Cable with sensor

Abstract

To provide a cable with a sensor capable of more firmly holding a connection part between the sensor and the cable.SOLUTION: The cable with sensor 1 includes the magnetic sensors 4 having the connection terminals 41, the cable 2, the crimp terminals 5 provided at the end portions of the cable 2 and connected to the connection terminals 41, and the holder 6 holding the magnetic sensors 4 and the crimp terminals 5, the crimp terminals 5 each include the tubular fitting portion 51 fitted to the connection terminals 41, and the fitting portion 51 has the slit 51a formed along the axial direction thereof and is configured to be elastically deformable such that the slit 51a is opened and closed. The holder 6 has a groove side 62a for housing the crimp terminal 5, and at least one of the fitting part 51 and the groove side 62a has a coming-off prevention part 8 for preventing the fitting part 51 from coming off from the groove side 62a when the fitting part 51 is housed in the groove side 62a and pressing the fitting part 51 in the direction of closing the slit side 51a.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cable with a sensor. [Background technology]

[0002] Conventionally, a cable with a sensor provided at the end of the cable has been known (see, for example, Patent Documents 1 and 2). In the cable with a sensor, a resin molded portion may be provided so as to cover the cable end and the sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-227095 [Patent Document 2] Patent Publication No. 10-319037 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional sensor-equipped cable, the connection between the sensor and the cable may be damaged by the molten resin that flows into the resin molded portion during molding.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a sensor-equipped cable that can more firmly hold the connection between the sensor and the cable. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides a sensor-equipped cable comprising: a sensor having a connection terminal; a cable; a crimp terminal provided at the end of the cable and connected to the connection terminal; and a holder for holding the sensor and the crimp terminal, wherein the crimp terminal accommodates the connection terminal and has a tubular fitting portion that fits with the connection terminal, the fitting portion has a slit formed along its axial direction and is configured to be elastically deformable so that the slit can open and close, the holder has a groove that accommodates the connection terminal including the fitting portion, and at least one of the fitting portion or the groove has a retaining portion that prevents the fitting portion from coming out of the groove when the fitting portion is accommodated in the groove and presses the fitting portion in the direction of closing the slit. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a sensor-equipped cable that can more firmly hold the connection between the sensor and the cable. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a schematic configuration of a rotation detection device using a sensor-equipped cable according to an embodiment of the present invention; [Figure 2] 1A and 1B are diagrams showing the internal structure of a cable with a sensor according to an embodiment of the present invention, in which (a) is a plan view and (b) is a cross-sectional view taken along line AA in (a). [Figure 3] FIG. 3 is a diagram showing the crimp terminal, where (a) is a plan view, (b) is a side view, and (c) is a cross-sectional view taken along line BB in (b). [Figure 4] 1(a) and 1(b) are diagrams illustrating the connection between a magnetic sensor 4 and a crimp terminal 5. FIG. [Figure 5] 10(a) and 10(b) are diagrams illustrating insertion of a crimp terminal into a groove. [Figure 6] 10(a) to 10(c) are diagrams showing a modified example of the barb portion. [Figure 7] 10A and 10B are diagrams showing a modified example of the retaining portion. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment Mode] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] Fig. 1 is a perspective view showing a schematic configuration of a rotation detection device 10 using a sensor-equipped cable 1 according to this embodiment. As shown in Fig. 1, the rotation detection device 10 includes the sensor-equipped cable 1 according to this embodiment and a detected member 11. The rotation detection device 10 is used, for example, to detect the rotational speed of the wheels of an automobile, i.e., the wheel speed.

[0011] The detection target member 11 is attached to a rotating member (not shown) and rotates together with the rotating member. When the rotation detection device 10 is used to detect wheel speed, the rotating member is, for example, an inner ring attached to the wheel and rotating together with the wheel. The detection target member 11 is formed in an annular shape and in a plate shape perpendicular to the rotation axis of the rotating member, and is attached, for example, to the outer circumferential surface of the rotating member.

