JP4851973B2 - Rotation sensor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a rotation sensor for detecting a rotation position, a rotation speed, and the like of a rotating body such as an engine crankshaft, a camshaft, and an automobile wheel, and a manufacturing method thereof.

  Such a rotation sensor generally controls a magnetoelectric transducer such as a Hall element on a rotating body to be detected such as a pulsar plate or a gear, controls a bias magnet that applies a certain magnetic bias to the magnetoelectric transducer, and a magnetoelectric transducer. An electronic circuit component that processes a detection signal of the magnetoelectric transducer is a main component.

By the way, in the conventional rotation sensor, as disclosed in the following Patent Document 1, in addition to the above components, a circuit board on which electronic circuit components are mounted, and a holder for positioning and holding the circuit board, the magnetoelectric element, and the bias magnet And a sensor body made of metal, synthetic resin, or a combination thereof that accommodates the holder and the above-described elements, and requires a large number of parts. In addition, since a partition wall integral with the holder is interposed between the magnetoelectric element and the bias magnet, the detection sensitivity of the magnetoelectric conversion element is somewhat impaired by the partition wall.
JP 2003-307523 A

  SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a rotation sensor having a small number of parts, a simple structure, good detection sensitivity, and a method for manufacturing the same, which enables the abolishment of circuit boards and holders. The purpose is to provide.

In order to achieve the above object, a rotation sensor according to the present invention embeds a lead frame, one end portion in the longitudinal direction of the lead frame, a magnetoelectric conversion element mounted on the one end portion, and the one end portion and the magnetoelectric conversion element. A magnetoelectric conversion unit comprising a first package to be sealed, the other end in the longitudinal direction of the lead frame, an electronic circuit component mounted on the other end, and a second for embedding the other end and the electronic circuit component An electronic circuit unit composed of a package and a bias magnet held by a magnet holding part formed on the side surface of the first package constitute an IC module, and the magnetoelectric conversion element is rotated outside to be detected outside the bias magnet. The IC module with the electronic circuit unit disposed on the opposite side of the magnetoelectric conversion element with the bias magnet interposed therebetween. The a rotation sensor which is embedded by a cylindrical synthetic resin sensor body,
The magnetoelectric conversion unit and the electronic circuit unit are formed by forming a U-shaped bent portion that bypasses one side portion of the bias magnet at a connection portion connecting the one end portion and the other end portion of the lead frame. The first feature is that they are arranged so that they are substantially perpendicular to each other and the respective centers thereof are on the substantially center line of the cylindrical sensor body .

Note that one end and the other end of the lead frame correspond to a first mounting portion 1a and a second mounting portion 1b, respectively, in an embodiment to be described later of the present invention .

Or the present invention is that when manufacturing the rotation sensor having a first feature, at the time of manufacture of the IC module, the first and second projecting respectively outwardly of the first package and the second package to the lead frame Two support pieces are formed integrally, and when the sensor body is molded by the mold device, the first and second support pieces are held in the mold device to correspond to the sensor body in the mold device. The IC module is positioned and held so that the center of each of the magnetoelectric conversion unit and the electronic circuit unit is positioned on the substantially center line of the cavity, and the sensor is filled with the synthetic resin in the cavity. A second feature is that after the body is molded, the first and second support pieces protruding from the sensor body are cut off.

According to the first feature of the present invention, the lead frame, the magnetoelectric conversion unit, the bias magnet, and the electronic circuit unit constitute an overall highly rigid IC module. Even if it is directly embedded in the sensor body, the high-rigidity IC module will not be deformed or damaged by the flow of synthetic resin. Therefore, the conventional circuit board and holder can be eliminated, and the number of parts can be reduced. It is possible to obtain a rotation sensor with a small configuration and a simple configuration. In addition, the magnetoelectric conversion unit directly holds the bias magnet, and the magnetoelectric conversion element is arranged outside the bias magnet toward the external rotating body to be detected . Therefore, when the rotation sensor is used, it is placed close to the rotating object to be detected. The detection sensitivity of the magnetoelectric conversion unit can be increased.

