Throttle device

Abstract

To provide a throttle device which can achieve improvement of moldability, reduction of costs, improvement of flexibility of equipment, downsizing and the like, and can detect a temperature of intake air with high accuracy.SOLUTION: A throttle device includes: a throttle body 10 having a main passage 12 through which intake air passes, an attachment surface 16 formed at an outer wall, and a communication passage 17 which is open on the attachment surface and leads to the main passage; a throttle valve 30 which opens or closes the main passage; and a sensor unit U joined to the attachment surface. The sensor unit U includes: a housing 60 having a joint surface 61 which is joined to the attachment surface, and a sensor housing recessed part 62 recessed from the joint surface and leading to the communication passage; a circuit board 70 buried in the housing; and a temperature sensor 80 which is electrically connected with the circuit board and disposed protruding in the sensor housing recessed part 62.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a throttle device that is applied to an intake system of an internal combustion engine mounted on a motorcycle or the like and that is equipped with a temperature sensor for detecting the temperature of intake air. [Background technology]

[0002] In conventional intake systems of motorcycles and the like, a known sensor unit attached to a throttle body includes a unit housing having a joint surface that is joined to the mounting surface of the throttle body and a hollow cylindrical body that protrudes from the joint surface, a circuit board embedded in the unit housing, a temperature detection element such as a thermistor that is connected to the circuit board and located inside the cylindrical body, and a sealing resin that is embedded so as to cover the circuit board from the outside (see, for example, Patent Document 1 and Patent Document 2).

[0003] However, in the above-mentioned sensor unit, the cylindrical body that houses the intake air temperature sensor is formed to protrude from the joint surface of the unit housing, so the cylindrical body must be handled carefully to avoid colliding with other objects, which results in the sensor unit as a whole becoming larger. Furthermore, because the cylindrical body is positioned so as to protrude into the intake passage of the throttle body, it increases intake resistance and reduces the degree of freedom in installing the throttle body. Furthermore, because the cylindrical body is integrally formed with the unit housing, molding the unit housing from a resin material results in the need for a complex mold, reduced moldability, and increased costs. Furthermore, if the cylindrical body is thick, the resin material between the intake air temperature sensor and the intake air makes it difficult to detect the intake air temperature with high accuracy.

[0004] Also, a known throttle device equipped with an intake air temperature sensor that detects the temperature of intake air includes a throttle body that defines an intake passage and a throttle valve that opens and closes the intake passage, the throttle body having a bypass passage that bypasses the throttle valve and an attachment hole that opens to the outside midway through the bypass passage, and the intake air temperature sensor being composed of a cylindrical body that is inserted into the attachment hole of the throttle body and a temperature detection element arranged inside the cylindrical body (see, for example, Patent Document 3).

[0005] However, in the above-mentioned throttle device, the intake air temperature sensor is placed inside a passage formed in the throttle body, which reduces the degree of freedom in terms of installation on the throttle body.Furthermore, if a sensor other than the intake air temperature sensor (for example, a pressure sensor) is placed, the degree of freedom in terms of installation is further reduced and handling becomes more complicated. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-20251 [Patent Document 2] Patent No. 3914128 [Patent Document 3] Japanese Utility Model Application Publication No. 5-17138 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a throttle device that can detect the temperature of intake air with high accuracy, while improving moldability, reducing costs, increasing flexibility in installation, and making it more compact. [Means for solving the problem]

[0008] The throttle device of the present invention comprises a throttle body having a main passage for passing intake air, a mounting surface formed on the outer wall, and a communication passage that opens to the mounting surface and leads to the main passage, a throttle valve that opens and closes the main passage, and a sensor unit joined to the mounting surface. The sensor unit has a joining surface that is joined to the mounting surface and a recessed portion that is recessed from the joining surface and that opens to the communication passage. Through the main passage The temperature sensor includes a housing having a sensor accommodating recess communicating with the housing, a circuit board embedded in the housing, and a temperature sensor electrically connected to the circuit board and positioned to protrude within the sensor accommodating recess.

[0009] In the above throttle device, the main passage may be formed in the shape of a cone whose passage area increases from a region where the throttle valve is disposed toward the upstream side.

[0010] In the above throttle device, the communication passage may be configured to communicate the main passage with the sensor accommodating recess on the upstream side of the throttle valve.

