JP7635288B2 - Cooling water piping arrangement - Google Patents

Description

The present invention relates to a cooling water piping arrangement structure mounted on a vehicle, and in particular to a cooling water piping arrangement structure that can effectively protect the cooling water piping in the event of a vehicle collision.

In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into electrification technology is being conducted to reduce CO2 emissions and improve energy efficiency in vehicles.

Generally, in electric vehicles and hybrid vehicles equipped with an electric motor for driving and an inverter as a power conversion device, a cooling device such as a radiator is installed in front of the motor room to cool the motor and inverter, which generate heat during operation. The motor and inverter are connected to the cooling device by cooling water piping, and the cooling water cooled by the cooling device is circulated through the cooling water piping.

In such electric vehicles or hybrid vehicles, various measures are taken to adequately protect important parts and units in the event of a vehicle collision. For example, Patent Document 1 discloses a pair of cooling water pipes connecting a drive unit including a motor control device and the like to a cooling device arranged in front of the drive unit, the pair of cooling water pipes including a pipe base connected to the front surface of the drive unit, a first straight section extending forward from the pipe base, a bent section bending downward from the first straight section, and a second straight section extending downward from the bent section, the second straight sections being arranged with a shifted position in the vehicle width direction as viewed from the front, and arranged so that the spacing between them increases as they extend downward. As a result, in the event of a frontal collision of the vehicle, the pair of cooling water pipes come into contact with an interfering body such as the cooling device over a wide area, preventing the interfering body from directly contacting the drive unit.

JP 2020-203545 A

Patent Document 1 discloses technology for protecting the motor, which is the driving source of the vehicle, and the inverter, which is subjected to high voltage, in the event of a vehicle collision, but does not give sufficient consideration to protecting the cooling water piping. However, if the cooling water piping is damaged and coolant leaks, it becomes impossible to cool the motor and inverter, which raises the risk of these devices becoming too hot and the vehicle becoming unable to run. Therefore, there is a need to effectively protect the cooling water piping in the event of a vehicle collision.

Figure 4 is a side view showing a conventional example of an eAxle unit that integrates a motor, an inverter, and a gearbox, and a cooling water pipe. In the figure, the direction indicated by Fr is the front of the vehicle, and the direction indicated by Rr is the rear of the vehicle. The direction indicated by U is the upper side of the vehicle, and the direction indicated by D is the lower side of the vehicle. In this conventional example, a gearbox 42 is arranged adjacent to the left and right direction of a motor 41 (on the depth side of the figure) whose output shaft faces the left and right direction (width direction) of the vehicle, and an inverter 43 is arranged above the motor 41. In addition, a cooling water pipe 44 (only the connection part is shown) that connects to a cooling water flow path provided inside the motor 41 is provided at the upper front side of the motor 41 so as to protrude forward. In addition, a ring-shaped protrusion 45 that serves as a suspension point when the eAxle unit moves is provided at the upper part of the motor 41.

In this conventional example, the motor 41, gearbox 42, and inverter 43 are protected by a highly rigid case, but no measures are taken to protect the cooling water piping. This poses a problem that, in the event of a frontal collision of the vehicle, the cooling water piping 44 is more likely to be pinched and damaged by a device such as a radiator (not shown) located in front of the motor 41, or by structures such as the vehicle's front bulkhead and bumper beam (neither of which are shown). In addition, because the front of the e-axle unit has a protruding shape such as protrusion 45, the load during a collision is concentrated near protrusion 45, making the case around protrusion 45 more likely to be damaged.

The present invention was made to solve these problems, and aims to provide a cooling water piping arrangement structure that can effectively protect the cooling water piping from collision loads and prevent damage during a frontal collision of the vehicle. This will ultimately contribute to improving energy efficiency.