Further, the sensor body is formed in a cylindrical shape, and a U-shaped bent portion that bypasses one side of the bias magnet is formed in the connection portion of the lead frame connecting the magnetoelectric conversion unit and the electronic circuit unit. Since the conversion unit and the electronic circuit unit are arranged so that they are substantially perpendicular to each other and the centers of the conversion unit and the electronic circuit unit are substantially on the center line of the cylindrical sensor body , the magnetoelectric conversion unit and the electronic circuit unit are cylindrical. Therefore, the sensor body can be sufficiently reduced in diameter.

According to the second feature of the present invention, it is possible to manufacture the rotation sensor of the present invention in which a magnetoelectric conversion unit and an electronic circuit unit are arranged on a substantially center line in a cylindrical sensor body having a relatively small diameter. it can. In addition, when the sensor body is molded, the first and second support pieces of the lead frame projecting outward from the first package and the second package are supported by the mold device, so that the inside of the cavity of the mold device can be obtained. Because the IC module can be positioned and held at the fixed position, the sensor module can be molded easily and reliably without deforming or damaging the IC module due to the high rigidity of the IC module. it can. In addition, after the molding, the first and second support pieces protruding from the sensor body are cut off, so that the use of the rotation sensor is not hindered.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

1 is a side view showing a use state of a rotation sensor according to an embodiment of the present invention, FIG. 2 is a plan view of the rotation sensor, FIG. 3 is a sectional view taken along line 3-3 in FIG. 2, and FIG. FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 3, FIG. 6 is a plan view showing a process for taking a large number of IC modules in the rotation sensor, and FIG. 7A is a piece cut out from the process of FIG. 7B is a side view of the IC module, FIG. 7C is a front end view of the IC module, and FIG. 8A is a lead frame connection of the IC module of FIG. FIG. 8B is a side view of the IC module, FIG. 8C is a front end view of the IC module, and FIG. 9A is the IC of FIG. FIG. 9 (B) is a side view of the IC module, and FIG. ) Is a front end view of the IC module, FIG. 10 is a longitudinal cross-sectional view of an injection mold device for a sensor body for embedding the IC module of FIG. 9, and FIG. 11 is a cross-sectional view taken along a line 11-11 in FIG. 12 is a perspective view showing the removal of the support piece from the molded sensor body, FIG. 13 shows a reference example , a view corresponding to FIG. 3, and FIG. 14 is a view taken along arrow 14 in FIG.

  First, in FIG. 1, for example, a pulsar plate P attached to an engine crankshaft or axle has a large number of protrusions Pa, such as gear teeth, formed on the outer peripheral surface thereof, and the front end thereof is closely opposed to the outer peripheral surface. The rotation sensor S of the present invention arranged as described above is attached to a crankcase or a fixed structure C of a vehicle body.

  In the description of the rotation sensor S, the front side refers to the pulsar plate P side, and the rear side refers to the side opposite to the pulsar plate P.

  As shown in FIGS. 1 to 5, the rotation sensor S includes a strip-like lead frame 1 extending in the front-rear direction with respect to the overall pulsar plate P. The lead frame 1 includes a first mounting portion 1a, a second mounting portion 1b located behind the first mounting portion 1a, and a multi-pole that integrally connects the first and second mounting portions 1a and 1b. And a multipolar connection terminal portion 1d extending rearward of the second mounting portion 1b, and a magnetoelectric conversion element 2 such as a Hall element is mounted on one side surface of the first mounting portion 1a. In addition, on one side surface of the second mounting portion 1b, various electronic circuit components 3 that process the output signal while controlling the magnetoelectric transducer 2 are mounted.

  The first mounting portion 1a and the magnetoelectric conversion element 2 are embedded in a first package 5 made of synthetic resin, and a magnetoelectric conversion unit 6 is configured by these. The second mounting portion 1b and the electronic circuit component 3 are embedded in a second package 7 made of synthetic resin, and an electronic circuit unit 8 is configured by these. The magnetoelectric conversion unit 6 and the electronic circuit unit 8 are each formed in a square plate shape.