[0011] In the throttle device, the sensor accommodating recess may be formed in the shape of a long groove extending along the extension direction of the main passage.

[0012] In the throttle device, the temperature sensor may include a temperature sensing element that is exposed and disposed within the sensor accommodating recess.

[0013] In the above throttle device, the connecting passage may include an intake air introduction passage that introduces intake air from the main passage to the sensor accommodating recess upstream of the throttle valve, and an intake air discharge passage that discharges intake air from the sensor accommodating recess to the main passage downstream of the inlet of the intake air introduction passage.

[0014] In the above throttle device, the throttle body may have a guide wall near an inlet of the intake air introduction passage that guides the intake air flowing through the main passage toward the intake air introduction passage.

[0015] In the above throttle device, the guide wall may be formed by removing part of the inner wall surface of the main passage so as to allow the intake air flowing through the main passage to collide with the guide wall.

[0016] In the above throttle device, a configuration may be adopted in which the outlet port of the intake air outlet passage opens into the main passage immediately upstream of the throttle valve.

[0017] The above throttle device may also employ a configuration that includes a bypass passage that branches off from the main passage, introduces intake air, and discharges the intake air into the main passage while bypassing the throttle valve, and an adjustment valve that adjusts the passage area of ​​the bypass passage, wherein the intake discharge passage communicates with the bypass passage upstream of the adjustment valve, and the discharge outlet of the bypass passage also serves as the discharge outlet of the intake discharge passage.

[0018] The throttle device may include a bypass passage that branches off from the main passage to introduce intake air and lead it to the main passage, bypassing the throttle valve, and an adjustment valve that adjusts the passage area of ​​the bypass passage, and the intake air introduction passage, the sensor accommodating recess, and the intake air lead-out passage may also serve as the bypass passage.

[0019] The above throttle device may include a bypass passage that branches off from the main passage to introduce intake air and lead it to the main passage, bypassing the throttle valve; an adjustment valve that adjusts the passage area of ​​the bypass passage; and a second intake discharge passage that opens into the main passage downstream of the inlet of the intake passage and immediately upstream of the throttle valve and leads the intake air from the sensor accommodating recess to the main passage, wherein the intake introduction passage, the sensor accommodating recess, and the intake discharge passage also serve as the bypass passage.

[0020] In the above throttle device, the throttle body may include a second communication passage that opens to the mounting surface and leads to the main passage, and the sensor unit may include the housing having a second sensor accommodating recess that is recessed from the joint surface and leads to the second communication passage, and a pressure sensor that is electrically connected to the circuit board and is disposed in the second sensor accommodating recess and detects the pressure of the intake air flowing through the main passage.

[0021] In the above throttle device, the second communication passage may be configured to communicate the main passage with the second sensor accommodating recess downstream of the throttle valve. [Effects of the Invention]

