JP6922758B2 - Fixed structure of cooling pipe - Google Patents

Description

The present invention relates to a fixed structure of a cooling pipe, and more particularly to a fixed structure of a plurality of cooling pipes for supplying a refrigerant to a rotary electric machine.

Motors that convert electrical energy into rotational kinetic energy, generators that convert rotational kinetic energy into electrical energy, and electrical equipment that functions as both electric motors and generators are known. In the following, these electric devices will be referred to as rotary electric appliances.

A rotary electric machine has two members that are coaxially arranged and rotate relative to each other. Normally, one is fixed and the other is rotated. A coil is arranged on a fixed member (stator), and a rotating magnetic field is formed by supplying electric power to the coil. The other member (rotor) rotates due to the interaction with this magnetic field.

Electric vehicles such as hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), and electric vehicles (EVs) equipped with a rotating electric machine as a prime mover together with an internal combustion engine are known. As a power unit for these electric vehicles, a power unit having a configuration in which a rotary electric machine is integrated with a transaxle or a transmission has been put into practical use. In this power unit, the rotary electric machine is housed in a case such as a transaxle, and direct cooling by the outside air cannot be expected. Therefore, the lubricating oil contained in the transaxle or the like or the hydraulic fluid for controlling the equipment is supplied to the rotary electric machine to cool the rotary electric machine.

For example, in Patent Document 1, oil is supplied to a power transmission mechanism from an oil pump unit including a mechanical oil pump driven by an internal combustion engine and an electric oil pump driven by an electric motor to supply power. It is described that each part of the transmission mechanism is lubricated and cooled.

Japanese Unexamined Patent Publication No. 2009-96326

When the refrigerant is supplied by a plurality of oil pumps to cool the rotary electric machine, a plurality of cooling pipes connected to a cooling circuit including each oil pump are arranged above the rotary electric machine, and the refrigerant delivered by each oil pump is provided. There is a known cooling structure that supplies power from different cooling pipes to the rotary electric machine. In such a cooling structure, for example, an insertion hole is provided in a case body such as a transformer axle accommodating a rotary electric machine, and the cooling pipe is fixed and communicated with the insertion hole by inserting the cooling pipe into the insertion hole. Refrigerant is supplied to the cooling pipe from the refrigerant supply path.

Here, when the cooling pipe for supplying the refrigerant to the rotary electric machine is assembled above the case body for accommodating the rotary electric machine, the position of the cooling pipe is relatively twisted due to the stress at the time of assembling, and the refrigerant provided in the cooling pipe is relatively twisted. The position of the discharge hole may shift. Further, from the viewpoint of accuracy, cost, mass, manufacturability, etc. of the shape of the cooling pipe, a cooling pipe made of a resin material is used, but in the cooling pipe made of a resin material, warpage occurs due to shrinkage of the resin after molding. As a result, the position of the refrigerant discharge hole may shift. If the position of the refrigerant discharge hole of the cooling pipe shifts, the designed cooling performance may not be satisfied. Therefore, when a plurality of cooling pipes are provided on the case body, it is conceivable to adopt a cooling structure in which the plurality of cooling pipes are connected by a connecting member and integrated in order to suppress twisting and deformation of the cooling pipes.

However, with respect to a cooling structure in which a plurality of cooling pipes are connected by a connecting member, a problem may arise regarding a fixing structure for fixing the plurality of cooling pipes to the case body. In the conventional cooling structure, when the cooling pipe is assembled to the case body, the tip end side of the opening end side of the cooling pipe is fitted into the insertion hole provided in the case body, but a plurality of cooling pipes are connected by a connecting member. In the structure, it becomes difficult to fit a plurality of cooling pipes by gap fitting. In gap fitting, the fitting tolerance is set small to prevent refrigerant leakage, but if there is a relative misalignment at the tip of multiple cooling pipes connected on the open end side due to variations during manufacturing, etc., This is because at least one of the plurality of connection points is out of the range of the fitting tolerance. However, if the fitting tolerance is increased in order to facilitate the fitting, the adhesion of the fitting portion due to the gap fitting is lowered and the refrigerant leaks. Therefore, the fitting tolerance must be kept small in order to prevent refrigerant leakage, but in order to assemble the structure, the structure of each cooling pipe and the insertion hole of the case body must be machined with high precision. In addition to being difficult, processing costs increase.

The present invention has been made in view of the above problems, and is provided with a plurality of pipes for supplying the refrigerant delivered from each of the plurality of pumps from above the rotary electric machine, and a bracket for connecting the plurality of pipes. It is an object of the present invention to provide a fixed structure of a cooling pipe which is a fixed structure of a pipe and can achieve both improvement of assembling property and prevention of refrigerant leakage.

