JP6477540B2 - Car electronics case - Google Patents

Description

  The technology disclosed in this specification relates to a case of an in-vehicle electronic device.

  In the engine room of a vehicle, rainwater and water bounced off from the road surface may enter, and in the trunk room, the liquid is assumed to leak from a baggage filled with liquid. In-vehicle electronic devices may have moisture intruding into the case even if appropriate waterproofing measures are taken. Patent Document 1 includes a water collecting tray that collects water that has entered the case, and a liquid detection sensor that detects water that has entered the case, in a junction block that is one of the in-vehicle electronic devices. A technique for detecting the above is disclosed. The liquid detection sensor is accommodated in a water collection box disposed at the tip of the water collection tray, and the liquid detection sensor detects water collected in the water collection box by the water collection tray. When the liquid detection sensor detects water, a warning lamp provided in the vehicle interior is turned on.

JP 2013-223330 A

  Although it is desirable to drain the water accumulated in the accumulation box (the bottom of the case), if a large drainage port is provided at the bottom of the case, there is a risk that water may enter from the drainage port. If the drain outlet is small, the drainage will not be in time when a large amount of water has entered, and the electronic components inside the case may be submerged. A valve that opens when water is detected may be provided at the drain, but the cost increases. This specification provides a technique for realizing a case of an in-vehicle electronic device having good drainage performance even at a small drainage port at a low cost.

  The case of the in-vehicle electronic device disclosed in the present specification is provided at the bottom having a funnel shape on the inner surface, and at the tip of the funnel shape. And a reactive substance that is disposed around at least one of the hole and the communication hole on the inner surface and generates a gas by reacting with the liquid.

  According to this configuration, the water that has entered the case adheres to the inner surface of the bottom of the case, and gathers at the funnel-shaped tip because the inner surface has a funnel shape. A communication hole is provided at the tip of the funnel, and the water collected at the tip is drained from the communication hole to the outside of the case. Here, a reactive substance is disposed at least around the communication hole and the communication hole on the inner surface, and water that has entered the case flows into the reaction substance while flowing from the inner surface to the communication hole. Contact. As a result, water reacts with the reactant, gas is generated from the reactant, and the internal pressure in the case is increased. As a result, water accumulated at the bottom of the case is pushed out from the communication hole. Even if the communication hole (drain port) is small, water inside the case is difficult to collect. This in-vehicle electronic device case can be realized at low cost because it is only necessary to arrange the reactive substance on the bottom. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a block diagram of the electric power system of an electric vehicle. It is sectional drawing of the case (case of a system main relay) of an Example. It is a figure which shows an example of the layout of a reactive material.

  A case of an in-vehicle electronic device according to an embodiment will be described with reference to the drawings. The technology disclosed in this specification is applied to a case of a system main relay mounted on the electric vehicle 2. FIG. 1 shows a block diagram of a power system of an electric vehicle 2 including a system main relay. The electric vehicle 2 includes a battery 3, a system main relay 5, an inverter 6, and a traveling motor 7. As shown in FIG. 1, the battery 3 and the motor 7 are connected via a system main relay 5 and an inverter 6. The system main relay 5 switches between conduction and interruption between the battery 3 and the inverter 6. The system main relay 5 is a two-contact type electromagnetic relay. The inverter 6 converts the DC power of the battery 3 into AC power suitable for driving the motor 7. When the system main relay 5 is turned on (that is, when the two contacts of the system main relay 5 are both in a conductive state), the DC power of the battery 3 is supplied to the inverter 6, and the DC power is converted into AC power by the inverter 6. The AC power is supplied to the motor 7. The motor 7 is driven by this AC power, the axle 8 connected to the motor 7 rotates, and the electric vehicle 2 travels.

  The system main relay 5 is accommodated in the case 4. Specifically, the case 4 is connected to the first contact portion 5 a that is one of the two contacts and is connected to the positive electrode of the battery 3, and the negative electrode of the battery 3. The second contact portion 5b constituting the other contact is accommodated. The system main relay 5 (case 4) is mounted in the front compartment of the vehicle together with the inverter 6 and the motor 7. The front compartment is not waterproofed and isolated from the outside of the vehicle, and rain water and splash water from the road surface may enter. If water accumulates in the case 4, there is a possibility that a malfunction may occur in the first contact part 5 a, the second contact part 5 b, or an electromagnetic coil (not shown) that switches between conduction and interruption of the contact parts 5 a, 5 b. For this reason, it is desirable to quickly drain the water that has entered the case 4 out of the case 4.

  The case 4 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the case 4. As described above, the case 4 is housed in the front compartment of the electric vehicle 2 together with the inverter 6 and the motor 7. FIG. 2 is a cross-sectional view of the electric vehicle 2 along the vertical direction. The Z axis of the XYZ coordinate system described in FIG. 2 corresponds to the vertical direction of the electric vehicle 2. In FIG. 2, a cross section of the case 4 is shown, and illustration of the first contact portion 5 a and the second contact portion 5 b housed in the case 4 is omitted.

  As shown in FIG. 2, the inner surface 41a of the bottom 41 of the case 4 has a funnel shape. The funnel-shaped tip 41b is provided with a communication hole 42 extending in the Z-axis direction. The communication hole 42 communicates the space inside the case 4 with the space outside. In other words, the inner surface 41 a of the bottom 41 of the case 4 is provided with a communication hole 42, and the height of the communication hole 42 is lower than the height of the peripheral edge of the inner surface 41 a of the bottom 41. The communication hole 42 corresponds to a drain outlet for discharging water that has entered the case 4 to the outside.