[0012] In this embodiment, the detected member 11 is a magnetic encoder having a plurality of magnetic poles arranged along the circumferential direction around the rotation axis of the rotating member. The detected member 11 has north and south magnetic poles arranged alternately along the circumferential direction.

[0013] (Sensor-equipped cable 1) Fig. 2 shows the internal structure of the sensor-equipped cable 1 according to this embodiment, with Fig. 2(a) being a plan view and Fig. 2(b) being a cross-sectional view taken along line AA in Fig. 2(a). As shown in Figs. 2(a) and 2(b), the sensor-equipped cable 1 comprises a cable 2 and a sensor unit 3 provided at the end of the cable 2.

[0014] (Cable 2) The cable 2 has a pair of electric wires 21 corresponding to a pair of connection terminals 41 of the magnetic sensor 4, which will be described later. Each electric wire 21 has a conductor 21a made of a stranded conductor formed by twisting together wires with good electrical conductivity, such as copper, and an insulator 21b made of an insulating resin, such as cross-linked polyethylene, that covers the outer periphery of the conductor 21a. The cable 2 also has a sheath 22 that collectively covers the pair of electric wires 21. At the end of the cable 2, the pair of electric wires 21 are exposed from the sheath 22, and at the end of each electric wire 21, the conductor 21a is exposed from the insulator 21b.

[0015] (Sensor part 3) The sensor unit 3 is provided at the end of the cable 2. The sensor unit 3 is attached to a fixed member that does not rotate with the rotation of the rotating member. For example, when the rotation detection device 10 is used to detect the wheel speed, the fixed member is, for example, a knuckle that is connected to the body of an automobile and supports the outer wheel. The sensor unit 3 is disposed opposite the member to be detected 11 (see FIG. 1). The sensor unit 3 has a magnetic sensor 4, a crimp terminal 5, a holder 6, and a resin molded portion 7. Each part will be described in detail below.

[0016] (Magnetic sensor 4) The sensor unit 3 includes a magnetic sensor 4 as a sensor of the present invention. The magnetic sensor 4 includes a plate-shaped detection unit 40 including a magnetic detection element (not shown) that detects a magnetic field from the detection target 11, and a pair of connection terminals 41 extending from the detection unit 40. The magnetic detection element may be a Hall element or an MR element (magnetoresistive effect element). The MR element may be a GMR (giant magnetoresistive effect) element, an AMR (anisotropic magnetoresistive effect) element, or a TMR (tunneling magnetoresistive effect) element. The detection unit 40 includes the magnetic detection element, a signal processing circuit (not shown), and a resin mold 40a that serves as a cover that collectively covers the magnetic detection element and the signal processing circuit. The pair of connection terminals 41 are formed in a strip shape (a long, narrow plate shape). The connection terminals 41 have chamfered corners at their tips, forming a tapered shape, to facilitate insertion into a fitting portion 51 (described later). A capacitance element for suppressing noise is connected between the two connection terminals 41, and a capacitance element protection part 42 formed by molding resin is provided to cover the capacitance element and the surrounding connection terminals 41.

[0017] (Crimp terminal 5) 3A and 3B are diagrams showing the crimp terminal 5, with FIG. 3A being a plan view, FIG. 3B being a side view, and FIG. 3C being a cross-sectional view taken along line BB in FIG. 3B. As shown in FIGS. 2 and 3A, the crimp terminal 5 is provided at the end of the cable 2, and is configured so that the cable 2 and the magnetic sensor 4 are electrically connected via the crimp terminal 5 by connecting the connection terminal 41 of the magnetic sensor 4 to the crimp terminal 5. In this embodiment, a pair of crimp terminals 5 having the same shape corresponding to each of the pair of connection terminals 41 is provided.

[0018] The crimp terminal 5 is made of a conductive material and is formed, for example, by pressing a metal plate. The crimp terminal 5 may be made of, for example, copper, a copper alloy such as brass, aluminum, an aluminum alloy, or the like. The crimp terminal 5 integrally has a fitting portion 51, a first crimping portion 52, and a second crimping portion 53. The first crimping portion 52 is crimped and fixed (crimped) to the conductor 21a exposed at the end of the electric wire 21. The second crimping portion 53 is crimped and fixed (crimped) to the end of the insulator 21b.