The fixed structure of the cooling pipe according to the present invention includes a first cooling pipe and a second cooling pipe for supplying the refrigerant sent from each of the first pump and the second pump from above the rotary electric machine, and the first cooling pipe and the first cooling pipe. 2 A structure in which the cooling pipe is fixed inside the case body for accommodating the rotary electric machine, which is provided with a bracket for connecting the cooling pipes, and the pressure fluctuation of the refrigerant flowing inside the first cooling pipe and the second cooling pipe. In a cooling pipe with a relatively small opening end, the tip on the opening end side is connected to a rubber seal provided on the case body, and in a cooling pipe in which the pressure fluctuation of the refrigerant flowing inside is relatively large, the tip on the opening end side is connected. Is characterized in that it is connected to an insertion hole provided in the case body by fitting a gap.

In a preferred embodiment, the pump that delivers the refrigerant to the cooling pipe having a relatively large pressure fluctuation is a mechanical oil pump, and the pump that delivers the refrigerant to the cooling pipe having a relatively small pressure fluctuation is an electric oil pump. be. In another preferred embodiment, the open end of the first cooling pipe and the open end of the second cooling pipe are provided on opposite sides of each cooling pipe in the longitudinal direction.

According to the above configuration, the tip of the cooling pipe and the case body, in which the pressure fluctuation of the refrigerant is relatively small, are connected via an elastically deformable rubber seal, so that the fixing position of the cooling pipe has a degree of freedom. Assembling the case body and each cooling pipe can be facilitated. At the same time, the sealing property of the joint portion can be ensured by fitting the tip end portion of the cooling pipe and the case body, in which the pressure fluctuation of the refrigerant is relatively large, by gap fitting. As a result, it is possible to improve the assemblability of the cooling pipe structure in which a plurality of cooling pipes are connected to the bracket and to prevent oil leakage in each cooling pipe.

It is a figure which shows the structure of the vehicle control system. It is a figure which shows the structure of a rotary electric machine and its surroundings. It is a figure which shows the structure of the fixed structure of the cooling pipe which concerns on an example of embodiment. It is a figure which shows the structure of a cooling pipe.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the following, a hybrid vehicle equipped with an internal combustion engine, two rotary electric machines, a mechanical oil pump, an electric oil pump, and the like will be described as vehicles, but this is merely an example for explanation.

FIG. 1 is a diagram showing a configuration of a vehicle control system 10 for a hybrid vehicle. The vehicle control system 10 includes a power unit 14 mounted on a hybrid vehicle.

The power device 14 includes an engine (not shown) which is an internal combustion engine, a first rotary electric machine 18 shown as MG1, a second rotary electric machine 20 shown as MG2, and a power transmission mechanism 16 provided between them. ,including.

The first rotary electric machine 18 and the second rotary electric machine 20 are motor generators (MGs) mounted on a vehicle, and function as motors when electric power is supplied, and generate electric power when braking or being driven by an engine. It is a three-phase synchronous rotary electric machine that functions as a machine. Here, one of the first rotary electric machine 18 and the second rotary electric machine 20 is mainly used as a generator for charging a battery (not shown), and the other is mainly used as a drive motor for traveling a vehicle.

For example, the first rotary electric machine 18 is used as a generator that is driven by an engine to generate electric power and supplies the generated electric power to a battery. Further, the second rotary electric machine 20 is used for vehicle traveling, receives electric power from a battery during power running, functions as a motor to drive the axle of the vehicle, and functions as a generator during braking to regenerate braking energy. , Can be supplied to the battery. Hereinafter, the description will be made assuming that the first rotary electric machine 18 is used as a generator and the second rotary electric machine 20 is used as a motor.

The power transmission mechanism 16 is a mechanism having a function of distributing the power supplied to the hybrid vehicle between the output of the engine and the outputs of the first rotary electric machine 18 and the second rotary electric machine 20. As the power transmission mechanism 16, a planetary gear mechanism connected to each of the output shaft of the engine, the output shafts of the first rotary electric machine 18 and the second rotary electric machine 20, and the output shaft to the axle can be used. The output shaft of the engine connects the power transmission mechanism 16 and the engine, and is connected to the drive shaft of the mechanical oil pump (hereinafter referred to as "MOP") 42 via the connection shaft, and is used for driving the MOP 42.

Charging of a rechargeable battery (power source) is performed, for example, by driving the first rotary electric machine 18 by an engine and supplying electric power generated by the first rotary electric machine 18. The battery is, for example, a lithium ion battery having a terminal voltage of about 200 V to about 300 V, which is composed of a plurality of cell cells or a combination of battery cells. As the battery, a large-capacity capacitor or the like may be used in addition to a secondary battery such as a lithium ion battery or a nickel metal hydride battery.

