Mounting structure for temperature sensor

Abstract

To provide a mounting structure for a temperature sensor capable of suppressing deterioration in durability of the temperature sensor provided on an electric wire arranged in a space open to the outside of a vehicle.SOLUTION: The present invention relates to a mounting structure for a temperature sensor 8 configured to detect the temperature of an electric wire 4 that is routed in an engine room and electrically connects in-vehicle devices, the structure including a protector 5 surrounding at least a part of the outer circumference of the electric wire 4 in the longitudinal direction of the electric wire 4. The temperature sensor 8 is mounted on the outer surface of a part of the electric wire 4 that is surrounded by the protector 5, and a part of the electric wire 4 and the temperature sensor 8 are covered in a liquid-tight manner by a heat-shrinkable tube 9.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a mounting structure for a temperature sensor that detects the temperature of an electric wire connected to an in-vehicle device. [Background technology]

[0002] Patent Document 1 describes a wire harness that electrically connects a charging inlet and a battery device. This wire harness is composed of electric wires, terminals connected to the ends of the electric wires, a holder with a U-shaped cross section, and a temperature sensor fixed to the holder and measuring the temperature of the terminals, and the temperature sensor and the connection between the electric wires and the terminals are covered with a covering member such as a heat-shrinkable tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-91592 Summary of the Invention [Problem to be solved by the invention]

[0004] The wire harness described in Patent Document 1 is configured to electrically connect a charging inlet and a battery device, both of which are located in a space isolated from the outside of the vehicle. Therefore, it is believed that water, debris flying during driving, and the like are unlikely to infiltrate the areas where the wire harness and the temperature sensor are located, and even if they do, the amount of infiltration is small. On the other hand, there are cases where an inverter and a motor are connected by a high-voltage wire in a space open to the outside of the vehicle, such as an engine compartment. In such cases, water, debris flying during driving, and the like are more likely to infiltrate, and the amount of infiltration is greater, in a space open to the outside of the vehicle, such as an engine compartment, compared to a space where the charging inlet and the battery device are located. Therefore, when attaching a temperature sensor to a high-voltage wire routed in a space open to the outside of the vehicle, simply providing the temperature sensor in a holder with a U-shaped cross section and covering the temperature sensor with a heat-shrinkable tube, as in the wire harness described in Patent Document 1, may result in a decrease in durability due to external factors, such as water, debris, and the like entering through or coming into contact with an open portion of the holder.

[0005] The present invention has been made with an eye on the above-mentioned technical problems, and aims to provide a temperature sensor mounting structure that can prevent a decrease in the durability of a temperature sensor attached to an electric wire routed in a space open to the outside of a vehicle. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a mounting structure for a temperature sensor that detects the temperature of an electric wire that is routed in a space open to the outside of a vehicle and electrically connects on-board devices, and is characterized in that it includes a protector that surrounds at least a portion of the outer periphery of the electric wire in the longitudinal direction, the temperature sensor is mounted on the outer surface of the portion of the electric wire that is surrounded by the protector, and the portion of the electric wire and the temperature sensor are covered in a liquid-tight manner.

[0007] In addition, in the present invention, a lead wire that outputs a signal detected by the temperature sensor may be connected to the temperature sensor, and the lead wire may be extended downward from the temperature sensor when mounted in a vehicle.

[0008] In the present invention, the electric wire may be covered with a braided wire that blocks noise, and the lead wire may be taken out from mesh-like gaps in the braided wire.

[0009] In the present invention, the protector may be fixed to a vibration source connected to the vehicle.

[0010] In the present invention, the temperature sensor may be attached to a central portion in the longitudinal direction of the electric wire. [Effects of the Invention]

[0011] According to the present invention, the temperature sensor is attached to the outer surface of the electric wire inside the protector that surrounds part of the outer periphery of the electric wire in the longitudinal direction. This prevents flying debris and the like from coming into contact with the temperature sensor while the vehicle is running. In other words, the protector has the function of protecting the temperature sensor in addition to protecting the electric wire. Furthermore, because the temperature sensor is enclosed by the protector and is liquid-tightly coated, it is possible to prevent water from directly contacting the temperature sensor. This prevents the durability of the temperature sensor, which is attached to an electric wire routed in a space open to the outside of the vehicle, from being reduced by external factors such as water being splashed on the temperature sensor or contact with flying debris. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram showing a state in which electric wires connecting an inverter and a motor are routed in an engine compartment. [Figure 2] FIG. 2 is an enlarged front view of part A in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the embodiment described below is merely an example of how the present invention can be implemented, and is not intended to limit the present invention.

