JP6065793B2 - Position detection device - Google Patents

Description

  The present invention relates to a position detection device.

2. Description of the Related Art Conventionally, a position detection device that detects a rotation angle of a throttle valve provided in an electronically controlled throttle, a rotation angle of an accelerator pedal provided in an accelerator pedal module, or a stroke amount of a clutch actuator is known.
The electronically controlled throttle described in Patent Document 1 controls the rotation angle of the throttle valve based on the output of a position detection device that detects the magnetic field of a magnet provided at the end of the rotary shaft of the throttle valve.
The position detection device is obtained by molding a Hall IC and a terminal welded to a lead frame of the Hall IC with a primary molding resin. This position detection device is resin-molded with a secondary molding resin, and is configured integrally with a housing cover of an electronic control throttle.

Japanese Patent No. 4367473

Generally, in the position detection device, the primary molding resin is formed extremely thin around the Hall IC. Thereby, the positional accuracy of the Hall IC with respect to the outer wall of the primary molding resin is guaranteed.
However, when the primary molding resin is injection-molded, the position of the Hall IC is shifted inside the mold used for the injection molding, and when the Hall IC is close to or in contact with the inner wall of the mold, a part of the Hall IC is primary. There is concern about exposure from the molding resin. If water or the like enters the inside of the primary molding resin from the location where the Hall IC is exposed from the primary molding resin and the lead frame and terminal of the Hall IC corrode, the detection accuracy of the position detection device may deteriorate.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a position detection device capable of increasing detection accuracy.

1st invention is the position detection apparatus with which the detection part and the terminal were molded with primary molding resin, and primary molding resin is a thin part which molds the edge part of the non-terminal side of a detection part, and a terminal rather than the thin part. It has a thick part that molds the detection part located on the side . Further, the detection unit has a metal exposed portion (48, 49) in which a part of the lead frame connected to the terminal is different from a position where the lead frame protrudes from the resin body and the other part of the lead frame is exposed from the resin body. Have. The thin part and the thick part of the primary molding resin are continuously formed from the same resin. The thin portion is provided on the side opposite to the terminal side than the exposed metal portion. The thick part is provided closer to the terminal than the thin part and covers the exposed metal part.
Thereby, the position detection apparatus can make the position shift of the detection part inside the thin part within an allowable range because the primary molding resin has the thin part. Further, the position detection device can prevent water and the like from entering the lead frame and the terminal side because the primary molding resin has a thick portion. Therefore, the position detection device can increase the detection accuracy.
According to the second aspect of the invention, the left side surface (37) and the right side surface (38) are positioned in a direction parallel to the surface of the lead frame in the detection unit and are orthogonal to the direction in which the lead frame projects from the resin body. ) Directly covers the outer wall.

It is sectional drawing of the electronically controlled throttle provided with the position detection apparatus by one Embodiment of this invention. It is a perspective view of the housing cover of the electronic control throttle provided with the position detection apparatus by one Embodiment. It is a top view of the position detection apparatus by one Embodiment. It is sectional drawing of the IV-IV line of FIG. It is a top view except the primary molding resin of the position detection apparatus by one Embodiment. It is sectional drawing of the metal mold | die used for injection molding of the position detection apparatus by one Embodiment. It is a perspective view which shows the state which combines two position detection apparatuses by one Embodiment. It is sectional drawing of the metal mold | die used for the injection molding of the position detection apparatus by a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(One embodiment)
A position detection apparatus according to an embodiment of the present invention is shown in FIGS. The position detection device 1 of the present embodiment is incorporated in a housing cover 11 of an electronic control throttle 10 that controls the amount of air taken into a cylinder of a vehicle engine.

First, a schematic configuration of the electronic control throttle 10 will be described.
As shown in FIG. 1, an intake passage 13 for introducing air into the engine is formed in the housing 12 of the electronic control throttle 10.
The throttle valve 14 formed in a substantially disc shape is provided in the intake passage 13. Both ends of the valve shaft 15 to which the throttle valve 14 is fixed are rotatably supported by the housing 12. As a result, the throttle valve 14 can rotate about the center of the valve shaft 15 as a rotation axis.
A motor 16 is attached to one end of the valve shaft 15. The motor 16 is driven and controlled by a command from an engine electronic control unit (ECU) (not shown). The opening of the throttle valve 14 is controlled by driving the motor 16, and the intake air amount supplied to the engine is adjusted.

