Throttle device sensor unit

Abstract

To provide a sensor unit of a throttle device capable of simplifying a manufacturing process and reducing manufacturing costs after preventing warpage of a circuit board caused by heat and pressure at the time of injection molding of a casing.SOLUTION: A sensor unit 10 of a throttle device 1 includes: a circuit board 12 that is connected to sensors 8, 13, 14 for detecting a state of intake air circulated within a throttle bore 2a of the throttle device 1 and outputs signals from the sensors 8, 13, 14 to the outside; a casing 11 manufactured by performing injection molding of a synthetic resin material with the circuit board 12 as an insert; support members 15, 16 embedded at the time of injection molding of the casing 11 as an insert along with the circuit board 12; and multiple displacement regulation parts 15f, 16d, 16e that are integrally formed with the support members 15, 16, abut on each of multiple parts dispersed on the circuit board 12, and regulate positional displacement in a thickness direction of the circuit board 12.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a sensor unit for a throttle device. [Background technology]

[0002] Some throttle device sensor units include a casing with a circuit board attached to the throttle device, which outputs signals related to the intake air condition detected by various sensors to an external device via the circuit board. For productivity reasons, the casing is often manufactured by injection molding synthetic resin, with the circuit board embedded in the casing as an insert. However, 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 soldered joints to peel off.

[0003] 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 manufactures a casing with a recess by injection molding, places a circuit board in the recess, and then seals the circuit board by injecting and hardening a sealing resin by mold filling. For injection molding, the temperature of the molten resin must be maintained at, for example, approximately 230°C. In contrast, thermosetting resins used as sealing resins harden at lower temperatures, for example, approximately 120°C. Furthermore, injection molding requires that the molten resin be injected into the mold cavity at a predetermined pressure. Meanwhile, mold filling is performed at atmospheric pressure or in a vacuum. This reduces the heat and pressure acting on the circuit board, preventing warping. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-113517 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 requires that after the casing is injection molded, the circuit board is placed in the recess and sealed by filling the mold. As a result, although warping of the circuit board can be prevented, compared to when the circuit board is insert molded, for example, the number of steps increases by the amount corresponding to filling the mold, leaving room for improvement in terms of manufacturing costs.

[0006] The present invention has been made to solve these problems, and its purpose is to provide a sensor unit for a throttle device that can prevent 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. [Means for solving the problem]

[0007] In order to achieve the above object, the sensor unit of the throttle device of the present invention is a sensor unit of the throttle device 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 support member that is integrally formed with the support member and that abuts against a plurality of dispersed positions on the circuit board, This restricts the positional displacement of the circuit board in the thickness direction. and a plurality of displacement regulating portions The support member has a lattice shape formed by combining a plurality of beam-like connection portions, and the plurality of displacement regulating portions are provided at positions corresponding to the intersections of the connection portions of the support member, protruding from the support member to space the support member from above the circuit board. It is characterized by:

[0013] In another embodiment, 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, and the support member abuts against the terminal. contact The displacement restricting portion may be integrally formed.

[0014] In another embodiment, the support member is in contact with the sensor. contactThe displacement restricting portion may be integrally formed.

[0015] In another embodiment, the support member may be integrally formed with a housing portion that houses electronic components mounted on the circuit board and isolates them from the outside.

[0016] 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. [Effects of the Invention]

[0019] The sensor unit for the throttle device of the present invention can prevent 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. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective view showing a state in which a sensor unit according to an embodiment is attached to a throttle device; [Figure 2] FIG. 2 is an exploded perspective view showing a state in which the sensor unit is removed from the throttle device. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a perspective view showing a single sensor unit. [Figure 5] FIG. 5 is a perspective view showing the sensor unit in FIG. 4 with the casing omitted. [Figure 6] 5 is an exploded perspective view corresponding to FIG. 4, illustrating the relationship between the circuit board and left and right support members. FIG. [Figure 7] FIG. 7 is an exploded perspective view seen from a different direction than FIG. 6. [Figure 8] FIG. 10 is a view showing a circuit board and a left support member. [Figure 9] FIG. 9 is a cross-sectional perspective view taken along line IX-IX in FIG. 8. [Figure 10] FIG. 9 is a cross-sectional perspective view taken along line XX in FIG. 8. [Figure 11]FIG. 10 is a cross-sectional perspective view taken along line XI-XI of FIG. 8. [Figure 12] FIG. 12 is a cross-sectional perspective view taken along line XII-XII in FIG. 8. [Figure 13] FIG. 13 is a cross-sectional perspective view taken along line XIII-XIII in FIG. 8. [Figure 14] FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 8. [Figure 15] FIG. 8 is an exploded perspective view corresponding to FIG. 7, showing another example of a sensor unit provided with a card edge connector. [Figure 16] FIG. 15 is a cross-sectional view corresponding to FIG. 14 and showing a sensor unit of another example. DETAILED DESCRIPTION OF THE INVENTION

