pressure discharge oil passage 56 are communicated with each other.

  As shown in FIGS. 2 and 3, the first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 are rearward in the rotational direction with respect to the first low-pressure discharge oil passage 52 and the second low-pressure discharge oil passage 56. On the side. Therefore, when the hydraulic chamber 30 is moved in the rotation direction as the drive gear 24 and the driven gear 28 rotate, the hydraulic chamber 30 sequentially moves to the first high-pressure discharge oil passage 50 and the first low-pressure discharge oil passage 52. In addition to being communicated, the second high-pressure discharge oil passage 54 and the second low-pressure discharge oil passage 56 are sequentially communicated. Here, each discharge oil passage has a high pressure with respect to the hydraulic chamber 30 directly connected to the low pressure discharge oil passage when the hydraulic chamber 30 passes between the high pressure discharge oil passage and the low pressure discharge oil passage. The discharge oil passage is directly communicated so that the hydraulic oil in the high pressure discharge oil passage does not leak into the low pressure discharge oil passage and the volume efficiency on the high pressure discharge side is not lowered. Specifically, the first high-pressure discharge oil passage 50 and the first low-pressure discharge oil passage 52 communicate with each other when the hydraulic chamber 30 is moved in the rotation direction. The hydraulic chamber 30 and the first low pressure discharge oil passage 52 are communicated with each other through the state in which the hydraulic chamber 30 and the first high pressure discharge oil passage 50 and the first low pressure discharge oil passage 52 are blocked. It is provided so that it may be made to the state made to. The same applies to the second high-pressure discharge oil passage 54 and the second low-pressure discharge oil passage 56.

  As shown in FIGS. 2 and 3, the housing 18 includes a predetermined hydraulic chamber 30 a of the plurality of hydraulic chambers 30 that has an opening edge of the first high-pressure discharge oil passage 50 and an opening of the first low-pressure discharge oil passage 52. And is located between the opening edge of the second high-pressure discharge oil passage 54 and the opening edge of the second low-pressure discharge oil passage 56 and communicates directly with these discharge oil passages. In order to allow the predetermined hydraulic chamber 30a to communicate with the first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 respectively, the first hydraulic pressure chamber 30a and the second high-pressure discharge oil passage 54 are respectively formed on the side surface 42 and the side surface 44 of the pump chamber 40. In order to connect the one oil relief oil passage 58, the predetermined hydraulic chamber 30a, the first low pressure discharge oil passage 52, and the second low pressure discharge oil passage 56, respectively, they are formed on the side surface 42 and the side surface 44 of the pump chamber 40, respectively. Second oil relief And a road 60. The predetermined hydraulic chamber 30a includes a first wall surface 62 (see FIG. 2) between the opening edge of the first high-pressure discharge oil passage 50 and the opening edge of the first low-pressure discharge oil passage 52 among the plurality of hydraulic chambers 30. And a second wall surface 64 (see FIG. 3) between the opening edge of the second high-pressure discharge oil passage 54 and the opening edge of the second low-pressure discharge oil passage 56, and is oiltight from the direction of the axis C1. It refers to the one at the moment.

  As shown in FIG. 2, the first oil relief oil passage 58 is more radial than the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 of the opening edge of the first high-pressure discharge oil passage 50. A first outer circumferential groove 66 extending in the circumferential direction from a part of the outer side toward the first low pressure discharge oil passage 52 on the front side in the rotational direction, and a second high pressure discharge as shown in FIG. From a part of the opening edge of the oil passage 54 radially outside the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 to the second low pressure discharge oil passage 56 on the front side in the rotational direction. And a second outer circumferential groove 68 extending in the circumferential direction. The first outer circumferential groove 66 and the second outer circumferential groove 68 are a predetermined hydraulic chamber 30a located at a closed position between the high pressure discharge oil passages 50, 54 and the low pressure discharge oil passages 52, 56. The length in the circumferential direction is set to such an extent that the tip portion communicates with each other, and is set sufficiently shallower than each discharge oil passage.

  As shown in FIGS. 2 and 3, from each high pressure discharge oil passage (first high pressure discharge oil passage 50 and second high pressure discharge oil passage 54), each high pressure discharge oil passage and each low pressure discharge oil passage (first low pressure discharge passage). The circumferential length to the predetermined hydraulic chamber 30a located between the discharge oil passage 52 and the second low-pressure discharge oil passage 56) is more radial than the locus K of the closest point X in the radial direction. The outside is shorter. Therefore, the first oil relief oil passage 58 for communicating the predetermined hydraulic chamber 30a positioned at the closed position between each high pressure discharge oil passage and each low pressure discharge oil passage and the high pressure discharge oil passage, In the case of the first outer circumferential groove 66 and the second outer circumferential groove 68 that are radially outward from the locus K of the closest point X as in the present embodiment, the diameter is larger than the locus K of the nearest point X. The circumferential length of the groove is shortened compared to a case where the circumferential groove is formed on the inner side in the direction.

  As shown in FIG. 2, the second oil relief oil passage 60 is more radial than the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 of the opening edge of the first low-pressure discharge oil passage 52. A first inner circumferential groove 70 extending in the circumferential direction from a part of the inner side toward the first high pressure discharge oil passage 50 on the rear side in the rotational direction, and a second low pressure discharge as shown in FIG. From a portion of the opening edge of the oil passage 56 radially inward of the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 to the second high-pressure discharge oil passage 54 on the rear side in the rotational direction. And a second inner circumferential groove 72 extending in the circumferential direction. The first inner circumferential groove 70 and the second inner circumferential groove 72 are advanced to a predetermined hydraulic chamber 30a located at a closed position between the high pressure discharge oil passages 50, 54 and the low pressure discharge oil passages 52, 56. The circumferential length is set to such an extent that the parts communicate with each other, and is set sufficiently shallow compared to each discharge oil passage.

