JP7798566B2 - Throttle device sensor unit - Google Patents

Description

The present invention relates to a sensor unit for a throttle device.

Some throttle device sensor units have a casing with a circuit board attached to the throttle device, and signals related to the intake air condition detected by various sensors are output to external equipment via this circuit board. For reasons of productivity, the casing is often manufactured by injection molding synthetic resin material, with the circuit board sometimes embedded within the casing as an insert. However, in this case, the circuit board can warp due to the heat and pressure of the molten resin. This warping can damage electronic components mounted on the circuit board or cause solder joints to peel off.

As a countermeasure, for example, Patent Document 1 discloses a technology that combines injection molding and mold filling to manufacture a casing. The sensor unit in Patent Document 1 uses injection molding to manufacture a casing with a recess. A circuit board is then placed in the recess, and a sealing resin is injected and hardened using mold filling to seal the circuit board. For injection molding, the temperature of the molten resin must be maintained at around 230°C, for example. In contrast, thermosetting resins used as sealing resins harden at lower temperatures, for example, around 120°C. Furthermore, injection molding requires that the molten resin be injected into the mold cavity at a specified pressure, while mold filling is carried out at atmospheric pressure or in a vacuum. This reduces the heat and pressure acting on the circuit board, preventing warping.

Japanese Patent Application Laid-Open No. 2021-113517

However, with the technology of Patent Document 1, after the casing is injection molded, the circuit board must be placed in the recess and sealed by filling the mold. As a result, while warping of the circuit board can be prevented, compared to insert-molding the circuit board, for example, the number of steps increases by the amount of mold filling, leaving room for improvement in terms of manufacturing costs.

The present invention was made to solve these problems, and its purpose is to provide a throttle device sensor unit that prevents warping of the circuit board caused by the heat and pressure of the molten resin when the casing is injection molded, while simplifying the manufacturing process and reducing manufacturing costs.

In order to achieve the above object, the throttle device sensor unit of the present invention is a throttle device sensor unit that is attached to a throttle device that adjusts the intake air of an engine, and comprises: a circuit board that is connected to a sensor that detects the state of the intake air flowing through the throttle bore of the throttle device and outputs a signal from the sensor to the outside; a casing made of a synthetic resin material in which the circuit board is embedded; a support member that is embedded in the casing together with the circuit board; and a plurality of displacement regulating portions that are integrally formed with the support member and abut against a plurality of dispersed positions on the circuit board to regulate positional displacement of the circuit board in the thickness direction , wherein the support member has a lattice shape made up of a plurality of beam-shaped connecting portions, and the plurality of displacement regulating portions are provided at positions corresponding to the intersections of each connecting portion of the support member and protrude from the support member, spacing the support member from above the circuit board .

In another aspect, the circuit board may have terminals that form a connector that is connected to a device to which a signal from the sensor is output, and the support member may be integrally formed with a displacement regulating portion that abuts against the terminal.

In another aspect, the support member may be integrally formed with a displacement restriction portion that abuts against the sensor.

In another embodiment, the support member may be integrally formed with a housing section that houses electronic components mounted on the circuit board and isolates them from the outside.

In another embodiment, the support member may be made of a synthetic resin material that has higher heat resistance and rigidity than the material of the circuit board.

The throttle device sensor unit of the present invention prevents warping of the circuit board caused by the heat and pressure of the molten resin when the casing is injection molded, while simplifying the manufacturing process and reducing manufacturing costs.

