Temperature sensor and temperature sensor assembly

Abstract

To reduce the size of a temperature sensor.SOLUTION: A temperature sensor 7 is used for detection of the cell temperature of an automotive battery, and is assembled to a case 2 to constitute a busbar module 1. The temperature sensor 7 comprises an FPC 3, a chip thermistor 4 mounted on the surface of the FPC 3, a metal heat-receiving component 5 that comes into contact with a top face 9 of the battery cell, and an elastic member 6 assembled to the heat-receiving component 5 and having the FPC 3 between the heat-receiving component 5 and itself. The elastic member 6 is used to press the heat-receiving component 5 so that the heat-receiving component 5 is brought into contact with the top face 9 of the battery cell with appropriate pressure, and is composed of rubber material. The elastic member 6 is provided with a cavity 64 so as not to be in contact with a section where the chip thermistor 4 of the FPC 3 is mounted.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a temperature sensor used for detecting the temperature of a cell in an in-vehicle battery, and to a temperature sensor assembly in which the temperature sensor is assembled in a case. [Background technology]

[0002] Batteries installed in hybrid vehicles and electric vehicles are configured by connecting multiple battery cells in series to obtain high voltage. To prevent overcharging and over-discharging of such batteries, temperature sensors are attached to the battery cells to monitor their temperature (see Patent Document 1).

[0003] An example of the above-mentioned temperature sensor is shown in Fig. 9. This temperature sensor 500 includes an FPC 503 on which a thermistor 504 is mounted, a metal heat-receiving part 505 that surrounds the thermistor 504 and is in contact with the upper surface of the battery cell, and a resin part 506 attached to the heat-receiving part 505. The resin part 506 includes a pair of locking spring parts 561 that lock onto a case attached to the upper surface of the battery.

[0004] In such a temperature sensor 500, the heat receiving component 505 comes into contact with the upper surface of the battery cell with an appropriate pressure due to the spring properties of the pair of locking spring portions 561 that are locked to the case. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-17638 Summary of the Invention [Problem to be solved by the invention]

[0006] The conventional temperature sensor 500 described above is in need of further miniaturization, and there is room for improvement.

[0007] SUMMARY OF THE INVENTION An object of the present invention is to reduce the size of a temperature sensor. [Means for solving the problem]

[0008] The temperature sensor of the present invention comprises a flexible printed circuit board, a chip thermistor surface-mounted on the flexible printed circuit board, a metal heat-receiving component that contacts a temperature-measured portion, and an elastic member that is assembled to the heat-receiving component and sandwiches the flexible printed circuit board between the heat-receiving component and the flexible printed circuit board, and a cavity is provided in the elastic member so that the elastic member is not in contact with the portion of the flexible printed circuit board where the chip thermistor is mounted. The heat-receiving component has a frame-shaped contact portion that contacts the temperature-measured part, the flexible printed circuit board is sandwiched between the contact portion and the elastic member, and the chip thermistor is surrounded by the contact portion. It is characterized by:

[0009] The temperature sensor assembly of the present invention comprises the temperature sensor and a case that is attached to the part to be measured while holding the temperature sensor, wherein the case has an opposing wall that faces the part to be measured, and a holding hole for the temperature sensor is formed in the opposing wall, and the elastic member comprises a press-fit locking portion pressed into the holding hole, a plate portion that sandwiches the flexible printed circuit board between it and the heat-receiving component, and an intermediate portion between the press-fit locking portion and the plate portion, and the cavity is provided from the plate portion to the intermediate portion. The temperature sensor assembly of the present invention comprises a flexible printed circuit board, a chip thermistor surface-mounted on the flexible printed circuit board, a metal heat-receiving component that contacts a part to be measured, and an elastic member that is assembled to the heat-receiving component and sandwiches the flexible printed circuit board between it and the heat-receiving component, the elastic member having a cavity so that the temperature sensor is not in contact with the part of the flexible printed circuit board where the chip thermistor is mounted, and a case that is attached to the part to be measured while holding the temperature sensor, the case having an opposing wall that faces the part to be measured, and the opposing wall A retaining hole for the temperature sensor is formed in the wall, the elastic member has a press-fit locking portion pressed into the retaining hole, a plate portion sandwiching the flexible printed circuit board between the heat-receiving component, and an intermediate portion between the press-fit locking portion and the plate portion, the cavity being provided from the plate portion to the intermediate portion, the case having a standing wall extending from the opposing wall toward the plate portion, a gap being provided between the standing wall and the plate portion when the case is attached to the temperature-measured part, and the dimension of the cavity in the direction from the opposing wall toward the plate portion is formed to be larger than the gap. [Effects of the Invention]