  As shown in FIGS. 2 and 3, the circumferential length from each low pressure discharge oil passage to a predetermined hydraulic chamber 30a located between each low pressure discharge oil passage and each high pressure discharge oil passage is: The inner radius is shorter than the outer radius K of the closest contact X. Therefore, the second oil relief oil passage 60 for communicating the predetermined hydraulic chamber 30a positioned at the closed position between each high pressure discharge oil passage and each low pressure discharge oil passage and the low pressure discharge oil passage, In the case of the first inner circumferential groove 70 and the second inner circumferential groove 72 radially inward of the locus K of the closest point X as in this embodiment, the diameter is larger than the locus K of the nearest point X. The circumferential length of the groove is shortened as compared with the case where the circumferential groove is formed on the outer side in the direction.

  Both the first outer circumferential groove 66 and the first inner circumferential groove 70 are formed on the side surface 42 of the pump chamber 40 while facing each other in the circumferential direction. Further, the second outer circumferential groove 68 and the second inner circumferential groove 72 are both formed on the side surface 44 of the pump chamber 40 while facing each other in the circumferential direction.

  Next, processing of each circumferential groove will be described. In the following, the processing of the first outer circumferential groove 66 and the first inner circumferential groove 70 will be described on behalf of the outer circumferential groove and the inner circumferential groove. FIG. 5 is a view showing only the pump body 36 viewed from the direction of arrows II-II in FIG. In FIG. 5, the first outer circumferential groove 66 and the first inner circumferential groove 70 are, for example, side edges 74 on the rear side in the rotational direction indicated by the arrow a among the opening edges of the first low-pressure discharge oil passage 52. Is used as a common processing position reference, that is, a workpiece fixing (chuck) position reference, and is formed by grooving with a machine tool such as a milling machine using a cutting tool such as an end mill. Here, since the first outer circumferential groove 66 and the first inner circumferential groove 70 are machined using the common machining position reference as described above, for example, the first low pressure discharge oil passage 52 side. Even if the circumferential position of the edge 74 varies in the circumferential direction for each individual or processing variation occurs, the circumferential interval L [mm] between the tips of the circumferential grooves is kept substantially constant.

  FIG. 6 is a diagram schematically illustrating an example of a hydraulic control circuit 76 provided on the downstream side of each discharge oil passage of the oil pump 10. In FIG. 6, a first suction oil passage 46 and a second suction oil passage 48 of the oil pump 10 are connected to each other, for example, via a first oil passage 78 and a strainer 80 formed in the transaxle case 14 or the like. The oil storage space in the oil pan 82 is fixed to the lower part of the transaxle case 14. The first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 of the oil pump 10 are connected to each other and, for example, via a second oil passage 84 formed in the transaxle case 14 or the like, a hydraulic control circuit. For example, a plurality of hydraulic friction engagement devices provided in a transmission mechanism of the automatic transmission are connected to a first input port 88 of a well-known relief-type regulator 86 provided in 76. It is connected to a valve device 90 including a shift control valve for controlling and a lockup control valve for controlling a lockup clutch provided in the torque converter. The first low pressure discharge oil passage 52 and the second low pressure discharge oil passage 56 of the oil pump 10 are connected to each other and, for example, a hydraulic control circuit 76 via a third oil passage 92 formed in the transaxle case 14 or the like. Connected to the second input port 94 of the regulator 86.

  The hydraulic oil supplied to the valve device 90 is adjusted in pressure by adjusting the relief amount of the hydraulic oil by the regulator 86. Specifically, the hydraulic oil supplied to the valve device 90 from each high-pressure discharge oil passage has a predetermined rotational speed at which the rotational speed N [rpm] of the drive gear 24 is predetermined as shown in the lower part of FIG. N1 [rpm] or less and the hydraulic pressure value of the hydraulic oil discharged from each high-pressure discharge oil passage, that is, the high-pressure port hydraulic pressure value Pp1 [MPa] is equal to or less than a predetermined high hydraulic pressure value Pphigh [MPa] Is used with its oil pressure value unchanged. The hydraulic oil supplied to the valve device 90 from each high-pressure discharge oil passage is when the rotational speed N exceeds a predetermined rotational speed N1 and the high-pressure port hydraulic pressure value Pp1 tends to exceed the high hydraulic pressure value Pphigh. In this case, the regulator 86 is used by adjusting the pressure to the high hydraulic pressure value Pphigh. 7 shows the discharge amount Q [L / min] of hydraulic oil from each discharge oil passage of the oil pump 10. As shown in FIG. 7, the total discharge amount of hydraulic oil discharged from each high-pressure discharge oil passage, that is, the high-pressure port discharge amount Q 1 [L / min] is proportional to the rotational speed N of the drive gear 24.

