JP2013122234A - Electric oil pump device and method of manufacturing the same - Google Patents

Abstract

An electric oil pump device capable of suppressing the protrusion of burrs into and out of a case without increasing the number of work steps during friction welding between resin members.
SOLUTION: Wall portions 24, 25 extending in an axial direction of an annular groove 23 of a motor housing 26 arranged in a friction joint portion 18 have an inner peripheral side (radially inner side) wall portion 24 and an outer peripheral side (radial outer side). It is formed higher than the wall portion 25. And the burr | flash which protruded from the welding surface 28 is accommodated in the clearance gap of the axial direction formed between wall part 24,25 as an annular wall and the sliding contact protrusion 22 of the lid | cover 27. FIG. Further, the lid 27 has a radial gap 29 formed between the inner peripheral side wall portion 24 of the friction joint 18 and the sliding contact projection 22 of the lid 27 so that the radial gap 29 becomes narrower from the radially outer side toward the inner side. Inclined. Then, burrs that protrude from the welding surface 28 along the wall surface are accommodated in the gap 29.
[Selection] Figure 2

Description

  The present invention relates to an electric oil pump device and a manufacturing method thereof.

  Conventionally, a specific example of an electric oil pump device includes a combination of an oil pump that circulates fluid (oil) and an electric motor that drives the oil pump. The electric oil pump device includes an electric motor in the central axis direction of the oil pump, a controller for controlling the motor in the central axis direction adjacent to the electric motor, and a common housing. Have been proposed in which an electric motor and a controller are integrated together (for example, see Patent Document 1 or Patent Document 2).

Japanese Patent Laid-Open No. 2006-274821 JP 2010-116914 A

  As a method for joining the resin body, a case for housing the electric motor and the control board of the controller that drives the electric motor as described above and a lid that covers the opening of the case are both formed of resin. For example, spin welding is used. However, when joining using frictional heat generated on the contact surface between the case and the lid, if the molten resin is pushed out by the pressing force of the jig, etc., burrs may occur from the joint to the inside and outside of the case There is. For this reason, a process of removing the burrs by cutting or air blow so as not to go out of the case is necessary, and the number of work steps increases. Furthermore, if the burr enters the electric motor or controller inside the case, it cannot be removed structurally, which may adversely affect the control board and other members.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide an electric oil pump that can suppress burrs from protruding into and out of the case without increasing the number of work steps at the time of friction bonding between resin members. It is to provide an apparatus and a method for manufacturing the same.

  In order to solve the above-mentioned problem, the invention according to claim 1 is an oil pump, an electric motor provided adjacent to the central axis direction of the oil pump, and rotationally driving the oil pump, and the central axis direction A controller that is provided adjacent to the electric motor and that controls driving of the electric motor, and includes a case that includes an opening that houses the electric motor and the controller, and a lid that covers the opening. In the electric oil pump device that forms an annular friction joint portion, the friction joint portion includes an axially extending groove portion having inner and outer wall portions, and a projecting portion slidably contacting the groove portion. The wall portion is configured such that the inner peripheral side is formed higher than the outer peripheral side.

  According to the above configuration, in the electric oil pump device in which the electric motor and the controller are arranged side by side adjacent to the oil pump, an annular friction is formed between the opening of the case housing the electric motor and the controller and the lid. A junction is formed. Friction joining is comprised from the cyclic | annular groove part and the cyclic | annular protrusion corresponding to a groove part. At this time, the wall portions extending in the axial direction on both sides of the groove portion are formed such that the inner peripheral side (radially inner side) is higher than the outer peripheral side (radial outer side). Thereby, since the burr | flash produced | generated by the welding surface of a groove part and a protrusion is accommodated along the clearance gap between the wall parts of an inner peripheral side, it does not penetrate | invade in a case. As a result, it is possible to prevent the burr from adversely affecting the operation of the electric motor or the controller.

  A second aspect of the present invention is the electric oil pump device according to the first aspect, wherein a radial direction formed between the inner peripheral wall portion of the groove portion and the protruding portion facing the groove portion. The gist is that the gap is inclined so as to become narrower inward in the radial direction.