[0022] The throttle device having the above configuration can detect the intake air temperature with high accuracy while achieving improved moldability, reduced costs, increased freedom in installation, and compactness. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is an external perspective view showing a throttle device according to a first embodiment of the present invention. [Figure 2] 1 is an exploded perspective view of a throttle device according to a first embodiment, viewed obliquely from the upstream side. FIG. [Figure 3] FIG. 3 is an exploded perspective view of the throttle device according to the first embodiment, viewed from another oblique direction on the upstream side. [Figure 4] 1 is a cross-sectional view of a throttle device according to a first embodiment, taken along a plane passing through the center of a valve shaft. [Figure 5] 1 is a partial cross-sectional perspective view showing a bypass passage (upstream passage) that introduces intake air from an upstream main passage in a throttle device according to a first embodiment. FIG. [Figure 6] 1 is a partial cross-sectional perspective view showing a bypass passage (downstream passage) that leads intake air to a downstream main passage in a throttle device according to a first embodiment. FIG. [Figure 7] 3 is a cross-sectional perspective view showing communication passages (intake air introduction passage and intake air discharge passage) that communicate the main passage with the sensor accommodating recess in which the temperature sensor is disposed in the throttle device according to the first embodiment. FIG. [Figure 8] 3 is a cross-sectional perspective view showing a second communication passage that communicates the main passage with a second sensor accommodating recess in which a pressure sensor is disposed in the throttle device according to the first embodiment. FIG. [Figure 9]3 is a cross-sectional perspective view of a sensor unit mounted on the throttle device according to the first embodiment, in the region of a sensor accommodating recess in which a temperature sensor is disposed. FIG. [Figure 10] 3 is a cross-sectional perspective view of a sensor unit mounted on the throttle device according to the first embodiment, in the region of a second sensor accommodating recess in which a pressure sensor is disposed. FIG. [Figure 11] FIG. 1 is a schematic diagram showing the communication passages (intake air introduction passage and intake air discharge passage) and bypass passage that connect the main passage with the sensor accommodating recess in which the temperature sensor is arranged, in a throttle device according to the first embodiment, with the temperature sensor omitted. [Figure 12] FIG. 10 is a schematic diagram showing the communication passages (intake air introduction passage and intake air discharge passage) and bypass passage that connect the main passage with the sensor accommodating recess in which the temperature sensor is arranged, in a throttle device according to a second embodiment, with the temperature sensor omitted. [Figure 13] FIG. 10 is a schematic diagram showing the communication passages (intake air introduction passage and intake air discharge passage) and bypass passage that connect the main passage with the sensor accommodating recess in which the temperature sensor is arranged, in a throttle device according to a third embodiment, with the temperature sensor omitted. [Figure 14] FIG. 10 is a schematic diagram showing the communication passages (intake air introduction passage and intake air discharge passage) and bypass passage that connect the main passage with the sensor accommodating recess in which the temperature sensor is arranged, in a throttle device according to a fourth embodiment, with the temperature sensor omitted. [Figure 15] FIG. 11 is a schematic diagram showing a communication passage (an intake air lead-out passage that communicates with the intake air introduction passage and the bypass passage midway) and a bypass passage that connect the main passage and the sensor accommodating recess in which the temperature sensor is located, in a throttle device according to a fifth embodiment, with the temperature sensor omitted. [Figure 16] This is a schematic diagram showing the intake air introduction passage and intake air discharge passage that communicate the main passage with the sensor accommodating recess in which the temperature sensor is located and also serve as a bypass passage in a throttle device related to the sixth embodiment, with the temperature sensor omitted. [Figure 17]This is a schematic diagram showing the intake air introduction passage and intake air discharge passage, which connect the main passage and the sensor accommodating recess in which the temperature sensor is located, and also serve as a bypass passage, as well as the second intake air discharge passage, in a throttle device related to the seventh embodiment, with the temperature sensor omitted. [Figure 18] 10 is a table showing the results of measuring the flow rate of intake air flowing through a communication passage (intake air discharge passage) that connects the main passage with the sensor accommodating recess in which the temperature sensor is arranged in the throttle device according to the first to seventh embodiments. [Figure 19] FIG. 13 is a schematic diagram showing a communication passage that connects the main passage with the sensor accommodating recess in which the temperature sensor is disposed in a throttle device according to an eighth embodiment, with the temperature sensor omitted. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The throttle device according to the first embodiment is installed in the intake system of an engine mounted on a motorcycle, midway along an intake pipe downstream of an air cleaner.

[0025] As shown in Figures 1 to 3, the throttle device includes a throttle body 10, a valve stem 20 having an axis S, a throttle valve 30, a drive unit 40 that drives the throttle valve 30 to open and close, an adjustment valve 50, and a sensor unit U (housing 60, circuit board 70, temperature sensor 80, and pressure sensor 90).

[0026] The throttle body 10 is formed from a metal material such as aluminum, and includes an upstream connecting portion 11a, a downstream connecting portion 11b, a locking portion 11c, an adjusting screw 11d, a main passage 12, a valve stem hole 13 through which the valve stem 20 passes, a bypass passage 14, an accommodating portion 15 that accommodates the adjusting valve 50, a mounting surface 16 formed on the outer wall, a communicating passage 17, a second communicating passage 18, and two boss portions 19.

[0027] The upstream connection portion 11a is connected to an intake duct that constitutes the intake system of the engine. The downstream connecting portion 11b is connected via a seal member Sr1 to a joint surface of the cylinder head of the engine, which constitutes the intake system of the engine. The locking portion 11c is adapted to lock one end 42a of a coil spring 42 included in the drive unit 40. The adjustment screw 11d is adapted to abut against a part of a locking lever 41c of a drum 41 included in the drive unit 40.