[0019] The fitting portion 51 is a portion into which the connection terminal 41 is fitted, and is formed in a cylindrical shape. The fitting portion 51 has a slit 51a formed along its axial direction (the left-right direction in FIG. 2(a)), and is configured to be elastically deformable so that the slit 51a opens and closes. In this embodiment, the fitting portion 51 is formed in a substantially cylindrical shape as a whole, and the formation of the slit 51a causes the cross section perpendicular to the axial direction to be formed in a substantially C-shape.

[0020] 4(a) and (b) are diagrams illustrating the connection between the magnetic sensor 4 and the crimp terminal 5. The inner diameter of the fitting portion 51 is slightly smaller than the width of the connection terminal 41, and is configured so that when the connection terminal 41 is inserted into and fitted into the fitting portion 51, the end face in the width direction of the connection terminal 41 firmly contacts the inner peripheral surface of the fitting portion 51. Furthermore, as the connection terminal 41 is inserted into the fitting portion 51, the fitting portion 51 elastically deforms so that the slit 51a opens slightly. After the magnetic sensor 4 and the crimp terminal 5 are connected, the connected magnetic sensor 4 and crimp terminal 5 are set in the holder 6.

[0021] Note that the fitting portion 51 may be provided with a contact such as a leaf spring that contacts the front or back surface of the connection terminal 41, thereby increasing the contact area between the crimp terminal 5 and the connection terminal 41. However, in this case, the structure of the connection terminal 41 becomes complex and costs increase. Therefore, in this embodiment, costs are reduced by omitting a contact such as a leaf spring, while the fitting portion 51 is pressed down by a retaining portion 8 described below, thereby firmly maintaining the connection between the crimp terminal 5 and the connection terminal 41. This makes it possible to stably maintain the electrical connection between them, even if only the end surface in the width direction of the connection terminal 41 contacts the crimp terminal 5. The retaining portion 8 will be described in detail later.

[0022] Furthermore, the shape of the fitting portion 51 is not limited to a cylindrical shape. However, it is desirable that the fitting portion 51 have a shape that can firmly hold the connection terminal 41 and prevent misalignment. For example, if the fitting portion 51 is formed in a rectangular tube shape and configured to sandwich the connection terminal 41 between opposing sides in the width direction, it is preferable to manage the connection terminal 41 so that it does not misalign in the thickness direction. By forming the fitting portion 51 in a cylindrical shape as in this embodiment, the connection terminal 41 can be firmly held and prevent misalignment, and further, processing can be easily performed, which reduces manufacturing costs.

[0023] (Holder 6) The holder 6 is a member for protecting the connection portion between the magnetic sensor 4 and the cable 2 when forming the resin molded portion 7 described below, and is configured to hold the magnetic sensor 4, the crimp terminal 5, and the end of the cable 2. The holder 6 is formed in advance by injection molding or the like. Here, the holder 6 is made of nylon. However, the holder 6 is not limited to this, and may be made of an insulating resin material such as PBT (polybutylene terephthalate).

[0024] The holder 6 integrally comprises a magnetic sensor holding portion 61 that holds the magnetic sensor 4, a terminal holding portion 62 having a groove 62a that accommodates the tip portion of the connection terminal 41 of the magnetic sensor 4, the crimp terminal 5, and the tip portion of the electric wire 21 (the portion exposed from the sheath 22), and a sheath holding portion 63 that holds the end of the sheath 22 of the cable 2.

[0025] The magnetic sensor holding portion 61 has locking claws 61a that lock the detection portion 40, and is configured to lock and fix the detection portion 40. Here, three locking claws 61a are used to lock the detection portion 40 on three sides excluding the extension side of the connection terminal 41.