1 is a perspective view showing a state in which a sensor unit according to an embodiment is attached to a throttle device; FIG. 2 is an exploded perspective view showing a state in which the sensor unit is removed from the throttle device. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1 . FIG. 2 is a perspective view showing a single sensor unit. FIG. 5 is a perspective view showing the sensor unit in FIG. 4 with the casing omitted. FIG. 5 is an exploded perspective view corresponding to FIG. 4, illustrating the relationship between the circuit board and left and right support members. FIG. 7 is an exploded perspective view seen from a different direction than FIG. 6 . FIG. 10 is a view showing a circuit board and a left support member. FIG. 9 is a cross-sectional perspective view taken along line IX-IX of FIG. 8. FIG. 9 is a cross-sectional perspective view taken along line X-X of FIG. 8. FIG. 10 is a cross-sectional perspective view taken along line XI-XI of FIG. 8. FIG. 12 is a cross-sectional perspective view taken along line XII-XII of FIG. 8. FIG. 13 is a cross-sectional perspective view taken along line XIII-XIII in FIG. 8 . FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 8. FIG. 8 is an exploded perspective view corresponding to FIG. 7 and showing another example of a sensor unit provided with a card edge connector. FIG. 15 is a cross-sectional view corresponding to FIG. 14 and showing a sensor unit of another example.

Hereinafter, an embodiment of a sensor unit for a throttle device embodying the present invention will be described.
FIG. 1 is a perspective view showing the sensor unit of this embodiment attached to a throttle device, FIG. 2 is an exploded perspective view showing the sensor unit removed from the throttle device, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1.

Throttle device
The throttle device 1 of this embodiment is mounted on a single-cylinder engine that is mounted on a motorized bicycle as a power source for driving the bicycle. First, the configuration of the throttle device 1 will be described.
A single throttle bore 2a is formed through the throttle body 2 of the throttle device 1, communicating with the interior of an engine cylinder (not shown). Intake air from an air cleaner (not shown) flows through the throttle bore 2a and is supplied to the engine cylinder. A throttle valve 3 is supported within the throttle bore 2a so as to be openable and closable by a throttle shaft 4, one end of which is attached to a wire drum 5. A throttle grip (not shown) of the vehicle is connected to the wire drum 5 via a throttle wire. In conjunction with operation of the throttle grip, the throttle shaft 4 rotates together with the wire drum 5 against the biasing force of a return spring 6 to open or close the throttle valve 3, thereby adjusting the amount of intake air into the engine. Reference numeral 7 in FIG. 3 denotes an idle speed control valve (ISCV) that controls the idle speed of the engine.

For ease of explanation, the axial direction along the throttle shaft 4 shown in Figure 1 will be referred to as the left-right direction, the direction in which intake air flows along the throttle bore 2a will be referred to as the front-rear direction, and the direction perpendicular to these will be referred to as the up-down direction.

The left side of the throttle shaft 4 protrudes from the throttle body 2, and the excitation conductor 8a of the inductive throttle opening sensor 8 is fixed to its end. A circular recess 2b is formed on the left side of the throttle body 2, opening to the left with the throttle shaft 4 as its center, and a mounting surface 2c is formed around the circular recess 2b.

Circuit board
Next, the configuration of the sensor unit will be described. Fig. 4 is a perspective view showing a single sensor unit, Fig. 5 is a perspective view showing the sensor unit from Fig. 4 with the casing omitted, Fig. 6 is an exploded perspective view corresponding to Fig. 4 showing the relationship between the circuit board and the first and second support members, and Fig. 7 is an exploded perspective view seen from a different direction than Fig. 6.

As shown in Figures 2, 4-7, the casing 11 of the sensor unit 10 is injection molded from a synthetic resin material. During injection molding, left and right support members 15, 16 to prevent warping of the circuit board 12 are embedded in the casing 11 as inserts, along with the circuit board 12 and each of the sensors 8, 13, 14. In this embodiment, the casing 11 is molded into the desired shape through a single injection molding process. The left support member 15 corresponds to the "second support member" of the present invention, and the right support member 16 corresponds to the "first support member" of the present invention.

The circuit board 12 is disposed facing left and right, with wiring patterns 12a formed on both sides. An IC 17 and various electronic components (not shown) are mounted on the left side of the circuit board 12, and the excitation conductor 8b and signal detection conductor 8c of the throttle opening sensor 8 are also formed thereon.

