JP6551834B2 - Resistor - Google Patents

Description

  The present invention relates to a temperature-controlled resistor provided on an electrical circuit, and more particularly to a resistor used in a system for controlling the current flowing through the electrical circuit according to the temperature.

  Conventionally, a resistor (pre-charge resistor) for preventing a large inrush current from flowing through a capacitor is known as a resistor provided on an electric circuit. Since the resistor generates heat when energized, this amount of heat generation is taken into consideration in circuit design. However, when an amount of current more than expected flows to the resistor due to an external factor such as a short circuit of an electric circuit or a failure of a circuit component, the resistor may generate abnormal heat and burnout.

  On the other hand, there is a method of directly monitoring the temperature by arranging a temperature sensor around the resistor, and a method of indirectly monitoring the temperature by estimating the temperature from the current supplied to the resistor and the conduction time. Are known. According to these methods, the resistor can be protected by providing a switch or the like that cuts off the electric circuit when the monitored temperature exceeds a predetermined value. In addition, there is a technique in which a resistor is protected by providing a thermal fuse instead of monitoring temperature and shutting off an electric circuit when abnormal heating of the resistor is detected (see, for example, Patent Document 1). .

JP-A-2014-501435

  However, in the method of providing the temperature sensor around the resistor as described above, the problem is that the temperature sensor is susceptible to the use environment of the resistor (for example, the air flow around the resistor, the temperature of other members, etc.) is there. For this reason, there is a possibility that the measured value detected by the temperature sensor and the actual temperature are shifted, and the temperature of the resistor cannot be properly monitored. In addition, the technique for estimating the temperature of the resistor requires complicated control in order to increase the estimation accuracy. Furthermore, since it is necessary to provide a high response sensor for monitoring the current value and tuning for each use environment, there is also a problem of cost increase. On the other hand, when a temperature fuse is provided instead of monitoring the temperature, the temperature fuse needs to be replaced every time it is activated, which takes time and costs.

  The present invention has been made in view of the problems as described above, and an object of the present invention is to provide a resistor whose cost can be reduced and temperature can be accurately monitored. The present invention is not limited to this object, and it is an operation and effect derived from each configuration shown in the “embodiments to be described later”, which can not be obtained by the prior art. It can be positioned as a goal.

(1) The resistor disclosed herein is formed of an insulator, a core member having a hole inside, a conductive resistor provided on the outer periphery of the core member, formed of a conductor, and the hole A sensor incorporated in the housing to detect the temperature inside the core material, the core material being formed in a columnar shape, and the hole from the one end in the axial direction of the core material to the central part are bored, it said sensor, Ru is installed in the bottom of the hole.

( 2 ) It is preferable that the resistor is a spiral winding wound around the core material, and the pitch of the winding is narrowed toward a portion closer to the sensor.

  According to the disclosed resistor, the temperature inside the core material is detected by the sensor built in the core material, so that the temperature can be accurately monitored. In addition, cost can be reduced because replacement such as a thermal fuse is unnecessary. Furthermore, the cost can be reduced because a high response sensor for estimating the temperature with high accuracy and a complicated control configuration are also unnecessary.

It is a schematic diagram of the electric circuit provided with the resistor which concerns on one Embodiment, and its control structure. It is a typical top view which shows the resistor of FIG. 1 accommodated in the case. It is a schematic perspective view of the resistor of FIG. It is typical sectional drawing (figure which shows the cross section of the axial direction of a hole) which shows the bottom part of the hole which concerns on one modification.

  A resistor according to an embodiment will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment.

[1. Constitution]
[1-1. Circuit configuration]
The resistor 10 according to the present embodiment is provided in the electric circuit 20 shown in FIG. The electric circuit 20 is provided with a power source 30 and an inverter load 40 mounted on an electric vehicle (an electric vehicle or a hybrid electric vehicle). The power supply 30 is, for example, a high-voltage vehicle-mounted battery, and supplies the stored power to the inverter load 40. On the other hand, the inverter load 40 converts DC power supplied from the power supply 30 into AC power and supplies it to a vehicle driving motor (not shown). The inverter load 40 has a capacitor (not shown) for smoothing fluctuations in voltage and current output from the power supply 30.