[0021] 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.

[0022] Throttle device The throttle device 1 of this embodiment is attached to 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 interior of the engine cylinder. A throttle valve 3 is supported within the throttle bore 2a so that it can be opened and closed by a throttle shaft 4, one end of which is attached to a wire drum 5. A throttle grip of the vehicle is connected to the wire drum 5 via a throttle wire (not shown). In conjunction with the 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, opening and closing 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.

[0023] For ease of explanation, the axial direction along the throttle shaft 4 shown in FIG. 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.

[0024] The left side of the throttle shaft 4 protrudes from the throttle body 2, and an excitation conductor 8a of an 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 leftward with the throttle shaft 4 as its center, and a mounting surface 2c is formed around the circular recess 2b.

[0025] 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 without the casing, 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.

[0026] As shown in Figures 2, 4 to 7, the casing 11 of the sensor unit 10 is formed by injection molding a synthetic resin material. During the injection molding, left and right support members 15 and 16 for preventing warping of the circuit board 12 are embedded in the casing 11 as inserts, along with the circuit board 12 and the sensors 8, 13, and 14. In this embodiment, the casing 11 is molded into a desired shape by a single injection molding. 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.

[0027] The circuit board 12 is disposed facing left and right, and has wiring patterns 12a formed on both sides thereof. 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.

[0028] 5 to 7, the base ends of two terminals 13b of intake air temperature sensor 13 are soldered to the upper front side of the right side of circuit board 12, and each terminal 13b extends to the right with a sensor main body 13a attached to its tip. Also, three terminals 14b of sensor main body 14a of intake air pressure sensor 14 are soldered to the upper rear side of the right side of circuit board 12, and a pressure case 14c is attached to sensor main body 14a.

[0029] A total of five terminals 18 are arranged in a vertical row on the front edge of the circuit board 12, and the base ends of the terminals 18 are soldered to each other and connected to the wiring patterns 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 to keep the terminals at a predetermined interval.

[0030] 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 manner, 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.

[0031] The detection principle of the inductive throttle opening sensor 8 is well known and will not be explained 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, and this is detected by the signal detection conductor 8c and converted by the IC 17 into a signal that correlates with the throttle opening.

[0032] 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.

[0033] 4 and 5, a communication chamber 11e is formed in the mounting surface 11b of the casing 11, and a 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 inside of the throttle bore 2a via a communication passage (not shown) formed in the throttle body 2, and the intake pressure acts on the inside of the pressure case 14c via the communication passage and the communication chamber 11e and is detected by the sensor main body 14a.

[0034] 4 and 5, a connector tubular portion 21a is formed to open toward the front of the casing 11. The terminals 18 are disposed inside the connector tubular portion 21a, thereby forming the connector 21.

[0035] <<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.

[0036] <Right support member 16> 8 is a diagram showing the circuit board 12 and the left support member 15, FIG. 9 is a cross-sectional perspective view taken along line IX-IX in FIG. 8, FIG. 10 is a cross-sectional perspective view taken along line XX in FIG. 8, FIG. 11 is a cross-sectional perspective view taken along line XI-XI in FIG. 8, FIG. 12 is a cross-sectional perspective view taken along line XII-XII in FIG. 8, FIG. 13 is a cross-sectional perspective view taken along line XIII-XIII in FIG. 8, and FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 8.

[0037] 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.