[0014] Fig. 1 shows a schematic diagram of the inside of an engine room R of a hybrid vehicle equipped with an engine 1 and a motor 2 as driving power sources. In the example shown in Fig. 1, the motor 2 and an inverter 3 are provided in the engine room R, and a temperature sensor is attached to a high-voltage wire (hereinafter simply referred to as an electric wire) 4 that electrically connects the motor 2 and the inverter 3.

[0015] The engine 1 can be a gasoline engine or a diesel engine, and includes a cylinder (not shown) formed in a cylinder block 1a and a piston (not shown) connected to an output shaft and reciprocating within the cylinder. Engine 1 configured in this manner supplies air and fuel into the cylinder and burns the air-fuel mixture, converting the load pressing against the piston into torque for transmission to the output shaft. Alternatively, by reducing the amount of air flowing into or out of the cylinder without burning the air-fuel mixture, braking torque due to sliding resistance when the piston reciprocates and pumping loss when compressing the air in the cylinder are applied to the output shaft.

[0016] Therefore, engine 1 generates vibrations due to the combustion of the air-fuel mixture and the reciprocating motion of the pistons. For this reason, engine 1 is fixed to a frame (not shown) that constitutes the vehicle body via an engine mount (not shown) made of rubber or the like, thereby damping the vibrations transmitted from engine 1 to the vehicle body. Engine 1 is located in the center of engine room R in the vehicle width direction.

[0017] Like motors used as driving power sources for conventional hybrid vehicles, electric vehicles, etc., motor 2 functions as an electric motor that outputs driving torque when supplied with power from a power storage device (not shown), and also functions as a generator that converts at least a portion of the mechanical energy of the output shaft into electrical energy by generating a braking torque that reduces the rotation speed of the output shaft. Specifically, motor 2 is an AC motor such as a synchronous motor or induction motor with a permanent magnet provided in the rotor.

[0018] 1 shows a three-phase AC synchronous motor as an example, with one end of an electric wire 4 connected to each of the U, V, and W phases of the motor 2. The other ends of the electric wires 4 are connected to an inverter 3 that converts DC power output from the power storage device into AC power and converts AC power generated by the motor 2 into DC power.

[0019] The inverter 3 can be configured in the same manner as inverters installed in conventional hybrid vehicles, electric vehicles, etc., and is composed of a plurality of transistors (e.g., IGBTs) and a plurality of diodes. The inverter 3 is fixed to a side member 6 on one side in the vehicle width direction of the outer frame that forms the engine compartment R.

[0020] Therefore, the electric wire 4 connecting the motor 2 and the inverter 3 has a first section 4a that spans between the inverter 3 and the engine 1 along the vehicle width direction, and a second section 4b that hangs down vertically along the engine 1, and the lower end of the second section 4b is connected to the motor 2.

[0021] Sand, chips, and other flying debris can enter the engine compartment R through gaps in the hood or openings below. Therefore, in order to maintain the routing path of the electric wires 4 and prevent flying debris from coming into contact with the electric wires 4, a protector 5 that surrounds the outer periphery of the electric wires 4 is provided along the longitudinal direction of the electric wires 4. This protector 5 can be made of a resin material and is composed of a base member 5a fixed to the engine 1 or the like, and a cover member 5b that is detachably provided on the base member 5a and has a U-shaped or arc-shaped cross section so as to surround (cover) the outer periphery of the electric wires 4. Note that the configuration (shape) of the protector 5 is not particularly limited as long as it can prevent flying debris and the like from coming into contact with the electric wires 4 while the vehicle is running.