  A bottomed cylindrical holder 17 is provided at the other end of the valve shaft 15. The inner wall of the holder 17 in the radial direction is provided with two magnets 18 and 19 serving as magnetism generating means, and two yokes (not shown) that connect the two magnets 18 and 19 in the circumferential direction. . The two magnets 18 and 19 are provided so as to face the rotation axis of the throttle valve 14 in the radial direction, and provide an N pole magnetic flux to one yoke and an S pole magnetic flux to the other yoke. As a result, the magnetic flux flows from one yoke to the other yoke inside the holder 17, thereby generating a magnetic field in which the magnetic flux flows in a direction substantially perpendicular to the rotation axis of the throttle valve 14. When the throttle valve 14 rotates, the direction of the magnetic field inside the holder 17 changes.

The housing cover 11 is attached to the holder side of the housing 12 with screws 23.
As shown in FIGS. 1 and 2, the housing cover 11 is formed of a resin in a dish shape, and includes a cover main body 20, a rotation angle sensor 21, a connector wiring 22, and the like. The rotation angle sensor 21 of the present embodiment is a combination of two position detection devices 1 that are primary molded products. The cover main body 20 is a secondary molded product obtained by resin-molding the two position detection devices 1 and the connector wiring 22 together. The housing cover 11 has a plurality of ribs 24 for increasing the rigidity.
The position detection device 1 is provided in a magnetic field inside the holder 17 and outputs a voltage signal corresponding to the magnetic flux density passing through the position detection device 1 in accordance with the direction of the magnetic field in the holder. This signal is transmitted to the ECU through the connector wiring 22. The ECU controls the drive of the motor 16 according to the signal from the position detection device 1 and also controls each part of the vehicle.

Next, the position detection apparatus 1 will be described with reference to FIGS. FIG. 5 shows a state before the primary molding resin 60 is provided in the position detection device 1.
The position detection device 1 includes a detection unit 30, a terminal 50, a primary molding resin 60, and the like.
The detection unit 30 is, for example, a Hall IC, and a semiconductor element 31 such as a Hall element capable of detecting magnetism, a lead frame 40 on which the semiconductor element 31 is installed, and a part of the semiconductor element 31 and the lead frame 40 are molded. The resin body 32 is provided.

As shown in FIG. 5, the lead frame 40 includes a first lead frame 41, a second lead frame 42, and a third lead frame 43. The first lead frame 41 disposed in the center includes an outer lead portion 44 positioned outside the resin body 32, a die pad portion 45 extending from the outer lead portion 44 to the inside of the resin body 32, and an outer lead portion extending from the die pad portion 45. Diver portion 46 extending in a direction different from 44 is provided.
The semiconductor element 31 is installed in the die pad portion 45. The second lead frame 42 and the third lead frame 43 are electrically connected to the die pad portion 45 by bonding wires 47, respectively.

The diver portion 46 is exposed from the resin body 32 at a position different from the position where the outer lead portion 44 protrudes from the resin body 32. The portions where the diver portion 46 is exposed from the resin body 32 become the metal exposed portions 48 and 49.
The metal exposed portions 48 and 49 are for preventing the positional displacement of the lead frame 40 inside a mold (not shown) used for injection molding when the semiconductor element 31 and a part of the lead frame 40 are molded with the resin body 32. is there. That is, when the resin body 32 is injection-molded, the resin is injected into the mold in a state where the outer lead portion 44 of the lead frame 40 and the metal exposed portions 48 and 49 are fixed. Thereby, the detection unit 30 accurately determines the position of the semiconductor element 31 installed on the lead frame 40 inside the resin body 32.

  As shown in FIGS. 3 and 4, the resin body 32 has an upper surface 33 and a lower surface 34 provided in parallel with the lead frame 40, a bottom surface 35 positioned on the side from which the lead frame 40 protrudes, and a side opposite to the bottom surface 35. It has a top surface 36 located, and a left side surface 37 and a right side surface 38 that connect the upper surface 33 and the lower surface 34. The two metal exposed portions 48 and 49 are provided on the left side surface 37 and the right side surface 38 of the resin body 32, respectively.

