Rotation angle sensors

Angle sensor device has magnetic force detectors detecting alternation of magnetic force caused by rotation of a throttle gear. The magnetic force detectors are buried in a molded body of the angle sensor device constructed of foamed resin. The magnetic force detectors each has a sensing unit detecting alteration of magnetic force and a computing unit computing based on signals from the sensing unit and outputting signals depending on the alteration of magnetic force and is formed in L-shape. Two of the magnetic force detectors are placed opposite each other such that one of the sensing units is disposed on the other sensing unit. The molded body has a cavity surrounded by the magnetic force detectors.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to Japanese patent applications No 2009-245296 and 2009-258202, the components of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to angle sensor devices and manufacturing methods thereof, and throttle controllers having one of the angle sensor devices.

2. Description of the Related Art

A throttle controller mounted on a gas vehicle comprises an angle sensor device for measuring rotational angle of a rotatable member. The angle sensor has at least one magnetic force detector for detecting alteration of magnetic force caused by rotation of the rotatable member.FIG. 1is a cross sectional view showing one of conventional angle sensor devices disclosed in Japanese Laid-Open Patent Publication No. 2008-145258. The angle sensor device266includes a housing272with an opening, two magnetic force detectors270provided in the housing272, a holder274closing the opening of the housing272and holding the magnetic force detectors270, and potting material276filled in an inner space enclosed by the housing272and the holder274.

Thus, the angle sensor device266needs the housing272, the holder274and the potting material276for holding the magnetic force detectors270.

Therefore, there is a need in the art for an improved angle sensor device and an improved manufacturing method thereof.

SUMMARY OF THE INVENTION

One aspect according to an angle sensor device for measuring rational angle of a rotatable member of the present disclosure includes a molded body constructed of foamed resin, and at least one magnetic force detector buried in the body for detecting alteration of magnetic force caused by rotation of the rotatable member and outputting signals depending on the rotation angle of the rotatable member.

The magnetic force detector is buried in and held by the molded body. Therefore, it is able to reduce number of members for holding the magnetic force detector compared with the conventional angle sensor device, so that production cost for the device can be decreased.

Another aspect according to a method for manufacturing an angle sensor device including at least one magnetic force detector for detecting alteration of magnetic force caused by rotation of a rotatable member of the present disclosure includes placing the magnetic force detector in a mold, and molding the foamed resin in the mold such that the magnetic force detector is buried in the foamed resin.

The magnetic force detector of the manufactured angle sensor device is buried in and held by the molded foamed resin. Therefore, it is able to reduce a step for placing a holder used for holding the magnetic force detector compared with the conventional manufacturing method, so that production cost can be decreased.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment of the present disclosure will be described in reference to attached drawings. This embodiment relates an angle sensor device used as throttle position sensor for detecting rotation angle, i.e. opening ratio, of a throttle valve in an electronically-controlled throttle controller, which is mounted on a vehicle such as gasoline automobile. Firstly, the throttle controller will be described.FIG. 2is a cross sectional view of the throttle controller. As for explanation of the throttle controller, “right”, “left”, “up” and “down” are defined based on directions inFIG. 2.

As shown inFIG. 2, a throttle controller10has a throttle body12. The throttle body12is constructed of, e.g., resin and has a bore defining wall14and a motor housing17integrally with each other. The bore defining wall14is formed in a hollow cylindrical shape extending in a direction perpendicular to the sheet ofFIG. 2. The bore defining wall14has a bore13as intake pathway therein. An upstream end of the bore defining wall14is connected with an air cleaner (not shown), whereas a downstream end is connected with an intake manifold (not shown). The bore defining wall14is provided with a metal throttle shaft16passing through the bore13in a radial direction, i.e. a horizontal direction inFIG. 2. The throttle shaft16is supported by bearings (not labeled) such that the throttle shaft16can rotate with respect to bearing portions15provided at both right and left sides of the bore defining wall14. A throttle valve18of butterfly valve type in circular plate shape is fastened on the throttle shaft16by screws18s. The throttle valve18rotates together with the throttle shaft16in order to open and close the bore13.

A right end of the throttle shaft16passes through the right bearing portion15. A throttle gear22is concentrically attached to the right end of the throttle shaft16such that the throttle gear22cannot rotate relative to the throttle shaft16. The throttle gear22is constructed of resin or the like and has an inner cylinder22eand an outer cylinder22fin a double cylinder structure such that the inner cylinder22eis inside the outer cylinder22f. A gear portion22win a fan-like shape is formed on an outer surface of the outer cylinder22f. A back spring26consisting of a coil spring is disposed between the throttle gear22and a right surface of the throttle body12facing the throttle gear22. The back spring26biases the throttle gear22in a closing direction. The throttle spring26is disposed around the outer cylinder22fof the throttle gear22and the right bearing portion15.