  According to the above configuration, the gap formed between the wall portion on the inner peripheral side of the groove portion and the protruding portion facing the groove portion is provided to be inclined so as to narrow from the radially outer side to the inner side. Yes. As a result, this gap is narrower on the inner side (exit) of the case. For example, even if the amount of burr generated and the movement speed increase, the burr that protrudes from the weld surface along the wall surface can be removed. Can be accommodated. As a result, it is possible to more reliably prevent the burr from jumping over the inner peripheral wall portion and jumping into the case.

The invention described in 請 Motomeko 3, the oil pump, the case having an opening for housing a controller for driving and controlling the electric motor and the electric motor rotates the oil pump, and a lid for covering the opening, In the manufacturing method of the electric oil pump device in which an annular friction joint is formed between the two, a cylindrical jig is provided concentrically on the outer peripheral side of the lid and fitted to the lid, and the lid and the cylindrical The gist is to form the annular friction welded portion after forming a predetermined clearance all around the jig.

  According to the above configuration, a cylindrical jig is fitted concentrically on the outer peripheral side of the lid so that a predetermined gap (clearance) is provided around the entire circumference between the lid and the jig. A friction joint is formed on the surface. At this time, the burr that has flowed out of the welding surface and has flowed into the gap is pressed by the inner peripheral surface of the jig and is fixed to the outer peripheral surface of the case and the lid. Thereby, the outflow of the molten resin to the outside can be suppressed, and the burr can be prevented from falling. Further, the protruding amount in the radial direction can be suppressed to a predetermined amount or less.

  ADVANTAGE OF THE INVENTION According to this invention, the electric oil pump apparatus which can suppress the protrusion of the burr | flash inside and outside a case, and its manufacturing method can be provided, without increasing work man-hour at the time of the friction joining between resin members.

The fragmentary sectional view of the axial direction which shows the principal part of the electric oil pump apparatus which concerns on one Embodiment of this invention. FIG. 2 is a schematic cross-sectional view showing a friction joint portion between the motor housing and the lid in FIG. 1. The front view seen from the arrow A direction in FIG. The figure which shows the fitting state of the lid | cover and jig | tool which concern on other embodiment. The schematic sectional drawing which shows the friction-joining part of the motor housing and cover in other embodiment.

Next, an electric oil pump device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view in the axial direction showing the main part of an electric oil pump device according to an embodiment of the present invention. As shown in FIG. 1, the electric oil pump device 1 is used as an automobile transmission hydraulic pump, and is electrically driven to rotate the oil pump 2 adjacent to the oil pump (for example, an internal gear pump) 2 and the oil pump 2. The motor 3 is unitized (integrated) in the housing. The controller 4 is also incorporated in the housing. An electric motor (hereinafter referred to as a brushless motor) 3 shown in FIG. 1 is a brushless sensorless motor having a three-phase winding.

  The oil pump 2 uses a trochoid curved pump here, and a pump (not shown) having external teeth on the inner peripheral side of a pump outer rotor (not shown) having internal teeth having a trochoidal tooth profile (hereinafter referred to as an outer rotor). The inner rotor (hereinafter referred to as the inner rotor) is engaged, and the outer rotor and the inner rotor are eccentrically disposed in the pump housing 15 so as to be rotatable.

  The inner rotor is externally fitted and fixed to a portion closer to one side (left side in FIG. 1) than the portion where the rotor 6 is formed in the rotational drive shaft 7, and rotates together with the rotational drive shaft 7. The outer rotor has one more inner tooth than the outer teeth of the inner rotor, and is arranged so as to be rotatable in the pump housing 15 around a position eccentric with respect to the rotational drive shaft 7. The inner rotor is configured such that the outer teeth mesh with the inner teeth of the outer rotor at a part of the entire circumference, and the outer teeth rotate while being substantially inscribed at the inner surface of the outer rotor at various locations on the entire circumference.