The case body 22 is a housing including a power transmission mechanism 16, a first rotary electric machine 18, and a second rotary electric machine 20 inside, and is also called a transaxle. Oil for lubricating and cooling the moving parts of the power transmission mechanism 16, the first rotary electric machine 18, and the second rotary electric machine 20 is stored in the internal space of the case body 22. As the oil having the function of a refrigerant, for example, a lubricating oil called ATF can be used. Further, it may be a part of a cooling circuit in which a through hole is formed in the case body 22 to circulate and supply oil.

The cooling system 12 has a first supply path 24 including the MOP42, which is the first pump, and an electric motor, which is the second pump, as a cooling circuit that circulates and supplies the oil used for cooling the first rotary electric machine 18 and the second rotary electric machine 20. It has a second supply path 26 including an oil pump (hereinafter referred to as "EOP") 44.

The MOP 42 and EOP 44 are configured to suck oil from an oil pan (not shown) in which oil is stored through a strainer 58. Specifically, the refrigerant intake path 38 is connected to the strainer 58 provided on the lower side of the case body 22, and the refrigerant intake path 38 branches into the MOP 42 side and the EOP 44 side on the downstream side of the strainer 58. That is, the MOP 42 and the EOP 44 are connected in parallel to the strainer 58.

The first supply path 24 includes a MOP 42, an air-cooled oil cooler (hereinafter referred to as “cooler”) 50, a first check valve 54, an MG1 supply pipe 36, and a first cooling pipe (hereinafter referred to as “first pipe”). ) 28 and is included.

The MOP 42 is a mechanical refrigerant pump whose drive shaft is connected to the output shaft of the engine and is driven when the engine operates. That is, when the vehicle is driven by the power of the engine, the MOP 42 delivers oil from the outlet. The oil delivered from the MOP 42 is supplied to the power transmission mechanism 16 and the first rotary electric machine 18 to function as lubricating oil, and at the same time, the oil is supplied to the first rotary electric machine 18 and the second rotary electric machine 20 via the first supply path 24. Functions as a refrigerant. The MOP 42 starts driving when the engine starts, and ends driving when the engine stops.

The first check valve 54 is provided between the MOP 42 and the cooler 50, and has a function of preventing the backflow of oil on the outlet side of the MOP 42. The oil delivered by the MOP 42 passes through the first check valve 54 and is pumped to the cooler 50.

The branch point P is a point where the flow path branches between the MOP 42 and the cooler 50 to the cooler 50 side and the first rotary electric machine 18 side. When the oil delivered from the MOP 42 is pumped to the first rotary electric machine 18 and the power transmission mechanism 16 side at the branch point P, it is supplied to the first rotary electric machine 18 and the power transmission mechanism 16 without passing through the cooler 50. NS. On the other hand, the oil pumped to the cooler 50 side at the branch point P flows into the cooler 50.

The cooler 50 is a heat exchanger that exchanges heat between oil and air (for example, the outside air of a vehicle), and has higher cooling performance than the water-cooled cooler 52. Since the cooler 50 is provided outside the case body 22, the oil pumped in the first supply path 24 once circulates outside the case body 22 and then returns to the inside of the case body 22 again. become.

The first supply path 24 is provided with two relief valves 40 for adjusting the oil pressure in the first supply path 24. In each relief valve 40, the supply port is connected to the first supply path 24, and the discharge port is open toward the inside of the case body 22. For example, the relief pressures of the two relief valves 40 are set to different sizes. The oil in the first supply path 24 is configured to be supplied to the inside of the case body 22 from each relief valve 40 at the time of overpressure.

The first supply path 24 is a branch point Q on the downstream side of the cooler 50, and is on the side of the MG1 supply pipe 36 that supplies the refrigerant to the first rotary electric machine 18 and the first pipe 28 that supplies the refrigerant to the second rotary electric machine 20. Branch to the side. The MG1 supply pipe 36 is a flow path provided inside the case body 22, and is provided above the first rotary electric machine 18 to discharge the refrigerant to the first rotary electric machine 18. Further, the first pipe 28 is a flow path provided inside the case body 22, and is provided above the second rotary electric machine 20 to discharge the refrigerant to the second rotary electric machine 20. As a result, the oil cooled by the cooler 50 is supplied to each of the first rotary electric machine 18 and the second rotary electric machine 20.

The second supply passage 26 includes an EOP 44, a water-cooled oil cooler (hereinafter referred to as “water-cooled cooler”) 52, a second check valve 56, and a second cooling pipe (hereinafter referred to as “second pipe”) 30. It is composed of.