[0022] Fig. 2 shows an enlarged front view of part A in Fig. 1. Note that Fig. 2 shows a state in which the cover member 5b of the protector 5 has been removed. As shown in Fig. 2, three electric wires 4 are arranged side by side, and a braided wire 7 is provided to bundle these electric wires 4. Note that, since different amounts of power are conducted between adjacent electric wires 4, the electric wires 4 are bundled while being covered with an insulating material such as enamel.

[0023] The braided wire 7 is configured to block noise from the electric wire 4, and is formed into a cylindrical shape by bundling and braiding a plurality of wires such as copper wires. The braided wire 7 is provided over the entire length of the electric wire 4 from one end to the other end. For ease of explanation, part of the braided wire 7 is shown as "shaded" in Fig. 2.

[0024] A temperature sensor 8 for detecting the temperature of the electric wire 4 is provided inside the braided wire 7 and on the outer surface of the electric wire 4. This temperature sensor 8 is configured by, for example, an NTC thermistor, a PTC thermistor, or a PT sensor, similar to temperature sensors conventionally used to detect the temperatures of various devices.

[0025] Specifically, the temperature sensor 8 is composed of an element 8a that detects temperature, a case 8b that houses the element 8a, and a lead wire 8c that outputs a signal detected by the element 8a. That is, the element 8a is housed in the case 8b in a liquid-tight manner. The element 8a is housed in a crystalline body of fluororesin and is molded integrally with the case 8b.

[0026] 2, the case 8b is formed in a rectangular parallelepiped shape, with its leading end facing vertically upward and the lead wire 8c extending from its rear end. That is, when the temperature sensor 8 is mounted on the electric wire 4 and is mounted in the vehicle, the lead wire 8c extends from the case 8b downward from the horizontal. The case 8b and a portion of the lead wire 8c are covered in a liquid-tight manner by a heat-shrinkable tube 9, which is also fixed to the electric wire 4. When covering the temperature sensor 8 with the heat-shrinkable tube 9, workability can be improved by temporarily fixing the temperature sensor 8 to the electric wire 4 with heat-resistant tape or the like, and then covering it with the heat-shrinkable tube 9 and heating it in this state.

[0027] Furthermore, in a portion of the braided wire 7, a lead wire outlet hole 7a is formed by widening the mesh of the braided wire 7, and a lead wire 8c is drawn out from the braided wire 7 through the lead wire outlet hole 7a. The portion of the lead wire 8c drawn out from the braided wire 7 is bent upward in the vertical direction and connected to a controller (not shown) or the like. Note that, in order to ensure the shielding function of the braided wire 7, the lead wire outlet hole 7a, which was widened to draw out the lead wire 8c, is returned to its original mesh by moving the wire after the lead wire 8c is drawn out. In other words, the lead wire 8c is drawn out from the mesh-like gaps of the braided wire 7 to the outside.

[0028] In the temperature sensor mounting structure described above, the temperature sensor 8 is mounted to the electric wire 4 inside the protector 5, which is designed to prevent flying debris and the like from coming into contact with the electric wire 4. This prevents flying debris and the like from coming into contact with the temperature sensor 8 while the vehicle is running. In other words, the protector 5 has the function of protecting the temperature sensor 8 in addition to the function of protecting the electric wire 4.

[0029] Furthermore, because the case 8b constituting the temperature sensor 8 is surrounded by heat-shrink tubing in addition to the protector 5, it is possible to prevent water that has entered the engine compartment R through a gap in the hood or water that has splashed up from a lower opening from directly contacting the temperature sensor 8. Furthermore, because the lead wire 8c for extracting a signal from the temperature sensor 8 is drawn out from the case 8b downward rather than horizontally, it is possible to prevent water flowing along the lead wire 8c from entering the case 8b through a gap between the case 8b and the lead wire 8c. This makes it possible to prevent water from entering the element portion 8a of the temperature sensor 8, and to prevent a decrease in the durability of the temperature sensor 8.