  Between the power supply 30 and the inverter load 40, a relay 50 for electrically connecting and disconnecting these is interposed. The relay 50 has three switches 51 to 53 disposed on the electric circuit 20. Switching between on (closed) and off (open) of the switches 51 to 53 is controlled by the on-vehicle controller 60. The three switches 51 to 53 are hereinafter referred to as the P-side switch 51, the N-side switch 52, and the precharge switch 53, respectively.

  The P-side switch 51 is provided on the P-side connection line 21 that connects the positive terminal of the power supply 30 and the inverter load 40. Further, the N-side switch 52 is provided on the N-side connection line 22 connecting the negative terminal of the power source 30 and the inverter load 40. Further, the precharge switch 53 is provided on the precharge connection line 23 connected to the P side connection line 21 so as to bypass the P side switch 51. That is, the precharge switch 53 is provided in parallel with the P-side switch 51.

  The resistor 10 according to the present embodiment is provided in series with the precharge switch 53 on the precharge connection line 23. The resistor 10 is a precharge resistor for preventing a large inrush current from flowing to the inverter load 40 when the precharge switch 53 and the N-side switch 52 are both turned on. That is, the resistor 10 limits the current flowing from the power supply 30 to the inverter load 40. The detailed configuration of the resistor 10 will be described later.

  The control device 60 is an electronic control unit (ECU) configured with a microcomputer, and is configured as, for example, a well-known microprocessor, ROM, RAM, or other LSI device or embedded electronic device, and is connected to a communication line of an in-vehicle network. Be done. The control device 60 receives on / off information of the main switch of the vehicle, information on the start and end of charging of the power source 30, and information on the vehicle state such as the accelerator opening degree and the vehicle speed. Furthermore, temperature information of the resistor 10 detected by the sensor 5 described later is input to the control device 60. The control device 60 controls the relay 50 based on these pieces of information, and switches between connection and disconnection of the electric circuit 20.

  Specifically, when connecting the electric circuit 20, the control device 60 controls the N-side switch 52 to be on and controls one of the P-side switch 51 and the precharge switch 53 to be on. Further, when interrupting the electric circuit 20, the control device 60 controls the N-side switch 52 to be turned off, or controls both the P-side switch 51 and the precharge switch 53 to be turned off. Control all 53 off.

  The precharge switch 53 is controlled to be on when the precharge is performed. That is, in order to prevent a large inrush current from flowing from the power supply 30 to the inverter load 40, the precharge switch 53 is controlled to be turned on to connect the electric circuit 20, and the resistor 10 is energized. As a result, the current flowing from the power supply 30 is limited by the resistor 10 and then supplied to the inverter load 40.

  The control device 60 switches the precharge connection line 23 to the P side connection line 21 by controlling the precharge switch 53 to be turned off and the P side switch 51 to be turned on when a predetermined condition is satisfied during the precharge. As a result, the current flowing from the power supply 30 is supplied to the inverter load 40 without passing through the resistor 10 (without being limited by the resistor 10). In addition, as said predetermined conditions, it is mentioned that the charge amount of the capacitor | condenser contained in the inverter load 40 reaches | attains predetermined amount, for example.

  By the way, when electric current more than assumed flows into resistor 10 by external factors, such as a short circuit of electric circuit 20, and failure of inverter load 40, there is a possibility that resistor 10 may generate heat abnormally. Therefore, the control device 60 of the present embodiment directly monitors the temperature of the resistor 10 and controls the precharge switch 53 to be off when the temperature of the resistor 10 becomes equal to or higher than a predetermined value. That is, when the amount of heat generated by the resistor 10 becomes large, the precharge connection line 23 is cut off. Thereby, abnormal heat generation of the resistor 10 is prevented and protection of the resistor 10 is achieved.

[1-2. Resistor]
As shown in FIGS. 2 and 3, the resistor 10 includes a substantially cylindrical core 1 made of an insulator (for example, ceramics) and a winding 2 (resistor) formed of a conductor (for example, metal). And caps 3 and 4. The winding 2 is provided on the outer periphery of the core material 1, and the caps 3 and 4 are attached to both ends 1 a and 1 b of the core material 1 in the axial direction.

  The core 1 is elongated in the axial direction. The winding 2 is formed in a spiral shape and wound around the outer periphery of the core 1. Both ends 2a and 2b of the winding 2 are connected to the electric circuit 20 through caps 3 and 4, respectively, so that a current from the power supply 30 can be supplied. When energized, the winding 2 gives an electric resistance to the electric circuit 20 and generates heat.