[0038] The base portion 16a is disposed so as to face forward and backward, and four displacement restriction pins 16d are provided at intervals on the left end thereof.

[0039] The board retaining portion 16b extends rearward from the left end of the base portion 16a and has an arch shape that fits around the periphery of the circuit board 12. Five displacement restriction pins 16e are provided at intervals on the left side surface of the board retaining portion 16b.

[0040] The displacement restriction pins 16d, 16e of the base portion 16a and the board pressing portion 16b are disposed at positions that avoid electronic components mounted on the right side surface of the circuit board 12, and their tips abut against multiple dispersed locations on the right side surface. The right side surface of the circuit board 12 corresponds to "one side of the circuit board" in the present invention.

[0041] As shown in Figures 5 and 14, each displacement control pin 16d, 16e protrudes from the base portion 16a or the board holding portion 16b, so that only its tip abuts on the circuit board 12, and the base portion 16a and the board holding portion 16b themselves are spaced apart from the circuit board 12 to form a gap.

[0042] 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 control pins 16f protrude from its front end toward the left, with their tips abutting each terminal 18 of the circuit board 12.

[0043] 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.

[0044] The board retainer 15a has numerous beam-shaped connecting portions 15e arranged vertically, horizontally, and diagonally to form 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 at intermediate positions between the connecting portions 15e or at positions corresponding to the intersections of three connecting portions 15e. Each displacement restriction pin 15f is disposed at a position that avoids 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.

[0045] As shown in Figures 6, 10 to 14, each displacement control pin 15f protrudes from the board holding portion 15a, so that only its tip abuts on the circuit board 12, and the board holding portion 15a itself is spaced apart from the circuit board 12 to form a gap.

[0046] 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 the periphery, 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 the present invention.

[0047] 13, sensor pressing portion 15c is disposed at a position corresponding to intake air pressure sensor 14, and is formed in a lattice shape with beam-like connecting portions 15g combined together, with a contact surface 15h formed on the right side thereof. Sensor pressing portion 15c faces intake air pressure sensor 14 at a position off the outer periphery of circuit board 12, and contact surface 15h is in contact with sensor main body 14a.

[0048] 6, 7 and 9, five displacement restriction pins 15i are provided on the terminal pressing portion 15d so as to protrude toward the right, with the tip of each pin abutting against a corresponding terminal 18 of the circuit board 12. The displacement restriction pins 15f, 15i, 16d, 16e and 16f of the left and right support members 15 and 16 and the abutment surface 15h correspond to the "displacement restriction portion" of the present invention.

[0049] 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 these protruding portions serve as mold contact portions 15j. The mold contact portions 15j also protrude 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 contact portions 15j abut against and press 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.

[0050] 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 ECU (engine control unit) mounted on the vehicle is connected to its connector 21. The throttle opening, intake temperature, and intake pressure output from the sensor unit are input to the ECU, and the ECU controls the operating state of the engine 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.

[0051] <<Casing 11 injection molding procedure>> 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. Also, the left and right support members 15, 16 are fabricated in advance by, for example, injection molding.

[0052] As shown in Figure 5, support members 15 and 16 are positioned on both sides of circuit board 12, and these members 12, 15, and 16 are placed in an injection molding die, which is then closed. The inner wall of the right-side die abuts against the right side of right support member 16, specifically the right side of base portion 16a, the right side of board pressing portion 16b, and the right side of terminal pressing portion 16c, respectively, and presses it leftward. At the same time, the inner wall of the left-side die abuts against the left side of left support member 15, specifically the die abutment portions 15j of board pressing portion 15a, IC accommodating portion 15b, and terminal pressing portion 15d, respectively, and presses it rightward.

[0053] 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 in 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, the left-right positional displacement of the circuit board 12 is restricted at each of the 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" of the present invention.

[0054] Furthermore, a mold contact portion 15j is protruded from the left support member 15. 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, and the circuit board 12 is sandwiched between the left support member 15 and the right support member 16.