[0010] According to the present invention, the temperature sensor can be made smaller. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view of a temperature sensor assembly according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view taken along the line AA in FIG. [Figure 3] FIG. 2 is a front view of the temperature sensor of FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view of the temperature sensor of FIG. 3. [Figure 5]1. FIG. 4 is a diagram for explaining a method of assembling the temperature sensor assembly of FIG. 1, showing how an elastic member is attached to a case. [Figure 6] 6 is a diagram showing how a heat-receiving component is assembled to the elastic member assembled to the case of FIG. 5. FIG. [Figure 7] 7A and 7B are diagrams illustrating the function of the vertical wall of the case when the heat-receiving part is attached to the elastic member of FIG. 6. [Figure 8] FIG. 10 is a cross-sectional view of a temperature sensor according to a reference example. [Figure 9] FIG. 1 is a front view of a conventional temperature sensor. DETAILED DESCRIPTION OF THE INVENTION

[0012] A "temperature sensor" and a "temperature sensor assembly" according to one embodiment of the present invention will be described with reference to FIGS.

[0013] The temperature sensor 7 shown in Figures 1 to 4 is used to detect the temperature of a battery cell mounted on a hybrid vehicle or an electric vehicle, and is installed on the upper surface 9 of the battery cell (corresponding to the part to be measured temperature) as shown in Figure 2. The battery is configured by connecting a plurality of battery cells in series, and a case 2 made of synthetic resin is attached to the upper surface of the battery.

[0014] The case 2 is fitted with a plurality of temperature sensors 7 and a plurality of bus bars that connect the electrodes of adjacent battery cells together to connect the battery cells in series. The case 2 fitted with the temperature sensors 7 is called a "temperature sensor assembly." In this example, since the case 2 is fitted with not only a plurality of temperature sensors 7 but also a plurality of bus bars, etc., this is called a "bus bar module" and is given the reference numeral 1. In other words, the bus bar module 1 corresponds to a "temperature sensor assembly."

[0015] The temperature sensor 7 comprises a flexible printed circuit board (hereinafter referred to as FPC) 3, a chip thermistor 4 surface-mounted on the FPC 3, a metal heat-receiving component 5 in contact with the upper surface 9 of the battery cell, and an elastic member 6 attached to the heat-receiving component 5.

[0016] The FPC 3 is a well-known device in which a circuit is formed on a thin flexible film. The FPC 3 is formed in a strip shape, and a chip thermistor 4 is surface-mounted on one end of the FPC 3. The other end of the FPC 3 is connected to the battery control unit. Note that in FIG. 1, the other end of the FPC 3 that extends toward the battery control unit (extending to the right in FIG. 1) is not shown.

[0017] The heat-receiving component 5 includes a contact portion 51 that contacts the upper surface 9 of the battery cell, and an attachment portion 52 that is attached to the elastic member 6.

[0018] The contact portion 51 is formed in a rectangular frame shape, and one end of the FPC 3 is sandwiched between the contact portion 51 and a plate portion 62 (described later) of the elastic member 6. In addition, one end of the FPC 3 is joined to the contact portion 51 for mechanical fixation.

[0019] 2 and 6, the mounting portion 52 extends from the outer edge of the contact portion 51 toward a plate portion 62 (described later) of the elastic member 6. The mounting portion 52 is press-fitted into a locking hole 65 formed in the plate portion 62. A retaining projection 52a is formed at the tip of the mounting portion 52 to prevent the mounting portion 52 from coming out of the locking hole 65.

[0020] The elastic member 6 is used to press the heat-receiving component 5 so that it comes into contact with the upper surface 9 of the battery cell with an appropriate pressure. Conventional cell temperature sensors perform this pressing using a resin spring or a coil spring, but the temperature sensor 7 of this example uses the elastic member 6 described below to reduce the size.

[0021] 2 to 5, the elastic member 6 includes a press-fit locking portion 61 press-fitted into a holding hole 21 (described later) of the case 2, a plate portion 62 sandwiching one end of the FPC 3 between the press-fit locking portion 61 and the contact portion 51 of the heat-receiving component 5, and an intermediate portion 63 between the press-fit locking portion 61 and the plate portion 62.

[0022] The press-fit locking portion 61 has a head portion 61a and a base portion 61c that are larger than the retaining hole 21, and a constricted portion 61b that is smaller than the retaining hole 21. The base portion 61c is connected to an intermediate portion 63, the constricted portion 61b is connected to the side of the base portion 61c opposite the intermediate portion 63, and the head portion 61a is connected to the side of the constricted portion 61b opposite the base portion 61c. The press-fit locking portion 61 passes through the retaining hole 21 with the head portion 61a in an elastically deformed state and returns to its original shape after passing through, thereby locking into the retaining hole 21 as shown in FIG. 2.