[0028] The main passage 12 passes intake air toward the combustion chamber of the engine and is formed in a cylindrical shape extending in a direction L perpendicular to the axis S. As shown in Fig. 4, the main passage 12 is formed in a conical shape whose passage area increases from the region where the throttle valve 30 is disposed toward the upstream side, that is, in a conical shape whose passage area decreases from the upstream connecting portion 11a toward the region where the throttle valve 30 is disposed. As shown in FIG. 4, the stem hole 13 is formed as a circular hole so that the stem 20 can be passed through freely, and an annular recess 13a is formed on the outer side in the direction of the axis S to fit the lip-type seal Rs.

[0029] As shown in Figures 5, 6 and 11, the bypass passage 14 is made up of an upstream passage 14a branching off from the main passage 12 upstream of the throttle valve 30, a downstream passage 14b joining the main passage 12 downstream of the throttle valve 30, and a communication passage 14c interposed between the upstream passage 14a and the downstream passage 14b and having a passage area adjusted by an adjustment valve 50. That is, the bypass passage 14 branches off from the main passage 12 at an inlet 14a1 located upstream of the throttle valve 30 to introduce intake air, and then bypasses the throttle valve 30 and discharges the intake air into the main passage 12 at an outlet 14b1 located downstream of the throttle valve 30.

[0030] 3, 5, and 6, the accommodation portion 15 is an area that accommodates the valve element 51 of the adjustment valve 50 so that it can reciprocate freely, and has a screw hole 15a at its end face into which a screw b3 is threaded that fastens a pressing member 54 that fixes the electromagnetic actuator 53 of the adjustment valve 50. The accommodation portion 15 also functions as a communication passage that communicates between the upstream passage 14a and the downstream passage 14b.

[0031] As shown in FIGS. 3 and 4, the mounting surface 16 is formed as a flat surface perpendicular to the axis S so that the sensor unit U can be mounted thereon. In addition, the mounting surface 16 is formed with two screw holes 16a for fastening the sensor unit U with screws b1, and an annular recess 16b for fitting the fitting portion 64 of the sensor unit U, and also has openings to a communicating passage 17 and a second communicating passage 18.

[0032] As shown in FIGS. 3 and 7, the communication passage 17 is formed so as to open to the mounting surface 16 and communicate with the main passage 12, and is composed of an intake air introduction passage 17a and an intake air discharge passage 17b. The intake air introduction passage 17a is formed so as to introduce intake air from the main passage 12 into the sensor accommodating recess 62 at an introduction port 17a1 located upstream of the throttle valve 30. The intake air discharge passage 17b is formed so as to discharge the intake air from the sensor accommodating recess 62 to the main passage 12 at a discharge port 17b1 located downstream of the inlet port 17a1 of the intake air introduction passage 17a. That is, the communication passage 17 communicates the main passage 12 with the sensor accommodating recess 62 upstream of the throttle valve 30 .

[0033] Here, the intake air introduction passage 17a and the intake air discharge passage 17b are formed as cylindrical holes extending parallel to the axis S, so that drilling or the like can be performed from the same direction as the valve stem hole 13, and manufacturing costs can be reduced by reducing the number of processing steps. Furthermore, in the throttle body 10, a guide wall 12a is formed near the inlet 17a1 of the intake air introduction passage 17a by hollowing out the inner wall surface of the main passage 12 so that the intake air flowing through the main passage 12 collides with the guide wall 12a, and the guide wall 12a guides the intake air flowing through the main passage 12 toward the intake air introduction passage 17a. The guide wall 12a is formed as a vertical wall perpendicular to the extension direction L of the main passage 12. Note that instead of a vertical wall, an inclined wall inclined downstream may be used as the guide wall.

[0034] In this way, by providing the guide wall 12a, the intake air is actively guided into the intake air introduction passage 17a, and the temperature sensor 80 disposed in the sensor accommodating recess 62 can be exposed to the intake air. Furthermore, the guide wall 12a does not protrude into the main passage 12, but is formed by removing weight from the inner wall surface of the main passage 12, and therefore does not obstruct the overall flow of intake air.