The EOP 44 is an electric refrigerant pump driven by an electric motor 48 and driven and controlled by a control device 46. The control device 46 is composed of a well-known electronic control device capable of controlling the EOP 44, and drives and controls the EOP 44 by controlling the electric motor 48. The control device 46 can be configured by a computer suitable for mounting on a hybrid vehicle. The control device 46 may be a part of another control device mounted on the hybrid vehicle, for example, a control device that controls each element of the cooling system 12, or an integrated control device that controls the entire vehicle.

The water-cooled cooler 52 is a heat exchanger that exchanges heat between oil and cooling water. Since the water-cooled cooler 52 is provided outside the case body 22, the oil pumped into the second supply path 26 once circulates outside the case body 22 and then returns to the inside of the case body 22 again. It will be.

The second check valve 56 is provided between the water-cooled cooler 52 and the second pipe 30, and has a function of preventing backflow of oil on the outlet side of the EOP44. The oil delivered by the EOP 44 passes through the water-cooled cooler 52 and the second check valve 56, and is pumped to the second pipe 30.

The second pipe 30 is a flow path provided inside the case body 22, and is provided above the second rotary electric machine 20 to discharge the refrigerant to the second rotary electric machine 20. As a result, the oil cooled by the water-cooled cooler 52 is supplied to the second rotary electric machine 20.

In the cooling system 12 according to the present embodiment, the oil (refrigerant) cooled by the cooler 50 and the water-cooled cooler 52 having different cooling performances are pumped by different routes, and the first pipe 28 and the second pipe 30 to the second rotary electric machine are different from each other. By supplying to 20, the second rotary electric machine 20 can be effectively cooled.

FIG. 2 is a diagram showing a configuration around the second rotary electric machine 20 housed in the case body 22. FIG. 2 shows a cross section perpendicular to the rotation axis of the second rotary electric machine 20, particularly a cross section of the stator 60, together with a cross section of the first pipe 28 and the second pipe 30.

The second rotary electric machine 20 has a cylindrical or annular stator 60 and a cylindrical or disk-shaped rotor 62 arranged coaxially with the cylindrical shape of the stator 60. The rotating shaft 64 penetrates the center of the rotor 62. The rotary shaft 64 functions as an output shaft for outputting a rotational force to the outside when the second rotary electric machine 20 operates as an electric motor, and an external rotational force when the second rotary electric machine 20 operates as a generator. Functions as an input axis for inputting. The second rotary electric machine 20 is used, for example, with the rotary shaft 64 lying down as shown in the figure.

The stator 60 includes a stator core 66 in which irregularities are alternately arranged along the circumferential direction on the inner circumference. A coil lead wire is housed in a concave portion provided on the inner circumference of the stator core 66, and the coil lead wire is formed so as to wind a convex portion to form a coil 68. By supplying electric power to the coil 68, a rotating magnetic field is formed in the space inside the stator 60. In other words, the coil 68 is wound around the stator core 66 so that a rotating magnetic field is formed when power is supplied.

The convex portion on the inner circumference of the stator core 66 is also called a tooth, and the concave portion is also called a slot. In the region adjacent to the end face of the stator core 66, a plurality of coil conductors are intricately bundled. The bundled portion of the coil conductor is the coil end 70. In the coil end 70, the coil conductors are intricately bundled as described above, and although there is a gap between the conductors, the coil end 70 has a rectangular ring shape as a whole and is adjacent to the cylindrical end face of the stator core 66. Is located. In FIG. 2, the coil end 70 is shown in a simplified annular shape without drawing individual bundled conductors.

The rotor 62 has a cylindrical shape as a whole, and is arranged on the inner circumference of the stator 60, particularly at the tip of the teeth with a slight gap. For example, a permanent magnet is embedded in the rotor 62 on the outer peripheral surface or in the vicinity of the outer peripheral surface so as to rotate by interacting with the rotating magnetic field formed by the stator 60. Further, it is also possible to provide portions having different reluctances in the circumferential direction of the rotor 62 and rotate the rotor 62 by the interaction between the portions and the rotating magnetic field. The rotation shaft 64 is fixed to the rotor 62 so as to rotate integrally with the rotor 62.

Here, the heat generated in the coil conducting wire in the slot flows to the surrounding stator core 66, but the coil end 70 does not have a good heat conductor in the surroundings, and the temperature tends to rise. Therefore, efficient cooling of the coil end 70 is desired. Cooling with oil can be expected to be efficient because liquids generally have better thermal conductivity than gases. Further, by applying oil from above and removing heat when the oil flows through the coil end 70, the amount of oil used can be reduced as compared with the case where the coil end 70 is immersed in the oil.