  In the first package 5, a non-circular positioning recess 10 serving as a magnet holding portion is formed on the opposite side of the magnetoelectric conversion element 2, and a bias magnet 11 that applies bias magnetism to the magnetoelectric conversion element 2 in the positioning recess 10. The fitting state is held by the magnetic attractive force of the bias magnet 11 with respect to the first mounting portion 1a.

The connecting portion 1c is formed with a U-shaped bent portion 1ca that bypasses one side portion of the bias magnet 11 , so that the magnetoelectric conversion unit 6 and the electronic circuit unit 8 are substantially perpendicular to each other. The magnetoelectric conversion element 2 is disposed outside the bias magnet 11 so as to face the external rotating body P to be detected. Furthermore, the magnetoelectric conversion unit 6 and the electronic circuit unit 8 are arranged so that their centers are on a substantially center line Y of a cylindrical sensor body 15 described later. A coupler terminal 13 is welded to the connection terminal portion 1d.

  Thus, the lead frame 1, the magnetoelectric conversion unit 6, the bias magnet 11 and the electronic circuit unit 8 constitute a highly rigid IC module M as a whole, and this IC module M is molded. It is directly embedded by a cylindrical sensor body 15 made of synthetic resin. At the time of molding, the highly rigid IC module M can resist the flow of synthetic resin. Thus, the conventional circuit board and holder can be eliminated, and the rotation sensor S having a small number of parts and a simple configuration can be obtained. Moreover, the magnetoelectric conversion unit 6 holds the bias magnet 11 directly, and the lead frame 1 has a bent portion so that the magnetoelectric conversion unit 6 is located outside the bias magnet 11 between the magnetoelectric conversion unit 6 and the electronic circuit unit 8. Since 1ca is formed, when the rotation sensor S is used, the detection sensitivity of the magnetoelectric conversion unit 6 placed close to and opposite to the pulsar plate P can be increased.

Further, in the IC module M, a U-shaped bent portion 1 ca is formed in the connection portion 1 c of the lead frame 1, and the centers of the magnetoelectric conversion unit 6 and the electronic circuit unit 8 are substantially on the center line Y of the sensor body 15. Therefore, the magnetoelectric conversion unit 6 and the electronic circuit unit 8 are arranged on the substantially diameter line of the cylindrical sensor body 15, and the sensor body 15 can be sufficiently reduced in diameter.

  At the rear end of the sensor body 15, a square tube coupler 14 made of synthetic resin that accommodates and holds the coupler terminal 13 is integrally provided. On one side of the sensor body 15, a synthetic resin bracket 16 with a metal bush 17 is integrally projected. When the rotation sensor S is used, the bracket 16 is bolted to the fixed structure C as shown in FIG.

  Next, a method for manufacturing such a rotation sensor S will be described with reference to FIGS.

  First, the IC module M is manufactured by the following procedure. That is, first, as shown in FIG. 6, a large number of strip-like lead frames 1, 1... Are punched out from the lead frame material 20 in a continuous state. Each lead frame 1 is surrounded by a rectangular frame portion 21 that forms a boundary with the adjacent lead frame 1, and the front end portion of the first mounting portion 1 a is integrated with the frame portion 21 via the first support piece 22. Further, the left and right side portions of the second mounting portion 1 b are integrally connected to the frame portion 21 via the second support piece 23.

  As described above, the magnetoelectric transducer 2 and the electronic circuit component 3 (see FIGS. 2 and 3) are mounted on the first and second mounting portions 1a and 1b of each lead frame 1, respectively, and then embedded. The first and second packages 5 and 7 are molded. At that time, the first and second support pieces 22 and 23 are placed in a state of protruding outward from the first and second packages 5 and 7, respectively.

  Next, the lead frame 1 is punched out from the frame portion 21 as shown in FIGS. 7 (A) to 7 (C). At that time, the first and second support pieces 23 remain on the lead frame 1 side. Accordingly, the first support piece 22 protrudes forward from the first package 5, and the second support piece 23 protrudes from the second package 7 in the left-right direction.