[0055] At the same time, as shown in Fig. 9, the terminals 18 are clamped by the displacement restriction pins 15i, 16f of the left and right support members 15, 16. Also, as shown in Fig. 13, the contact surface 15h of the sensor pressing portion 15c comes into contact with the sensor body 14a of the intake pressure sensor 14, clamping the intake pressure sensor 14 between itself and the inner wall of the right mold. This restricts the positional displacement of the terminals 18 and the intake pressure sensor 14 in the left-right direction.

[0056] 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 act on the circuit board 12 and can cause 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. Therefore, the left and right support members 15, 16 do not deform even when subjected to the heat and pressure of the molten resin, and continue to maintain their intended shape.

[0057] Therefore, the circuit board 12 is kept sandwiched from the left and right by the displacement restriction pins 15f, 16d, and 16e of the support members 15 and 16. As a result, the positional displacement of the circuit board 12 in the left-right direction is continuously restricted at the multiple locations on the circuit board 12 where the displacement restriction pins 15f, 16d, and 16e abut, and warping of the circuit board 12 can be prevented.

[0058] In addition, the support members 15, 16 disposed within the mold cavity play a role in promoting the temperature reduction of the molten resin. In particular, the support member 15 of this embodiment has a lattice pattern in which numerous beam-like connecting portions 15e are combined vertically, horizontally, and diagonally, allowing a wide surface area to come into contact with the molten resin, thereby quickly reducing its temperature, which is also one of the factors that contribute 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 or peeling of the soldered joints, but this can prevent such situations from occurring.

[0059] 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 to perform mold molding after injection molding of 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.

[0060] Furthermore, the board retaining portion 15a of the left support member 15 is formed in a lattice pattern 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. As a result, the molten resin injected into the cavity of the mold is not obstructed by the support members 15 and 16, and passes through the board retaining portions 15a and 16b to fill the cavity. As a result, a good casing 11 is formed without any air bubbles, which reliably protects the circuit board 12 and ultimately prevents malfunctions and improves the reliability of the sensor unit 10.

[0061] In addition, displacement restriction pins 15f, 16d, and 16e protruding from support members 15 and 16 are brought into contact with circuit board 12, thereby separating support members 15 and 16 from circuit board 12. Therefore, the molten resin passes through between circuit board 12 and support members 15 and 16 and spreads throughout the cavity, which also contributes to the formation of a good casing 11.

[0062] 6, some of the displacement restriction pins 15f of the left support member 15 protrude from the intersections of three connecting portions 15e of the lattice-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 holds the circuit board 12, making it possible to reliably prevent warping.

[0063] Furthermore, terminal pressing portions 15d, 16c are provided on the left and right support members 15, 16, and displacement restriction pins 15i, 16f thereof clamp each terminal 18 of 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 and the like of the connector 21. Furthermore, because the left and right support members 15, 16 are used, which were originally intended to prevent warping of the circuit board 12, the above effect can be achieved without increasing the number of parts in the sensor unit 10.

[0064] Furthermore, a sensor pressing portion 15c is provided on the left support member 15, and its contact surface 15h is brought into contact with the sensor body 14a of the intake pressure sensor 14, sandwiching it between the sensor body 14a and 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 leakage of intake pressure, etc. 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.

[0065] Furthermore, the left support member 15 is spaced from the inner wall of the mold by abutting the mold contact portion 15j protruding from the left support member 15 against 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 surface of the casing 11 after injection molding. If the mold contact portion 15j were not formed, the entire left side surface 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 aesthetic appearance of the sensor unit 10.

[0066] The left support member 15 also has an IC accommodating portion 15b, which accommodates the IC 17 on the circuit board 12 and isolates it from the outside. The IC 17 is an important component for enabling the throttle opening sensor 8 to function, but it is particularly susceptible to heat and pressure among electronic components. Preventing molten resin from flowing into the IC accommodating portion 15b during injection molding reduces the heat and pressure acting on the IC 17. In this embodiment, a mold contact portion 15j is also provided on the top surface of the IC accommodating portion 15b. This allows the IC accommodating portion 15b to be directly pressed by the inner wall of the mold, adhering tightly to the circuit board 12 and more reliably preventing molten resin from flowing inside. As a result, the IC 17 can operate normally and maintain good throttle opening detection function, which also contributes to improving the reliability of the sensor unit 10.