  The caps 3 and 4 electrically connect the ends 2a and 2b of the winding 2 and the terminals 12 and 13, respectively, and are fixed to the ends 1a and 1b of the core 1. Hereinafter, when these caps 3 and 4 are distinguished from each other, one fixed to one end 1a of the core 1 is called the first cap 3 and the other fixed to the other end 1b of the core 1 is the second It is called cap 4. The terminals 12 and 13 are terminals (connection points) on the precharge connection line 23.

The first cap 3 includes a cylindrical tube portion 3a and a disk-shaped plate portion 3b that closes one opening of the tube portion 3a. Similarly, the second cap 4 also has a cylindrical tubular portion 4a and a disk-like plate portion 4b closing one opening of the tubular portion 4a. However, the plate portion 3b of the first cap 3 is different from the plate portion 4b of the second cap 4 in that it has a through-hole 3c described later.
The caps 3 and 4 are fixed to the core material 1 by fitting the respective cylindrical portions 3 a and 4 a to the core material 1. Further, the plate portions 3 b and 4 b of the caps 3 and 4 respectively cover the one end 1 a and the other end 1 b of the core 1 in a state where the caps 3 and 4 are fixed to the core 1.

  Further, one end 2a and the other end 2b of the winding 2 are connected to the outer peripheral surfaces of the cylindrical portions 3a and 4a respectively by welding. Further, the cylindrical portions 3a and 4a are connected to the electric circuit 20 via terminals 12 and 13, respectively. The connection destinations of the one end 2a and the other end 2b of the winding 2 and the terminals 12 and 13 may be plate portions 3b and 4b instead of the cylindrical portions 3a and 4a.

  The resistor 10 according to the present embodiment suppresses the cost, and in order to appropriately monitor the temperature rise of the core 1 due to the heat generation of the winding 2, the sensor 5 for detecting the temperature inside the core 1 is used. Furthermore, it has. The sensor 5 is incorporated in the core 1. That is, the sensor 5 is installed inside the core 1 and directly detects the temperature inside the core 1. The sensor 5 transmits information of the detected temperature to the control device 60 through the wiring 14.

  The core 1 of the present embodiment is provided with a hole 1 c for incorporating the sensor 5 at an appropriate position. Further, the first cap 3 of the present embodiment is formed with a through hole 3c for facilitating installation of the sensor 5 in the hole 1c.

  The hole 1 c is a hollow portion where the sensor 5 is installed, and is provided inside the core material 1. The hole portion 1c of the present embodiment is bored from one end 1a in the axial direction of the core 1 to the central portion (an intermediate portion between the one end 1a and the other end 1b of the core 1). That is, the core 1 is not penetrated, and a wall surface 1 d corresponding to the bottom (end) of the hole 1 c is provided in the center of the core 1.

  The wall surface 1 d is flat and has a function of defining the position of the sensor 5. That is, the sensor 5 can be positioned by inserting the sensor 5 from the end 1 a of the core 1 into the hole 1 c and entering the hole 1 c until it comes in contact with the wall surface 1 d. As a result, the position of the sensor 5 is defined at the central portion in the axial direction of the core 1, and the sensor 5 is incorporated in the central portion (hole 1 c) in the axial direction of the core 1. At this time, the sensor 5 is preferably in contact with the wall surface 1 d of the hole 1 c. According to this, accurate positioning of the sensor 5 in the central portion of the core 1 is facilitated. As a result, the maximum temperature of the core 1 can be monitored more accurately.

  The hole portion 1 c is formed on the axial center of the core 1 and opens in a circle at one end 1 a of the core 1. The hole diameter of the hole 1c is set to a size that allows the sensor 5 to be installed in the hole 1c. In addition, the core material 1 may be formed in a shape having a hole 1c by being partially hollowed out after being formed in a columnar shape, or may be formed in a shape having a hole 1c in advance.

  The through-hole 3c is penetrated by the board part 3b of the 1st cap 3 so that it may open in the same shape on the same axis as the hole part 1c. The through hole 3 c communicates with the hole 1 c of the core material 1 in a state where the first cap 3 is attached to the core material 1. The sensor 5 is inserted into the hole 1 c of the core 1 through the through hole 3 c. Moreover, the wiring 14 of the sensor 5 is drawn out of the resistor 10 through the through hole 3 c.

