JP7600838B2 - Electronic Control Module - Google Patents

Description

The present invention relates to an electronic control module.

Patent document 1 discloses that a heat dissipation gel is provided between the base and the printed circuit board, and that this heat dissipation gel is used to suppress vibrations of the printed circuit board.

Patent No. 6601328

However, in the invention described in Patent Document 1, the printed circuit board is fixed directly to the base with screws. This means that there is a risk that the vibrations transmitted to the printed circuit board cannot be sufficiently suppressed.

The present invention was made in consideration of these technical issues, and aims to more reliably suppress vibrations transmitted to the board on which electronic components are mounted.

According to one aspect of the present invention, an electronic control module is disposed on a rotating electrical machine unit mounted on a vehicle having an engine. The electronic control module also includes a first board on which electronic components are mounted, a second board that is disposed on the upper surface of the first board at a distance therefrom and on which electronic components are mounted, a cylindrical bracket that is provided between the first board and the second board and forms a closed space between the first board and the second board, a first vibration-isolating member that absorbs vibrations between the first board and the bracket, and a second vibration-isolating member that absorbs vibrations between the bracket and the second board, and the spring constant of the first vibration-isolating member is greater than the spring constant of the second vibration-isolating member.

This aspect makes it possible to more reliably suppress vibrations transmitted to the board on which the electronic components are mounted.

FIG. 1 is a perspective view of the appearance of an electronic control module according to the present embodiment. FIG. 2 is an exploded perspective view of the electronic control module of the present embodiment. FIG. 3 is a diagram showing the electronic control module of this embodiment attached to a housing. FIG. 4 is an enlarged cross-sectional view of the vicinity of the vibration-isolating rubber of this embodiment.

The following describes an embodiment of the present invention with reference to the attached drawings.

Figure 1 is an external perspective view of the electronic control module 100 of this embodiment. Figure 2 is an exploded perspective view of the electronic control module 100 of this embodiment. Figure 3 is a diagram of the electronic control module 100 of this embodiment attached to a housing 1. Figure 4 is an enlarged cross-sectional view of the vicinity of the anti-vibration rubbers 50a and 50b in this embodiment. Note that in the following explanation, up and down do not mean top and bottom, but rather mean top and bottom in the drawings.

The electronic control module 100 of this embodiment is disposed, for example, on a rotating electric machine unit mounted on a vehicle equipped with an engine. More specifically, it is used in a power control unit of a motor generator in a hybrid vehicle. As shown in Figs. 1 and 2, the electronic control module 100 includes a power module 10 as a base, a driver board 20 as a first board disposed on the power module 10 and having electronic components 21 mounted on the upper surface 20a, a motor control board 30 as a second board disposed on the upper surface 20a side of the driver board 20 with a gap therebetween and having electronic components 31 mounted on the upper surface 30a, and a cylindrical bracket 40 provided between the driver board 20 and the motor control board 30.

The electronic control module 100 is fixed to the bottom surface of the metal housing 1 by screws 2 and is housed within the housing 1 (see Figure 3).

The power module 10 includes an inverter (not shown) that converts DC power supplied from a battery mounted on the vehicle into polyphase AC power. The power module 10 supplies the polyphase AC power converted by the inverter to a motor generator (not shown).

The driver board 20 controls the switching operation of the power module 10. The driver board 20 is formed, for example, by a multi-layer printed circuit board. As shown in FIG. 2, a plurality of electronic components 21 (transformers, diodes, capacitors, chip resistors, etc.) are arranged on the upper surface 20a of the driver board 20. These electronic components 21 form a switching circuit.

Near both ends of the two opposing sides of the driver board 20, there are provided screws 2 for fixing the electronic control module 100 to the housing 1 and notches 20b for preventing contact between the driver board 20 and a tool for fastening the screws 2.

The driver board 20 further includes a through hole 20c through which a screw 2 for fixing the driver board 20 to the power module 10 is inserted, a through hole 20d through which a positioning protrusion 40d (see FIG. 2) provided on the bracket 40 is inserted, and a through hole 20e through which a screw 2 for fixing the bracket 40 is fastened.

The motor control board 30 controls the operation of the switching circuit provided on the driver board 20 in response to the vehicle driving state. A number of electronic components 31 (CPU, power supply IC, diodes, capacitors, chip resistors, connectors, etc.) are arranged on the upper surface 30a of the motor control board 30. These electronic components 31 form a control circuit that controls the frequency of the switching operation in the switching circuit provided on the driver board 20. A harness 60 is connected to the connector 31a provided on the motor control board 30 (see Figure 3), and the harness 60 is connected to a controller (not shown) provided outside the housing 1.