To achieve this objective, the invention according to claim 1 of the present invention is a cooling water piping arrangement structure 1 for a vehicle including a motor 11 arranged with its output shaft 11a facing the left-right direction of the vehicle, an inverter 12 arranged approximately directly above or below the motor 11, and a cooling water piping 13 through which cooling water flows to cool the motor 11 and/or the inverter 12, characterized in that the frontmost position of the motor 11 and the frontmost position of the inverter 12 are arranged to be approximately aligned in the longitudinal direction of the vehicle, and the cooling water piping 13 is arranged in the space S between the motor 11 and the inverter 12 in the vertical direction.

In this cooling water piping arrangement, the inverter is placed approximately directly above or below the motor, which is arranged so that its output shaft faces the left-right direction (width direction) of the vehicle, creating a gap between the motor and inverter, which are lined up one above the other, and the cooling water piping is placed in that space. Furthermore, since the motor and the inverter are arranged so that their front-most positions are approximately aligned, in the event of a front-on collision of the vehicle, most of the collision load transmitted from the structure and device in front of the motor is transmitted to the motor and inverter, whose front-most positions are approximately aligned. Therefore, the input of the collision load to the cooling water piping placed in the gap space between the motor and inverter is significantly mitigated, effectively protecting the cooling water piping and preventing damage.

The invention according to claim 2 of the present invention is characterized in that in the cooling water piping arrangement structure described in claim 1, the motor 11 has a substantially circular shape in side view, the inverter 12 has a substantially rectangular shape in side view, and the gap space S is formed near the front surface of the motor 11 and the front surface of the inverter 12.

According to this configuration, the motor has a substantially circular shape when viewed from the side, and the inverter has a substantially rectangular shape when viewed from the side. Therefore, when the motor and the inverter are arranged so that their respective frontmost positions are substantially aligned, a gap space is formed between the motor and the inverter arranged vertically, so that it spreads from near the frontmost position of the motor and the frontmost position of the inverter to the rear side of the vehicle. And, since the cooling water piping is arranged in such a gap space, the cooling water piping can be arranged behind the frontmost position of the motor and the inverter, and in the event of a collision from the front of the vehicle, the collision load generated is less likely to be transmitted to the cooling water piping. Therefore, in the event of a collision, the input of the collision load to the cooling water piping is significantly mitigated, so that the cooling water piping can be effectively protected and damage can be prevented. In addition, even if the devices and structures arranged in front of the motor and the inverter are deformed due to a collision, the possibility that these devices and structures will directly come into contact with the cooling water piping can be reduced, and the cooling water piping can be more effectively protected.

The invention according to claim 3 of the present invention is characterized in that in the cooling water piping arrangement structure described in claim 1, the cooling water piping 13 has a connection part 13a for connecting to a cooling water flow path provided inside the motor 11 and/or inverter 12, and the connection part 13a is arranged in the gap space S.

With this configuration, the connection part for connecting to the cooling water flow path provided inside the motor and/or inverter is arranged in the space between the motor and the inverter in the vertical direction, so that in the event of a frontal collision of the vehicle, the collision load generated is less likely to be transmitted to the connection part. Therefore, in the event of a collision, the input of the collision load to the connection part of the cooling water piping is significantly mitigated, so that the cooling water piping can be effectively protected and damage can be prevented.

The invention according to claim 4 of the present invention is characterized in that in the cooling water piping arrangement structure described in claim 1, the vehicle further includes a radiator 31 for cooling the cooling water, a radiator fan for cooling the radiator 31, and a fan motor 33 for driving the radiator fan, and the fan motor 33 is arranged in front of the cooling water piping 23 arranged in the gap space S in the front-rear direction of the vehicle.

According to this configuration, the fan motor for driving the radiator fan is positioned in front of the cooling water pipes that are placed in the gap space. Generally, fan motors are made of metal and have high rigidity, and often survive a frontal collision without being crushed. Therefore, by positioning the fan motor in this way, it functions as a protective structure for the cooling water pipes. In other words, in the event of a collision, the fan motor is likely to maintain its shape without being deformed by the collision load, so the collision load received by the fan motor is more likely to be transmitted to the front of the motor and inverter, which are located further forward than the cooling water pipes and are closer to the fan motor. Therefore, in the event of a collision, the input of the collision load to the cooling water pipes is further significantly reduced, so the cooling water pipes can be protected more effectively and damage can be prevented.