  Furthermore, in order to monitor the temperature of the resistor 10 more accurately, the resistor 10 of the present embodiment is provided so that the pitch of the spiral of the winding 2 is not constant but different in the axial direction. The pitch is a distance that advances in the axial direction of the core 1 when the outer periphery of the core 1 is rotated one turn along the winding 2 (that is, adjacent windings when the resistor 10 is viewed from the outer side in the radial direction). Means the spacing of the lines 2). Specifically, in the winding 2, the pitch at the central portion in the axial direction (the axial direction of the core material 1) is narrower than the pitch at both end portions. That is, the pitch of the winding 2 is formed so as to be narrower as it gets closer to the sensor 5. 2 and 3, in order to make the configuration of the resistor 10 easier to understand, the number of turns of the winding 2 is reduced and the pitch is shown larger.

  As shown in FIG. 2, the resistor 10 is provided on the electric circuit 20 in a state housed in the horizontally long case 11. The resistor 10 is fixed to the inside of the case 11 by being set inside the case 11 and then a non-illustrated insulating material (for example, a nonflammable insulating paint) is poured into the case 11 and solidified. Further, the sensor 5 is fixed inside the core material 1 when the insulating material poured into the case 11 flows into the hole 1c of the core material 1 through the through hole 3c of the first cap 3 and solidifies.

[2. Action, effect]
(1) In the resistor 10 described above, the sensor 5 is built in the hole 1 c of the core 1, so the temperature inside the core 1 is directly measured by the sensor 5 without being affected by the surrounding environment of the resistor 10. Can be detected. That is, as compared with the case where a sensor is provided around the resistor 10 to monitor the temperature, the sensor 5 is not affected by the use environment of the resistor 10, so that the temperature of the resistor 10 can be detected accurately it can. Therefore, according to the above-mentioned resistor 10, temperature can be monitored correctly. Thus, for example, as described above, by configuring the precharge switch 53 to be turned off when the temperature of the resistor 10 becomes a predetermined value or more, abnormal heat generation of the resistor 10 is prevented, and the resistor 10 is prevented. Can be protected.

  Moreover, since the above-mentioned resistor 10 detects the temperature inside the core material 1 directly with the sensor 5, the control structure for estimating the temperature of the resistor 10 and a high response sensor become unnecessary. For this reason, according to the above-mentioned resistor 10, cost can be suppressed. Furthermore, since the above-mentioned resistor 10 can monitor temperature accurately with sensor 5, a thermal fuse is unnecessary. In addition, since it is not necessary to replace the thermal fuse, the cost can be suppressed by this. Further, the sensor 5 can be easily incorporated in the core member 1 by installing the sensor 5 in the hole 1 c formed in the core member 1.

  (2) In the resistor 10 described above, the sensor 5 is built in the central portion of the core material 1 in the axial direction. The central portion in the axial direction of the core member 1 is a portion where the temperature tends to be high compared to the other portions during energization of the winding 2. That is, the above-described sensor 5 is incorporated in the portion of the core member 1 where the temperature tends to be the highest. Therefore, according to the resistor 10 described above, the maximum temperature in the core material 1 can be monitored by the sensor 5. Thus, for example, as described above, by configuring the precharge switch 53 to be turned off when the temperature detected by the sensor 5 becomes a predetermined value or more, abnormal heat generation of the resistor 10 is more reliably prevented. And the resistor 10 can be protected.

  Further, in the above-described resistor 10, the hole portion 1c is bored from the one end 1a in the axial direction of the core material 1 to the central portion. Thus, the sensor 5 is brought into contact with the wall surface 1d of the hole portion 1c by providing the bottom portion (wall surface 1d) of the hole portion 1c at the center portion in the axial direction of the core material 1, thereby causing the sensor 5 to contact the core material 1. It can be positioned precisely in the axial center of the Therefore, the maximum temperature of the core 1 can be monitored more accurately.

  (3) In the resistor 10 described above, since the pitch of the spiral of the winding 2 is narrower as the winding 2 is closer to the sensor 5, the amount of heat generation of the core 1 becomes larger as the location is closer to the sensor 5. Thereby, the sensor 5 can detect the temperature rise of the core material 1 more sensitively. Therefore, for example, as described above, by configuring the precharge switch 53 to be turned off when the temperature of the resistor 10 detected by the sensor 5 becomes a predetermined value or more, abnormal heat generation of the resistor 10 can be further improved. The resistor 10 can be protected reliably and quickly.