The motor housing17of the throttle body12defines a hollow cylinder space opening at right side such that an axis of the space is parallel to the throttle shaft16. The motor housing17houses a driving motor28such as direct-current (DC) motor. An output shaft (not shown) of the driving motor28is rotated due to signals from an engine control unit, ECU, (not shown) depending on angle of accelerator pedal of the vehicle or the like. The output shaft of the driving motor28protrudes in a right direction inFIG. 2, and a pinion gear29is attached to the output shaft. A counter shaft23parallel to the throttle shaft16is disposed at the right side of the throttle body12. The counter shaft23has a counter gear24rotatably mounted on the counter shaft23. The counter gear24has a two gear portions24aand24b, radii of which are different from each other. The larger gear portion24amates with the pinion gear29, whereas the smaller gear portion24bmates with the gear portion22wof the throttle gear22. Therefore, rotary drive power of the driving motor28is transmitted to the throttle shaft16via the pinion gear29, the counter gear24and the throttle gear22. Thus, the throttle valve18is rotated in the bore13, i.e., opened and closed in order to control an amount of air flowing through the bore13. Here, a reduction gear mechanism is composed of the pinion gear29, the counter gear24and the throttle gear22.

A cylinder shaped yoke43and a pair of permanent magnets disposed inside the yoke43are provided integrally inside the inner cylinder22eof the throttle gear22(FIG. 3). The pair of the permanent magnets41is constructed of ferrite magnet or the like and positioned in parallel in order to generate substantially parallel magnetic field between thereof. The yoke43is constructed of magnetic material and is buried in the inner cylinder22e. Here,FIG. 3is a cross sectional view showing a throttle gear and a surrounding area thereof.

As shown inFIG. 2, the right surface of the throttle body12is provided with a sensor cover30for covering the reduction gear mechanism (the pinion gear29, the counter gear24and the throttle gear22), etc. The sensor cover30is constructed of resin or the like and is integrated with an angle sensor device40for measuring rotation angle of the throttle gear22, i.e. opening ratio of the throttle valve18, due to insert molding (FIG. 4). Here,FIG. 4is a perspective view of the sensor cover.

The angle sensor device40is formed in a substantially cylindrical shape. A base of the angle sensor device40is buried in a cover body31of the sensor cover30, which is constructed of resin, whereas a top end is exposed at an inner surface of the cover body31(FIGS. 3 and 4). The top end of the angle sensor device40is concentrically and loosely inserted into the inner cylinder22eof the throttle gear22(FIG. 3). Therefore, the angle sensor device40does not contact with the permanent magnets41and the yoke43of the throttle gear22. Here, the throttle gear22corresponds to “rotatable member” in the present disclosure.

Next, the angle sensor device40will be described.FIGS. 5,6and7are a front view, a top view and a cross sectional view of the angle sensor device, respectively. For convenience of explanation, as for the angle sensor device40, “front” is defined at the end side (lower side inFIGS. 6 and 7), and “back” is defined at the base side (upper side inFIGS. 6 and 7). In addition, “inside” is defined at center side in horizontal direction inFIGS. 6 and 7, whereas “outside” is defined at right and left sides inFIGS. 6 and 7.

As shown inFIG. 7, the angle sensor device40has a pair of magnetic force detectors44and a molded resin (i.e., molded body)52in a cylinder shape, in which the magnetic force detectors44are buried. The angle sensor device40detects alteration of magnetic force caused by rotation of throttle gear22(FIG. 3), and has two magnetic force detectors44in view of fail-safe such that if one of the magnetic force detectors44goes out of order, the other can detect alteration of magnetic force.

For convenience of explanation for configuration of the magnetic force detectors44, one of the magnetic force detectors44will be described. As shown inFIG. 7, the magnetic force detector44is composed of a sensor integrated circuit (sensor IC) having a magnetoresistance element referred to as MR element or the like, where a sensing unit45is connected with a computing unit47via a plurality of connecting terminals46. The sensing unit45has a body45aconstructed of resin in a rectangular parallelepiped shape, which houses a chip45bcomposed of a magnetoresistance element. The computing unit47has a body47aconstructed of resin in a rectangular parallelepiped shape, which houses a semiconductor integrated circuit (not shown). The sensing unit45and the computing unit47are electrically connected with each other via the plurality of the connecting terminals46connecting a front surface of the computing unit47and an end surface of the sensing unit45. The connecting terminals46are bent in L-shape, so that the magnetic force detector44including the sensing unit45, the connecting terminals46and the computing unit47is formed in L-shape. A back end surface of the computing unit47is connected with ends (base portions) of a plurality of, e.g., three, lead terminals48.

The chip45bof the sensing unit45is disposed at a center region of a metallic support plate45cin elongate shape. The support plate45cis buried in the body45asuch that a longitudinal axis of the support plate45cis parallel to a width direction of the sensing unit45(a direction perpendicular to the sheet inFIG. 7). Each ends of the support plate45cin the longitudinal direction of the support plate45cprotrudes from either surfaces of the body45ain the width direction of the body45a(FIGS. 5 and 6). The sensing unit45is disposed such that its both end surfaces in a through-thickness direction of the sensing unit45(vertical direction inFIG. 7) are perpendicular to an axis of the throttle gear22and that the chip45bis positioned on an axis of the molded resin52. In a state that the sensor cover30is mounted on the throttle body12(FIG. 2), the chip45bof the sensing unit45is positioned between the pair of the permanent magnets41of the throttle gear22and on an axis of the throttle shaft16. Thus, the sensing unit45, in particular the chip45b, can detect alteration of magnetic force, that is, direction of magnetic field generated between the pair of the permanent magnets41.