As shown in Figures 5 to 7, the base ends of two terminals 13b of the intake air temperature sensor 13 are soldered to the upper front side of the right side of the circuit board 12, and each terminal 13b extends to the right with a sensor body 13a attached to its tip. Furthermore, three terminals 14b of the sensor body 14a of the intake air pressure sensor 14 are soldered to the upper rear side of the right side of the circuit board 12, and a pressure case 14c is attached to the sensor body 14a.

Five terminals 18 are arranged in a vertical row at the front edge of the circuit board 12, with their base ends soldered to each other and connected to the wiring pattern on the circuit board 12. Each terminal 18 is bent at a right angle and extends forward, and is inserted into a binding member 19 made of synthetic resin, maintaining a predetermined spacing between them.

<<Casing 11 of Sensor Unit 10>>
The circuit board 12 described above is used as an insert part in the injection molding of the casing 11 of the sensor unit 10, and the casing 11 is then attached to the throttle device 1. As shown in FIGS. 2 and 4, a circular cylindrical portion 11a is integrally formed on the right side of the casing 11, and a mounting surface 11b is formed around the circular cylindrical portion 11a. A pair of bolt holes 11c are formed through the casing 11, and the casing 11 is fastened to the throttle body 2 by bolts 20 inserted through these bolt holes 11c. When the casing 11 is attached in this state, as shown in FIG. 3, the circular cylindrical portion 11a of the casing 11 fits into the circular recess 2b of the throttle body 2, and the mounting surface 11b of the casing 11 overlaps the mounting surface 2c of the throttle body 2. The excitation conductor 8a of the throttle shaft 4 is disposed within the circular cylindrical portion 11a and faces the excitation conductor 8b and signal detection conductor 8c on the circuit board 12.

The detection principle of the inductive throttle opening sensor 8 is well known, so we will not explain it in detail, but when a magnetic field is generated in the excitation conductor 8b, an eddy current flows in the excitation conductor 8a in response. When the excitation conductor 8a rotates together with the throttle shaft 4, the inductance of the excitation conductor 8b changes due to mutual induction, which is detected by the signal detection conductor 8c and converted by the IC 17 into a signal that correlates with the throttle opening.

As shown in Figures 4 and 5, a detector 11d extending to the right is integrally formed with the casing 11, and an intake air temperature sensor 13 is embedded inside this detector 11d. When the casing 11 is attached to the throttle body 2, the tip of the detector 11d is exposed inside the throttle bore 2a, and the intake air temperature is detected by the intake air temperature sensor 13.

As shown in Figures 4 and 5, a communication chamber 11e is formed in the mounting surface 11b of the casing 11, and the pressure case 14c of the intake pressure sensor 14 is exposed within the communication chamber 11e. When the casing 11 is attached to the throttle body 2, the communication chamber 11e communicates with the throttle bore 2a via a communication passage (not shown) formed in the throttle body 2, and the intake pressure acts on the pressure case 14c via the communication passage and communication chamber 11e and is detected by the sensor main body 14a.

As shown in Figures 4 and 5, the casing 11 has a connector tubular portion 21a that opens forward. The terminals 18 are arranged inside this connector tubular portion 21a, thereby forming the connector 21.

<<Support members 15, 16>>
6 and 7, a right support member 16 is disposed on the right side of the circuit board 12, and a left support member 15 is disposed on the left side. Each support member 15, 16 is made of, for example, a synthetic resin material that is more heat-resistant and rigid than the material of the circuit board 12, and is designed to maintain its intended shape without deformation even when subjected to the heat and pressure of the molten resin when it is insert-molded into the casing 11. As shown in FIG. 5, the circuit board 12 is insert-molded while sandwiched between these support members 15, 16 and embedded in the casing 11.