[0067] In this embodiment, the terminals 18 of the circuit board 12 are disposed inside the cylindrical connector portion 21a of the casing 11 to form the connector 21, but a card edge connector may also be used instead. Another example of such a configuration will be described below.

[0068] 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.

[0069] 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 embodiment, the common configurations will be given the same component numbers and explanations will be omitted, and the differences will be described in detail.

[0070] The circuit board 12 is extended forward compared to that of the embodiment and protrudes into the connector tubular portion 21a of the casing 11. A total of five contacts 31a of the card edge connector 31 are vertically aligned on the front edge of the circuit board 12, and are each connected to a wiring pattern on the circuit board 12. The connector 21 is configured by this card edge connector 31 and connector tubular portion 21a.

[0071] The terminal pressing portions 15d, 16c of the left and right support members 15, 16 have also been eliminated in conjunction with the elimination of the terminal 18. However, since the other configurations are the same as those of the embodiment, a redundant description will not be given, but the various operational effects described in the embodiment, such as prevention of warping of the circuit board 12 and protection of the IC 17, can be achieved.

[0072] The present invention is not limited to this embodiment. For example, in the above embodiment, the sensor unit 10 is embodied in a throttle device 1 having a single throttle bore 2a mounted on a motorized bicycle. However, the type of vehicle and throttle device 1 to be used is not limited to this. For example, the present invention may be applied to a four-wheeled vehicle. Alternatively, the present invention may be applied to a saddle-ride vehicle such as a small two-wheeled vehicle, such as a scooter or moped, a larger motorcycle, or an ATV (All Terrain Vehicle) such as a four-wheeled buggy. Furthermore, the sensor unit of the present invention may be applied to a throttle device of an engine used for purposes other than a power source for driving, such as a generator engine. Furthermore, the present invention may be embodied as a sensor unit for a multiple throttle device having multiple throttle bores.

[0073] In addition, in the above embodiment, the sensor unit 10 is embodied as including the throttle opening sensor 8, the intake air temperature sensor 13, and the intake air pressure sensor 14, but it is not necessarily necessary to include all of the sensors 8, 13, and 14, and any of the sensors may be omitted, for example, depending on requirements from engine control, etc.

[0074] In the above embodiment, the support members 15 and 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 and 16 may be made of a metal material such as aluminum.

[0075] In the above embodiment, the casing 11 is molded 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 limiting. For example, the casing 11 may be divided into left and right halves at the circuit board 12 as a boundary, and the right half of the casing in FIG. 4 may be formed by a preceding injection molding process. The left half of the casing may then be integrally molded with the right half to form the desired shape of the casing 11. When forming the right casing, casing displacement restriction pins may be provided on its left side surface 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 pins correspond to the "casing displacement restriction portion" in this specification.

[0076] When the mold is closed, the casing-side displacement restriction pin abuts against the right side surface of the circuit board 12, and the displacement restriction pins 15f, 15i of the left support member 15 abut against the left side surface of the circuit board 12, sandwiching the circuit board 12, and in this state, molten resin is injected into the cavity to form the casing 11. With the above-mentioned configuration, warping of the circuit board 12 can be prevented, and the effects described in the above embodiment can be achieved.

[0077] 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. [Explanation of symbols]

[0078] 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 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 part) 15g connection 15h Contact surface (displacement control part) 15j Mold contact part 16 Right support member (first support member) 18 terminals 21 Connector

Claims

1. 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.

2. 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, The support member is integrally formed with a displacement restriction portion that abuts against the terminal.

2. The sensor unit for a throttle device according to claim 1.

3. The support member is integrally formed with a displacement restriction portion that contacts the sensor.

3. The sensor unit for a throttle device according to claim 1 or 2.

4. The support member is integrally formed with a housing portion that houses electronic components mounted on the circuit board and isolates them from the outside.

4. The sensor unit for a throttle device according to claim 1, wherein the sensor unit is a sensor for a throttle device.

5. The support member is made of a synthetic resin material that has higher heat resistance and rigidity than the material of the circuit board.

5. The sensor unit for a throttle device according to claim 1.

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