[0023] The plate portion 62 is formed in a rectangular plate shape that is larger than the outer shape of the contact portion 51. A locking hole 65 into which the mounting portion 52 is press-fitted is formed at one end of the plate portion 62. A groove 66 through which the FPC 3 is passed is formed at the other end of the plate portion 62.

[0024] 1 and 2, one end of the FPC 3 is sandwiched between the contact portion 51 and the plate portion 62 with the mounting surface of the chip thermistor 4 in contact with the contact portion 51 and the back surface in contact with the plate portion 62. The chip thermistor 4 is surrounded by the frame-shaped contact portion 51 and faces the upper surface 9 of the battery cell.

[0025] The intermediate portion 63 is formed into a conical shape with the plate portion 62 side as the bottom surface.

[0026] Such elastic member 6 has a pressing function equivalent to that of the resin spring or coil spring of a conventional cell temperature sensor, and also realizes a smaller and thinner temperature sensor 7. As a result, the mounting space for temperature sensor 7 in case 2 is smaller in height (the dimension in the opposing direction between opposing wall 20 and battery cell top surface 9) than conventional products.

[0027] Furthermore, a cavity 64 is provided in the elastic member 6 so as to be out of contact with the portion of the FPC 3 on which the chip thermistor 4 is mounted. In this example, the cavity 64 is provided from the plate portion 62 to the intermediate portion 63.

[0028] 8 does not have a cavity 64 in the elastic member 406. In such a temperature sensor 407, the FPC 3 and elastic member 406 are in constant contact, and the chip thermistor 4 is constantly subjected to force, which may cause cracks. In contrast, the temperature sensor 7 of this example has a cavity 64, so no force is applied to the chip thermistor 4, preventing damage.

[0029] The case 2 includes an opposing wall 20 that faces the upper surface 9 of the battery cell, and standing walls 22 and 23 that extend from the opposing wall 20 toward the plate portion 62.

[0030] The opposing wall 20 has a retaining hole 21 formed therein, into which the press-fit retaining portion 61 of the temperature sensor 7 is retained. The retaining hole 21 is a rectangular hole that penetrates the opposing wall 20.

[0031] The standing wall 22 is formed in a C-shape on the outer periphery of the retaining hole 21. The standing wall 22 faces the outer periphery of the cavity 64 in the plate portion 62. The standing wall 23 is formed in a straight line. The standing wall 23 faces the portion of the plate portion 62 that is further outward than the locking hole 65.

[0032] 2, when the case 2 is attached to the upper surface 9 of the battery cell, a gap H2 is provided between the standing wall 22 and the plate portion 62, and a gap H3 is provided between the standing wall 23 and the plate portion 62. The gaps H2 and H3 are equal. Furthermore, when the case 2 is attached to the upper surface 9 of the battery cell, the height dimension H1 of the elastic member 6 in the cavity 64 (the dimension in the direction from the opposing wall 20 toward the plate portion 62) is set larger than the gaps H2 and H3.

[0033] Next, an example of a method for assembling the busbar module 1 will be described. First, as shown in Fig. 5, the press-fit locking portions 61 of the elastic member 6 are press-fit into the retaining holes 21 of the case 2, thereby assembling the elastic member 6 to the case 2. Next, as shown in Fig. 6, the mounting portions 52 of the heat-receiving component 5, to which the FPC 3 is joined, are press-fit into the locking holes 65 of the elastic member 6 assembled to the case 2, thereby assembling the heat-receiving component 5 to the elastic member 6. In this manner, the plurality of temperature sensors 7 are assembled to the case 2, and the plurality of bus bars are assembled to the case 2, thereby assembling the busbar module 1.

[0034] Furthermore, as described above, when the heat-receiving component 5 is assembled to the elastic member 6, the elastic member 6 is pressed by the heat-receiving component 5, causing elastic deformation. That is, the elastic member 6 slips out when the heat-receiving component 5 is assembled. If slippage occurs, assembly becomes difficult. In this example, however, as shown in FIG. 7 , the standing walls 22, 23 support the elastic member 6, and the tip surfaces of the standing walls 22, 23 act as receiving surfaces. This makes it possible to suppress elastic deformation of the elastic member 6 near the locking hole 65, and also to suppress movement of the elastic member 6, making it easier to press the mounting portion 52 into the locking hole 65.

[0035] In Figure 7, when force is applied to the elastic member 6, it temporarily elastically deforms and the plate portion 62 abuts against the standing walls 22, 23, but after the heat-receiving component 5 is assembled, the elastic deformation is restored and the plate portion 62 is spaced apart from the standing walls 22, 23.