<Right support member 16>
8 is a diagram showing the circuit board 12 and the left support member 15, FIG. 9 is a sectional perspective view taken along line IX-IX in FIG. 8, FIG. 10 is a sectional perspective view taken along line XX in FIG. 8, FIG. 11 is a sectional perspective view taken along line XI-XI in FIG. 8, FIG. 12 is a sectional perspective view taken along line XII-XII in FIG. 8, FIG. 13 is a sectional perspective view taken along line XIII-XIII in FIG. 8, and FIG. 14 is a sectional view taken along line XIV-XIV in FIG. 8.

As shown in Figures 6, 7, and 14, the right support member 16 consists of a rectangular plate-shaped base portion 16a, a board pressing portion 16b integrally formed on the rear side of the base portion 16a, and a terminal pressing portion 16c integrally formed on the front side of the base portion 16a.

The base portion 16a is arranged to face forward and backward, and four displacement restriction pins 16d protrude from its left end at intervals.

The board retainer 16b extends rearward from the left end of the base 16a and has an arch shape that follows the periphery of the circuit board 12. Five displacement restriction pins 16e protrude from the left side of the board retainer 16b at intervals.

The displacement restriction pins 16d, 16e of the base portion 16a and the board retainer portion 16b are positioned to avoid electronic components mounted on the right side of the circuit board 12, and their tips abut against multiple dispersed locations on the right side. The right side of the circuit board 12 corresponds to "one side of the circuit board" in this invention.

As shown in Figures 5 and 14, each displacement restriction pin 16d, 16e protrudes from the base portion 16a or the board retaining portion 16b, so that only its tip abuts on the circuit board 12, and the base portion 16a and the board retaining portion 16b themselves are spaced apart from the circuit board 12, forming a gap.

On the other hand, as shown in Figure 9, the terminal pressing portion 16c extends forward from the right end of the base portion 16a, and five displacement restriction pins 16f protrude leftward from its front end, with their tips abutting against the respective terminals 18 on the circuit board 12.

Left support member 15
As shown in Figures 6, 7, 8, and 14, the left support member 15 consists of a lattice-shaped board pressing portion 15a, an IC accommodating portion 15b integrally formed approximately in the center of the board pressing portion 15a, a sensor pressing portion 15c integrally formed diagonally above the rear side of the board pressing portion 15a, and a terminal pressing portion 15d integrally formed on the front side of the board pressing portion 15a.

The board retainer 15a has numerous beam-shaped connecting portions 15e arranged vertically, horizontally, and diagonally, forming a grid pattern when viewed from the circuit board 12 side. A total of 21 displacement restriction pins 15f protrude from the right side of the board retainer 15a, located at intermediate positions between each connecting portion 15e or at positions corresponding to the intersections of three connecting portions 15e. Each displacement restriction pin 15f is positioned to avoid electronic components mounted on the left side of the circuit board 12, and each tip abuts against multiple dispersed locations on the left side. The left side of the circuit board 12 corresponds to the "other side of the circuit board" in this invention.

As shown in Figures 6 and 10 to 14, each displacement restriction pin 15f protrudes from the board retaining portion 15a, so only its tip abuts on the circuit board 12, and the board retaining portion 15a itself is spaced apart from the circuit board 12, forming a gap.

As shown in Figures 12 and 13, IC accommodating section 15b is disposed in correspondence with IC 17 on circuit board 12, is connected to connecting section 15e of board retaining section 15a located around it, and has a rectangular box shape that opens toward circuit board 12. The opening side of IC accommodating section 15b abuts against the circuit board 12, and IC 17 is accommodated inside and isolated from the outside. IC 17 corresponds to the "electronic component mounted on a circuit board" of this invention.

As shown in Figure 13, the sensor retainer 15c is disposed in a position corresponding to the intake pressure sensor 14 and has a lattice-like configuration made up of beam-shaped connecting portions 15g, with a contact surface 15h formed on its right side. The sensor retainer 15c faces the intake pressure sensor 14 at a position outside the outer periphery of the circuit board 12, with the contact surface 15h in contact with the sensor body 14a.