[0035] As shown in FIGS. 7 and 8, the second communication passage 18 is formed so as to open to the mounting surface 16 and communicate with the main passage 12, and is made up of two passages 18a, 18b. That is, the second communication passage 18 communicates the main passage 12 with the second sensor accommodating recess 63 downstream of the throttle valve 30 . The boss portion 19 has a circular hole through which a screw (not shown) is passed to fasten the throttle body 10 to the joining surface of the cylinder head of the engine with the seal member Sr1 sandwiched therebetween.

[0036] As shown in FIG. 4, the valve shaft 20 is made of a metal material or the like and is formed to have a circular cross section and extend in the direction of the axis S. The valve shaft 20 has a slit 21 and a screw hole 22 in the central region for fitting the throttle valve 30, a connecting portion 23 at one end for connecting the drive unit 40, and a disk portion 24 at the other end. The connecting portion 23 has a two-face width portion into which the drum 41 of the drive unit 40 is fitted so as to rotate integrally. The disk portion 24 is disposed inside the cylindrical fitting portion 64 of the sensor unit U. Therefore, when a rotational position detection sensor including a Hall element or the like is embedded in the bottom wall of the fitting portion 64 of the sensor unit U, it can be used as a detected member.

[0037] The valve stem 20 is inserted into the valve stem hole 13 of the throttle body 10, and the throttle valve 30 is fitted into the slit 21 and fastened to the valve stem 20 by a screw b2, thereby holding the throttle valve 30 in a freely opening and closing state. The outer circumferential surface of the valve stem 20 is sealed by a lip-type seal Rs on the outside of the valve stem hole 13 in the direction of the axis S.

[0038] As shown in FIGS. 1 and 4, the throttle valve 30 is made of a metal material or the like and has a generally circular disk shape, and is provided with a circular hole 31 through which the screw b2 passes. The throttle valve 30 is disposed so that the valve stem 20 is passed through the valve stem hole 13, and then passed through the slit 21 and fixed to the valve stem 20 by a screw b2, thereby opening and closing the main passage 12. The throttle valve 30 opens the main passage 12 to a desired opening degree in response to the rotation of the valve stem 20 .

[0039] As shown in Figures 1, 4 and 6, the drive unit 40 drives the valve shaft 20 to rotate around the axis S, and includes a drum 41 connected to and fixed to the connecting portion 23 of the valve shaft 20, and a coil spring 42 arranged around the valve shaft 20 between the drum 41 and the throttle body 10. The drum 41 has locking holes 41a and 41b to which a wire connected to the throttle grip is locked, and a locking lever 41c that locks the coil spring . The locking lever 41c is brought into contact with an adjustment screw 11d provided on the throttle body 10 by the rotational biasing force of the coil spring 42. Therefore, by appropriately adjusting the extension amount of the adjustment screw 11d, the valve opening degree of the throttle valve 30 at the stop position can be set to a desired position. As shown in Figures 1 and 7, one end 42a of the coil spring 42 is engaged with the engaging portion 11c of the throttle body 10, and the other end 42b is engaged with the engaging lever 41c of the drum 41, and exerts a rotational force in the direction of closing the throttle valve 30.

[0040] As shown in Figures 2, 3, 5, and 6, the adjustment valve 50 includes a valve element 51, a coil spring 52 that biases the valve element 51 in the valve opening direction, an electromagnetic actuator 53 that drives the valve element 51 so that it can move back and forth in a direction parallel to the axis S, and a pressing member 54 that fixes the electromagnetic actuator 53 to the throttle body 10. The adjusting valve 50 adjusts the flow rate of intake air flowing through the bypass passage 14 by increasing or decreasing the passage area of ​​the bypass passage 14 (communication passage 14c) in the idle operation range of the engine.

[0041] The sensor unit U is attached to the mounting surface 16 of the throttle body 10, and as shown in Figures 2, 3, 7, 9 and 10, includes a housing 60, a circuit board 70, a temperature sensor 80 and a pressure sensor 90. The housing 60 is molded using a resin material and includes a joint surface 61, a sensor accommodating recess 62, a second sensor accommodating recess 63, a fitting portion 64, an annular groove 65, an outer accommodating recess 66, two boss portions 67 for passing the screw b1, and a connector 68.