  The space inside the case 4 is sealed from the space outside the case 4 except for the communication hole 42. For example, the case 4 is closed by a cover (not shown) after accommodating the contact portions 5a, 5b and the like. The mating surface between the case 4 and the cover is sealed with a gasket. Normally, water does not enter the case 4 by this gasket. However, part of the gasket becomes fragile due to deterioration or the like, and water may enter the case 4 from the mating surface. The communication hole 42 is provided in order to drain the water that has entered in such a case from the inside of the case 4. The diameter of the communication hole 42 is about several millimeters.

  The arrows in FIG. 2 indicate the flow of water that has entered the case 4. The water that has entered the case 4 adheres to the inner surface 41a of the bottom 41 of the case 4 and collects at the funnel-shaped tip 41b because the inner surface 41a has a funnel shape. The water collected at the tip 41b is drained from the communication hole 42 provided at the tip 41b to the outside of the case 4. However, as described above, since the diameter of the communication hole 42 is about several millimeters, if a relatively large amount of water enters, the drainage cannot be made in time and water may accumulate at the bottom of the case 4. .

  A reactant 43 is disposed around the communication hole 42 of the inner surface 41a of the bottom 41. The reactive substance 43 reacts with the liquid to generate a gas. The reactant 43 is, for example, sodium bicarbonate, which reacts with water to generate carbon dioxide. As described above, the water flowing through the inner surface 41 a collects at the funnel-shaped tip, so that the water that has entered contacts the reactant 43 while flowing from the inner surface 41 a to the communication hole 42. As a result, the water that has entered and the reactant 43 react to generate gas from the reactant.

  3 is a top view of the inner surface 41a around the communication hole 42 as seen from the Z-axis direction. As shown in FIG. 3, the reactant 43 intermittently surrounds the communication hole 42. In other words, the reactant 43 surrounding the communication hole 42 is provided with a plurality of gaps. The water that has entered the case 4 passes through the gap while contacting the reactant 43 and reaches the communication hole 42.

  An opening / closing valve 44 (internal pressure adjusting valve) is provided on the side wall of the case 4. The on-off valve 44 is a valve that opens when the internal pressure in the case 4 becomes greater than a predetermined pressure. The on-off valve 44 is provided to adjust the pressure in the case 4 to a predetermined pressure or less. Note that the case 4 may not include the on-off valve 44.

  The effect of the present embodiment will be described. As described above, the water that has entered the case 4 comes into contact with the reactant 43, so that gas is generated from the reactant 43. As a result, the internal pressure of the case 4 is higher than the external pressure. As the internal pressure of the case 4 increases, drainage of the water collected at the tip 41b of the bottom 41 of the case 4 is promoted.

  For example, as a comparative example, in order to drain water that has entered the case 4, a sensor that detects water accumulated on the bottom 41 of the case 4 and a valve that opens when the sensor detects water are provided on the bottom 41. It is possible. However, in such a comparative example, a sensor and a valve are required and the cost increases. The configuration of the present embodiment can be realized at a lower cost as compared with the comparative example because the reactant 43 only needs to be disposed on the inner surface 41a of the bottom 41. Further, in the comparative example, when electric power is not supplied to the sensor or the valve, for example, when the electric vehicle 2 is not activated, the water accumulated on the bottom 41 of the case 4 cannot be drained. Since the configuration of the present embodiment does not require electric power for drainage, water accumulated on the bottom 41 of the case 4 can be drained even when the electric vehicle 2 is not activated.

  Further, as described above, when the water in the case 4 reacts with the reactant 43 to generate gas, the internal pressure in the case 4 is increased from the external pressure. Thereby, the invasion of new water into the case 4 can also be suppressed.

  A modification of the embodiment will be described. In the modified example, a valve (another internal pressure adjusting valve) that opens when the internal pressure of the case increases may be provided in the communication hole 42. The internal pressure regulating valve is a valve that opens when the internal pressure in the case 4 becomes greater than a predetermined pressure. After the internal pressure in the case 4 is increased to a predetermined pressure, the internal pressure adjusting valve is opened, and the water collected at the tip 41b can be drained from the case 4 vigorously.

  Hereinafter, points to be noted regarding the technology shown in the embodiments will be described. In FIG. 2, the funnel-shaped tip 41 b is close to one side in the Y-axis direction, but may be arranged at the center in the Y-axis direction (or X-axis direction). The funnel-shaped tip 41b may be disposed at the end of the bottom 41 in the Y-axis direction (or X-axis direction).

  Further, the bottom 41 of the case 4 only needs to have at least an inner surface 41a having a funnel shape. For example, the outer surface of the bottom of the case 4 may be horizontal.

  The reactive substance 43 may be disposed on the inner side surface of the communication hole 42. The reactive substance 43 may be disposed on both the inner surface 41 a around the communication hole 42 and the inner side surface of the communication hole 42. Generally speaking, the reactant 43 may be disposed in at least one of the communication hole 42 and the periphery of the communication hole 42 of the inner surface 41a.

  The case 4 of the embodiment is mounted in the front compartment of the vehicle. The technology disclosed in the present specification is not limited to an electronic device mounted in a front compartment, and may be applied to a case of an in-vehicle electronic device disposed outside a vehicle compartment that is waterproof and isolated from the outside of the vehicle.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Electric vehicle 3: Battery 4: Case 5: System main relay 5a: First contact portion 5b: Second contact portion 6: Inverter 7: Motor 8: Axle 41: Bottom 41a: Inner surface 41b: Tip 42: Communication hole 43: Reactive substance 44: On-off valve

Claims (1)

A case of an in-vehicle electronic device,
A bottom whose inner surface is funnel-shaped;
Provided at the tip of the funnel shape, a communication hole for communicating the space inside the case and the space outside,
A reactant that is disposed on at least one of the communication hole and the inner surface around the communication hole, and reacts with a liquid to generate a gas;
With case.

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