  Next, as shown in FIGS. 8A to 8C, after a U-shaped bent portion 1ca is formed in the connecting portion 1c of the lead frame 1, FIGS. 9A to 9C are formed. ), The coupler terminal 13 is welded to the connection terminal portion 1d of the lead frame (), and the bias magnet 11 is fitted and held in the positioning recess 10 on the back surface of the first package 5. In this way, the IC module M is manufactured. As a result, the first support piece 22 and the second support pieces 22 and 23 are arranged in a relationship that is perpendicular to each other.

Next, a synthetic resin sensor body 15 for embedding the IC module M is injection molded. As shown in FIGS. 10 and 11, the mold apparatus 30 used for the molding includes a lower mold 31, an upper mold 32 that is opened and closed in the vertical direction with respect to the lower mold 31, a lower mold 31, and an upper mold 31. The first auxiliary mold 33 is detachably supported by the mold 32 and the second auxiliary mold 34 is removably supported by the lower mold 31. When these molds are closed, the sensor with the coupler 14 and the bracket 16 is provided. A cylindrical cavity 35 corresponding to the outer shape of the body 15 is formed. The lower die 31 is provided with a holding hole 37 for receiving and holding the first support piece 22, and the first auxiliary die 33 is provided with a holding hole 39 for receiving and holding the coupler terminal 13. A holding recess 38 for receiving and holding the second support piece 23 is provided on the upper surface of the die 34 in cooperation with the lower surface of the upper die 32. A holding pin 40 for holding the metal bush 17 is detachably attached to the second auxiliary die 34.

Thus, as shown in FIGS. 10 and 11, when the IC module M is set in the mold apparatus 30, the first support piece 22 and the holding hole 37 are fitted, and the second support piece 23 and the holding recess 38. By fitting the coupler terminal 13 and the holding hole 39, the IC module M is positioned and held in the vertical and horizontal directions and is disposed at a predetermined position in the cavity 35. In other words, the IC module M is positioned and held so that the centers of the magnetoelectric conversion unit 6 and the electronic circuit unit 8 are substantially on the center line of the cavity 35. Therefore, if a molten synthetic resin is injected and filled into the cavity 35 from a gate (not shown) provided on the mating surface of the lower die 31 and the upper die 32, not only the sensor body 15 embedding the IC module M but also the coupler 14 And the bracket 16 with the bush 17 can be integrally molded.

  As described above, when the sensor body 15 is molded, the first and second support pieces 22 and 23 and the coupler terminal 13 are supported by the mold apparatus 30, so that the IC is placed at a fixed position in the cavity 35 of the mold apparatus 30. Since the module M can be positioned and held, the sensor body 15 can be easily and reliably formed without deforming or damaging the IC module M due to the high rigidity of the IC module M. It is.

  After the molding, the mold is opened and the molded product is taken out. Then, as shown in FIG. 12, the first and second support pieces 22 and 23 protruding from the sensor body 15 are cut off to obtain a desired rotation sensor S. be able to.

Next, reference examples shown in FIGS. 13 and 14 will be described. In this reference example , in the lead frame 1, an L-shaped bent portion 1 ca is formed in a connection portion 1 c that connects between the magnetoelectric conversion unit 6 and the electronic circuit unit 8, whereby the magnetoelectric conversion unit 6 is a cylindrical sensor. The electronic circuit unit 8 is arranged so as to be offset from the central line Y while being arranged on the substantially central line Y of the body 15. Therefore, in the second mounting portion 1b of the lead frame 1, the electronic circuit component 3 is mounted on the side surface on the center line Y side, and the first package 5 is formed to constitute the electronic circuit unit 8. Since other configurations are substantially the same as those of the previous embodiment, the same reference numerals are given to the corresponding parts in FIG. 13 and FIG. 14 to omit the overlapping description.

  According to this reference example, it is only necessary to form the bent portion 1ca of the lead frame 1 in a simple L shape, and in the electronic circuit unit 8, the lead frame 1 on the side of the center line Y of the cylindrical sensor body 15 is sufficient. Since the electronic circuit component 3 is mounted on the side surface, the electronic circuit unit 8 generally moves closer to the center line Y side of the sensor body 15 from the lead frame 1, and the diameter of the sensor body 15 can be reduced accordingly. it can.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention.