The sensing unit45outputs signals based on detection result of alteration of magnetic force, and the computing unit47, particularly the semiconductor integrated circuit, receives the signals via the connecting terminals46. The computing unit47computes based on the signals from the sensing unit45and outputs signals depending on the direction of the magnetic field. The engine control unit, ECU, (not shown) calculates rotation angle of the throttle gear22, i.e., opening ratio of the throttle valve18depending on the signals from the computing unit47. The computing unit47is programmed to output voltage signals in a linear manner depending on the rotation angle of the throttle gear22.

As shown inFIG. 7, the pair of the magnetic force detectors44is disposed opposite each other in the horizontal direction such that the sensing units45aare aligned in a front-back direction (vertical direction inFIG. 7) and contact with each other. The chips45bof the sensing units45are positioned to face one another on the axis of the molded resin52. The support plates45cof the sensing units45are in a line along the front-back direction (vertical direction inFIG. 7). The computing units47of the magnetic force detectors44are positioned parallel to each other and at a distance in the horizontal direction inFIG. 7.

Each lead terminal48of the computing units47is bent such that an end and a base portion thereof are uneven and parallel to each other. Therefore, the end of the lead terminal48(upper end inFIG. 7) is located medially compared with the base portion. Inner surfaces of the ends of lead terminals48are coupled with halves of an L-shaped mounting terminals49(referred to as “base portion”) by, e.g., welding, respectively. On the other hand, the other halves of the mounting terminals49(referred to as “end portion”) protrude outwardly, i.e., oppositely each other in the horizontal direction inFIG. 7, at a back end of the molded resin52.

The molded resin52is constructed of chemical foamed resin and is formed in cylinder shape. Both the magnetic force detectors44, which include the sensing unit45, the connecting terminals46, the computing unit47and the lead terminals48, and connections between the lead terminals48and the mounting terminals49of the magnetic force detectors44are buried in the molded resin52. The molded resin52has a cavity53surrounded by the magnetic force detectors44. The cavity53opens at the back surface (upper surface inFIG. 7) of the molded resin52. Due to this configuration, thickness of the molded resin52in an area surrounded by the magnetic force detectors44, (in particular, thickness of the molded resin inside the computing units47) is equalized in a longitudinal direction of the computing units47(vertical direction inFIG. 7). That is, thickness t1of the molded resin52inside either of the computing units47in the horizontal direction is equalized along the front-back direction (vertical direction inFIG. 7). And, thickness t2of the molded resin52outside either of the computing units47in the horizontal direction is equalized in the longitudinal direction of the computing unit47(front-back direction). In addition, the thickness t1and the thickness t2are equalized each other. Inner surfaces of the base portions of the mounting terminals49of the magnetic force detectors44are exposed at an inner wall defining the cavity53.

When the angle sensor device40is integrated with the sensor cover30by insert molding (FIG. 4), ends of the mounting terminals49are connected with base portions of wiring terminals54by, e.g., welding, respectively (FIG. 8). Here, the wiring terminal54(a) is used for connection with a power supply, the wiring terminal54(b) is used for connection to ground, and the wiring terminals54(c) and54(d) are used for outputting signals.FIG. 8is a front view of the angle sensor device with the wiring terminals, andFIG. 9is a perspective view showing the wiring terminals and the angle sensor device disassembled each other.

The angle sensor device40connected with the wiring terminals54(FIG. 8) is integrated with the sensor cover30by insert molding (FIG. 4). The base of the angle sensor device40is buried in the cover body31of the sensor cover30, which is constructed of resin, and the top end of the angle sensor device40is exposed at the inner surface of the cover body31. Therefore, the connections between the mounting terminals49of the angle sensor device40and the wiring terminals49, and most of the wiring terminals54except each end54aof the wiring terminals54are buried in the cover body31. The ends54aof the wiring terminals54(FIG. 8) are exposed within a connecter portion55formed on the cover body31(FIG. 4). The connector portion55is formed to connect with an outer connector (not shown) of the engine control unit (ECU). Therefore, signals output from the computing units47of the magnetic force detectors44(FIG. 3) are transmitted to the engine control unit. In addition, an outer surface of the end of the molded resin52of the angle sensor device40, which is exposed at the inner surface of the cover body31, is preferably coated with moisture-proof material.

The cover body31is constructed of another resin different from the foamed resin used for the molded resin52of the angle sensor device40. That is, the foamed resin for the molded resin52is composed of the resin for the cover body31and foaming agent. For, example, polybutylene terephthalate (PTB) resin can be used for the cover body31.

Next, a manufacturing method for the angle sensor device40, i.e., a method for forming the molded resin52, will be described.FIG. 10is a cross sectional view of a mold used for manufacture of the angle sensor device.FIG. 11is a cross sectional view showing the mold and the magnetic force detectors disassembled each other.FIG. 12is a cross sectional view along a line XII-XII inFIG. 11.