Near both ends of the two opposing sides of the motor control board 30, there are cutouts 30b to prevent contact between the motor control board 30 and a tool used to fasten the screws 2 that secure the electronic control module 100 to the housing 1.

The motor control board 30 further includes a through hole 30c as a second through hole through which a screw 2 is inserted to fix the motor control board 30 to the bracket 40, and a through hole 30d through which a positioning protrusion 40d provided on the bracket 40 is inserted.

The bracket 40 is made of a resin material (e.g., PPS resin (polyphenylene sulfide resin)). The bracket 40 is formed as a cylindrical frame that conforms to the shape of the outer edge of the driver board 20.

Near both ends of the two opposing sides of the bracket 40, recesses 40b are provided to prevent contact between a tool for fastening the screws 2 that secure the electronic control module 100 to the housing 1 and the electronic components 21, etc., arranged on the driver board 20. The recesses 40b are formed so that the peripheral wall 40a is recessed inward.

The bracket 40 further includes a receiving portion 40c into which the screw 2 that fixes the motor control board 30 to the bracket 40 is screwed, and a seating portion 40e into which the screw 2 that attaches the bracket 40 to the driver board 20 is seated. The receiving portion 40c is provided adjacent to the inside of the recess 40b. The seating portion 40e is provided so as to protrude outward from the peripheral wall 40a.

As shown in Figures 2 and 4, the electronic control module 100 further includes a vibration-isolating rubber 50a as a first vibration-isolating member that absorbs vibrations between the driver board 20 and the bracket 40, and a vibration-isolating rubber 50b as a second vibration-isolating member that absorbs vibrations between the bracket 40 and the motor control board 30. The vibration-isolating rubbers 50a and 50b are formed in a cylindrical shape with flanges on both ends. The vibration-isolating rubbers 50a and 50b are formed, for example, from NBR (nitrile rubber).

As shown in Figures 2 and 4, the anti-vibration rubber 50a is inserted into the through-hole 40f, which is the first through-hole formed in the seating portion 40e of the bracket 40. The anti-vibration rubber 50a is held in the through-hole 40f by the flanges on both ends that function as retainers. When the screw 2 for mounting to the driver board 20 is attached, the anti-vibration rubber 50a is held between the screw 2 and the through-hole 40f.

As shown in Figures 2 and 4, the anti-vibration rubber 50b is inserted into the through-hole 30c of the motor control board 30. The anti-vibration rubber 50b is held in the through-hole 30c by the flanges on both ends that function as retainers. When the screw 2 for mounting to the motor control board 30 is attached, the anti-vibration rubber 50b is held between the screw 2 and the through-hole 30c.

Next, we will explain how to assemble the electronic control module 100.

The driver board 20 is placed on the power module 10, and the screw 2 inserted into the through hole 20c is screwed into the protrusion 10b provided on the top surface of the power module 10. This fixes the driver board 20 onto the power module 10.

Next, the anti-vibration rubber 50a is inserted into the through-hole 40f formed in the seating portion 40e of the bracket 40, and the bracket 40 is placed on the driver board 20 by inserting the positioning protrusion 40d into the through-hole 20c. Then, the bracket 40 is fixed to the driver board 20 by screwing the screw 2 inserted through the through-hole 40f formed in the seating portion 40e of the bracket 40 into the through-hole 20e.

Next, the vibration-isolating rubber 50b is inserted into the through-hole 30c of the motor control board 30, and the motor control board 30 is placed on the bracket 40 so that the positioning protrusion 40d on the bracket 40 is inserted into the through-hole 30d. After that, the screw 2 inserted into the through-hole 30c of the motor control board 30 is screwed into the receiving portion 40b of the bracket 40, completing the electronic control module 100.

The electronic control module 100 assembled in this manner is fixed to the housing 1 by screwing the screw 2 inserted into the through hole 10c of the power module 10 into the housing 1.

Vibrations from the engine and vibrations while the vehicle is running are transmitted to the electronic control module 100. These vibrations are transmitted from the housing 1 through the power module 10, the driver board 20, and the bracket 40 to the motor control board 30. For example, when vibrations are applied to the housing 1 in the front-to-rear direction (see Figures 2 and 3), the motor control board 30, which is located farthest from the housing 1, will be most vibrated. If such vibrations continue to be applied, stress will concentrate at the connection between the electronic component 31 and the motor control board 30, which may cause a break in the connection.