[0042] The joining surface 61 is to be closely joined to the mounting surface 16 of the throttle body 10 and is formed as a flat surface perpendicular to the axis S. The sensor accommodating recess 62 is recessed from the joint surface 61 in the direction of the axis S and is formed in the shape of a long groove that is elongated in the extension direction L of the main passage 12. The temperature sensor 80 is disposed in the sensor accommodating recess 62 so as not to protrude outward from the joint surface 61. Here, the sensor accommodating recess 62 is formed in the shape of a long, elongated groove in the extension direction L of the main passage 12, so that the intake air introduction passage 17a and the intake air discharge passage 17b can be arranged at a predetermined interval in the flow direction of the intake air (extension direction L), allowing the intake and discharge of intake air to be carried out smoothly and without stagnation.

[0043] The second sensor accommodating recess 63 is formed to be recessed in the direction of the axis S from the joining surface 61, and the pressure sensor 90 is disposed therein. The fitting portion 64 is formed in a cylindrical shape centered on the axis S so as to fit into an annular recess 16b formed in the mounting surface 16 of the throttle body 10. The fitting portion 64 is fitted into the annular recess 16b, thereby positioning the sensor unit U and the throttle body 10. An annular groove 65 is formed around the second sensor accommodating recess 63 to fit the seal member Sr2.

[0044] The outer accommodating recess 66 is formed so as to be recessed from the outer end face opposite to the joining face 61, and is filled with a sealing resin agent R so as to bury the circuit board 70 arranged inside. The boss portion 67 has a circular hole through which a screw b1 for fastening the sensor unit U to the throttle body 10 is passed. The connector 68 surrounds terminals electrically connected to the circuit board 70 and is formed so that an external connector can be connected thereto.

[0045] The circuit board 70 has various electronic components and circuits mounted thereon and has a plurality of terminals electrically connected thereto, and is also electrically connected to the lead wires 82 of the temperature sensor 80 and the lead wires 92 of the pressure sensor 90.

[0046] 7 and 9, the temperature sensor 80 includes a temperature sensing element 81 such as a thermistor, and lead wires 82 extending from the temperature sensing element 81. The temperature sensor 80 is arranged such that the temperature sensing element 81 is exposed inside the sensor accommodating recess 62, and the lead wires 82 are electrically connected to the circuit board 70. That is, the temperature sensor 80 is electrically connected to the circuit board 70 and is disposed protruding within the sensor accommodating recess 62 so as not to protrude outward from the joint surface 61 .

[0047] In this way, the temperature sensor 80 is positioned so as not to protrude from the joint surface 61, which contributes to improving the moldability of the housing 60 and reducing the size of the sensor unit U, as well as preventing interference with external parts, etc., and therefore preventing damage to the temperature sensor 80, etc. Furthermore, the temperature sensor 80 is not covered with a protective wall such as a resin material, but is arranged in an exposed state within the space of the sensor accommodating recess 62, so that the temperature sensor 80 is directly exposed to the intake air guided into the sensor accommodating recess 62. This allows the temperature of the intake air to be detected with high accuracy.

[0048] As shown in FIGS. 8 and 10, the pressure sensor 90 includes a pressure receiving portion 91 such as a diaphragm equipped with a semiconductor strain gauge, lead wires 92 extending from the pressure receiving portion 91, and a protective film 93. The pressure sensor 90 has a pressure receiving portion 91 disposed within the second sensor accommodating recess 63, and detects the pressure of the intake air guided from the main passage 12 to the second sensor accommodating recess 63 via the second communicating passage 18 through a small diameter hole 93a in the protective film 93.

[0049] As described above, the sensor unit U houses the temperature sensor 80 and the pressure sensor 90 so that they do not protrude from the joint surface 61. This prevents the temperature sensor 80 from interfering with external components, thereby preventing damage and enabling miniaturization. Furthermore, compared to conventional configurations in which the temperature sensor protrudes from the joint surface and is inserted into the throttle body, the configuration of the throttle body 10 can be simplified and the degree of freedom in fitting the sensor to the throttle body 10 is improved. Furthermore, the moldability of the housing 60 is improved, allowing for cost reduction.