Firstly, the mold for insert molding of the foamed resin with the magnetic force detectors44will be described. As shown inFIG. 11, the mold60is composed of a lower mold62and an upper mold64. The lower mold62is used for forming a front surface and an outer circumference surface of the molded resin52(FIG. 5-7) and has a cylinder-shaped mold cavity63opening at one end. The upper mold64is used for forming a back surface and the cavity53(FIG. 7) and has a projection65at a lower surface, which is directed to the lower mold62during molding operation.

Both sidewalls of the mold cavity63of the lower mold62(in the width direction of the magnetic force detector44, i.e., a direction perpendicular to the sheet inFIG. 11) are provided with L-shaped positioning parts66in symmetry manner with respect to an axis of the mold cavity63(FIG. 12). As shown inFIG. 11, the positioning parts66can engage with either ends of the support plates45cof the sensing units45of the magnetic force detectors44. Each of the positioning parts66has a first horizontal surface66a, which contacts with a front surface of the end of the support plate45cof the sensing unit45, a second vertical surface66b, which contacts with one of side surfaces (left side surface inFIG. 11) of the end of the support plate45cof the sensing unit45, and a third vertical surface66c, which contacts with an end surface of the support plate45cof the magnetic force detector44in the longitudinal direction of the support plate45c(FIG. 12). In addition, recesses67are formed on an upper surface of the lower mold62for receiving the end portions of the mounting terminals49(FIG. 11).

One of the sidewalls of the mold cavity63of the lower mold62(one of the sidewalls in the width direction of the magnetic force detector44) is provided with a pair of gates68. The gates68are positioned such that when the magnetic force detectors44are disposed in the lower mold62, each of the gates68is near and outside the ends of the lead terminals48of the corresponding magnetic force detector44(FIG. 10).

Next, a step of inset molding of foamed resin with the magnetic force detectors44in the mold60.

In a state that the mold60is opened (FIG. 11), the right magnetic force detector44is placed in the mold cavity63of the lower mold62. Each end of the support plate45of the right magnetic force detector44is contacted with the first surface66a, the second surface66band the third surface66cof the corresponding positioning part66(FIGS. 11 and 12). Thus, the sensing unit45of the right magnetic force detector44is held in place (FIG. 10). The end portions of the mounting terminals49of the right magnetic force detector44are received in the right recesses67, respectively, so that the right magnetic force detector44is held in place.

Then, the left magnetic force detector44is placed in the mold cavity63of the lower mold62such that the right and the left magnetic force detectors44are opposite each other. The sensing unit45of the left magnetic force detector44is positioned that the magnetic force detectors44are arranged in the front-back direction (vertical direction inFIGS. 10 and 11) and contacted with each other. With this, each end of the support plate45cof the sensing unit45of the left magnetic force detector44is contacted with the second surface66band the third surface66cof the corresponding positioning part66(FIGS. 11 and 12). Therefore, the sensing unit45of the left magnetic force detector44is held in place (FIG. 10). In addition, the end portions of the mounting terminals49of the left magnetic force detector44are received in the left recesses67, respectively, so that the left magnetic force detector44is held in place.

After the magnetic force detectors44are placed in the lower mold62as described above, the mold60is closed, i.e., the lower mold62is fitted with the upper mold64(FIG. 10). Thus, the opening of the mold cavity63of the lower mold62is closed by the upper mold64, so that an enclosed cavity70is formed. With this, the end portions of the mounting terminals49of the magnetic force detectors44are held between the lower mold62, in particular bottom surfaces of the recesses67, and the upper mold64. And, inner surfaces of the base portions of the mounting terminals49of the magnetic force detectors44are contacted with corresponding sidewall of the projection of the upper mold64, respectively. Thus, the end portions of the mounting terminals49of the magnetic force detectors44are held by the mold60, so that it is able to prevent movement of the magnetic force detectors44caused by flow of the foamed resin during insert molding.

Then, the foamed resin (melting resin) is injected into the cavity70from both of the gates68of the lower mold62in order to form the molded resin52. In this step, the foamed resin is flowed equally along both of the inner surface and the outer surface of the computing unit47of each of the magnetic force detectors44, so that stress applied to the magnetic force detectors44due to flow of the foamed resin is equalized. The cavity53is formed in the molded resin52due to the projection65of the upper mold64(FIG. 7). After forming and then cooling the molded resin52in order to harden the foamed resin, the mold60is opened and a product, i.e., the angle sensor device40is taken from the lower mold62.

As for the angle sensor device40(FIG. 5-7), the magnetic force detectors44are buried in the molded foamed resin (the molded resin52). Therefore, the magnetic force detectors44are held by molded foamed resin (the molded resin52), in which the magnetic force detectors44are buried, so that it is able to reduce the number of members for holding the magnetic force detectors44compared with the conventional device, which is disclosed in, for example, Japanese Laid-Open Patent Publication No. 2008-145258, thereby decreasing cost for the product. In addition, the foamed resin (the molded resin52) has high heat insulation properties, so that it is able to protect the magnetic force detectors44well from temperature alteration, etc. The foamed resin in melting condition has high fluidity, so that flow pressure of the resin injected during insert molding can be decreased. Therefore, it is able to reduce flow pressure of resin, which is applied to the magnetic force detectors44during insert molding, in order to prevent deformation and damage of the magnetic force detectors44. Furthermore, potting resin, which is used in the conventional device, is not required, thereby decreasing cost for potting resin and for equipment required for the potting resin.