  Therefore, when the rotational drive shaft 7 is rotationally driven by the brushless motor 3, the volume of the gap between the inner teeth of the outer rotor of the oil pump 2 and the outer teeth of the inner rotor increases during one rotation of the rotational drive shaft 7. Since the reduction is repeated, a pump operation is performed in which oil is sent from an import (not shown) provided in the pump plate 14 leading to the gap toward the outport.

  The brushless motor 3 includes a rotating motor rotor (hereinafter referred to as “rotor”) 6 and a motor stator (hereinafter referred to as “stator”) 5 fixed to the outside of the outer peripheral surface of the rotor 6. The rotor 6 is formed by arranging, for example, a plurality of permanent magnets (not shown) side by side along the circumferential direction on the outer peripheral surface of the rotary drive shaft 7. The rotation drive shaft 7 is a rotation shaft shared by the brushless motor 3 and the oil pump 2, and both ends thereof are rotatably supported by bearings 11 and 12 inside the pump housing 15 and the cage 17. Here, the stator 5 of the brushless motor 3 is fixed by screwing a plurality of bolts 21 inserted from the through holes of the cage 17 to the pump housing 15. In the present embodiment, the three bolts 21 are arranged at equal intervals in the circumferential direction with respect to the axial center.

  In the stator 5, a plurality of inward salient poles (teeth) of the stator core 9 are arranged outside the outer peripheral surface of the rotor 6 through a slight air gap. A coil 10 is wound around each tooth of the stator core 9. Here, an insulator 13 for insulating the coil 10 from the stator core 9 is mounted from both axial ends of the stator core 9. The stator 5 is composed of a plurality of divided stator cores 9, and each stator core 9 is fastened and fixed by a cylindrical thin ring 8.

  The end of the coil 10 is electrically connected to a bus bar (not shown). The insulator 13 is resin-molded integrally with three bus bars that serve as drive terminals for the brushless motor 3. Each bus bar extends from the right end portion of the insulator 13 in parallel to the central axis.

  The pump plate 14 and the pump housing 15 are made of a metal nonmagnetic material (for example, aluminum die casting). The motor housing (case) 26 and the lid 27 that house the brushless motor 3 and the controller 4 are formed of a resin material (for example, a thermoplastic resin such as polyamide). The entire housing of the electric oil pump device 1 is constituted by the pump plate 14, the pump housing 15, the motor housing 26, and the lid 27.

  The motor housing 26 and the lid 27 are joined to the fixed motor housing 26 by spin welding in which the lid 27 is rotated while the lid 27 is in contact with the motor housing 26 by the frictional heat generated by the rotation. As a result, the sealing performance of the friction joint 18 is secured, and the brushless motor 3 and the controller 4 are hermetically housed in the motor housing 26, so that the waterproofness of the controller 4 in the motor housing 26 is secured. ing.

  In the electric oil pump device 1 of the present embodiment, a control board (hereinafter referred to as a board) 19 of the controller 4 for controlling the brushless motor 3 is attached to the motor housing 26. On the substrate 19, information on the rotational position of the outer rotor of the pump unit 16 detected by an inverter circuit that converts a direct current power source into alternating current and supplies a drive current to each coil 10 of the brushless motor 3, for example, a sensor such as a Hall element, etc. Is mounted with a control circuit unit 20 comprising a control circuit for controlling the inverter circuit. Electronic components such as a microcomputer, a coil, and a capacitor of the inverter circuit and the control circuit constituting the control circuit unit 20 of the controller 4 are mounted on both surfaces of the substrate 19.

  A bus bar which is a drive terminal of the brushless motor 3 connected to each coil 10 and insulated and supported by the insulator 13 is inserted into the substrate 19 and connected to the control circuit unit 20 on the substrate 19. Further, a connector shell is provided integrally with the motor housing 26 on the side surface of the motor housing 26, and a connector pin inside thereof is connected to the control circuit unit 20 on the substrate 19.