[0050] Next, the assembly work of the throttle device having the above-mentioned configuration will be described. First, the throttle body 10, the valve stem 20, the throttle valve 30, the drive unit 40, the adjusting valve 50, the sensor unit U, the lip-type seal Rs, the seal member Sr2, and the screws b1, b2, and b3 are prepared. The sensor unit U is prepared as a module in which a circuit board 70 is embedded in a housing 60, and a temperature sensor 80 and a pressure sensor 90 are housed and arranged.

[0051] Next, the lip seal Rs is fitted into the annular recess 13a of the throttle body 10, and the valve stem 20 is passed through the valve stem hole 13 from the mounting surface 16 side. Then, the throttle valve 30 is inserted into the slit 21 of the valve stem 20 and fixed to the valve stem 20 with the screw b2. Next, the drive unit 40 is connected to the connecting portion 23 of the valve stem 20. Specifically, a coil spring 42 is disposed around the valve stem 20, and a drum 41 is connected to the connecting portion 23 of the valve stem 20 from the outside and fixed with a nut.

[0052] One end 42 a of the coil spring 42 is engaged with the engaging portion 11 c of the throttle body 10 , and the other end 42 b of the coil spring 42 is engaged with the engaging lever 41 c of the drum 41 . The rotation angle position of the drum 41 is set to a predetermined angle by appropriately adjusting the amount of extension of the adjustment screw 11d that contacts the locking lever 41c. This adjustment may be performed after all the parts have been assembled.

[0053] Next, the adjusting valve 50 is attached to the accommodation portion 15 of the throttle body 10. That is, the coil spring 52 is inserted into the accommodation portion 15, and then the valve element 51 is inserted into the accommodation portion 15 while connected to the electromagnetic actuator 53. Then, the pressing member 54 is joined to the end face of the accommodation portion 15 so as to fix the electromagnetic actuator 53, and is fastened to the throttle body 10 by the screw b3.

[0054] Next, the sensor unit U is joined to the mounting surface 16 of the throttle body 10 and fastened and fixed with screws b1. That is, with the seal member Sr2 fitted in the annular groove 65, the fitting portion 64 of the housing 60 is fitted into the annular recess 16b of the throttle body 10, and the joining surface 61 is joined to the mounting surface 16. Then, the housing 60 is fastened to the throttle body 10 with screws b1, and the sensor unit U is fixed to the throttle body 10.

[0055] As a result, the main passage 12 is connected to the sensor accommodating recess 62 upstream of the throttle valve 30 via the connecting passages 17 (intake intake passage 17a and intake discharge passage 17b) that open to the mounting surface 16, and is also connected to the second sensor accommodating recess 63 downstream of the throttle valve 30 via the second connecting passage 18 that opens to the mounting surface 16. Here, the temperature sensor 80 is positioned protruding within the sensor accommodating recess 62 so as not to protrude from the joint surface 61 of the housing 60, so that the sensor unit U can be easily attached to the throttle body 10 without having to pay attention to ensure that the temperature sensor 80 does not interfere with other parts. The assembly of the throttle device is not limited to the above method, and other methods may be used.

[0056] Next, the operation of the throttle device when it is mounted on an engine will be described. First, when the engine is in the idle operating range, the throttle valve 30 closes the main passage 12, and the intake air flowing through the main passage 12 flows through the bypass passage 14 to bypass the throttle valve 30 and then flows out again into the downstream main passage 12. In this state, the adjusting valve 50 adjusts the passage area of ​​the bypass passage 14 (communication passage 14c) to maintain the engine in a stable idle state.

[0057] On the other hand, when the engine is in an operating range other than the idle operating range, the throttle valve 30 is in a predetermined opening range and opens the main passage 12 . Therefore, the intake air flowing through the main passage 12 is drawn into the engine without passing through the bypass passage 14. In this case, the regulating valve 50 does not need to be used to regulate the amount of intake air flowing through the bypass passage 14.

[0058] 11, the intake air flowing through the main passage 12 is introduced through the intake air introduction passage 17a and led into the sensor accommodating recess 62, and the intake air in the sensor accommodating recess 62 is led out through the intake air lead-out passage 17b to the main passage 12. At this time, the temperature sensor 80 detects the temperature of the intake air led into the sensor accommodating recess 62. Here, because the guide wall 12a is provided near the inlet 17a1 of the intake air introduction passage 17a, the intake air flowing through the main passage 12 is actively guided towards the intake air introduction passage 17a.