  Then, the hydraulic oil supplied from each low pressure discharge oil passage to the third oil passage 92 has a predetermined rotational speed N2 [rpm] where the rotational speed N of the drive gear 24 is predetermined as shown in the lower part of FIG. When the pressure is lower than the second oil pressure, the second input port 94 of the regulator 86 is closed and boosted to become larger than the oil pressure value in the second oil passage 84, and the third oil passage 92 and the second oil The oil is discharged to the second oil passage 84 through a one-way valve 96 provided between the passage 84 and the passage 84. The predetermined rotational speed N2 is such that the required consumption Q ′ [L / min] of the relatively high hydraulic fluid consumed by the valve device 90 is the high-pressure port discharge amount Q1 [L / min] from the high-pressure discharge oil passage. ] Is the minimum rotation speed in the rotation speed range that can be satisfied only with. Further, the hydraulic oil supplied from each low pressure discharge oil passage to the third oil passage 92 has its oil pressure value, that is, the low pressure port oil pressure value Pp2 when the rotational speed N of the drive gear 24 is equal to or higher than a predetermined rotational speed N2. Is maintained at a predetermined low hydraulic pressure value Pplow [MPa] determined in advance by the regulator 86. As shown in the upper part of FIG. 7, the total discharge amount of hydraulic oil discharged from each low pressure discharge oil passage, that is, the low pressure port discharge amount Q2 [L / min] is proportional to the rotational speed N of the drive gear 24. The total discharge amount Q (= Q1 + Q2) [L / min] of hydraulic oil discharged from the discharge oil passages 50 to 56 is proportional to the rotational speed N of the drive gear 24.

  In the oil pump 10 configured as described above, when the drive gear 24 and the driven gear 28 are rotated in the rotational direction, the hydraulic chamber 30 that is moved in the circumferential range in which the capacity V increases is provided in the oil pan 82. The stored oil is sucked through the strainer 80 and the first oil passage 78. Then, pressurized oil is supplied from the hydraulic chamber 30 that is moved in the circumferential range in which the first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 open in the circumferential range in which the capacity V decreases. It is discharged and pumped to the hydraulic control circuit 76 through the second oil passage 84. Then, pressurized oil is supplied from the hydraulic chamber 30 that is moved in the circumferential range in which the first low-pressure discharge oil passage 52 and the second low-pressure discharge oil passage 56 open in the circumferential range in which the capacity V decreases. It is discharged and pumped to the hydraulic control circuit 76 through the third oil passage 92. When the plurality of hydraulic chambers 30 are moved in the rotational direction and pass through the closed position between the high-pressure discharge oil passage and the low-pressure discharge oil passage, as shown in FIGS. When the hydraulic chamber 30a is positioned between the high-pressure discharge oil passage and the low-pressure discharge oil passage, the hydraulic oil in the predetermined hydraulic chamber 30a passes through the circumferential grooves and the high-pressure discharge oil passage and the low-pressure discharge oil. It is designed to escape to at least one of the roads.

  Here, as shown in FIG. 8 which shows an enlarged view corresponding to the portion indicated by the arrow A in FIG. 2, for example, a predetermined hydraulic chamber 30a in which the first inner circumferential groove 70 is positioned at the closed position. When it is formed shorter by about 1 [degree] in the circumferential direction away from the first circumferential groove 70, the first inner circumferential groove 70 is blocked by the drive gear 24. However, even in such a case, the predetermined hydraulic chamber 30a positioned at the closed position is in communication with the first high-pressure discharge oil passage 50 via the first outer circumferential groove 66, and The hydraulic oil in the hydraulic chamber 30 a can be released to the first high-pressure discharge oil passage 50.

  Further, as shown in FIG. 9, which shows an enlarged view of the portion corresponding to the portion indicated by the arrow A in FIG. 2, for example, when the drive gear 24 and the driven gear 28 are decentered upward during rotation, the first inner side The circumferential groove 70 is blocked by the drive gear 24. However, even in such a case, the predetermined hydraulic chamber 30a positioned at the closed position is in communication with the first high-pressure discharge oil passage 50 via the first outer circumferential groove 66, and The hydraulic oil in the hydraulic chamber 30 a can be released to the first high-pressure discharge oil passage 50.

  Incidentally, as shown in FIG. 17, in the conventional oil pump 100, a predetermined hydraulic chamber 30a is positioned between the first high pressure discharge oil passage 50 and the first low pressure discharge oil passage 52, and these discharge oil passages are arranged. When the predetermined hydraulic chamber 30a and the first low-pressure discharge oil passage 52 are communicated with each other when they are not in direct communication with each other, a part on the radially outer side of the opening edge of the first low-pressure discharge oil passage 52 and An outer circumferential groove 102 and an inner circumferential groove 104 are provided respectively extending in the circumferential direction from a part on the radially inner side toward the first high-pressure discharge oil passage 50. As shown in FIG. 18, these oil relief grooves are formed by using the side edge 74 of the opening edge of the first low-pressure discharge oil passage 52 as a processing position reference, and using a cutting tool such as an end mill, for example. It is formed by grooving by a machine. As shown in FIG. 17, the outer circumferential groove 102 and the inner circumferential groove 104 are designed such that the tip ends are slightly communicated with a predetermined hydraulic chamber 30 a located at the closed position.