  With the above configuration, the drive current controlled by the substrate 19 is supplied to each coil 10 of the brushless motor 3. As a result, a rotating magnetic field is generated in the coil 10, torque is generated in the permanent magnet, and the rotor 6 is rotationally driven. Thus, when the inner rotor of the pump unit 16 is driven to rotate, the outer rotor is driven and rotated, and the gap between the inner teeth of the outer rotor and the outer teeth of the inner rotor repeatedly expands and contracts. Pump operation is performed to suck and discharge oil through the port.

  Next, FIG. 2 is a schematic sectional view showing the frictional joint 18 between the motor housing 26 and the lid 27 in FIG. The motor housing 26 shown in FIG. 2 has a cylindrical shape, and an annular groove (groove portion) 23 is formed over the entire circumference at the opening end of the opening portion 30 that opens in the axial direction (right side in FIG. 2). Yes. An annular sliding contact projection (projection) 22 corresponding to the annular groove 23 is formed on the lid 27 that covers the opening 30 of the motor housing 26. Both the motor housing 26 and the lid 27 are made of a resin material. Then, the sliding contact projection 22 is heated and melted while the lid 27 is rotated in a state where the tip of the sliding contact projection 22 and the bottom of the annular groove 23 are in contact with each other, and the annular groove 23 of the motor housing 26 of the fixed counterpart component is fixed. The welding surface 28 of the friction joint 18 is formed by being pressed against the surface. Here, spin welding is used as this bonding method. At this time, a melted product that protrudes from the welding surface 28 in the friction joint 18, that is, a burr is generated.

  Specifically, the axial wall portions 24 and 25 of the annular groove 23 of the motor housing 26 disposed in the friction joint portion 18 are the inner peripheral side (radially inner side, lower side in FIG. 2) wall portion 24. The outer peripheral side (radially outer side, upper side in FIG. 2) is formed higher than the wall portion 25. And the burr | flash which protruded from the welding surface 28 is accommodated in the clearance gap 29 of the axial direction formed between wall part 24,25 as an annular wall, and the sliding contact protrusion 22 of the lid | cover 27. As shown in FIG. . Further, the lid 27 is formed so that a gap 29 formed between the inner peripheral side wall portion 24 of the annular groove 23 of the friction joint portion 18 and the radial end portion of the lid 27 becomes narrower from the radially outer side toward the inner side. Inclined. The burr that protrudes from the welding surface 28 along the wall surface is accommodated in the gap 29.

  FIG. 3 is a front view seen from the direction of arrow A in FIG. A lid 27 that rotates relative to the motor housing 26 in a fixed state (for example, counterclockwise in FIG. 3) is slidably contacted to form the friction joint 18. In addition, a positioning convex portion 32 for rotating and holding the lid 27 at the time of spin welding is provided at the rotation center portion on the outer surface side of the lid 27.

Next, FIG. 4 is a diagram illustrating a fitting state between a lid and a jig according to another embodiment, and FIG. 5 is a schematic cross-sectional view illustrating a frictional joint portion between the motor housing and the lid.
As shown in FIG. 4, a lid 27 is fitted in a predetermined position from the end face concentrically in the axial direction to the opening of a cylindrical metal (for example, stainless steel) jig 33 and fixed by suction. The axial length of the jig 33 is sufficiently longer than the resin flowing along the wall surface, and the clearance (clearance) 34 around the radial direction between the lid 27 and the jig 33 is such that the amount of resin protruding during spin welding is less than a predetermined amount. (For example, the gap 34 on one side is 0.5 mm or less). Here, for example, screw holes 36 for fixing the equipment are provided at regular intervals (six in this embodiment) in the circumferential direction behind the side surface of the jig 33, and the jig 33 is fixed to the equipment side by bolt fastening. It has a structure.