As shown in Figures 6, 7, and 9, five displacement restriction pins 15i protrude to the right from the terminal pressing portion 15d, with their tips abutting against the terminals 18 on the circuit board 12. The displacement restriction pins 15f, 15i, 16d, 16e, and 16f of the left and right support members 15 and 16, as well as the abutment surface 15h, correspond to the "displacement restriction portion" of the present invention.

As shown in Figures 7, 13, and 14, the displacement restriction pins 15f and 15i protrude leftward from the board retaining portion 15a or the terminal retaining portion 15d, i.e., on the side opposite the circuit board 12, and this protruding location serves as the mold abutment portion 15j. The mold abutment portion 15j also protrudes from the top surface of the IC accommodating portion 15b. As described below, when the left support member 15 is placed in a mold (not shown) during injection molding of the casing 11, the mold abutment portion 15j abuts and presses against the inner wall of the mold. Therefore, the board retaining portion 15a, the IC accommodating portion 15b, and the terminal retaining portion 15d are spaced apart from the inner wall of the mold, forming gaps.

The left and right support members 15, 16 are embedded in the casing 11 of the sensor unit 10 in the above-described positional relationship with the circuit board 12. The sensor unit 10 is mounted on the vehicle while attached to the throttle device 1, and a harness from the vehicle's ECU (engine control unit) is connected to its connector 21. The throttle opening, intake temperature, and intake pressure output from the sensor unit are input to the ECU, which controls the engine operating state based on this detected information. The throttle opening, intake temperature, and intake pressure correspond to the "state of intake air" in this invention, and the ECU corresponds to the "device to which the signal from the sensor is output" in this invention.

<<Injection molding procedure for the casing 11>>
Next, the procedure for injection molding the casing 11 will be described.
First, the wiring pattern 12a, the excitation conductor 8b, and the signal detection conductor 8c are formed on the circuit board 12, and then the IC 17, electronic components, the intake air temperature sensor 13, the intake pressure sensor 14, and the terminals 18 bound by the binding member 19 are mounted on the circuit board 12. In addition, the left and right support members 15, 16 are fabricated in advance by, for example, injection molding.

As shown in Figure 5, support members 15, 16 are positioned on both sides of the circuit board 12, and these members 12, 15, 16 are placed in an injection molding die and the die is closed. The inner wall of the right-side die abuts against the right side of the right support member 16, specifically the right side of the base portion 16a, the right side of the board pressing portion 16b, and the right side of the terminal pressing portion 16c, respectively, and presses it to the left. At the same time, the inner wall of the left-side die abuts against the left side of the left support member 15, specifically the die abutment portions 15j of the board pressing portion 15a, IC accommodating portion 15b, and terminal pressing portion 15d, respectively, and presses it to the right.

As a result, the circuit board 12 is tightly sandwiched between the displacement restriction pins 15f, 16d, and 16e of the left and right support members 15 and 16 within the mold cavity. In other words, the left and right support members 15 and 16 are pressed from the left and right by the mold to sandwich the circuit board 12, thereby positioning the entire circuit board 12 in the left-right direction. Furthermore, the displacement restriction pins 15f, 16d, and 16e of the support members 15 and 16 are dispersedly arranged on the circuit board 12. Therefore, left-right positional displacement of the circuit board 12 is restricted at multiple locations on the circuit board 12 where the displacement restriction pins 15f, 16d, and 16e come into contact. This left-right positional displacement corresponds to the "positional displacement in the thickness direction of the circuit board" in this invention.

The left support member 15 also has a protruding mold contact portion 15j. Therefore, when the left support member 15 is spaced apart from the inner wall of the mold, the mold contact portion 15j is pressed against the inner wall of the mold, sandwiching the circuit board 12 between the left support member 15 and the right support member 16.

At the same time, as shown in Figure 9, the terminals 18 are clamped by the displacement restriction pins 15i and 16f of the left and right support members 15 and 16. Also, as shown in Figure 13, the contact surface 15h of the sensor pressing portion 15c contacts the sensor body 14a of the intake pressure sensor 14, clamping the intake pressure sensor 14 between itself and the inner wall of the mold on the right side. This restricts the left-right positional displacement of the terminals 18 and the intake pressure sensor 14.