The side view which shows the use condition of the rotation sensor which concerns on the Example of this invention. The top view of the rotation sensor. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a view taken in the direction of arrow 4 in FIG. 3. FIG. 5 is a sectional view taken along line 5-5 of FIG. The top view which shows the multiple picking process of the IC module in the rotation sensor. The top view of one IC module cut out from the process of FIG. The side view of the IC module. The front end view of the IC module. FIG. 8 is a plan view showing a state in which a refraction process is performed on a connection portion of a lead frame of the IC module of FIG. 7. The side view which shows the use condition of the rotation sensor of this invention. The front end view of the IC module. The top view which shows the state which mounted | wore the IC module of FIG. 8 with the bias magnet. The side view of the IC module. The front end view of the IC module. FIG. 10 is a longitudinal cross-sectional view of a sensor body injection mold device for embedding the IC module of FIG. 9. FIG. 11 is a sectional view taken along line 11-11 in FIG. 10; The perspective view which shows cutting out a support piece from the shape | molded sensor body. Corresponding figure with FIG. 3 which shows a reference example . FIG. 5 is a sectional view taken along line 5-5 of FIG.

P ・ ・ ・ ・ Non-detection rotating body (Pulsar plate)
S ··· rotation sensor 1 ··· lead frame 1a · one end of the lead frame (first mounting portion)
1b ... the other end of the lead frame (second mounting part)
1 ca ··· bent portion 2 of lead frame ··· magnetoelectric conversion element 5 ··· first package 6 · · · magnetoelectric conversion unit 7 · · · second package 8 · · · electronic circuit unit 10 ... Magnet holder (positioning recess)
DESCRIPTION OF SYMBOLS 11 ... Bias magnet 15 ... Sensor body 22 ... 1st support piece 23 ... 2nd support piece 30 ... Mold apparatus 35 ... Cavity

Claims (2)

A lead frame (1), one end (1a) in the longitudinal direction of the lead frame (1), a magnetoelectric conversion element (2) mounted on the one end (1a), the one end (1a) and the magnetoelectric conversion Mounted on the magnetoelectric conversion unit (6) comprising the first package (5) embedding the element (2), the other end (1b) in the longitudinal direction of the lead frame (1), and the other end (1b) And an electronic circuit unit (8) comprising a second package (7) for embedding the other end (1b) and the electronic circuit component (3), and the first package (5) ) Constitutes an IC module (M) with a bias magnet (11) held by a magnet holding part (10) formed on the side of the magnet), and the magnetoelectric conversion element (2) is externally connected to the outside of the bias magnet (11). Toward the detected rotor (P) In both cases, the IC module (M) is placed in a cylindrical synthetic resin sensor body in a state where the electronic circuit unit (8) is disposed on the opposite side of the magnetoelectric conversion element (2) with the bias magnet (11) interposed therebetween. A rotation sensor embedded in (15),
The lead frame (1) has a U-shape that bypasses one side of the bias magnet (11) in a connection portion (1c) that connects the magnetoelectric conversion unit (6) and the electronic circuit unit (8). A bent portion (1ca) is formed, and the magnetoelectric conversion unit (6) and the electronic circuit unit (8) are substantially perpendicular to each other, and the center of each sensor body (15 The rotation sensor is arranged so as to be substantially on the center line (Y) . In manufacturing the rotation sensor according to claim 1,
When the IC module (M) is manufactured, first and second support pieces (22, 23) projecting outward from the first package (5) and the second package (7) on the lead frame (1), respectively. ), And the first and second support pieces (22, 23) are held by the mold device (30) when the sensor body (15) is molded by the mold device (30). In the cylindrical cavity (35) corresponding to the sensor body (15) in the mold apparatus (30), the magnetoelectric conversion unit (6) and the electronic circuit unit are arranged on a substantially center line of the cavity (35). The IC module (M) is positioned and held so that the respective centers of (8) come to the center , and the cavity (35) is filled with synthetic resin to form the sensor body (15), and then the sensor body (15 From) Method of manufacturing a rotation sensor, which comprises ablating said in output state first and second support piece (22, 23).

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