  Here, as shown in FIG. 19, which shows an enlarged view of the portion corresponding to the portion indicated by the arrow D in FIG. 17, for example, the machining position reference is shifted in the circumferential direction away from the hydraulic chamber 30a positioned at the closed position. In the case where the circumferential grooves 102 and 104 are formed to be shortened by about 1 [degree] in the circumferential direction away from the hydraulic chamber 30a, the circumferential grooves 102 and 104 are blocked by the drive gear 24. It will come off. Therefore, when the hydraulic chamber 30 passes through the closed position between the first high-pressure discharge oil passage 50 and the first low-pressure discharge oil passage 52, the hydraulic oil in the hydraulic chamber 30 to be increased in pressure is discharged into the discharge oil passage. There is a problem that the pump drive torque increases due to a sudden rise in the pressure value of the hydraulic oil in the hydraulic chamber 30 without being escaped.

  Further, as shown in FIG. 20 showing an enlarged portion corresponding to the portion indicated by the arrow D in FIG. 17, for example, when the drive gear 24 and the driven gear 28 are eccentric upward during rotation, the circumferential groove 102 and 104 are blocked by the drive gear 24. Therefore, as in the above case, when the hydraulic chamber 30 passes through the closed position between the first high-pressure discharge oil passage 50 and the first low-pressure discharge oil passage 52, There is a problem that the pump drive torque increases due to the fact that the hydraulic oil is not released to the discharge oil passage and the pressure value of the hydraulic oil in the hydraulic chamber 30 increases rapidly.

  In a conventional oil pump that does not have a circumferential groove (oil relief oil passage) that communicates a predetermined hydraulic chamber 30a positioned at the closed position with the discharge oil passage, the hydraulic chamber 30 is provided with a high-pressure discharge oil passage. 4 and the low-pressure discharge oil passage, the hydraulic chamber 30 is closed, and the hydraulic pressure value P2 in the hydraulic chamber 30 rapidly increases as shown by the broken line in FIG. There was a problem that the driving torque of the pump would increase. On the other hand, in the oil pump 10 of the present embodiment, when the rotation angle θ of the hydraulic chamber 30 is between the first discharge section and the second discharge section, the hydraulic chamber 30 and each discharge oil are mostly used. Since at least one of the paths communicates with at least one of the circumferential grooves, the hydraulic chamber hydraulic pressure value P1 is maintained substantially constant as shown by the solid line in FIG. The first oil relief oil passage 58 and the second oil relief oil passage 60 of the present embodiment are arranged in the hydraulic chamber 30 when the hydraulic chamber 30 is moved between each high pressure discharge oil passage and each low pressure discharge oil passage. It functions as a boost suppression groove that prevents abrupt boosting.

  As described above, in the oil pump 10 of the present embodiment, the predetermined hydraulic chamber 30a among the plurality of hydraulic chambers 30 is the high pressure discharge oil passage (the first high pressure discharge oil passage 50 and the second high pressure discharge oil passage 54). When the predetermined position is set between the opening and the opening of the low pressure discharge oil passage (the first low pressure discharge oil passage 52 and the second low pressure discharge oil passage 56) and is not in direct communication with these discharge oil passages. In order to make the hydraulic chamber 30a communicate with the high-pressure discharge oil passage, the first low-pressure discharge oil on the front side in a predetermined rotational direction from a part of the opening edge of the first high-pressure discharge oil passage 50 on the side surface 42 of the pump chamber 40 A first outer circumferential groove 66 extending in the circumferential direction toward the passage 52 and a part of the opening edge of the second high-pressure discharge oil passage 54 on the side surface 44 of the pump chamber 40 from the front side in the rotational direction. 2 a second outer circumferential groove 68 extending in the circumferential direction toward the low pressure discharge oil passage 56; In order to connect the first oil relief oil passage 58, the predetermined hydraulic chamber 30a and the low pressure discharge oil passage, from a part of the opening edge of the first low pressure discharge oil passage 52 on the side surface 42 of the pump chamber 40. A first inner circumferential groove 70 extending in the circumferential direction toward the first high-pressure discharge oil passage 50 on the rear side in the rotation direction, and an opening edge of the second low-pressure discharge oil passage 56 on the side surface 44 of the pump chamber 40. A second oil relief oil passage 60 including a second inner circumferential groove 72 extending in a circumferential direction from a part of the oil passage to a second high pressure discharge oil passage 54 on the rear side in the rotational direction. Therefore, the machining reference position for machining each circumferential groove varies for each circumferential groove, and the circumferential groove formed in one of the high-pressure discharge oil passage and the low-pressure discharge oil passage thereby has a high-pressure discharge oil. Even if it is processed short to the side away from the other of the passage and the low pressure discharge oil passage, that is, to the side away from the predetermined hydraulic chamber 30a located at the closed position between the discharge oil passages, it faces the circumferential groove in the circumferential direction. The circumferential groove formed on the other of the high pressure discharge oil passage and the low pressure discharge oil passage is not processed to the side away from the predetermined hydraulic chamber 30a located at the closed position. When the hydraulic chamber 30a is located at the closed position, even if the short circumferential groove is blocked by the driven gear 28 or the drive gear 24, the other circumferential groove is not blocked. Predetermined hydraulic pressure chamber 30a is communicated with the discharge passage. Further, when the driven gear 28 and the drive gear 24 are eccentric or deformed during rotation, a predetermined hydraulic chamber 30a located at the closed position is formed in a circumferential groove formed in one of the high pressure discharge oil passage and the low pressure discharge oil passage. Even if it moves away from the side, it moves toward the side closer to the circumferential groove formed in the other of the high-pressure discharge oil passage and the low-pressure discharge oil passage, so that the predetermined hydraulic chamber 30a is located at the closed position. At this time, even if the one circumferential groove is closed by the driven gear 28 and the drive gear 24, the predetermined hydraulic chamber 30a is communicated with the discharge oil passage without closing the other circumferential groove. Therefore, it is a case where each circumferential groove is set as short as possible while it is required not to set each circumferential groove longer than necessary in order to suppress a decrease in volumetric efficiency on the high pressure discharge side. Even when the machining of these circumferential grooves occurs or when the driven gear 28 and the drive gear 24 are eccentric or deformed during rotation, the predetermined hydraulic chamber 30a has a high-pressure discharge oil passage and a low-pressure discharge oil passage. When passing through the closed position, the hydraulic oil in the predetermined hydraulic chamber 30a is released to the discharge oil passage through at least one of the plurality of circumferential grooves, so that the closed state is established. A sudden increase in the pressure value of the hydraulic oil in the predetermined hydraulic chamber 30a is suppressed, and an increase in pump driving torque due to an increase in the hydraulic pressure in the hydraulic chamber 30a can be suppressed. Further, even if the circumferential groove is set longer due to eccentricity or deformation of the driven gear 28 and the drive gear 24 or due to variations in processing of the circumferential groove (oil relief groove), the predetermined hydraulic chamber 30a located at the closed position remains. Since it does not communicate directly with each discharge oil passage and communicates via a circumferential groove whose flow cross-sectional area is sufficiently small compared with each discharge oil passage, there is little influence of a decrease in volumetric efficiency.