Each of the magnetic force detectors44has the sensing unit45detecting alteration of magnetic force and outputting signals depending on the alteration and the computing unit47computing based on signals from the sensing unit45and then outputting signals depending on alteration of the magnetic force such that the sensing unit45and the computing unit47are coupled in L-shape (FIG. 7). Therefore, it is able to downsize the magnetic force detectors each having the sensing unit45and the computing unit47.

In this embodiment, the pair of the magnetic force detectors44is placed opposite each other such that one of the sensing units45is laid on top of another (FIG. 7). Therefore, it is able to place the pair of the magnetic force detectors44compactly.

The molded resin52has the cavity53in the area surrounded by the magnetic force detectors44(FIG. 7). Therefore, it is able to equalize the thickness of the molded resin52in the area between the magnetic force detectors44.

The lead terminals48of the magnetic force detectors44are connected with the mounting terminals49, and the connections between the lead terminals48and the mounting terminals49are buried in the foamed resin (the molded resin52) (FIG. 7). Thus, the connections between the lead terminals48of the magnetic force detectors44and the mounting terminals49can be protected due to the foamed resin (the molded resin52).

The molded resin52is constructed of the chemical foamed resin. Therefore, it is able to utilize a conventional injection molding equipment for injection molding of the foamed resin with the magnetic force detectors44.

The molded resin52is partially buried in another resin, of which the cover body31is constructed, and the materials for the molded resin52is composed of materials for such another resin and a forming agent. Therefore, the foamed resin for the molded resin52can has substantially same basic properties as those of the resin for the cover body31.

According to the manufacturing method of the angle sensor device40, insert molding of the foamed resin with the magnetic force detectors44is carried out in order to bury the magnetic force detectors44in the molded resin52constructed of the foamed resin. Therefore, the molded resin52holds the magnetic force detectors44in place, so that it is able to decrease the number of members required for holding the magnetic force detectors44and to decrease production cost compared with a conventional angle sensor device, which is disclosed in, for example, Japanese Laid-Open Patent Publication No. 2008-145258.

Each of the magnetic force detectors44has the sensing unit45detecting alteration of magnetic force and outputting signals depending on the alteration and the computing unit47computing based on the signals from the sensing unit45and then outputting signals depending on alteration of the magnetic force such that the sensing unit45and the computing unit47are coupled in L-shape (FIG. 7). Therefore, it is able to downsize the magnetic force detectors each having the sensing unit45and the computing unit47. Furthermore, the insert molding is carried out in a state that the pair of the magnetic force detectors44is placed opposite each other such that one of the sensing units45is laid on top of another (FIG. 7). Therefore, it is able to place the pair of the magnetic force detectors44compactly.

The mold60has the projection65, which can be located in the area between the pair of the magnetic force detectors44, and the insert molding is carried out in a state that the projection65of the mold60is placed at the area (FIG. 10). Thus, it is able to equalize the thickness of the molded resin52in the area between the magnetic force detectors44. This equalizes stress applied to the magnetic force detectors44and caused by flow of the foamed resin in melting condition during insert molding process, thereby preventing deformation and damage of the magnetic force detectors44caused by the stress.

Each of the magnetic force detectors44has the lead terminals48connected with the corresponding mounting terminals49, and in a state that the mold60supports the mounting terminals49, the insert molding is carried out such that both the magnetic force detectors44and the connections between the lead terminals48and the mounting terminals49are buried in the foamed resin (FIG. 10). Therefore, it is able to prevent deformation of the mounting terminals49caused by flow of the foamed resin in melting condition during insert molding process. In addition, both the magnetic force detectors44and the connections between the lead terminals48and the mounting terminals49can be protected due to the foamed resin forming the molded resin52.

The inert molding is carried out in a state that the positioning parts66of the mold60support the sensing units45of the magnetic force detectors44(FIG. 10). Therefore, it is able to improve location accuracy of the sensing units45of the magnetic force detectors44, thereby improving detection accuracy for alteration of magnetic force.

In injection of the foamed resin into the mold60, the foamed resin is injected from the gates68away from the sensing units45of the magnetic force detectors44along the longitudinal direction of the computing units47of the magnetic force detectors44. Therefore, the foamed resin is injected into the mold60from the gates68away from the sensing units45of the magnetic force detectors44, so that it is able to reduce stress applied to the sensing units45of the magnetic force detectors44caused by flow of the foamed resin in melting condition in order to prevent deformation and damage of the sensing units45. In addition, the foamed resin is injected along the longitudinal direction of the computing units47of the magnetic force detectors44(vertical direction inFIG. 10), so that it is able to decrease stress applied to the computing units47of the magnetic force detectors44caused by flow of the foamed resin in melting condition in order to prevent deformation and damage of the computing units47of the magnetic force detectors44.