The invention according to claim 5 of the present invention is characterized in that in the cooling water piping arrangement structure described in claim 1, no protruding shape is provided on the front surface of the motor 11 and the front surface of the inverter 12.

With this configuration, the frontmost surface of the motor and inverter does not have a protruding shape that protrudes forward, so compared to when such a protruding shape is provided, it is possible to avoid the load from concentrating in a specific location during a collision, and the load can be dispersed by widening the load receiving surface. This makes it possible to suppress damage to the motor and inverter casing during a collision. In addition, by suppressing damage to the motor and inverter, the cooling water piping located in the space between the motor and inverter can be more effectively protected and damage can be prevented.

1 is a front view showing a schematic arrangement of cooling water piping according to an embodiment of the present invention; 2 is a cross-sectional view taken along line AA in FIG. 1. 1A and 1B are diagrams showing an outline of a cooling water piping arrangement structure according to another embodiment of the present invention, in which FIG. 1A is a side view showing the positional relationship between a motor, an inverter, and a radiator, and FIG. 1B is a front view showing the positional relationship between the cooling water piping and a fan motor. FIG. 1 is a side view showing a schematic diagram of a conventional example of a cooling water piping arrangement structure.

Below, a preferred embodiment of the cooling water piping arrangement structure of the present invention will be described in detail with reference to the drawings. The configuration described below is one example of the present invention, and the present invention is not limited thereto.

In the following explanation, front, rear, left, right, up and down are described according to the direction as seen by the driver of the vehicle, and in the drawings, the front of the vehicle is indicated as Fr, the rear as Rr, the left side as L, the right side as R, the top as U, and the bottom as D.

Figure 1 shows a schematic diagram of a cooling water piping arrangement 1 according to one embodiment of the present invention. The cooling water piping arrangement 1 of this embodiment is an arrangement for protecting the cooling water piping 13 that constitutes a circulation path for cooling the motor 11 or inverter 12 that generates heat during operation in an eAxle that packages a motor 11 mounted as a drive source on an electric vehicle (not shown), an inverter 12 that controls the drive of the motor 11 by converting electric power from a battery (not shown) and applying it to the motor 11, and a gearbox 14 that changes the speed of the power generated by the motor 11.

The e-axle, which is mainly composed of a motor 11, an inverter 12, and a gearbox 14, is mounted in a front room defined by a dash panel (not shown) at the front of the vehicle's passenger compartment. The front room is a space surrounded by the front bulkhead and the body frame, and stores the e-axle as well as a radiator (not shown), etc.

The motor 11 is, for example, a three-phase AC motor that converts electrical energy supplied from a battery into mechanical energy and provides power to rotate and drive wheels (not shown). Figure 2 is a cross-sectional view taken along line A-A in Figure 1. As shown in the figure, the motor 11 is positioned so that its output shaft 11a faces in the left-right direction of the vehicle. The motor 11 also has a cooling water flow passage (not shown) provided inside for the flow of cooling water.

The inverter 12 is, for example, a three-phase inverter, and controls the rotation speed and torque of the motor 11 by converting the direct current supplied from the battery into an alternating current of an arbitrary frequency and applying it to the motor 11. As shown in Figures 1 and 2, the inverter 12 is disposed almost directly above the motor.

The gearbox 14 is a transmission that meshes with a drive gear provided on the output shaft of the motor 11, and transmits the torque and rotation speed extracted from the motor 11 to the wheels by increasing or decreasing them according to the driving conditions. As shown in FIG. 1, the gearbox 14 is disposed adjacent to the motor 11 in the left-right direction.

The cooling water pipe 13 is a tubular flow path through which cooling water (refrigerant) circulates, and may be made of resin, rubber, or metal, and may include so-called pipes, tubes, hoses, etc. Furthermore, the connection portion of the cooling water pipe 13 with other devices is preferably made of a material with higher rigidity, and may be made of, for example, metal, hard resin, fiber-reinforced plastic, etc. In this embodiment, the cooling water pipe 13 is connected to a cooling water flow path provided inside the motor 11 via the connection portion 13a. Note that in each figure, only the connection portion 13a of the cooling water pipe 13 is shown, and other piping portions are omitted.