  Further, in the oil pump 10 of the present embodiment, the first outer circumferential groove 66 is based on the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 of the opening edge of the first high-pressure discharge oil passage 50. Is also extended in the circumferential direction from a part on the outer side in the radial direction toward the first low-pressure discharge oil passage 52 on the front side in the rotational direction, and the second outer circumferential groove 68 is provided with the second high-pressure discharge. A portion extending in the circumferential direction from a part of the opening edge of the oil passage 54 radially outside the locus K of the closest point X toward the second low-pressure discharge oil passage 56 on the front side in the rotational direction. The first inner circumferential groove 70 is a first rear side in the rotational direction from a part radially inward of the locus K of the closest point X in the opening edge of the first low-pressure discharge oil passage 52. The second inner circumferential groove 72 extends in the circumferential direction toward the high pressure discharge oil passage 50, and the second inner circumferential groove 72 is provided in the second low pressure discharge oil passage. 6 extending from the part radially inward of the locus K of the closest contact point X toward the second high-pressure discharge oil passage 54 on the rear side in the rotational direction. . Therefore, a first oil relief oil passage 58 for communicating a predetermined hydraulic chamber 30a positioned at a closed position between each high pressure discharge oil passage and each low pressure discharge oil passage and the high pressure discharge oil passage, In the case of the first outer circumferential groove 66 and the second outer circumferential groove 68 that are radially outward from the locus K of the closest point X as in the present embodiment, the diameter is larger than the locus K of the nearest point X. The circumferential length of the groove is shortened compared to a case where the circumferential groove is formed on the inner side in the direction. And the 2nd oil relief oil path 60 for connecting the predetermined | prescribed hydraulic chamber 30a located in the said closed position and a low pressure discharge oil path is more than the locus | trajectory K of the nearest point X like a present Example. The case where the first inner circumferential groove 70 and the second inner circumferential groove 72 on the radially inner side are composed of the circumferential groove on the radially outer side than the locus K of the closest point X is compared with the case of being composed of the circumferential groove on the radially outer side. Thus, the circumferential length of the groove is shortened. Therefore, the processing time for forming each oil release oil passage is shortened and the life of the processing tool used at that time is extended.

  Further, according to the oil pump 10 of the present embodiment, the first outer circumferential groove 66 of the first oil relief oil path 58 and the first inner circumferential groove 70 of the second oil relief oil path 60 are provided with the first low pressure discharge. The side edge 74 on the rear side in the rotational direction of the opening edge of the oil passage 52 is formed by grooving using a common processing position reference, and the second outer circumferential groove of the first oil relief oil passage 58 is formed. 68 and the second inner circumferential groove 72 of the second oil relief oil passage 60 are similarly formed by grooving using a common machining position reference. Even if there is a variation in the circumferential direction or a machining error occurs, the circumferential interval L [mm] between the tips of the outer circumferential groove and the inner circumferential groove is kept substantially constant, so that the outer One of the circumferential groove and the inner circumferential groove is in the closed position Even if it is processed short to the side away from the predetermined hydraulic chamber 30a, the other is processed longer to the side approaching the predetermined hydraulic chamber 30a. Therefore, it is a case where each circumferential groove is set as short as possible while it is required not to set each circumferential groove longer than necessary in order to suppress a decrease in volumetric efficiency on the high pressure discharge side. Even when there is variation in the machining of these circumferential grooves, when the hydraulic chamber 30a passes through the closed position between the high-pressure discharge oil passage and the low-pressure discharge oil passage, the hydraulic chamber 30a The hydraulic fluid inside is released to the discharge oil passage through at least one of the plurality of circumferential grooves. Therefore, even if one of the first outer circumferential groove 66 and the first inner circumferential groove 70 is machined longer due to processing variations of the oil relief groove, for example, the other is shortened, and the tip interval between the one and the other is kept accurately. Therefore, an increase in pump drive torque and a decrease in volumetric efficiency of the high-pressure discharge oil passage due to variations in processing of the oil relief groove are further suppressed.