According to the throttle controller10(FIG. 2), the throttle valve18has the throttle gear22, the sensor cover30of the throttle body12has the angle sensor device40, and the opening ratio of the throttle valve18is detected based on signals from the magnetic force detectors44of the angle sensor device40. Therefore, it is able to provide the throttle controller10having the angle sensor device40, cost of which is decreased due to reduction of the number of members required for holding the magnetic force detectors44.

Other embodiments will be described below. Here, differences of following embodiments will be described, whereas the same configurations as those of the described embodiment will not be described.

FIG. 13is a cross sectional view showing a second embodiment of the angle sensor device.

As shown inFIG. 13, the angle sensor device40of this embodiment does not have the mounting terminals49of the first embodiment, and has the magnetic force detectors44with the lead terminals48, which have ends48aprojecting from a back surface of the molded resin52. The lead terminals48are bent in L-shape such that the ends48aare directed outwardly. Inner surfaces of base potions (except ends near the computing units47) are exposed at surfaces of the molded resin52, which defines the cavity53.

According to this embodiment, it is not necessary to connect the lead terminals48of the magnetic force detectors44with the mounting terminals49protruding from the molded resin52constructed of the foamed resin (FIG. 7). Therefore, it is able to reduce the number of components relating to the mounting terminal49compared with the first embodiment, thereby decreasing component cost. Furthermore, it is able to omit a step for connecting the lead terminals48with the mounting terminals49by welding or the like, so that productivity can be improved.

FIG. 14is a cross sectional view of an angle sensor device140according to a third embodiment. Here, the angle sensor device140is an alternative embodiment of the angle sensor device40of the first embodiment.

In this embodiment, lead terminals148are bent such that ends of the lead terminals148(upper ends inFIG. 14) are positioned outside compared with base portions (lower ends inFIG. 14) connecting with the computing units47. The end of each lead terminal148has a surface directed outwardly and connected with a base portion of a corresponding L-shaped mounting terminal149by welding or the like.

Next, a manufacturing method of the angle sensor device140and a mold used for the method will be described.FIG. 15is a cross sectional view showing a mold used for manufacture of the angle sensor device.FIG. 16is a cross sectional view showing the mold and the magnetic force detectors disassembled each other.FIG. 17is a cross sectional view showing the mold with retracted support molds.

As shown inFIG. 16, a mold160is composed of a lower mold162and an upper mold164. The upper mold164has a pair of plate-shaped support molds188contacting with either side surfaces of a projection165, respectively. The support molds188extend an open-close direction of the mold160, i.e., vertical direction inFIG. 16, and are constructed to move in the vertical direction. When the support molds188are located at a lower position, end surfaces (lower surfaces) of the support molds188are in a plane of an end surface (lower surface) of the projection165(FIG. 15). On the other hand, when the support molds188are located at an upper position, the end surfaces of the support molds188are located above the computing units47of the magnetic force detectors44in order to maintain a predetermined distance from the computing units47(FIG. 17). At the start of molding, the support molds188are moved to the lower position, and then are retracted to the upper position after completion of injection of the foamed resin and before hardening of the injected foamed resin.

A pair of gates168is provided at one sidewall defining the mold cavity63of the lower mold162. The sidewall is perpendicular to the width direction of the magnetic force detectors44. Each of the gates168is positioned near ends of the lead terminals148of the corresponding magnetic force detector44, which is located closer than another (FIG. 15).

Next, a step for insert molding of foamed resin with the magnetic force detectors44in the mold160will be described.

Here, a step for putting the magnetic force detectors44in the lower mold162is same as that of the first embodiment, and thus will not be explained.

As shown inFIG. 15, after putting the magnetic force detectors44in the lower mold162, the mold160is closed, i.e., the lower mold162and the upper mold164are engaged with each other. Thus, an open end of the mold cavity63of the lower mold162is closed with the upper mold164in order to form a sealed cavity170. With this, the end portions of the mounting terminals149of the magnetic force detectors44are sandwiched and held between the lower mold162(in detail, bottom surfaces of the recesses67) and the upper mold164. In this way, the end portions of the mounting terminals149of the magnetic force detectors44are held by the mold160in order to prevent displacement of the magnetic force detectors44caused by flow of the foamed resin in melting condition during insert molding.

In a condition that the mold160is closed (FIG. 15), when the support molds188of the upper mold164are located at the lower position, an outside surface of one of the support molds188is contacted with an inside surface of the computing unit47of one of the magnetic force detectors44, and the other support mold188contacts with the other magnetic force detector44. Thus, the inside surfaces of the computing units47of the magnetic force detectors44are supported by the support molds188, respectively.

Then, the foamed resin in the melting state is injected from the gates168of the lower mold162into the cavity170in order to produce the molded resin152. In this step, the foamed resin is flowed substantially equally along both the inside surfaces and the outside surfaces of the computing units47of the magnetic force detectors44in order to equalize stress applied to the magnetic force detectors44by such flow.