  (4) In the resistor 10 described above, the first cap 3 covering the one end 1 a of the core 1 is provided with the through hole 3 c communicating with the hole 1 c of the core 1. Therefore, even in the state where the first cap 3 is attached to the core 1, the sensor 5 can be easily inserted into the hole 1 c through the through hole 3 c. Further, for example, when the resistor 10 is fixed using an insulating material as described above, the insulating material flows into the hole 1c through the through hole 3c. Can be fixed. Furthermore, the wiring 14 of the sensor 5 can be easily pulled out of the resistor 10 using the through hole 3 c.

[3. Modified example]
Regardless of the embodiment described above, various modifications can be made without departing from the scope of the invention. The configurations of the present embodiment can be selected as needed, or may be combined as appropriate.

  In the above-described embodiment, the case where the resistor 10 is a precharge resistor provided in a vehicle is illustrated, but the application of the resistor 10 is not limited to this. The resistor 10 may be provided, for example, in a home appliance or an IT communication device, or may be used for purposes other than precharging. In any application, the above-described resistor 10 can provide the same operations and effects as described above.

  The winding 2 shown in the above embodiment is an example of a resistor provided in the resistor 10. The resistor provided in the resistor 10 may be at least a conductor and provided on the outer periphery of the core member 1 as long as it can be energized, and may be, for example, a metal film. That is, the structure in which the above-described sensor 5 is incorporated in the core 1 is not limited to the winding resistor provided with the winding 2, and electrodes are provided at both ends of the core 1 and a metal film is formed between the pair of electrodes. It is applicable also to the metal film resistor provided.

  Moreover, in the above-mentioned embodiment, although the case where the sensor 5 is a center part of the axial direction of the core material 1 and is built-in on an axial center was illustrated, the position of the sensor 5 is not limited to this. As long as the sensor 5 is built in at least the core material 1, the temperature inside the core material 1 can be directly detected as described above. Thus, the temperature of the resistor 10 can be monitored accurately.

Moreover, the caps 3 and 4 shown by the above-mentioned embodiment may be abbreviate | omitted, and both ends 2a and 2b of the winding 2 and the terminals 12 and 13 may be connected directly. That is, the caps 3 and 4 described above are not essential components for the resistor 10.
Further, the shape of the winding 2 shown in the above embodiment is an example, and the pitch and the number of turns can be set as appropriate. In FIGS. 2 and 3, adjacent windings 2 (adjacent windings 2 when the resistor 10 is viewed from the outside in the radial direction) are separated also in the axial center portion of the core 1 ( However, the shape of the winding 2 is not limited to this, and adjacent windings may be brought into contact with each other.

  Further, in the above-described embodiment, the case where the hole 1c is drilled from the axial end 1a to the center of the core material 1 is illustrated, but the hole 1c has a shape in which at least the sensor 5 can be incorporated. There is no limitation to the above-described shape, as long as it is sufficient. Moreover, in the above-mentioned embodiment, although the bottom part (wall surface 1d) of the hole 1c provided in the core material 1 was made flat, you may change this into a shape as shown in FIG. That is, a recess K may be provided at the bottom of the hole 1 c, and a part of the sensor 5 shown by a two-dot chain line in the drawing may be accommodated in the recess K. The position of the sensor 5 can be set by the position of the recess K. Further, the ratio of the sensor 5 accommodated in the recess K can be changed according to the size and the depth of the recess K. By providing the depression K in this way, the sensor 5 can be positioned with higher accuracy in the central portion in the axial direction of the core material 1, and as a result, the maximum temperature of the core material 1 can be monitored more accurately. It becomes.

1 Core material 1a One end 1c Hole 1d Wall surface (bottom)
2 Winding (resistor)
5 sensors 10 resistors

Claims (2)

A core formed of an insulator and having a hole inside;
A resistor that is provided on the outer periphery of the core member and is formed of a conductor and capable of being energized;
A sensor built in the hole and detecting the temperature inside the core ,
The core material is formed in a columnar shape, and
The hole is bored from one end in the axial direction of the core material to the central portion,
The resistor, wherein the sensor is installed at the bottom of the hole . The resistor, the a wound helically winding the core material, characterized in that the pitch of the windings are narrower portion closer to the sensor, 1 Symbol placement resistor claims .

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