  Next, another embodiment of the present invention will be described. In the following description of the embodiments, portions that overlap each other are denoted by the same reference numerals and description thereof is omitted.

  FIGS. 10 and 11 are views respectively showing an oil pump 110 according to another embodiment of the present invention, which corresponds to the section taken along the line II-II and the section taken along the line III-III in FIG. It is sectional drawing which expands and shows each part to perform. In the housing 112 of the oil pump 110, a predetermined hydraulic chamber 30 a among the plurality of hydraulic chambers 30 is positioned between the opening edge of the first high-pressure discharge oil passage 50 and the opening edge of the first low-pressure discharge oil passage 52. 11 is positioned between the opening edge of the second high-pressure discharge oil passage 54 and the opening edge of the second low-pressure discharge oil passage 56 and is not in direct communication with these discharge oil passages. As shown in FIG. 10, the first oil relief oil passage 114 formed on the side surface 44 of the pump chamber 40 and the predetermined oil pressure chamber 30a communicate with the second high pressure discharge oil passage 54, as shown in FIG. In order to allow the predetermined hydraulic chamber 30a and the first low-pressure discharge oil passage 52 to communicate with each other, a second oil relief oil passage 116 formed on the side surface 42 of the pump chamber 40 is provided. The second high-pressure discharge oil passage 54 of the present embodiment corresponds to the first discharge oil passage in the present invention, and the first low-pressure discharge oil passage 52 of the present embodiment is the second discharge oil passage in the present invention. It is equivalent to.

  As shown in FIG. 11, the first oil relief oil passage 114 is more radial than the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 among the opening edges of the second high-pressure discharge oil passage 54. A first outer circumferential groove 118 extending in the circumferential direction from a part on the outer side and a part on the inner side in the radial direction toward the second low-pressure discharge oil passage 56 on the front side in the predetermined rotation direction indicated by the arrow a. And a first inner circumferential groove 120. Further, as shown in FIG. 10, the second oil relief oil passage 116 is more than the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 among the opening edges of the first low pressure discharge oil passage 52. A second outer circumferential direction extending in the circumferential direction from a part on the radially outer side and a part on the radially inner side toward the first high-pressure discharge oil passage 50 on the rear side in the predetermined rotational direction indicated by the arrow a. It consists of a groove 122 and a second inner circumferential groove 124. Each of the outer circumferential grooves and the inner circumferential grooves has a predetermined tip when the predetermined hydraulic chamber 30a is located between the discharge oil passages and is not in direct communication with the discharge oil passages. It is designed to be slightly communicated with the hydraulic chamber 30a.

  Next, processing of each circumferential groove will be described. In the following, the processing of the first outer circumferential groove 118 and the first inner circumferential groove 120 will be described on behalf of the outer circumferential groove and the inner circumferential groove. FIG. 12 shows only the pump cover 32 of FIG. In FIG. 12, the first outer circumferential groove 118 and the first inner circumferential groove 120 have a common side edge 126 on the front side in the rotational direction indicated by arrow a among the opening edges of the second high-pressure discharge oil passage 54. For example, a cutting tool such as an end mill is used and a groove is formed by a machine tool such as a milling machine.

  In the oil pump 110 configured as described above, when the drive gear 24 and the driven gear 28 are rotated in the rotational direction, oil is sucked into the hydraulic chamber 30 that is moved in the circumferential range in which the capacity V increases. . Then, pressurized oil is supplied from the hydraulic chamber 30 that is moved in the circumferential range in which the first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 open in the circumferential range in which the capacity V decreases. Discharged. Then, pressurized oil is supplied from the hydraulic chamber 30 that is moved in the circumferential range in which the first low-pressure discharge oil passage 52 and the second low-pressure discharge oil passage 56 open in the circumferential range in which the capacity V decreases. Discharged. When the plurality of hydraulic chambers 30 are moved in the rotational direction and pass through the closed position between the high pressure discharge oil passage and the low pressure discharge oil passage, as shown in FIGS. When the hydraulic chamber 30a is positioned between the high-pressure discharge oil passage and the low-pressure discharge oil passage, the hydraulic oil in the predetermined hydraulic chamber 30a passes through the circumferential grooves and the high-pressure discharge oil passage and the low-pressure discharge oil. It is designed to escape to at least one of the roads.

  Here, as shown in FIG. 13 which shows an enlarged view corresponding to the portion indicated by the arrow B in FIG. 10, for example, the second outer circumferential groove 122 and the second inner circumference constituting the second oil relief oil passage 116. When the direction grooves 124 are formed to be shorter by about 1 [degree] in the circumferential direction away from the predetermined hydraulic chamber 30a positioned at the closed position, the circumferential grooves are blocked by the drive gear 24. It becomes. However, even in such a case, as shown in FIG. 14 which shows an enlarged view corresponding to the portion indicated by arrow C in FIG. 11, the predetermined hydraulic chamber 30a positioned at the closed position is The second high pressure discharge oil passage 54 is in communication with the first outer circumferential groove 118 and the first inner circumferential groove 120, and the hydraulic oil in the hydraulic chamber 30 a is released to the second high pressure discharge oil passage 54. To get.