[0026] The terminal holding portion 62 has a pair of grooves 62a corresponding to the pair of crimp terminals 5, respectively. Here, the pair of linear grooves 62a are formed parallel to each other, but the shape of the grooves 62a can be modified as appropriate. A convex partition 62b formed between the pair of grooves 62a serves to prevent the pair of crimp terminals 5 from coming into contact with each other and causing a short circuit. The sheath holding portion 63 is formed in a substantially C-shape in cross section. When the cable 2 is held by the sheath holding portion 63, the cable 2 is inserted into the sheath holding portion 63 while elastically deforming the sheath holding portion 63 so as to widen the slit portion 63a. In this embodiment, the sheath holding portion 63 holds the end of the sheath 22 of the cable 2.

[0027] (Resin mold part 7) 1, in this embodiment, the resin molded portion 7 is formed by resin molding with the magnetic sensor 4, the crimp terminal 5, and the end of the cable 2 set in the holder 6. The resin molded portion 7 is formed by integrally forming a main body portion 71 that collectively covers the magnetic sensor 4, the crimp terminal 5, the end of the cable 2, and the holder 6, and a flange portion 72 for fixing the sensor portion 3 to a fixing member.

[0028] (Prevention part 8) In this embodiment, the holder 6 is configured to hold the detection unit 40 of the magnetic sensor 4 and the sheath 22 of the cable 2, but the crimp terminal 5 located between them may float from the holder 6 due to the flow of molten resin when the resin molded portion 7 is formed, which could result in problems such as poor contact or disconnection. Therefore, in the sensor-equipped cable 1 according to this embodiment, the fitting portion 51 of the crimp terminal 5 is formed with a retaining portion 8 that prevents the fitting portion 51 from coming out of the groove 62a when the fitting portion 51 is accommodated in the groove 62a.

[0029] In this embodiment, the retaining portion 8 is composed of one or more pairs of tongue-shaped barb portions 81 formed in the fitting portion 51. Each pair of barb portions 81 is formed to face each other across the slit 51a and extends outward in the facing direction (left-right direction in FIG. 3(c)) and obliquely (diagonally toward the upper right or upper left in FIG. 3(a)) toward the slit (upper side in FIG. 3(c)) in a direction perpendicular to the facing direction and the axial direction. The barb portions 81 are formed, for example, by punching out a part of the metal plate that will become the fitting portion 51 by press working or the like to form a tongue-shaped portion, bending the portion other than the tongue-shaped portion into a cylindrical shape, and causing the unbent tongue-shaped portion to protrude outward. Note that the barb portions 81 may also be formed by bending the tongue-shaped portion outward. The pair of barb portions 81 is preferably formed symmetrically with respect to a plane passing through the center of the slit 51a and the center of the fitting portion 51.

[0030] As shown in FIG. 5(a), the crimp terminal 5 is fitted into the groove 62a with the slit 51a facing upward. In a no-load state where no load is applied to the barbed portions 81, the distance W between the ends of the paired barbed portions 81 is greater than the width w of the groove 62a. Therefore, as shown in FIG. 5(b), when the crimp terminal 5 is pressed into the groove 62a, the barbed portions 81 are pressed inward (inward in the opposing direction of the barbed portions 81) (arrow C1 in the figure), and the barbed portions 81 bite into the inner wall of the groove 62a, preventing the crimp terminal 5 from slipping out. Furthermore, as the barbed portions 81 are pressed inward, the mating portion 51 is pressed in a direction that closes the slit 51a (arrow C2 in the figure). This presses the inner circumferential surface of the mating portion 51 more firmly against the end face of the connecting terminal 41 (arrow C3 in the figure), resulting in a more secure connection between the magnetic sensor 4 and the crimp terminal 5.

[0031] In order to further strengthen the connection of the connection terminal 41, at least one pair of barbed portions 81 should be formed in positions facing each other across the connection terminal 41 when the connection terminal 41 is fitted into the fitting portion 51. That is, the axial positions of the pair of barbed portions 81 should be formed in positions where they overlap the connection terminal 41 in the radial direction when the connection terminal 41 is fitted into the fitting portion 51. Also, in order to further enhance the retaining effect, multiple pairs of barbed portions 81 should be formed in the fitting portion 51, spaced apart in the axial direction. Here, the case is shown in which two pairs of barbed portions 81 are formed, one pair of barbed portions 81 is formed in an axial position where it overlaps the connection terminal 41, and the other pair of barbed portions 81 is formed in an axial position where it does not overlap the connection terminal 41 (overlapping only the chamfered portion at the tip of the connection terminal 41).