In this state, molten resin is injected into the mold cavity, where it cools and hardens to form the casing 11, completing the production of the sensor unit 10. The heat and pressure of the molten resin can act on the circuit board 12, causing it to warp. However, the circuit board 12 is sandwiched between left and right support members 15, 16, which are made of a synthetic resin material that is both highly heat-resistant and rigid. As a result, the left and right support members 15, 16 do not deform even when exposed to the heat and pressure of the molten resin, and continue to maintain their intended shape.

Therefore, the circuit board 12 is kept sandwiched between the left and right sides by the displacement restriction pins 15f, 16d, and 16e of the support members 15 and 16. As a result, the left-right positional displacement of the circuit board 12 is continuously restricted at the multiple locations on the circuit board 12 where the displacement restriction pins 15f, 16d, and 16e abut, preventing warping of the circuit board 12.

In addition, the support members 15, 16 arranged within the mold cavity serve to promote a temperature drop in the molten resin. In particular, the support member 15 in this embodiment is configured in a lattice pattern with numerous beam-shaped connecting portions 15e arranged vertically, horizontally, and diagonally, allowing a wide surface area to come into contact with the molten resin, quickly lowering its temperature, which is another factor that contributes to preventing warping of the circuit board 12. If the circuit board 12 warps, loads will be applied to the electronic components and their soldered joints on the circuit board 12, which can cause damage to the electronic components and peeling of the soldered joints, but this can prevent such situations from occurring.

Furthermore, as is clear from the above explanation, the sensor unit 10 can be manufactured by manufacturing the circuit board 12 and the left and right support members 15, 16, and then injection molding the casing 11 using these members 12, 15, 16 as inserts. This eliminates the need for mold molding after injection molding the casing, as in the technology of Patent Document 1, and simplifies the manufacturing process by the amount of mold filling, thereby reducing manufacturing costs.

Furthermore, the board retaining portion 15a of the left support member 15 is lattice-shaped, with numerous beam-like connecting portions 15e arranged vertically, horizontally, and diagonally, while the board retaining portion 16b of the right support member 16 is arch-shaped. Therefore, the molten resin injected into the mold cavity is not impeded by the support members 15 and 16, and passes through the respective board retaining portions 15a and 16b to spread throughout the cavity. As a result, a good, bubble-free casing 11 is formed, reliably protecting the circuit board 12, thereby preventing malfunctions and improving the reliability of the sensor unit 10.

In addition, the displacement restriction pins 15f, 16d, and 16e protruding from the support members 15 and 16 are abutted against the circuit board 12, separating the support members 15 and 16 from the circuit board 12. Therefore, the molten resin passes through the gap between the circuit board 12 and the support members 15 and 16 and spreads throughout the cavity, which also contributes to the formation of a good casing 11.

As shown in Figure 6, some of the displacement restriction pins 15f on the left support member 15 protrude from the intersections of three connecting portions 15e of the grid-shaped board retaining portion 15a, and have higher support rigidity than the displacement restriction pins 15f protruding from the middle positions of the connecting portions 15e. As a result, the cooperation of these displacement restriction pins 15f more firmly clamps the circuit board 12, reliably preventing warping.

Furthermore, terminal holders 15d and 16c are provided on the left and right support members 15 and 16, and their displacement restriction pins 15i and 16f clamp each terminal 18 on the circuit board 12 from the left and right. This allows each terminal 18 to be accurately positioned in the left-right direction, preventing poor contact with the connector 21. Furthermore, because the left and right support members 15 and 16 are originally used to prevent warping of the circuit board 12, the above effects can be achieved without increasing the number of parts in the sensor unit 10.