The cooling water pipe 13 is connected to a radiator (not shown). When the cooling water flowing through the cooling water pipe 13 passes through the radiator core of the radiator, it is cooled by the airflow generated by the running wind or the radiator fan (not shown). The cooled cooling water flows through the connection part 13a into the cooling water flow path in the motor 11, and cools the motor 11 by removing the heat generated by the motor 11. The cooling water, which has become hot due to heat exchange with the motor, circulates again through the cooling water pipe 13 and is cooled as it passes through the radiator.

The positional relationship between the motor 11, inverter 12, and cooling water pipe 13 in this embodiment will be described in detail below. As shown in FIG. 2, a gap space S that can become a dead space is formed between the motor 11 and inverter 12 that are arranged vertically. The connection part 13a of the cooling water pipe 13 in this embodiment is disposed within this gap space S.

The front ends of the motor 11 and inverter 12 are positioned so that they are nearly aligned near the dashed line L1. Therefore, when the vehicle collides from the front, the collision load propagated from the collision point to the devices and structures located in front of the e-axle is received by the front ends of the motor 11 and inverter 12, which are nearly aligned in the fore-and-aft direction, and the input of the collision load to the cooling water pipes 13 and the connection parts 13a can be significantly mitigated.

In particular, in this embodiment, the motor 11 has a substantially circular shape in a side view, and the inverter 12 has a substantially rectangular shape in a side view, so that the clearance space S extends from near the front of the motor 11 and the front of the inverter 12 to the rear side of the vehicle between the motor 11 and the inverter 12 arranged in the vertical direction. Therefore, the cooling water pipe 13 and the connection part 13a can be arranged rearward of the front of the motor 11 and the inverter 12, so that the collision load transmitted from the front can be more effectively prevented from being transmitted to the cooling water pipe 13 and the connection part 13a. In addition, even if the devices and structures in front of the e-axle are deformed by a collision, the possibility that these devices and structures will directly come into contact with the cooling water pipe 13 and the connection part 13a can be reduced, and the cooling water pipe 13 can be more effectively protected.

In addition, in this embodiment, the motor 11 and inverter 12 do not have the protrusion 45 seen in the conventional example shown in FIG. 4 or any other shape that protrudes significantly forward near the frontmost part. Therefore, it is possible to avoid the load from concentrating at a specific location in the event of a collision from the front of the vehicle. Also, by not having a shape that protrudes significantly forward, the surface that receives the collision load is widened, and the load can be dispersed. This makes it possible to suppress damage to the cases of the motor 11 and inverter 12 in the event of a collision. Furthermore, by suppressing damage to the motor 11 and inverter 12, the gap space S is also more easily maintained, and the cooling water piping 13 can be protected more effectively.

Next, referring to FIG. 3, the arrangement of the cooling water piping according to the second embodiment of the present invention will be described. The structure and positional relationship of the motor 21 and inverter 22, as well as the cooling water piping 23 and the connection part 23a in the second embodiment are similar to those of the motor 11 and inverter 12, as well as the cooling water piping 13 and the connection part 13a in the above-mentioned embodiment, and therefore will not be described. The second embodiment is characterized by the arrangement of the radiator 31, which is disposed in front of the motor 21 and inverter 22. The details will be described below.

Figure 3 shows a schematic diagram of the cooling water piping arrangement according to the second embodiment. Figure 3(a) shows the positional relationship between the motor 21 and inverter 22 and the radiator 31, and Figure 3(b) shows the positional relationship between the cooling water piping 23 and the fan motor 33 of the radiator 31. Note that in Figure 3(b), the radiator 31, radiator fan, and fan case 32 are omitted from the illustration in order to make it easier to understand the position of the fan motor 33.

As shown in FIG. 3(a), in this embodiment, a radiator 31 is provided in front of the motor 21 and inverter 22 so as to face the motor 21 and inverter 22. Like the radiator described above, this radiator 31 is connected to the cooling water pipe 23 and cools the cooling water passing through the radiator core by the airflow generated by the running wind or a radiator fan (not shown).