[0032] In addition, although the shape of the barbed portion 81 is rectangular in side view (see FIG. 3(b)), the shape of the barbed portion 81 is not limited to this. For example, the retaining effect can be further enhanced by making the shape of the barbed portion 81 triangular in side view as shown in FIG. 6(a) or semicircular as shown in FIG. 6(b). In addition, by making the shape of the barbed portion 81 pointed on the extending side of the electric wire 21 as shown in FIG. 6(c), even when a force is applied in the direction of pulling the cable 2, it is possible to prevent the connection terminal 41 from shifting position due to the pulling.

[0033] Although the present embodiment has been described with reference to the case where the retaining portion 8 is formed on the crimp terminal 5 side, the retaining portion 8 may also be formed on the holder 6 side, i.e., on the inner wall of the groove 62a. For example, as shown in FIG. 7 , the retaining portion 8 may be configured so that one or more protrusions 82 protruding inward are provided on the inner wall of the groove 62a, and the protrusions 82 prevent the fitting portion 51 from coming out of the groove 62a and press the fitting portion 51 in the direction of closing the slit 51a. Alternatively, the retaining portion 8 may be formed on both the fitting portion 51 and the groove 62a. In this way, it is sufficient that the retaining portion 8 is formed on at least one of the fitting portion 51 and the groove 62a.

[0034] (Actions and Effects of the Embodiments) As described above, in the sensor-equipped cable 1 of this embodiment, at least one of the fitting portion 51 of the crimp terminal 5 or the groove 62a of the holder 6 has a retaining portion 8 that prevents the fitting portion 51 from slipping out of the groove 62a when the fitting portion 51 is accommodated in the groove 62a, and also presses the fitting portion 51 in the direction of closing the slit 51a.

[0035] The provision of the retaining portion 8 prevents the crimp terminal 5 from floating away from the holder 6 due to the molten resin when the resin molded portion 7 is formed, and also enables a stronger connection between the crimp terminal 5 and the connection terminal 41. That is, according to this embodiment, the connection portion between the magnetic sensor 4 and the cable 2 can be held more firmly, and the electrical connection between them can be stably maintained.

[0036] (Variation) In the above embodiment, the magnetic sensor 4 and the crimp terminal 5 are connected and then fitted into the holder 6. However, this is not limiting. For example, the magnetic sensor 4 may be fitted into the holder 6 by itself, and then the crimp terminal 5 may be inserted by sliding it along the groove 62a, and the connection terminal 41 may be fitted into the crimp terminal 5. However, particularly when automating the production of the sensor-equipped cable 1, it is preferable to increase the rigidity of the exposed portion of the electric wire 21 to facilitate insertion into the groove 62a. Methods for increasing the rigidity include, for example, increasing the diameter of the twisted wires constituting the conductor 21a or increasing the number of twisted wires. Therefore, particularly when automating the production of the sensor-equipped cable 1, it is more desirable to connect the magnetic sensor 4 and the crimp terminal 5 and then fit them into the holder 6 from above (through the opening facing the bottom of the groove 62a).

[0037] (Summary of the embodiment) Next, the technical ideas grasped from the above-described embodiments will be described by using the reference numerals and the like in the embodiments. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiments.