  Further, as shown in FIG. 15 which shows an enlarged portion corresponding to the portion indicated by the arrow B in FIG. 10, for example, when the drive gear 24 and the driven gear 28 are decentered upward during rotation, the second outer side The circumferential groove 122 and the second inner circumferential groove 124 are blocked by the drive gear 24. However, even in such a case, as shown in FIG. 16 which shows an enlarged view corresponding to the portion indicated by arrow C in FIG. 11, the predetermined hydraulic chamber 30a positioned at the closed position is The second high pressure discharge oil passage 54 is in communication with the first outer circumferential groove 118 and the first inner circumferential groove 120, and the hydraulic oil in the hydraulic chamber 30 a is released to the second high pressure discharge oil passage 54. To get.

  As described above, in the oil pump 10 of the present embodiment, the predetermined hydraulic chamber 30a among the plurality of hydraulic chambers 30 is the high pressure discharge oil passage (the first high pressure discharge oil passage 50 and the second high pressure discharge oil passage 54). When the predetermined position is set between the opening and the opening of the low pressure discharge oil passage (the first low pressure discharge oil passage 52 and the second low pressure discharge oil passage 56) and is not in direct communication with these discharge oil passages. In order to make the hydraulic chamber 30a communicate with the high-pressure discharge oil passage, out of the opening edge of the second high-pressure discharge oil passage 54, it is radially outward from the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20. A first outer circumferential groove 118 extending in the circumferential direction from a part of the first and the radially inner part toward the second low pressure discharge oil passage 56 on the front side in a predetermined rotational direction indicated by an arrow a. A first oil relief oil passage 114 comprising a first inner circumferential groove 120; Of the opening edge of the pressure discharge oil passage 52, a predetermined portion indicated by an arrow a from a part radially outside and a part radially inward of the locus K of the closest point X between the inner peripheral tooth 26 and the outer peripheral tooth 20 respectively. A second oil relief oil passage 116 composed of a second outer circumferential groove 122 and a second inner circumferential groove 124 extending in the circumferential direction toward the first high-pressure discharge oil passage 50 on the rear side in the rotation direction. Is included. Therefore, in order to suppress a decrease in volumetric efficiency on the high pressure discharge side, it is required not to set each circumferential groove longer than necessary, and when each circumferential groove is set as short as possible, Even when the driven gear 28 and the drive gear 24 are decentered or deformed during rotation, or when variations occur in the processing of the circumferential grooves, the predetermined hydraulic chamber 30a has a high-pressure discharge oil passage and a low-pressure discharge oil passage. In the same manner as in the first embodiment, the hydraulic oil in the predetermined hydraulic chamber 30a is released to the discharge oil passage through at least one of the plurality of circumferential grooves. The pressure value of the hydraulic oil in the predetermined hydraulic chamber 30a in the closed state is suppressed from rapidly increasing, and the pump driving torque is prevented from increasing due to the increase in the hydraulic pressure in the hydraulic chamber 30a. To be able to That.

  Further, according to the oil pump 110 of the present embodiment, the first oil relief oil passage 114 is radially outside of the opening edge of the second high-pressure discharge oil passage 54 formed on the one side surface 44 of the pump chamber 40. A first outer circumferential groove 118 and a first inner circumferential direction extending in a circumferential direction from a part of the first circumferential direction and a part on the radially inner side toward the second low-pressure discharge oil passage 56 on the front side in the rotational direction. The second oil relief oil passage 116, which is composed of the groove 120, is a part on the radially outer side and the radially inner side of the opening edge of the first low-pressure discharge oil passage 52 formed on the other side surface 42 of the pump chamber 40. Since it consists of a second outer circumferential groove 122 and a second inner circumferential groove 124 that extend in the circumferential direction from a part toward the first high-pressure discharge oil passage 50 on the rear side in the rotational direction, Two circumferential grooves formed on one side face Since machining is formed is subjected to one discharge oil passage which is the mouth, there is an advantage that the processing time of the oil relief oil passage is relatively short. Specifically, the two first outer circumferential grooves 118 and the first inner circumferential groove 120 formed on one side surface 44 are formed with respect to one second high-pressure discharge oil passage 54 opened on the side surface 44. The two second outer circumferential grooves 122 and the second inner circumferential groove 124 formed on the other side surface 42 are formed by one first low pressure formed in the side surface 42. The discharge oil passage 52 is formed by being processed. Here, for example, one first oil relief oil passage and one second oil relief oil passage are formed on one side surface 44 of the pump chamber 40, and the first oil relief oil passage and the other side surface 42 of the pump chamber 40 are formed. When forming the second oil relief oil passages one by one, the two circumferential grooves formed on one side surface are formed by processing the two discharge oil passages opened on the side surface, respectively. There is a disadvantage that the processing time of each oil relief groove becomes relatively long.

  As mentioned above, although one Example of this invention was described in detail with reference to drawings, this invention is not limited to this Example, It can implement in another aspect.

  For example, the high-pressure discharge oil passages 50 and 52 are provided on the front side in the rotation direction, and the low-pressure discharge oil passages 54 and 56 are provided on the rear side in the rotation direction. The high pressure discharge oil passages 50 and 52 may be provided on the rear side in the rotation direction, and the low pressure discharge oil passages 54 and 56 may be provided on the front side in the rotation direction.

  In the first embodiment, at least one of the first high-pressure discharge oil passage 50 and the second high-pressure discharge oil passage 54 may be provided, and the first low-pressure discharge oil passage 52 and the second low-pressure discharge oil passage 56 It is sufficient that at least one of them is provided.

  In the first embodiment, the first oil relief oil passage 58 only needs to include at least one of the first outer circumferential groove 66 and the second outer circumferential groove 68, and the second oil relief oil passage 60 is provided. May have at least one of the first inner circumferential groove 70 and the second inner circumferential groove 72.