  The terminal 50 includes a first terminal 51, a second terminal 52, and a third terminal 53. In the first terminal 51, a convex portion 56 provided at an end portion on the detection portion side is electrically welded to the first lead frame 41, and an end portion on the counter detection portion side extends outward from the primary molding resin 60. Similarly, the ends of the second and third terminals 52 and 53 are electrically welded to the second and third lead frames 42 and 43, and the ends of the counter-detecting part are outward from the primary molding resin 60. It is extended. The ends of the first to third terminals 51, 52, 53 on the side opposite to the detection portion are electrically welded to the connector wiring 22 of the housing cover 11 described above. Chip capacitors 54 and 55 are provided between the first terminal 51 and the second terminal 52 and between the first terminal 51 and the third terminal 53.

The primary molding resin 60 molds a part of the detection unit 30 and the terminal 50.
The primary molding resin 60 of the present embodiment includes a thin portion 61 that molds the end portion of the detection unit 30 on the side opposite to the terminal, and a thick portion 62 that molds the detection unit 30 that is located on the terminal side of the thin portion 61. The resin main body portion 63 molds the terminal side of the thick wall portion 62. The thin portion 61 and the thick portion 62 are provided at least on the left side surface 37 and the right side surface 38 of the resin body 32.

  The thin portion 61 is provided on the side opposite to the terminal side than the metal exposed portions 48 and 49. The thickness S1 of the thin portion 61 is extremely thin, and is set to such an extent that the detection portion 30 is not exposed even if a position shift occurs due to the tolerance of the detection portion 30 inside the thin portion 61. However, the thickness S1 of the thin portion 61 allows an error in the detection accuracy of the position detection device 1 even when the detection portion 30 is exposed from the thin portion 61 when the tolerance of the positional deviation of the detection portion 30 is large. Is set to about.

  The thick part 62 is provided closer to the terminal than the thin part 61 and covers the metal exposed parts 48 and 49. The thickness T1 of the thick portion 62 is thicker than the thickness S1 of the thin portion 61. Therefore, a step 64 is formed at the connection portion between the thin portion 61 and the thick portion 62. A predetermined distance L <b> 1 is provided between the step 64 and the metal exposed portions 48 and 49. This predetermined distance L1 is greater than zero. Thereby, the metal exposed portions 48 and 49 are reliably covered with the thick portion 62. Therefore, even if the detection unit 30 is exposed from the thin-walled portion 61, the thick-walled portion 62 can prevent intrusion of water or the like into the metal exposed portions 48 and 49, the lead frame 40, and the terminal 50.

FIG. 6 shows a state in which the detection unit 30 and the terminal 50 are installed inside the mold 70 used for injection molding of the primary molding resin 60.
A gap S between the inner wall 71 of the mold 70 forming the thin portion 61 and the detection unit 30 corresponds to the thickness S1 of the thin portion 61. That is, as shown by the arrow A, the gap S is a distance that does not allow the detection unit 30 to contact the inner wall 71 of the mold 70 even if a positional shift occurs due to the tolerance of the detection unit 30. Furthermore, the gap S is a distance that allows an error in the detection accuracy of the position detection device 1 even if it abuts against the inner wall 71 of the mold 70 if the tolerance of the positional deviation of the detection unit 30 is large.

  A gap T between the inner wall 72 of the mold 70 forming the thick part 62 and the detection part 30 corresponds to the thickness T1 of the thick part 62. The distance L between the inner wall 73 of the mold 70 that forms the step 64 between the thin portion 61 and the thick portion 62 and the metal exposed portions 48 and 49 is the distance between the step 64 and the metal exposed portions 48 and 49. This corresponds to the distance L1. That is, the thick portion 62 formed by the mold 70 can reliably cover the metal exposed portions 48 and 49.