  As shown in FIG. 5, the axial wall portions 24 and 25 of the annular groove 23 of the motor housing 26 disposed in the friction joint portion 18 are formed so that the inner peripheral wall portion 24 and the outer peripheral side wall portion 25 are at the same height. Has been. The resin protruding from the welding surface 28 is accommodated in a gap in the axial direction formed between the wall portions 24 and 25 serving as annular walls and the sliding contact protrusion 22 of the lid 27. In addition, the resin that has risen in the outer circumferential side gap 35 formed between the outer circumferential side wall portion 25 and the radial end portion of the lid 27 along the wall surface flows out into the gap 34 of the jig 33 that is fixed to the lid 27 and rotates. Then, the outer peripheral side wall portion 25 and the outer peripheral surface of the lid 27 are fixed as burrs. Further, the lid 27 has an inner circumferential gap 29 formed between the inner circumferential side wall 24 of the annular groove 23 of the friction joint 18 and the radial end of the lid 27 narrowing from the radially outer side to the inner side. It is inclined to become. The burrs protruding from the welding surface 28 along the wall surface are accommodated in the gap 29.

  Next, the operation and effect of the electric oil pump device 1 according to the present embodiment configured as described above will be described.

  According to the above configuration, in the electric oil pump device 1 in which the sensorless brushless motor 3 and the controller 4 are arranged side by side in the central axis direction of the oil pump 2 adjacent to the oil pump 2, the brushless motor 3 and the controller 4 An annular groove 23 is formed in the opening end 31 of the motor housing 26 that accommodates the control board 19, and an annular sliding contact portion 22 corresponding to the annular groove 23 is formed in the lid 27 that covers the opening 30 of the motor housing 26. ing. The lid 27 is rotated in a state where the tip of the sliding contact protrusion 22 is in contact with the bottom of the annular groove 23. At this time, the motor housing 26 is fixed so as not to rotate. Then, the lid 27 is frictionally joined (spin welded) to the welding surface 28 of the motor housing 26 by sliding and bringing them into relative contact with each other. At this time, the wall portions 24 and 25 extending in the axial direction on both sides of the annular groove 23 are formed such that the inner peripheral side wall portion 24 is higher than the outer peripheral side wall portion 25. Further, a radial gap 29 formed between the inner peripheral side wall 24 of the motor housing 26 and the sliding contact protrusion 22 of the lid 27 facing the annular groove 23 becomes narrower from the radially outer side to the inner side. So as to be inclined.

  As a result, the burr melted and generated from the welding surface 28 by the frictional heat between the tip of the sliding contact protrusion 22 and the bottom of the annular groove 23 is pushed out and accommodated in the gap in the inner peripheral side wall 24 and removed by post-processing. Since it does not enter into the difficult motor housing 26, it is possible to prevent the burr from adversely affecting the operation of the brushless motor 3 and the control board 19 of the controller 4. Further, even if the amount of burr generated and the movement speed increase, the burr that protrudes from the welding surface 28 along the wall surface is accommodated in the gap 29 in which the radially inner side (exit) of the motor housing 26 is narrowed. Can do. As a result, it is possible to prevent the burr from jumping over the inner peripheral side wall portion 24 and jumping into the motor housing 26. Further, by making it easier to accommodate the burr on the inner peripheral side, it is possible to suppress the motor housing 26 from protruding outward in the radial direction.

  Further, according to another embodiment, the opening of the cylindrical jig 33 is fitted concentrically in the axial direction on the outer peripheral side of the lid 27, and a predetermined diameter is provided on the entire circumference in the radial direction between the lid 27 and the jig 33. A clearance (clearance) 34 is provided to spin-weld the opening end 31 of the motor housing 26 and the lid 27. At this time, the resin flowing out from the welding surface 28 into the protruding gap 34 is pressed against the inner peripheral surface of the jig 33 and is fixed to the outer peripheral side wall portion 25 of the motor housing 26 and the outer peripheral surface of the lid 27. Thereby, the outflow of resin from the outer peripheral side gap 35 between the outer peripheral side wall 25 of the groove 23 of the motor housing 26 and the lid 27 is suppressed, and the burr can be prevented from falling.

  As described above, according to the present embodiment, it is possible to provide an electric oil pump device and a method for manufacturing the same that can suppress the protrusion of burrs into and out of the motor housing without increasing the number of work steps during friction welding between resin members. .

  Although one embodiment according to the present invention has been described above, the present invention can also be implemented in other forms.