As shown inFIG. 17, after injection of the foamed resin into the cavity170, the support molds188are retracted to the upper position before the resin injected into the mold160become hardened. Empty spaces190are created due to retraction of the support molds188, and the foamed resin flows into the empty spaces190. Therefore, the inside surfaces of the computing units47of the magnetic force detectors44, which had been supported by the support molds180, are covered with the foamed resin (FIG. 14). InFIG. 14, portions constructed of the foamed resin and covering the inside surfaces of the computing units47of the magnetic force detectors44are labeled with symbol “152a”. A cavity153is formed in the molded resin152due to the projection165of the upper mold164(FIG. 14). The molded resin152is cooled in order to become the foamed resin hardened, and then the mold160is opened and a product, i.e., the angle sensor device140is removed from the lower mold162.

According to the production method of the angle sensor device140, i.e., a forming method for the molded resin152, insert molding of the foamed resin with the magnetic force detectors44is carried out in the condition that the inside surfaces of the computing units47of the magnetic force detectors44are supported by the support molds188of the mold160(FIG. 15). Therefore, it is able to prevent displacement of magnetic force detectors44caused by stress forced in the width direction of the computing units47of the magnetic force detectors44by flow of the foamed resin, thereby preventing decrease in positional accuracy of the magnetic force detectors44. In a result, it is able to prevent decrease in magnetic force detection ability of the angle sensor device40.

The support molds188supporting the computing units47of the magnetic force detectors44are retracted before the foamed resin injected into the cavity170in the mold160become hardened, so that the empty spaces190are formed (FIG. 17) and the foamed resin flows into the empty spaces190. Thus, the inside surfaces of the computing units47of the magnetic force detectors44, which had been supported by the support molds188, are covered with the resin, which is labeled with152a(FIG. 14).

In the step for injecting the foamed resin into the mold160, the foamed resin in melting condition is injected along the longitudinal direction of the computing units47of the magnetic force detectors44from the gates168departing from the sensing units45of the magnetic force detectors44(FIG. 15). Therefore, it is able to reduce stress applied to the sensing units45of the magnetic force detectors44and caused by flow of the foamed resin. In addition, the foamed resin is flowed along the longitudinal direction of the computing units47of the magnetic force detectors44, so that it is able to decrease stress applied to the computing units47of the magnetic force detectors44and caused by flow of the foamed resin in the through-thickness direction of the computing units47.

The foamed resin composed of resin material and foaming agent is used as material for the molded resin152. Thus, it is able to reduce flow pressure of the resin, thereby decreasing stress applied to the sensing units45and the computing units47of the magnetic force detectors44.

A fourth embodiment will be described.

FIG. 18is a cross sectional view of the mold, andFIG. 19is a cross sectional view showing the mold with retracted support molds.

As shown inFIG. 18, in this embodiment, the lead terminals148of the magnetic force detectors44in the third embodiment (FIG. 16) are straightened. Inner surfaces of the ends of the lead terminals148are connected with the mounting terminals149by welding or the like. The base portion of each mounting terminals149has an inner surface flush with the inner surface of the computing unit47of the corresponding magnetic force detector44, which is connected with the mounting terminal149. The support molds188of the upper mold164in the lower position contact the inner surfaces of the computing units47of the magnetic force detectors44and the inner surfaces of the base portions of the mounting terminals149such that the support molds188support the inner surfaces of the computing units47of the magnetic force detectors44and those of the base portions of the mounting terminals149.

In this embodiment, insert molding is carried out in a condition that the mounting terminals149connected with the lead terminals148of the magnetic force detectors44are supported by the support molds188of the mold160(FIG. 18). Thus, it is able to improve positional accuracy of the mounting terminals149.

In addition, the retracted support molds188can support the inner surfaces of the base portions of the mounting terminals149except regions near the lead terminals148(FIG. 19). When the support molds188of the upper mold164are retracted, ends of the base portions of the mounting terminals149near the lead terminals148are exposed on surfaces defining the empty spaces190. Thus, when the foamed resin flows into the empty spaces190, connections between the lead terminals148of the magnetic force detectors44and the base portions of the mounting terminals149are covered with the foamed resin.

A fifth embodiment will be described.

FIG. 20is a cross sectional view of the mold.FIG. 21is a cross sectional view showing the mold with the retracted support molds.

As shown inFIGS. 20 and 21, in this embodiment, the base portions of the L-shaped mounting terminals149in the third embodiment (FIG. 16) are omitted, and the mounting terminals are formed in strip shape, which are labeled with symbol “192”. Thus, the lead terminals148of the magnetic force detectors44are formed in linear shape, and ends of the lead terminals148are bent outwardly in L-shape. A back surface (upper surface inFIG. 20) of the end of each lead terminal148is connected with a front surface (lower surface inFIG. 20) of each mounting terminal192by welding or the like.

A sixth embodiment will be described. This embodiment corresponds to the third embodiment further including additional modifications, so that the modifications will be described, and other configurations will not be described.FIG. 22is a cross sectional view of the mold.FIG. 23is a cross sectional view showing the mold with the retracted support molds.FIG. 24is a front view of the angle sensor device.FIG. 25is a cross sectional view of the angle sensor device.

As shown inFIG. 22, the mold160of this embodiment has the lower mold162of the mold160of the third embodiment (FIG. 17) further including a pair of second support molds194in square bar shape, which contact either side surfaces defining the mold cavity63, respectively. Hereafter, the support mold188is referred to as first support mold.