A molten thermosetting resin or thermoplastic resin is injected into the mold 70 shown in FIG. 6, and after the resin is cured, the position detection device 1 is taken out from the mold 70. Thereby, the position detection apparatus 1 as a primary molded product is completed.
Thereafter, as shown in FIG. 7, the two position detection devices 1 are combined so as to face each other. The two position detection devices 1 are configured integrally with the housing cover 11 by performing secondary molding using a secondary molding die 70 (not shown).

Here, a position detection device of a comparative example will be described.
FIG. 8 shows a state in which the detection unit 30 and the terminal 50 are installed inside a mold 80 used when injection molding the primary molding resin of the position detection device of the comparative example.
In the position detection device of the comparative example, the primary molding resin does not have a thick portion. Therefore, the inner wall 81 of the mold 80 around the detection unit 30 is adjacent to the detection unit 30 and prevents the position of the detection unit 30 from being displaced. In this case, as indicated by an arrow B, when the detection unit 30 is displaced inside the mold 80 and the detection unit 30 approaches or contacts the inner wall 81 of the mold 80, a part of the detection unit 30 is primary molded. There is concern about exposure from the resin. If water or the like enters from a portion where the detection unit 30 is exposed from the primary molding resin and the metal exposed portions 48 and 49, the lead frame 40, or the terminal 50 are corroded, the detection accuracy of the position detection device may be deteriorated.

On the other hand, the position detection apparatus 1 of this embodiment has the following effects.
(1) In this embodiment, the primary molding resin 60 molds the thin portion 61 that molds the end portion of the detection portion 30 on the side opposite to the terminal, and the thickness that molds the detection portion 30 that is located on the terminal side of the thin portion 61. It has a meat part 62.
Thereby, the position detection apparatus 1 can make the position shift of the detection part 30 inside the thin part 61 within an allowable range. Further, even if the detection unit 30 is exposed from the thin portion 61, the position detection device 1 prevents the entry of water or the like into the metal exposed portions 48 and 49, the lead frame 40, and the terminal 50 by the thick portion 62. Is possible. Therefore, the position detection apparatus 1 can improve detection accuracy.

(2) In the present embodiment, the thin portion 61 is thick enough to allow displacement of the detection unit 30.
Thereby, even when the position of the detection unit 30 is shifted when the detection unit 30 is molded with the primary molding resin 60, the detection unit 30 contacts the inner wall 71 of the mold 70 that forms the primary molding resin 60. Therefore, the degree of positional deviation of the detection unit 30 can be within an allowable range.

(3) In the present embodiment, the thin portion 61 is thick enough to prevent the detection unit 30 from being exposed due to a positional shift due to tolerance of the detection unit 30.
Thereby, it is suppressed that the detection part 30 is exposed from the thin part 61. FIG. Therefore, it is possible to prevent water or the like from entering the primary molding resin 60.

(4) In the present embodiment, the thin portion 61 is provided on the side opposite to the terminal with respect to the metal exposed portions 48 and 49 included in the detection unit 30. The thick part 62 is provided closer to the terminal than the thin part 61 and covers the metal exposed parts 48 and 49.
Thereby, even if the detection unit 30 is exposed from the thin portion 61, the exposed metal portions 48 and 49 are prevented from being exposed from the thick portion 62. Therefore, corrosion of the metal exposed portions 48 and 49 can be prevented, and intrusion of water or the like from the metal exposed portions 48 and 49 to the inside of the resin body 32 can be prevented. Therefore, the detection accuracy of the position detection device 1 can be maintained.

(5) In the present embodiment, the thin portion 61 and the thick portion 62 are provided on the left side surface 37 and the right side surface 38 of the resin body 32 of the detection unit 30.
Accordingly, when the metal exposed portions 48 and 49 are provided on the left side surface 37 and the right side surface 38 of the resin body 32, the thick portion 62 can prevent the metal exposed portions 48 and 49 from being exposed. Moreover, the thin part 61 can make the extent of the position shift of the detection part 30 right and left within an allowable range.

(Other embodiments)
(1) In the above-described embodiment, the position detection device constituting the rotation angle sensor of the electronic control throttle mounted on the vehicle has been described.
On the other hand, in other embodiments, the position detection device can be used for various products. For example, the position detection device may detect a rotation angle of an accelerator pedal. Further, the position detection device may detect a rotation angle of the tumble control valve. The position detection device may be a stroke sensor that detects the stroke amount of the clutch actuator.