  In the second embodiment, the first high-pressure discharge oil passage 50 and the second low-pressure discharge oil passage 56 are not necessarily provided.

  In the second embodiment, the first oil relief oil passage 114 only needs to include at least one of the first outer circumferential groove 118 and the first inner circumferential groove 120, and the second oil relief oil passage 116 is provided. May have at least one of the second outer circumferential groove 122 and the second inner circumferential groove 124.

  The oil pump 10 (110) includes a torque converter and is included in an automatic transmission suitable for use in an FF (front engine / front drive) type vehicle, but is not limited thereto. Any oil pump provided in the vehicle may be used, such as a transmission suitably used in other drive type vehicles such as an FR type vehicle.

  It should be noted that the above description is merely an embodiment, and other examples are not illustrated. However, the present invention is implemented in variously modified and improved modes based on the knowledge of those skilled in the art without departing from the gist of the present invention. Can do.

DESCRIPTION OF SYMBOLS 10,110: Vehicle internal gear type oil pump 18,112: Housing 20: Outer peripheral tooth 24: Drive gear 26: Inner peripheral tooth 28: Driven gear 30: Hydraulic chamber 30a: Predetermined hydraulic chamber 40: Pump chamber 42: Side 44: Side 50: First high-pressure discharge oil passage (first discharge oil passage)
52: First low pressure discharge oil passage (second discharge oil passage)
54: Second high-pressure discharge oil passage (first discharge oil passage)
56: Second low pressure discharge oil passage (second discharge oil passage)
58, 114: first oil relief oil passage 60, 116: second oil relief oil passage 66, 118: first outer circumferential groove (outer circumferential groove)
68, 122: second outer circumferential groove (outer circumferential groove)
70, 120: first inner circumferential groove (inner circumferential groove)
72, 124: second inner circumferential groove (inner circumferential groove)
74, 126: Side edge (processing position reference)
C1: Axial (single axis)
C2: eccentric axis K: locus of closest contact V: volume X: closest contact a: direction of rotation

Claims (5)

A drive gear having outer peripheral teeth and rotatably provided around one axis, and an inner circumference tooth meshed with the outer teeth of the drive gear and having an eccentric shaft center eccentric from the one axis An annular driven gear that is rotatably provided and is driven to rotate by the drive gear, a pump chamber in which the driven gear and the drive gear are accommodated, and a side surface of the pump chamber for discharging oil from the pump chamber And a plurality of hydraulic chambers formed in the circumferential direction by meshing gaps between the inner peripheral teeth and the outer peripheral teeth as the drive gear and the driven gear rotate. A first discharge oil passage and a second discharge oil passage that are sequentially communicated with the hydraulic chamber in a process in which the volume of the hydraulic chamber is reduced when being moved in a predetermined rotation direction; A housing, a vehicular internal gear type oil pump comprising,
A predetermined hydraulic chamber of the plurality of hydraulic chambers is positioned between the opening of the first discharge oil passage and the opening of the second discharge oil passage and is not in direct communication with the discharge oil passage. In order to communicate the predetermined hydraulic chamber and the first discharge oil passage, the front side in the rotational direction from a part of the opening edge of the first discharge oil passage formed on the side surface of the pump chamber In order to communicate the first oil relief oil passage extending in the circumferential direction toward the second discharge oil passage, the predetermined hydraulic chamber and the second discharge oil passage, the side surface of the pump chamber Including a second oil relief oil passage extending in a circumferential direction from a part of the opening edge of the formed second discharge oil passage toward the first discharge oil passage on the rear side in the rotation direction. An internal gear type oil pump for vehicles. The first oil relief oil passage is a front side in the rotational direction from a part radially outside the locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the first discharge oil passage. Consisting of an outer circumferential groove extending in the circumferential direction,
The second oil relief oil passage is a rear side in the rotational direction from a part radially inward of a locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the second discharge oil passage. The vehicular internal gear type oil pump according to claim 1, wherein the vehicular internal gear type oil pump comprises an inner circumferential groove extending in a circumferential direction. The first oil relief oil passage is a front side in the rotational direction from a part radially inward of a locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the first discharge oil passage. Consisting of an inner circumferential groove extending in the circumferential direction,
The second oil relief oil passage is a rear side in the rotational direction from a part radially outside the locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth of the opening edge of the second discharge oil passage. The vehicle internal gear type oil pump according to claim 1, comprising an outer circumferential groove extending in a circumferential direction. The first oil relief oil passage is more radial than the locus of the closest contact point between the inner peripheral tooth and the outer peripheral tooth among the opening edges of the first discharge oil passage formed on one side surface of the pump chamber. It consists of an outer circumferential groove and an inner circumferential groove extending in the circumferential direction from the outer part and the radially inner part to the front side in the rotational direction, respectively.
The second oil relief oil passage is more radial than the locus of the closest contact between the inner peripheral tooth and the outer peripheral tooth among the opening edges of the second discharge oil passage formed on the other side surface of the pump chamber. 2. The vehicle according to claim 1, further comprising an outer circumferential groove and an inner circumferential groove extending in a circumferential direction from a part on the outer side and a part on the radially inner side to the rear side in the rotational direction. Internal gear type oil pump.   4. The vehicle according to claim 1, wherein the first oil relief oil passage and the second oil relief oil passage are each grooved using a common machining position reference. 5. Internal gear type oil pump.

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