In the present embodiment, as described above, two systems are provided as cooling paths for supplying the oil used for cooling the second rotary electric machine 20. Then, as shown in FIG. 2, the first pipe 28 and the second pipe 30 connected to each system are arranged above the second rotating electric machine 20 in the case body 22 so as to be substantially parallel to the rotating shaft 64. Oil is supplied from the discharge holes 32 provided in the 1 pipe 28 and the 2nd pipe 30 toward the 2nd rotary electric machine 20 to cool the 2nd rotary electric machine 20.

FIG. 3 is a diagram showing the configuration of the fixed structure 80 of the cooling pipe according to the present embodiment. FIG. 3 is a horizontal cross section of the case body 22 above the second rotary electric machine 20 (not shown in FIG. 3), and is a partial cross section of the horizontal cross section including the first pipe 28 and the second pipe 30 as viewed from above. It is a figure. As shown in FIG. 3, the fixed structure 80 according to the present embodiment includes the first pipe 28 and the second pipe 30, and the bracket 82 connecting the first pipe 28 and the second pipe 30, and the first pipe 28. The tip portion 28c of the second pipe 30 is connected to the insertion hole 25 provided in the case body 22, and the tip portion 30c of the second pipe 30 is connected to the rubber seal 84 provided in the case body 22.

FIG. 4 is a diagram showing the configuration of the first pipe 28 and the second pipe 30 connected by the bracket 82. FIG. 4A is a view of the first pipe 28 and the second pipe 30 as viewed from above, and FIG. 4B is a horizontal direction of the fixing structure 80 of the cooling pipe shown in FIG. 4A. It is a cross-sectional view.

The first pipe 28 is formed of a cylindrical pipe body 28a, one end in the longitudinal direction is opened to form an open end 28b, and the other end is closed. Further, on the side of the pipe body 28a facing the second rotary electric machine 20 (the back side of the paper in FIGS. 3 and 4), a plurality of discharge holes 32 for discharging oil toward the second rotary electric machine 20 are provided.

Like the first pipe 28, the second pipe 30 is formed of a cylindrical pipe body 30a, one end in the longitudinal direction is opened to form an open end 30b, and the other end is closed. However, as shown in FIG. 4, the opening end 30b of the second pipe 30 is provided on the opposite side of the opening end 28b of the first pipe 28. As a result, inside the second pipe 30, the oil flows in the direction opposite to the direction of the oil flowing inside the first pipe 28.

The discharge hole 32 extends radially outward from the inner peripheral portion of the pipe bodies 28a and 30a and penetrates the pipe bodies 28a and 30a. As shown in FIG. 4B, for example, the discharge holes 32 face two locations facing the coil ends 70 on both sides of the stator core 66 and the outer periphery of the stator core 66 along the longitudinal direction of the pipe bodies 28a and 30a. It is provided in one place. The number and arrangement of discharge holes provided in the pipe bodies 28a and 30a are not limited to this example, and may be appropriately set in consideration of the arrangement and cooling performance of the cooling pipes.

The bracket 82 is a member that connects the pipe bodies 28a and 30a to each other in a state where the first pipe 28 and the second pipe 30 are arranged in parallel, whereby the first pipe 28, the second pipe 30 and the bracket 82 are one. It forms a structure. In the present embodiment, the bracket 82 is a plate-shaped member made of a metal material arranged along a direction orthogonal to the longitudinal direction, and is integrally molded with the first pipe 28 and the second pipe 30. The bracket 82 may be a plate-shaped member having two through holes into which the outer peripheral surfaces of the pipes 28 and 30 are inserted into the inner peripheral surfaces thereof. In the fixed structure 80 shown in FIG. 4, each cooling pipe is connected by one bracket 82, but members connecting the first pipe 28 and the second pipe 30 may be provided at a plurality of locations in the longitudinal direction.

In the fixing structure 80 according to the present embodiment, as shown in FIG. 3, the first pipe 28 and the second pipe 30 connected by the bracket 82 are fixed to the case body 22 above the second rotary electric machine 20. The tip end portion 28c of the first pipe 28 is inserted into the insertion hole 25 provided in the case body 22 and fitted by gap fitting. That is, both are fitted with a gap between the outer peripheral surface of the tip portion 28c and the inner peripheral surface of the insertion hole 25 so that oil does not leak. Here, the insertion hole 25 penetrates the case body 22 along the longitudinal direction of the first pipe 28. The tip 28c of the first pipe 28 is fitted to one end of the insertion hole 25. A supply pipe (not shown) forming a part of the first supply path 24 is connected to the other end of the insertion hole 25, and oil is supplied from the supply pipe to the first pipe 28 via the insertion hole 25. NS.