In addition, a sensor pressing portion 15c is provided on the left support member 15, and its contact surface 15h abuts against the sensor body 14a of the intake pressure sensor 14, sandwiching it between the inner wall of the right mold. This allows the intake pressure sensor 14 to be accurately positioned in the left-right direction, reliably preventing intake pressure leaks and the like. In this regard, too, by using the left and right support members 15, 16, the above effect can be achieved without increasing the number of parts.

Furthermore, the mold contact portion 15j protruding from the left support member 15 is brought into contact with the inner wall of the mold, thereby separating the left support member 15 from the inner wall of the mold. Therefore, as shown in FIG. 1, only the end face of the mold contact portion 15j is exposed to the outside on the left side of the casing 11 after injection molding. If the mold contact portion 15j were not formed, the entire left side of the left support member 15 would be exposed to the outside, which could result in a poor appearance; however, this also has the effect of preventing such a problem and improving the aesthetics of the sensor unit 10.

The left support member 15 also has an IC housing 15b, which houses the IC 17 on the circuit board 12 and isolates it from the outside. The IC 17 is an important component that enables the throttle opening sensor 8 to function, but is particularly susceptible to heat and pressure among electronic components. Preventing molten resin from flowing into the IC housing 15b during injection molding reduces the heat and pressure acting on the IC 17. In this embodiment, a mold contact portion 15j is also protruding from the top surface of the IC housing 15b. This allows the inner wall of the mold to directly press the IC housing 15b against the circuit board 12, firmly adhering it to the interior, more reliably preventing molten resin from flowing inside. As a result, the IC 17 can operate normally and maintain good throttle opening detection functionality, which also contributes to improving the reliability of the sensor unit 10.

In this embodiment, the terminals 18 of the circuit board 12 are arranged inside the connector tubular portion 21a provided in the casing 11 to form the connector 21, but a card edge connector can also be used instead. This configuration will be described below as another example.

Other examples
15 is an exploded perspective view corresponding to FIG. 7, showing another example of a sensor unit provided with a card edge connector, and FIG. 16 is a cross-sectional view corresponding to FIG. 14, showing another example of a sensor unit.

The difference from the above embodiment is that the terminal 18 has been replaced with a card edge connector 31. Since the other configurations are the same as those of the above embodiment, the same component numbers will be used to designate the common components, and a description will be omitted, with the focus instead on the differences.

Compared to the embodiment, the circuit board 12 extends forward and protrudes into the connector tubular portion 21a of the casing 11. Five contacts 31a of the card edge connector 31 are arranged vertically on the front edge of the circuit board 12, and are each connected to the wiring pattern on the circuit board 12. The card edge connector 31 and the connector tubular portion 21a form the connector 21.

With the elimination of the terminal 18, the terminal pressing portions 15d and 16c of the left and right support members 15 and 16 have also been eliminated. However, the rest of the configuration is the same as in the embodiment, so a redundant description will not be given. However, it is possible to achieve the various effects described in the embodiment, such as preventing warping of the circuit board 12 and protecting the IC 17.

The present invention is not limited to this embodiment. For example, in the above embodiment, the sensor unit 10 was embodied in a throttle device 1 equipped with a single throttle bore 2a mounted on a motorized bicycle. However, the target vehicle and type of throttle device 1 are not limited to this, and the present invention may be applied to, for example, four-wheeled vehicles. Alternatively, the present invention may be applied to small two-wheeled vehicles such as scooters and mopeds, larger motorcycles, and saddle-ride vehicles such as ATVs (All Terrain Vehicles) such as four-wheeled buggies. The sensor unit of the present invention may also be applied to the throttle device of engines used for purposes other than as a power source for driving, such as generator engines. Furthermore, the present invention may be embodied as a sensor unit for a multiple throttle device equipped with multiple throttle bores.

In addition, in the above embodiment, the sensor unit 10 is embodied as including a throttle opening sensor 8, an intake air temperature sensor 13, and an intake air pressure sensor 14. However, it is not necessary to include all of the sensors 8, 13, and 14; for example, any of the sensors may be omitted depending on requirements from engine control, etc.