  In the above embodiment, the present invention is embodied in the friction joint structure of the motor housing 26 and the lid 27 of the electric oil pump device 1. However, the application site is not necessarily limited to this, and may be applied to any material as long as it frictionally joins two members. In addition, the frictional joining is performed by bringing the rotating lid 27 into contact with the open end of the motor housing 26 in a fixed state. Any device other than the electric oil pump device may be used as long as it can be relatively rotated in a contact state.

  In the above embodiment, the annular groove 23 is formed in the opening end 31 of the motor housing 26, so that the motor housing 26 has the wall portions 24 and 25 and the lid 27 has the sliding contact projection 22. did. However, when the lid 27 is fixed from the lower side in the direction of gravity, an annular groove is formed on the lid 27 side, the wall portion is an annular wall, and a sliding contact projection is formed on the motor housing 26 side. It may be configured to.

  Furthermore, in the above-described embodiment, the case of spin welding is shown as a method for bonding resin materials to each other. However, the present invention is not limited to this, and hot plate welding, ultrasonic welding, vibration welding, infrared welding, or the like, or an adhesive. Adhesion by may also be used. Furthermore, in the said embodiment, although the motor housing 26 and the lid | cover 27 were both formed with the resin member, it is desirable not only for this but at least the sliding contact part is resin. And if the friction joining is possible, both may be metal members. Similarly, by using a cylindrical jig 33 provided with a gap 34 between the entire circumference in the radial direction and the metal lid 27, it is possible to prevent the molten metal from protruding to the outside.

  Although the case where an internal gear type pump is used as the oil pump 2 has been described in the above embodiment, the present invention is not limited to this, and a rotary pump using a vane drive or an external gear may be applied.

  In the above embodiment, the case where a plurality of permanent magnets are arranged and fixed on the outer peripheral portion of the rotary drive shaft 7 as the rotor 6 of the brushless motor 3 has been described. However, a rotor in which a ring-shaped permanent magnet is fixed is used. You may do it.

1: electric oil pump device, 2: oil pump, 3: brushless motor (electric motor),
4: controller, 5: stator for motor, 6: rotor for motor, 7: rotary drive shaft,
8: Ring, 9: Stator core, 10: Motor coil, 11, 12: Bearing
13: Insulator, 14: Pump plate, 15 Pump housing,
16: Pump part, 17: Cage, 18: Friction joint, 19: Substrate (control board),
20: Control circuit part, 21: Bolt, 22: Sliding contact protrusion (protrusion part), 23: An annular groove (groove part),
24: inner peripheral side wall, 25: outer peripheral side wall, 26: motor housing (case),
27: Lid, 28: Welding surface, 29: Inner circumferential clearance, 30: Motor housing opening,
31: motor housing open end, 32: convex part for lid positioning, 33: jig,
34: Jig side clearance (clearance), 35: Outer peripheral side clearance, 36: Screw hole for fixing equipment

Claims (3)

An oil pump,
An electric motor provided adjacent to the central axis direction of the oil pump and rotating the oil pump;
A controller that is provided adjacent to the electric motor in the central axis direction and that drives and controls the electric motor,
In the electric oil pump device that forms an annular friction joint between a case having an opening for housing the electric motor and the controller and a lid that covers the opening,
The friction joint portion is composed of a groove portion having an inner peripheral side and an outer peripheral wall portion extending in the axial direction, and a protrusion slidably contacting the groove portion,
The electric oil pump device according to claim 1, wherein the wall portion is formed such that an inner peripheral side is higher than an outer peripheral side. The electric oil pump device according to claim 1,
A radial gap formed between the inner peripheral wall of the groove and the protrusion facing the groove is inclined so as to become narrower radially inward. Electric oil pump device. An electric oil pump that forms an annular friction joint between a case that includes an electric motor that rotationally drives an oil pump and a controller that houses a controller that controls driving of the electric motor, and a lid that covers the opening In the device manufacturing method,
A cylindrical jig is provided concentrically on the outer peripheral side of the lid and is fitted to the lid, and after forming a predetermined clearance around the entire circumference between the lid and the cylindrical jig, the annular jig A method of manufacturing an electric oil pump device, characterized by forming a friction weld.

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