For the outer peripheral surface of the tip portion 28c and the inner peripheral surface of the insertion hole 25, the type of oil, the pressure of the oil applied to the fitting portion, the length at which the tip portion 28c is inserted into the insertion hole 25, and the like are taken into consideration. It may be set appropriately in consideration of the balance between the ease of assembly and the effect of preventing oil leakage.

On the other hand, the tip portion 30c of the second pipe 30 is fixed to the case body 22 by a rubber seal 84 provided on the inner peripheral surface of the case body 22. The rubber seal 84 has a cylindrical shape and is fixed to the inner peripheral surface of the case body 22. The inside of the rubber seal 84 penetrates the case body 22 and communicates with the inside of the through hole 27 forming a part of the second supply path 26. The tip 30c of the second pipe 30 has a cylindrical shape having a diameter slightly smaller than that of the pipe body 30a, and the second pipe 30 is a rubber seal so that the outer peripheral surface of the tip 30c is in contact with the inner peripheral surface of the rubber seal 84. It is inserted in 84. As a result, the oil flowing from the second supply path 26 is supplied to the second pipe 30 through the through hole 27. Further, the tip portion 30d on the side opposite to the tip portion 30c of the second pipe 30 in the longitudinal direction has a cylindrical shape having a diameter slightly smaller than that of the pipe body 30a, and abuts on the recess 23 provided in the case body 22. There is.

The first pipe 28 and the second pipe 30 according to the present embodiment are assembled to the case body 22 as follows. First, the positions of the tip 28c of the first pipe 28 and the tip 30d of the second pipe 30 are aligned with the insertion holes 25 and the recesses 23 provided in the case body 22a of the case body 22 and inserted. At this time, the tip 28c of the first pipe 28 is connected to the insertion hole 25 by gap fitting. On the other hand, the size and the like of the recess 23 are designed so that the tip 30d abuts even if the relative positions of the tip 30d and the recess 23 of the second pipe 30 deviate slightly from the design. Next, as shown in FIG. 3, the bracket 82 connecting the first pipe 28 and the second pipe 30 is fixed to the case main body 22a by the fastening member 86 composed of bolts and nuts. After that, the cover 22b (for example, the rear cover) of the case body 22 is aligned with the tip portion 30c of the second pipe 30 and the rubber seal 84 provided on the cover 22b, and the fastening member 88 or the like shown in FIG. 3 is used. Attached to the case body 22a. At this time, the outer peripheral surface of the tip portion 30c of the second pipe 30 and the inner peripheral surface of the rubber seal 84 are fitted. In this way, in the fixing structure 80 according to the present embodiment, the first pipe 28 and the second pipe 30 connected by the bracket 82 are fixed to the case body 22.

Next, the operation and effect of the fixed structure 80 of the cooling pipe according to the present embodiment will be described.

In the fixed structure 80 of the present embodiment, as described above, the tip 28c of the first pipe 28 is connected to the insertion hole 25 provided in the case body 22 by gap fitting, and the tip 30c of the second pipe 30 is the case body 22. It is connected to the rubber seal 84 provided in. As a result, the first pipe 28 and the second pipe 30 integrated by the bracket 82 are fixed and held to the case body 22.

Here, when fixing the two cooling pipes integrated by the bracket to the case body, consider a case where both the joints between the tip end side of the opening end side of each cooling pipe and the case body are fitted by gap fitting. .. When the cooling pipe is fitted by gap fitting, the fitting tolerance is set to be small in order to prevent leakage at the fitting portion of the supplied oil. On the other hand, since the two cooling pipes are integrated by the bracket, the relative positions of the two cooling pipes are fixed. Therefore, when the cooling pipe is attached, even if the insertion hole of the case body 22 or each cooling pipe is slightly displaced due to machining error or expansion / contraction due to temperature, it is set at two fitting positions. It may not be possible to fit within the fitted fitting tolerances at the same time, making it difficult to assemble the cooling pipe. In particular, when the opening ends 28b and 30b of each cooling pipe are provided on the opposite sides in the longitudinal direction as in the present embodiment, the connection portions of the cooling pipes are separated from each other as compared with the case where they are provided on the same side in the longitudinal direction. This makes it even more difficult. On the other hand, if the fitting tolerance is increased in order to facilitate fitting at the time of assembling the cooling pipe, the adhesion of the fitting portion is lowered and oil leakage occurs. In order to prevent refrigerant leakage, the fitting tolerance must be reduced, so the fitting structure of each cooling pipe and case body 22 must be machined with high precision, but such high precision machining becomes difficult. In addition, it causes an increase in processing cost, which is not preferable.