[0036] Furthermore, when attaching the busbar module 1 to the battery, the busbar module 1 is pressed against the upper surface of the battery, compressing the elastic member 6 toward the upper surface. That is, the elastic member 6 strokes toward the upper surface 9. However, because the cavity 64 is provided in the elastic member 6, the elastic member 6 does not come into contact with the portion of the FPC 3 where the chip thermistor 4 is mounted. If the stroke exceeds the expected stroke, the standing walls 22 and 23 come into contact with the plate portion 62, restricting further stroke of the elastic member 6. That is, because the height H1 of the cavity 64 is greater than the distances H2 and H3 between the standing walls 22 and 23 and the plate portion 62 as described above, the elastic member 6 does not come into contact with the portion of the FPC 3 where the chip thermistor 4 is mounted, even if it strokes, and no force is applied to the chip thermistor 4.

[0037] Furthermore, even when the busbar module 1 is mounted with a battery, the presence of the standing walls 22 and 23 restricts the tilt of the temperature sensor 7. That is, even if an external force is applied after the busbar module 1 is attached, the standing walls 22 and 23 restrict the stroke of the elastic member 6, and the tilt of the temperature sensor 7 is restricted, just as when the busbar module 1 is attached.

[0038] As described above, the busbar module 1 equipped with the temperature sensor 7 requires less space in the case 2 to mount the temperature sensor 7 than conventional products. The cavity 64 and the vertical walls 22, 23 are also employed as a structure to prevent damage to the chip thermistor 4. Furthermore, the vertical walls 22, 23 function as a structure to facilitate assembly of the busbar module 1, and also regulate the tilt of the temperature sensor 7 after assembly.

[0039] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be implemented with various modifications within the scope of the gist of the present invention. As long as such modifications still include the configuration of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0040] 1 Busbar module (temperature sensor assembly) 2 cases 3 Flexible Printed Circuit Board 4 Chip thermistor 5 Heat receiving parts 6 Elastic member 7 Temperature Sensor 9 Top surface of battery cell (temperature measurement part) 20 Opposite wall 22,23 Standing wall 61 Press-fit locking portion 62 Board part 63 Middle section 64 Cavity

Claims

1. A flexible printed circuit board; a chip thermistor surface-mounted on the flexible printed circuit board; a metal heat receiving part that comes into contact with the part to be measured; an elastic member attached to the heat-receiving component, sandwiching the flexible printed circuit board between the elastic member and the heat-receiving component; a cavity is provided in the elastic member so as to be out of contact with a portion of the flexible printed circuit board on which the chip thermistor is mounted, the heat receiving component has a frame-shaped contact portion that contacts the temperature measurement target component, The flexible printed circuit board is sandwiched between the contact portion and the elastic member, and the chip thermistor is surrounded by the contact portion. A temperature sensor characterized by:

2. a temperature sensor according to claim 1; and a case that is attached to the temperature-measured part while holding the temperature sensor; the case has an opposing wall facing the temperature-measured part, and a holding hole for the temperature sensor is formed in the opposing wall; the elastic member includes a press-fit locking portion press-fitted into the holding hole, a plate portion sandwiching the flexible printed circuit board between the press-fit locking portion and the heat-receiving component, and an intermediate portion between the press-fit locking portion and the plate portion, The cavity is provided from the plate portion to the intermediate portion. A temperature sensor assembly comprising:

3. the case includes a standing wall extending from the opposing wall toward the plate portion, When the case is attached to the temperature-measured part, a gap is provided between the standing wall and the plate part, and the dimension of the cavity in a direction from the opposing wall toward the plate part is formed larger than the gap.

3. The temperature sensor assembly of claim 2.

4. A temperature sensor comprising a flexible printed circuit board, a chip thermistor surface-mounted on the flexible printed circuit board, a metal heat-receiving component that contacts the temperature-measured part, and an elastic member that is assembled to the heat-receiving component and sandwiches the flexible printed circuit board between the heat-receiving component, wherein a cavity is provided in the elastic member so that the flexible printed circuit board is not in contact with the part where the chip thermistor is mounted on the flexible printed circuit board; a case that is attached to the temperature measurement target part while holding the temperature sensor; the case has an opposing wall facing the temperature-measured part, and a holding hole for the temperature sensor is formed in the opposing wall; the elastic member includes a press-fit locking portion press-fitted into the holding hole, a plate portion sandwiching the flexible printed circuit board between the press-fit locking portion and the heat-receiving component, and an intermediate portion between the press-fit locking portion and the plate portion, The cavity is provided from the plate portion to the intermediate portion, the case includes a standing wall extending from the opposing wall toward the plate portion, When the case is attached to the temperature-measured part, a gap is provided between the standing wall and the plate part, and the dimension of the cavity in a direction from the opposing wall toward the plate part is formed larger than the gap. A temperature sensor assembly comprising:

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