Therefore, in the electronic control module 100 of this embodiment, anti-vibration rubber 50a is provided to absorb vibrations between the driver board 20 and the bracket 40, and anti-vibration rubber 50b is provided to absorb vibrations between the bracket 40 and the motor control board 30. This allows the anti-vibration rubbers 50a and 50b to absorb vibrations transmitted from the housing 1 to the motor control board 30. Therefore, the vibrations transmitted to the motor control board 30 can be suppressed.

The spring constant of the anti-vibration rubber 50a is set to be greater than the spring constant of the anti-vibration rubber 50b. The spring constant here refers to the spring constant in a direction perpendicular to the axial direction of the anti-vibration rubbers 50a and 50b (the front-to-rear direction shown in Figures 2 and 3).

The electronic control module 100 has a laminated structure. Therefore, when vibration is transmitted to the housing 1, the load acting on the vibration-proof rubber 50a arranged between the bracket 40 and the driver board 20 due to the vibration is greater than the load acting on the vibration-proof rubber 50b arranged between the bracket 40 and the motor control board 30, which is located away from the housing 1 and the driver board 20. In other words, since the mass moment acting on the vibration-proof rubber 50a is large, the vibration energy acting on the vibration-proof rubber 50a is large accordingly. Therefore, by making the spring constant of the vibration-proof rubber 50a larger than the spring constant of the vibration-proof rubber 50b, the vibration can be absorbed by the vibration-proof rubber 50a, and the vibration transmitted to the driver board 20 can be suppressed.

The frequency characteristics of the anti-vibration rubbers 50a and 50b include a vibration-isolating region above the resonant frequency multiplied by √2. Therefore, by setting the spring constant of the anti-vibration rubber 50a provided between the driver board 20 and bracket 40 in a region that is more than √2 times higher than the resonant frequency of the anti-vibration rubber 50b between the bracket 40 and the motor control board 30, which has a low resonant frequency (low spring constant), vibration between the driver board 20 and bracket 40 can be more effectively suppressed.

Furthermore, in the electronic control module 100, as shown in FIG. 3, the harness 60 is connected to the connector 31a provided on the motor control board 30. A part of the cable 60a of the harness 60 is supported by the housing 1. This allows the vibration transmitted to the motor control board 30 to be absorbed by the elasticity of the cable 60a, so that the vibration of the motor control board 30 can be further suppressed. Note that FIG. 3 illustrates an example in which a part of the cable 60a is supported by the housing 1, but the same effect can be achieved even if a part of the cable 60a is supported by the motor control board 30 or the bracket 40, or if a part of the cable 60a is not supported by any member and is connected to another electronic device.

In addition, of the anti-vibration rubbers 50b that support the motor control board 30, two of the anti-vibration rubbers 50b are arranged to sandwich the connector 31a, and the spring constant of these two anti-vibration rubbers 50b is set higher than the spring constant of the remaining anti-vibration rubbers 50b, thereby suppressing the effects of vibrations of the harness 60, which is a heavy object connected to the connector 31a.

The configuration, operation, and effects of the embodiment of the present invention configured as described above are now explained.

The electronic control module 100 is placed on a rotating electric unit (motor generator) that is mounted on a vehicle equipped with an engine.

The electronic control module 100 includes a driver board 20 (first board) on whose upper surface 20a electronic components 21 are placed, a motor control board 30 (second board) that is spaced apart from the driver board 20 (first board) on the upper surface 20a side and has electronic components 31 placed on its upper surface 30a, a cylindrical bracket 40 that is provided between the driver board 20 (first board) and the motor control board 30 (second board) and forms a closed space S between the driver board 20 (first board) and the motor control board 30 (second board), a vibration-proof rubber 50a (first vibration-proof member) that absorbs vibrations between the driver board 20 (first board) and the bracket 40, and a vibration-proof rubber 50b (second vibration-proof member) that absorbs vibrations between the bracket 40 and the motor control board 30 (second board), and the spring constant of the vibration-proof rubber 50a (first vibration-proof member) is greater than the spring constant of the vibration-proof rubber 50b (second vibration-proof member).

In this configuration, vibrations between the driver board 20 (first board) and the bracket 40 are absorbed by the anti-vibration rubber 50a (first anti-vibration member), and vibrations between the bracket 40 and the motor control board 30 (second board) are absorbed by the anti-vibration rubber 50b (second anti-vibration member), so that vibrations transmitted to the driver board 20 (first board) and the motor control board 30 (second board) can be more reliably suppressed. Furthermore, by making the spring constant of the anti-vibration rubber 50a (first anti-vibration member) larger than the spring constant of the anti-vibration rubber 50b (second anti-vibration member), vibrations between the driver board 20 and the bracket 40 can be more effectively suppressed.