On the other hand, in the fixed structure 80 of the present embodiment, the tip portion 30c on the open end side of one of the two cooling pipes, the second pipe 30, is connected to the rubber seal 84 provided on the case body 22. Since the rubber seal 84 is elastically deformed, when the fitting positions of the tip 28c of the first pipe 28 and the insertion hole 25 are aligned, the inner peripheral surface of the rubber seal 84 and the outer peripheral surface of the tip 30c of the second pipe 30 are aligned. Even if the relative positions of the rubber seals are displaced, the generated assembly tolerance can be absorbed by the elastic deformation of the rubber seal 84, and the two can be connected. Therefore, it is possible to give a degree of freedom to the position of the tip portion 30c of the second pipe 30 connected to the rubber seal 84. As a result, even if the first pipe 28 and the second pipe 30 are connected by the bracket 82, the first pipe 28 and the second pipe 30 can be easily assembled to the case body 22.

Further, in order to improve the assembling performance, when fixing a plurality of cooling pipes to the case body, it is conceivable to connect all the tips of the cooling pipes on the open end side to the rubber seal provided on the case body. However, in the first pipe 28 to which the oil is supplied by the MOP 42, since the drive shaft of the MOP 42 is connected to the output shaft of the engine, when the engine operates at a high speed, the oil pumped to the first pipe 28 The flow rate and pressure will increase. When a rubber seal is used for joining a refrigerant supply path having a large pressure fluctuation, it may be difficult to maintain the sealing property for a long period of time.

On the other hand, in the fixed structure 80 of the present embodiment, the tip 28c of the first pipe 28, in which oil is supplied from the MOP 42 and the pressure fluctuation of the oil flowing inside is relatively large, is fitted to the insertion hole 25 by gap fitting. doing. As a result, the fitting tolerance between the tip end portion 28c of the first pipe 28 and the insertion hole 25 can be set within an appropriate range, and oil leakage can be prevented for a long period of time. Further, in the second pipe 30 to which the oil is supplied from the EOP 44, the EOP 44 is driven and controlled by the control device 46, and the pressure fluctuation of the oil flowing inside is relatively small. Even if it is fixed to the case body 22 by the rubber seal 84, the sealing property after assembly can be ensured.

As described above, in the present embodiment, the tip portion 30c of the second pipe 30 in which the oil pressure fluctuation is relatively small is fixed to the case body 22 by using the rubber seal 84, so that the fixing position of the second pipe 30 can be freely set. It is possible to easily assemble the two integrated cooling pipes to the case body 22 with a certain degree, and the case body by fitting the tip 28c of the first pipe 28, which has a relatively large oil pressure fluctuation, into the case body. By fitting it with the insertion hole 25 of 22, the sealing property of the joint portion can be ensured. Therefore, the cooling pipe fixing structure 80 of the present embodiment can achieve both improvement of assembling property of the cooling pipe structure in which a plurality of cooling pipes are integrated and prevention of oil leakage in each cooling pipe. As a result, the cooling performance of the second rotary electric machine 20 by the cooling system 12 of the present embodiment can be improved.

Further, in the cooling pipe fixing structure 80 of the present embodiment, the pipe bodies 28a and 30a are connected to each other by the bracket 82 to form one structure. Conventionally, a cooling pipe made of a resin material is generally used from the viewpoint of accuracy, cost, mass, manufacturability, etc. of the shape of the cooling pipe. Warpage may occur due to the shrinkage of the plastic. In addition, the position of the cooling pipe may be relatively twisted due to the stress when assembling the cooling pipe to the case body. In such a case, the position of the oil discharge hole provided in the cooling pipe may shift, and the designed cooling performance may not be satisfied. On the other hand, in the present embodiment, since the pipe bodies 28a and 30a are connected to each other by the bracket 82, the misalignment that may occur in the two cooling pipes 28 and 30 is suppressed. As a result, by continuing to discharge the oil from each cooling pipe from the discharge hole 32 at an appropriate position, the oil can be continuously supplied to the portion having the highest cooling efficiency of the second rotary electric machine 20, and the cooling efficiency is high. Can be maintained. In the fixed structure 80 shown in FIG. 4, the pipes 28 and 30 are connected by one bracket 82, but in order to prevent the displacement of the oil discharge holes and further improve the efficiency of the cooling performance, the longitudinal direction is used. Two cooling pipes may be connected by a plurality of connecting members provided at a plurality of locations of the above.