  (2) In the above-described embodiment, the Hall element is described as an example of the semiconductor element included in the detection unit. On the other hand, in other embodiments, various semiconductor elements such as MR elements can be used.

  (3) In the above-described embodiment, the rotation angle sensor is configured by combining two position detection devices. On the other hand, in another embodiment, the rotation angle sensor may be configured with only one position detection device. Further, the position detection device may have two detection parts molded with a primary molding resin.

  (4) In embodiment mentioned above, the thin part and the thick part were provided in the left side surface and right side surface of the resin body. On the other hand, in other embodiments, if the metal exposed portions are provided on the upper and lower surfaces of the resin body, the thin and thick portions may be provided on the upper and lower surfaces of the resin body.

(5) In the above-described embodiment, the resin body has a metal exposed portion. On the other hand, in other embodiments, the resin body may not have a metal exposed portion. Even in this case, the thin-walled portion can make the displacement of the detection portion within an allowable range, and the thick-walled portion is effective in preventing water and the like from entering the lead frame and the terminal.
Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... Position detection apparatus 30 ... Detection part 31 ... Semiconductor element 32 ... Resin body 40 ... Lead frame 50 ... Terminal 60 ... Primary molding resin 61 ... Thin part 62 ... Thick part

Claims (6)

A lead frame (40) provided with a semiconductor element (31), and a detection unit (30) having a resin body (32) for molding the semiconductor element and a part of the lead frame;
A terminal (50) connected to an end of the lead frame protruding from the resin body of the detection unit;
Primary molding resin (60) having a thin part (61) for molding the end of the detection part on the side opposite to the terminal and a thick part (62) for molding the detection part located on the terminal side of the thin part. And comprising
The detection unit is a metal exposed portion (48) in which a part of the lead frame connected to the terminal is different from a position where the lead frame protrudes from the resin body, and the other part of the lead frame is exposed from the resin body. 49)
The thin part and the thick part of the primary molding resin are continuously formed of the same resin,
The thin-walled portion is provided on the side opposite the terminal than the exposed metal portion,
The said thick part is a position detection apparatus (1) which is provided in the terminal side rather than the said thin part, and covers the said metal exposure part. A lead frame in which a semiconductor element is installed, and a detection unit having a resin body for molding the semiconductor element and a part of the lead frame;
A terminal connected to an end of the lead frame protruding from the resin body of the detection unit;
A thin-walled portion that molds the end portion of the detection portion on the side opposite to the terminal, and a primary molding resin that has a thick-walled portion that molds the detection portion located on the terminal side of the thin-wall portion, and
The thin part and the thick part of the primary molding resin are continuously formed of the same resin,
The detection unit has a metal exposed portion where a part of the lead frame connected to the terminal is different from a position where the lead frame protrudes from the resin body, and the other part of the lead frame is exposed from the resin body. And
A left side surface (37) and a right side surface (38) which are positioned in a direction parallel to the surface of the lead frame in the detection unit and are orthogonal to a direction in which the lead frame protrudes from the resin body. A position detecting device for directly covering the outer wall of the thin portion. Before SL thin portion provided on the counter-terminal side of the metal exposure portion,
The position detection apparatus according to claim 2, wherein the thick part is provided on a terminal side of the thin part and covers the exposed metal part.   4. The position detection device according to claim 1, wherein the thin portion has a thickness that allows a positional shift of the detection portion. 5.   5. The position detection device according to claim 1, wherein the thin-walled portion has a thickness such that the detection unit is not exposed due to a positional shift due to a tolerance of the detection unit. The resin body of the detection unit includes an upper surface (33) and a lower surface (34) provided in parallel with the lead frame, a bottom surface (35) positioned on the side from which the lead frame protrudes, and a position opposite to the bottom surface. A top surface (36), and a left side surface (37) and a right side surface (38) that connect the upper surface and the lower surface and are provided with two metal exposed portions, respectively.
The position detection device according to claim 1, wherein the thin portion and the thick portion are provided on the left side surface and the right side surface of the resin body.

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