In the electronic control module 100, the bracket 40 has a through hole 40f (first through hole) through which a screw 2 (first screw) is inserted to fix the bracket 40 to the driver board 20 (first board), and the vibration-proof rubber 50a (first vibration-proof member) is provided between the screw 2 (first screw) and the through hole 40f (first through hole).

In this configuration, the anti-vibration rubber 50a (first anti-vibration member) is provided between the screw 2 (first screw) and the through hole 40f (first through hole), which prevents the electronic control module 100 from becoming too large.

In the electronic control module 100, the motor control board 30 (second board) has a through hole 30c (second through hole) through which a screw 2 (second screw) is inserted to fix the motor control board 30 (second board) to the bracket 40, and the vibration-proof rubber 50b (second vibration-proof member) is provided between the screw 2 (second screw) and the through hole 30c (second through hole).

In this configuration, the vibration-isolating rubber 50b (second vibration-isolating member) is provided between the screw 2 (second screw) and the through hole 30c (second through hole), which prevents the electronic control module 100 from becoming too large.

The electronic control module 100 further includes a housing 1 that houses a driver board 20 (first board), a motor control board 30 (second board), and a bracket 40, and a harness 60 that is connected to a connector 31a provided on the motor control board 30 (second board).

In this configuration, the elasticity of the cable 60a can also absorb the vibrations transmitted to the motor control board 30 (second board), further suppressing the vibrations of the motor control board 30 (second board).

In the electronic control module 100, the connector 31a is attached to the vehicle with its longitudinal direction aligned with the fore-and-aft direction of the vehicle.

Vibrations often occur in the fore-aft direction of the vehicle. In particular, when the engine is mounted horizontally, the rotation of the crankshaft increases the vibrations in the fore-aft direction of the vehicle. Therefore, by attaching the connector 31a to the vehicle so that its longitudinal direction is positioned in the fore-aft direction of the vehicle, the elasticity of the harness 60 connected to the connector 31a can effectively absorb the vibrations.

Although the embodiments of the present invention have been described above, the above embodiments merely show some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

In the above embodiment, the first and second vibration-proof members are described using vibration-proof rubbers 50a and 50b as an example, but the present invention is not limited to this and any material, such as resin, may be used as long as it is capable of absorbing vibrations.

In the above embodiment, the anti-vibration rubber 50a is provided between the screw 2 and the through hole 40f, and the anti-vibration rubber 50b is provided between the screw 2 and the through hole 30c. However, this is not limiting, and the anti-vibration rubber 50b may be provided in any location as long as it can absorb vibrations in the planar direction of the driver board 20 and the motor control board 30. For example, the anti-vibration rubber 50a may be provided between the upper surface 20a of the driver board 20 and the lower surface of the seating portion 40e, or the anti-vibration rubber 50b may be provided between the upper surface of the receiving portion 40c and the lower surface of the motor control board 30.

100 Electronic control module 1 Housing 2 Screw (first screw, second screw)
10 Power module 20 Driver board (first board)
30 Motor control board (second board)
30a Top surface 30c Through hole (second through hole)
31 Electronic component 31a Connector (electronic component)
40 bracket 40f through hole (first through hole)
50a: Anti-vibration rubber (first anti-vibration member)
50b Anti-vibration rubber (second anti-vibration member)
60 Harness

Claims (5)

An electronic control module to be disposed on a rotating electric machine unit mounted on a vehicle having an engine, the electronic control module comprising: a first substrate having an electronic component mounted on an upper surface thereof;
a second substrate disposed on the upper surface side of the first substrate with a gap therebetween, the second substrate having an electronic component mounted on its upper surface;
a cylindrical bracket provided between the first board and the second board to form a closed space between the first board and the second board;
a first vibration isolating member that absorbs vibration between the first substrate and the bracket;
a second vibration isolating member that absorbs vibration between the bracket and the second board,
The spring constant of the first vibration isolation member is greater than the spring constant of the second vibration isolation member. 2. The electronic control module of claim 1,
the bracket has a first through hole through which a first screw for fixing the bracket to the first board is inserted,
The first vibration isolation member is disposed between the first screw and the first through hole of the electronic control module. 3. The electronic control module according to claim 1,
the second board has a second through hole through which a second screw for fixing the second board to the bracket is inserted,
The second vibration isolating member is disposed between the second screw and the second through hole of the electronic control module. 4. The electronic control module according to claim 1,
a housing that houses the first board, the second board, and the bracket;
and a harness connected to a connector provided on the second board. 5. The electronic control module of claim 4,
The connector is an electronic control module that is mounted on a vehicle with its longitudinal direction aligned in the fore-and-aft direction of the vehicle.

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