[0038] [1] A sensor (magnetic sensor 4) having a connection terminal (41), a cable (2), a crimp terminal (5) provided at an end of the cable (2) and connected to the connection terminal (41), and a holder (6) for holding the sensor (magnetic sensor 4) and the crimp terminal (5), wherein the crimp terminal (5) has a cylindrical fitting portion (51) that fits with the connection terminal (41), and the fitting portion (51) has a slit (51a) formed along its axial direction, and the slit (51) a) is configured to be elastically deformable so as to open and close, the holder (6) has a groove (62a) that accommodates the crimp terminal (5), and at least one of the fitting portion (51) or the groove (62a) has a retaining portion (8) that prevents the fitting portion (51) from coming out of the groove (62a) when the fitting portion (51) is accommodated in the groove (62a) and presses the fitting portion (51) in the direction that the slit (51a) closes.

[0039] [2] The sensor-equipped cable (1) described in [1], wherein the anti-slip portion (8) includes one or more pairs of tongue-shaped barbed portions (81) formed in the fitting portion (51), and the barbed portions (81) are formed to face each other across the slit (51a), and extend outward in the facing direction and obliquely toward the slit in a direction perpendicular to the facing direction and the axial direction.

[0040] [3] At least one pair of the barbed portions (81) are formed in opposing positions across the connection terminal (41) when the connection terminal (41) is fitted into the fitting portion (51). [2] The sensor-equipped cable (1) described in [2].

[0041] [4] The sensor (magnetic sensor 4) has a pair of the connection terminals (41), and is provided with a pair of the crimp terminals (5) corresponding to each of the pair of connection terminals (41), and the holder (6) has a pair of the grooves (62a) corresponding to each of the pair of the crimp terminals (5), in the sensor-equipped cable (1) described in [2].

[0042] [5] The sensor-equipped cable (1) described in [1], wherein the connection terminal (41) is formed in a plate shape, and the fitting portion (51) of the crimp terminal (5) is formed in a cylindrical shape, and when the connection terminal (41) is fitted into the fitting portion (51), the end face in the width direction of the connection terminal (41) is configured to come into contact with the inner surface of the fitting portion (51).

[0043] (Addendum) Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above-described embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. Furthermore, the present invention can be appropriately modified and implemented within the scope of its spirit. [Explanation of symbols]

[0044] 1...Sensor-equipped cable 2...Cable 21...Electric wire 22...Sheath 3...Sensor section 4...Magnetic sensor (sensor) 40...Detection unit 41...Connection terminal 5... Crimp terminal 51...Fitting part 51a...Slit 52...First crimping part 53...Second crimping section 6...Holder 61...Magnetic sensor holder 62...Terminal holding part 62a...Groove 63...Sheath holding part 7...Resin molded part 8...Prevention part 81...Curbside

Claims

1. a sensor having a connection terminal; Cable and a crimp terminal provided at an end of the cable and connected to the connection terminal; a holder for holding the sensor and the crimp terminal; Equipped with the crimp terminal has a cylindrical fitting portion that fits into the connection terminal, The fitting portion has a slit formed along its axial direction, and is configured to be elastically deformable so as to open and close the slit, the holder has a groove for receiving the crimp terminal, At least one of the fitting portion and the groove has a retaining portion that prevents the fitting portion from coming off the groove when the fitting portion is accommodated in the groove and presses the fitting portion in a direction in which the slit closes. Cable with sensor.

2. The retaining portion includes one or more tongue-shaped barbs formed on the fitting portion, The barb portions are formed to face each other across the slit, and extend outward in the facing direction and obliquely toward the slit in a direction perpendicular to the facing direction and the axial direction. The sensor-equipped cable according to claim 1 .

3. At least one pair of the barbed portions are formed at positions facing each other across the connection terminal when the connection terminal is fitted into the fitting portion. The sensor-equipped cable according to claim 2 .

4. The sensor has a pair of the connection terminals, a pair of the crimp terminals corresponding to the pair of the connection terminals, The holder has a pair of the grooves corresponding to the pair of the crimp terminals, respectively. The sensor-equipped cable according to claim 2 .

5. The connection terminal is formed in a plate shape, The fitting portion of the crimp terminal is formed in a cylindrical shape, When the connection terminal is fitted into the fitting portion, an end face of the connection terminal in the width direction contacts an inner peripheral surface of the fitting portion. The sensor-equipped cable according to claim 1 .

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