[0030] Furthermore, the engine 1 vibrates when driven, whereas the inverter 3 is fixed to the side member 6. Therefore, there is relative movement between the position of the electric wire 4 in the first region 4a where it is connected to the inverter 3 and the position where it contacts the engine 1, or the uppermost position of the protector 5 in FIG. 1 that is provided on the engine 1. For this reason, if the protector 5 is provided on a fixing member or the like provided within the first region 4a and the temperature sensor 8 is provided within the protector 5, there is a possibility that the protector 5 will move relative to the electric wire 4 or the temperature sensor 8, causing stress to act on sliding points, etc., and reducing durability.

[0031] For this reason, in the temperature sensor mounting structure in the embodiment of the present invention, the temperature sensor 8 is provided in a protector 5 fixed to the engine 1, which is a vibration source in the engine compartment R. Specifically, as shown in part A in Fig. 1 , the temperature sensor 8 is provided in the second region 4b of the electric wire 4, more specifically, in the protector 5 provided in the central portion of the second region 4b. Therefore, the protector 5, the electric wire 4, and the temperature sensor 8 move (vibrate) together, so that sliding between the protector 5 and the electric wire and the temperature sensor 8 can be suppressed, and a decrease in the durability of the temperature sensor 8 can be suppressed.

[0032] Furthermore, because heat is transferred between the ends of the electric wire 4 and the motor 2 and the inverter 3, it may not be possible to properly detect the temperature corresponding to the load on the electric wire 4. For this reason, in the temperature sensor mounting structure according to the embodiment of the present invention, the temperature sensor 8 is mounted in the center in the longitudinal direction of the electric wire 4, as shown by part A in Fig. 1. As a result, the temperature corresponding to the load on the electric wire 4 can be properly detected.

[0033] The temperature sensor mounting structure in the embodiment of the present invention is not limited to a structure in which a temperature sensor is mounted on an electric wire provided in a hybrid vehicle equipped with an engine 1, but may also be a structure in which a temperature sensor is mounted on an electric wire provided in an electric vehicle equipped only with a motor 2. In that case, the temperature sensor is mounted in a protector for the electric wire routed in the space in which the motor 2 and the power transmission device that transmits its torque are mounted, and the lead wire of the temperature sensor is pulled out and mounted below horizontal. If there is a vibration source other than the engine in that space, it is preferable to mount the temperature sensor in a protector attached to that vibration source.

[0034] Furthermore, the temperature sensor mounting structure in the embodiments of the present invention is not limited to a structure in which a temperature sensor is provided on an electric wire connecting an inverter and a motor, but may be a structure in which a temperature sensor is mounted on an electric wire that connects on-board equipment and is routed in a space open to the outside of the vehicle where water and flying debris during driving may enter. [Explanation of symbols]

[0035] 1 engine 2 motors 3 inverters 4 electric wire 4a 1st area 4b 2nd area 5 Protector 5a Base member 5b Cover member 6 Side members 7 Braided wire 7a Lead wire outlet hole 8 Temperature Sensor 8a Element section 8b Case 8c lead wire 9 Heat-shrink tubing R Engine compartment

Claims

1. A temperature sensor mounting structure for detecting the temperature of an electric wire that is routed in a space open to the outside of a vehicle and electrically connects on-board devices, a protector surrounding at least a portion of the outer periphery of the electric wire in the longitudinal direction; the temperature sensor is attached to an outer surface of a portion of the electric wire surrounded by the protector, A portion of the electric wire and the temperature sensor are covered in a liquid-tight manner. A temperature sensor mounting structure comprising:

2. The temperature sensor mounting structure according to claim 1, a lead wire for outputting a signal detected by the temperature sensor is connected to the temperature sensor; The lead wire is led out downward from the temperature sensor when the temperature sensor is mounted on the vehicle. A temperature sensor mounting structure comprising:

3. 3. The temperature sensor mounting structure according to claim 2, The electric wire is covered with a braided wire that blocks noise, The lead wires are taken out from the mesh gaps of the braided wire. A temperature sensor mounting structure comprising:

4. The temperature sensor mounting structure according to any one of claims 1 to 3, The protector is fixed to a vibration source connected to the vehicle. A temperature sensor mounting structure comprising:

5. The temperature sensor mounting structure according to any one of claims 1 to 3, The temperature sensor is attached to the center of the electric wire in the longitudinal direction. A temperature sensor mounting structure comprising:

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