The second support molds194extend in an open-close direction of the mold160, i.e., vertical direction, and are constructed movably in the vertical direction. When the second support molds194are in upper position, end surfaces (upper end surfaces) of the second support molds194are positioned near the back ends of the computing units47of the magnetic force detectors44(FIG. 22). When the second support molds194are in lower position, the end surfaces of the second support molds194are positioned near the front sensing unit45(FIG. 23). The second support molds194are moved to the upper position at the start of molding, and then are retracted to the lower position after injection of the resin and before hardening of the resin.

In a condition that the mold160is closed (FIG. 22), the second support molds194of the lower mold162are positioned at the upper position, and inner surfaces of the second support molds194contact outer surfaces of the computing units47of the magnetic force detectors44. Thus, one side surface in the through-thickness direction of the computing unit47of each magnetic force detector44(in the horizontal direction inFIG. 22), i.e., the outside surface, is supported by each of the second support molds194.

As shown inFIG. 23, the second support molds194are retracted to the lower position after injection of the foamed resin into the cavity170and before hardening of the resin injected into the mold160. Empty spaces196are created due to retraction of the second support molds194, and the foamed resin flows into the empty spaces196. Therefore, the outside surfaces of the computing units47of the magnetic force detectors44, which had been supported by the second support molds194, are covered with the foamed resin (FIG. 25). InFIG. 25, parts of the foamed resin covering the outside surfaces of the computing units47of the magnetic force detectors44are labeled with symbol “152b”. In addition, after retraction of the second support molds194, grooves198are formed on either side of the front end of the molded resin152by the ends (upper ends) of the second support molds194(FIGS. 24 and 25).

According to the manufacture method of the angle sensor device140, i.e., the method for forming the molded resin152, the insert molding is carried out in the condition that both surfaces (the inside surfaces and the outside surfaces) in the through-thickness direction of the computing units47of the magnetic force detectors44are supported by the first support molds188and the second support molds194(FIG. 22). Thus, during insert molding of foamed resin with the magnetic force detectors44, it is able to prevent displacement of magnetic force detectors44caused by stress, which is induced by flow of the foamed resin in the through-thickness direction of the computing units47of the magnetic force detectors44.

The second support molds194supporting the computing units47of the magnetic force detectors44are retracted before hardening of the foamed resin injected into the cavity170in the mold160in order to create the empty spaces196(FIG. 23). Then, the foamed resin flows into the empty spaces196. Thus, the outside surfaces of the computing units47of the magnetic force detectors44, which had been supported by the second support molds194, can be covered with the resin152b(FIG. 25).

A seventh embodiment will be described.

FIG. 26is a cross sectional view of the mold.FIG. 27is a cross sectional view showing the mold with the retracted support molds.

As shown inFIGS. 26 and 27, in this embodiment, the lead terminals148of the magnetic force detectors44in the sixth embodiment (FIGS. 22 and 23) are changed in liner shape and ends of the lead terminals148are connected with the mounting terminals149by, for example, welding like the forth embodiment (FIGS. 18 and 19). Other configurations are same as those of the fourth embodiment and thus will not be explained.

An eighth embodiment will be described.

FIG. 28is a cross sectional view of the mold.FIG. 29is a cross sectional view showing the mold with the retracted support molds.

As shown inFIGS. 28 and 29, in this embodiment, the lead terminals148of the magnetic force detectors44in the sixth embodiment (FIGS. 22 and 23) are changed in linear shape and ends of the lead terminals148are bent outwardly in L-shape and are connected with the mounting terminals192in strip shape by, e.g., welding like fifth embodiment (FIGS. 20 and 21). Other configurations are same as those of the fifth embodiment and thus will not be explained.

This disclosure is not limited to the above-described embodiments and can be modified without departing from the scope of the invention. For example, the angle sensor devices40,140for detecting opening ratio of the throttle valve18of the throttle controller10are shown in the embodiments, however this disclosure can be applied to other angle sensor devices for detecting rotation angle of various rotatable members other than the throttle controller10. The electrically controlled throttle controller10is shown in the embodiment, however this disclosure can be applied to a mechanical throttle controller where the throttle valve18is mechanically opened and closed based on an angle of accelerator pedal via link, cable, etc. Though the sensor IC is used for the magnetic force detector44, hall element, hall IC or the like can be used for the magnetic force detector. Though each of the magnetic force detectors44of the embodiments detects rotation angle of the throttle gear22depending on direction of magnetic field between the pair of permanent magnets41, a device detecting rotation angle of the throttle gear22depending on strength of the magnetic field between the pair of permanent magnets41can be used. Though the magnetic force detectors44each having the sensing unit45and the computing unit47are used in the embodiment, a magnetic force detector having a module in which the sensing unit45and the computing unit47are integrated or a magnetic force detector having only the sensing unit45can be used. The pair of the magnetic force detectors44is used in the embodiments, however only one magnetic force detector44can be used. The resin for the molded resin52,152is not limited to foamed resin. The projection65,165of the upper mold64,164of the mold60,160can be provided with the first support molds188of the sixth embodiment (FIG. 22) fixedly, or can be integrated with support members substantially corresponding to the first support molds188.