The radiator fan is disposed inside the fan case 32 attached to the radiator 31, and is disposed in the space between the radiator 31 and the motor 21 and inverter 22. In the center of the radiator fan, a fan motor 33 is provided, which receives power from a battery (not shown) to drive the radiator fan. The fan motor 33 is formed of a material having high rigidity, and is preferably made of metal. The position of the radiator 31 is adjusted so that the fan motor 33 is disposed in front of the connection part 23a of the cooling water pipe 23 disposed in the space between the motor 21 and the inverter 22. In addition, the fan motor 33 is disposed in a positional relationship such that it is close to the motor 21 and the inverter 22 in the front-rear direction, but does not secure a crash stroke sufficient for the fan motor 33 to be significantly plastically deformed in the event of a vehicle collision.

By arranging the fan motor 33 in this manner, the fan motor 33 functions as a protective structure for the cooling water pipe 23 in the event of a collision from the front of the vehicle. In other words, the highly rigid metallic fan motor 33 is located close to the motor 21 and inverter 22 to the extent that the crash stroke is not ensured, so that the fan motor 33 is more likely to maintain its shape without deformation in the event of a collision. As a result, the collision load received by the fan motor 33 is more likely to be transmitted to the front of the motor 21 and inverter 22, which are located further forward than the cooling water pipe 23 and closer to the fan motor 33. Therefore, the input of the collision load to the cooling water pipe 23 in the event of a collision is more greatly mitigated, so that the cooling water pipe 23 can be more effectively protected and damage can be prevented.

The present invention is not limited to the embodiment described above, and can be implemented in various ways. For example, the embodiment describes a cooling water pipe that connects to a cooling water flow path inside a motor, but the cooling water pipe may be for cooling an inverter or other devices.

In the embodiment, an example in which the inverter is disposed substantially directly above the motor has been described, but the inverter may be disposed substantially directly below the motor. In the embodiment, the cooling water piping arrangement structure of the present invention is applied to an electric vehicle that uses only a motor as a drive source, but the cooling water piping arrangement structure of the present invention may be applied to a hybrid vehicle that uses both a motor and an internal combustion engine as a drive source. In addition, the detailed configuration may be modified as appropriate within the scope of the spirit of the present invention.

REFERENCE SIGNS LIST 1... Cooling water piping arrangement 11, 21... Motor 11a... Output shaft 12, 22... Inverter 13, 23... Cooling water piping 13a, 23a... Connection portion 31... Radiator 33... Fan motor S... Gap space

Claims (5)

A cooling water piping arrangement structure for a vehicle including a motor arranged such that an output shaft faces a left-right direction of a vehicle, an inverter arranged substantially directly above or below the motor, and a cooling water piping through which cooling water flows for cooling the motor and/or the inverter,
a front end position of the motor and a front end position of the inverter are arranged so as to be substantially aligned in a front-rear direction of the vehicle;
13. A cooling water piping arrangement structure, wherein the cooling water piping is arranged in a vertical gap between the motor and the inverter. The motor has a substantially circular shape in a side view,
The inverter has a substantially rectangular shape in a side view,
2. The cooling water piping arrangement structure according to claim 1, wherein the gap space is formed near the front surface of the motor and the front surface of the inverter. the cooling water pipe has a connection portion for connection to a cooling water flow path provided inside the motor and/or the inverter,
The cooling water piping arrangement structure according to claim 1 , wherein the connection portion is disposed in the gap space. The vehicle further includes a radiator for cooling a coolant, a radiator fan for cooling the radiator, and a fan motor for driving the radiator fan,
2. The cooling water piping arrangement structure according to claim 1, wherein the fan motor is arranged in front of the cooling water piping arranged in the gap space in the front-rear direction of the vehicle. The cooling water piping arrangement structure according to claim 1, characterized in that the front surface of the motor and the front surface of the inverter are not provided with a protruding shape that protrudes forward.