In addition, in the above embodiment, the support members 15, 16 are made of synthetic resin, but the material is not limited to this. For example, if measures are taken to prevent short circuits in the wiring patterns or electronic components on the circuit board 12, the support members 15, 16 may be made of a metal material such as aluminum.

In the above embodiment, the casing 11 is formed into the desired shape by a single injection molding process using the circuit board 12 and the left and right support members 15, 16 as insert parts. However, this is not limited to this. For example, the casing 11 may be divided into left and right halves at the circuit board 12, with the right half of the casing in FIG. 4 formed by an initial injection molding process, and the left half of the casing formed integrally with this right half by a subsequent injection molding process to achieve the desired shape of the casing 11. When forming the right casing, casing displacement restriction pins are provided on its left side as protruding portions corresponding to the displacement restriction pins 16d, 16e, and 16f of the right support member 16. During the subsequent injection molding process, the circuit board 12 and left support member 15 are placed in the mold as insert parts. The right casing corresponds to the "first casing" in this specification, the left casing corresponds to the "second casing" in this specification, and the casing displacement restriction pin corresponds to the "casing displacement restriction portion" in this specification.

When the mold is closed, the casing displacement restriction pin abuts against the right side of the circuit board 12, and the displacement restriction pins 15f, 15i of the left support member 15 abut against the left side of the circuit board 12, sandwiching the circuit board 12. In this state, molten resin is injected into the cavity to form the casing 11. This configuration also prevents warping of the circuit board 12, achieving the effects described in the above embodiment.

Comparing this alternative example with the above embodiment, the number of parts can be reduced because it is not necessary to manufacture the right support member 16. However, if the casing displacement restriction pin is deformed by the heat and pressure of the molten resin during the subsequent injection molding, it will no longer be possible to properly clamp the circuit board 12. For this reason, it is desirable to take measures such as using a synthetic resin material with high heat resistance and rigidity, like the support members 15 and 16, when injection molding the right casing.

REFERENCE SIGNS LIST 1 throttle device 2a throttle bore 8 throttle opening sensor 10 sensor unit 11 casing 12 circuit board 13 intake air temperature sensor 14 intake air pressure sensor 15 left support member (second support member)
15b IC storage section (storage section)
15f, 15i, 16d, 16e, 16f Displacement control pin (displacement control portion)
15g Connection part 15h Contact surface (displacement control part)
15j mold contact portion 16 right support member (first support member)
18 Terminal 21 Connector

Claims (5)

A throttle sensor unit attached to a throttle device that adjusts the intake air of an engine,
a circuit board connected to a sensor that detects the state of intake air flowing through a throttle bore of the throttle device and that outputs a signal from the sensor to an external device;
a casing made of a synthetic resin material in which the circuit board is embedded;
a support member embedded in the casing together with the circuit board;
a plurality of displacement restriction portions that are integrally formed with the support member and that come into contact with a plurality of dispersed portions on the circuit board, respectively, to restrict positional displacement of the circuit board in a thickness direction ;
Equipped with
The support member has a lattice shape formed by combining a plurality of beam-shaped connection portions,
The plurality of displacement regulating portions are provided at positions corresponding to the intersections of the connection portions of the support member, protrude from the support member, and space the support member from above the circuit board.
A sensor unit for a throttle device. the circuit board has a terminal that constitutes a connector that is connected to a device that is a destination of a signal from the sensor,
2. The sensor unit of the throttle device according to claim 1 , wherein the support member is integrally formed with a displacement restriction portion that abuts against the terminal. 3. The sensor unit of a throttle device according to claim 1 , wherein the support member is integrally formed with a displacement restriction portion that abuts against the sensor. A sensor unit for a throttle device as described in any one of claims 1 to 3 , characterized in that the support member is integrally formed with a housing portion that houses electronic components mounted on the circuit board inside and isolates them from the outside. 5. The sensor unit of a throttle device according to claim 1 , wherein the support member is made of a synthetic resin material that has higher heat resistance and rigidity than the material of the circuit board.