In the cooling pipe fixing structure 80 of the present embodiment, as described above, the bracket 82 connecting the two pipes 28 and 30 is made of a metal material. As shown in FIG. 3, the cooling pipe fixing structure 80 according to the present embodiment is joined to each of the case main body 22a and the cover 22b (for example, the rear cover) constituting the case body 22. Therefore, when the case body 22a and the cover 22b are assembled, a large amount of input is generated in the two integrated pipes 28 and 30. In the present embodiment, the strength of each of the pipes 28 and 30 with respect to such a large amount of input can be improved by integrating with the bracket 82 made of a metal material.

In the present embodiment, the opening end 28b of the first pipe 28 and the opening end 30b of the second pipe 30 are provided on opposite sides in the longitudinal direction, and oil is discharged inside the first pipe 28 and inside the second pipe 30. It is designed to flow in opposite directions. For example, the engine speed is increased, the pressure of the oil that is pumped by the MOP 42 and flows in the first pipe 28 increases, and the oil discharge direction from the discharge hole 32 is in the direction in which the oil flows in the first pipe 28. It is possible that it will shift. At this time, if the first pipe 28 and the second pipe 30 are configured so that the oil flows in opposite directions, the pressure of the oil flowing in the second pipe 30 is increased to increase the pressure of the oil flowing in the second pipe 30 so that the discharge holes of the second pipe 30 are discharged. The oil discharge direction from 32 can be shifted in the direction opposite to that of the first pipe 28. Then, the deviation in the oil discharge direction in the first pipe 28 and the deviation in the oil discharge direction in the second pipe 30 cancel each other out, so that the oil can be discharged in a desired range.

In the above description, the MOP 42 pumps the oil to the first pipe 28 and the EOP 44 pumps the oil to the second pipe 30, but each cooling pipe uses a plurality of mechanical oil pumps. Oil may be pumped to. Also in that case, of the first cooling pipe and the second cooling pipe that supply oil to the second rotary electric machine 20, the tip of the cooling pipe on the opening end side where the oil pressure fluctuation is relatively small and the case body 22 are inserted. The holes may be fixed using the rubber seal 84, and the tip end side of the opening end side of the cooling pipe in which the oil pressure fluctuation is relatively large and the insertion hole of the case body 22 may be fitted by gap fitting. The difference in pressure fluctuation between the two when supplying to the cooling pipe through each refrigerant supply path using a plurality of mechanical oil pumps is, for example, the pressure loss due to the difference in the path and inner diameter of the refrigerant supply path. It is thought that it is caused by the difference between.

In the above description, an example in which the opening end 28b of the first pipe 28 and the opening end 30b of the second pipe 30 are provided on opposite sides in the longitudinal direction is shown, but the opening ends of a plurality of cooling pipes are the same in the longitudinal direction. It may be provided on the side. Further, in the above description, a configuration is shown in which one each of the first pipe 28 to which the oil is supplied from the MOP 42 and the second pipe 30 to which the oil is supplied from the EOP 44 is arranged, but one oil pump. The oil may be supplied to two or more cooling pipes arranged in parallel from the above.

10 Vehicle control system, 12 Cooling system, 14 Power unit, 16 Power transmission mechanism, 18 1st rotary electric machine, 20 2nd rotary electric machine (rotary electric machine), 22 case body, 22a case body, 22b cover, 23 recesses, 24th 1 supply path, 25 insertion hole, 26 second supply path, 27 through hole, 28 first pipe (first cooling pipe), 28a, 30a pipe body, 28b, 30b open end, 28c, 30c, 30d tip, 30 2nd pipe (2nd cooling pipe), 32 discharge holes, 36 MG1 supply pipe, 38 refrigerant intake path, 40 relief valve, 42 MOP (1st pump), 44 EOP (2nd pump), 46 controller, 48 electric Motor, 50 cooler, 52 water-cooled cooler, 54 1st check valve, 56 2nd check valve, 58 strainer, 60 stator, 62 rotor, 64 rotating shaft, 66 stator core, 68 coil, 70 coil end, 80 fixed structure, 82 brackets, 84 rubber seals, 86,88 fastening members, P, Q branch points.

Claims (1)

The first cooling pipe and the second cooling pipe that supply the refrigerant sent from each of the first pump and the second pump from above the rotary electric machine,
A structure including the first cooling pipe and a bracket for connecting the second cooling pipe, in which the cooling pipe is fixed inside a case body for accommodating a rotary electric machine.
Of the first cooling pipe and the second cooling pipe, in the cooling pipe in which the pressure fluctuation of the refrigerant flowing inside is relatively small, the tip portion on the opening end side is connected to the rubber seal provided on the case body and is inside. A cooling pipe having a relatively large pressure fluctuation of the refrigerant flowing through the cooling pipe has a fixed structure of the cooling pipe, characterized in that the tip end portion on the opening end side is connected to an insertion hole provided in the case body by gap fitting.

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