[0059] Furthermore, since the intake air introduction passage 17a is located upstream of the intake air discharge passage 17b, and the main passage 12 is formed in a conical shape with a passage area that increases toward the upstream side, i.e., decreases toward the downstream side, the flow velocity of the intake air downstream is faster than the flow velocity of the intake air upstream. Therefore, the intake air is expected to be sucked out of the intake air discharge passage 17b, and the intake air is effectively introduced into the sensor-accommodating recess 62.

[0060] Furthermore, downstream of the throttle valve 30, the intake air flowing through the main passage 12 is guided into the second sensor accommodating recess 63 via the second communication passage 18, and the pressure of the intake air is detected by the pressure sensor 90.

[0061] As described above, the temperature of the intake air is detected by the temperature sensor 80, and the pressure of the intake air is detected by the pressure sensor 90. The detected information is input as control information into the control unit, and the engine is controlled appropriately.

[0062] The throttle device according to the first embodiment can detect the intake air temperature with high accuracy while achieving improved moldability, reduced costs, improved freedom in installation, and compactness.

[0063] FIG. 12 is a schematic diagram of a throttle device according to a second embodiment, which is the same as the first embodiment except that the guide wall 12a is eliminated, and the same components are given the same reference numerals and will not be described. In the throttle device according to the second embodiment, the inlet port 17a1 of the intake air introduction passage 17a opens on the same plane as the inner wall surface of the main passage 12.

[0064] According to this, although there is no guide wall 12a, the main passage 12 is formed in a conical surface shape, so that the flow velocity of the intake air on the downstream side is faster than the flow velocity of the intake air on the upstream side, and the intake air is effectively introduced into the sensor accommodating recess 62 by the suction action of the intake air from the intake discharge passage 17b. According to the throttle device of the second embodiment, as with the first embodiment, it is possible to achieve improved moldability, reduced costs, increased freedom in installation, and compactness, while also being able to detect the intake air temperature with high accuracy.

[0065] FIG. 13 is a schematic diagram of a throttle device according to a third embodiment, which is the same as the second embodiment except that the position of the outlet 17b1 of the intake outlet passage 17b is changed. The same components are assigned the same symbols and will not be described. In the throttle device according to the third embodiment, an inlet port 17a1 of the intake air introduction passage 17a opens flush with the inner wall surface of the main passage 12. In addition, an outlet port 17b1 of the intake air discharge passage 17b opens into the main passage 12 immediately upstream of the throttle valve 30.

[0066] As a result, the intake air is sucked out of the intake lead-out passage 17b by the conical main passage 12, and is effectively introduced into the sensor housing recess 62. In addition, because the outlet 17b1 is located immediately adjacent to the throttle valve 30, where the intake air flows at a high speed, the effect of sucking out the intake air from the intake lead-out passage 17b is further enhanced, and the flow rate of the intake air introduced into the sensor housing recess 62 can be increased. According to the throttle device of the third embodiment, as in the previously described embodiments, it is possible to achieve improved moldability, reduced costs, increased freedom in installation, miniaturization, etc., while detecting the intake air temperature with high accuracy.

[0067] FIG. 14 is a schematic diagram of a throttle device according to a fourth embodiment, which is the same as the first embodiment except that the position of the outlet 17b1 of the intake outlet passage 17b is changed. The same components are denoted by the same reference numerals and will not be described. In the throttle device of the fourth embodiment, a guide wall 12a is formed near the inlet 17a1 of the intake intake passage 17a, and the outlet 17b1 of the intake outlet passage 17b opens into the main passage 12 immediately upstream of the throttle valve 30.

[0068] With this, the intake air is effectively introduced into the sensor housing recess 62 by the intake air introduction action of the guide wall 12a and the intake air suction action from the intake air lead-out passage 17b by the conical main passage 12. In addition, because the lead-out port 17b1 is located immediately adjacent to the throttle valve 30, where the intake air flows at a high speed, the intake air suction effect from the intake air lead-out passage 17b is further enhanced, and the flow rate of intake air introduced into the sensor housing recess 62 can be increased. According to the throttle device of the fourth embodiment, as in the previously described embodiments, it is possible to achieve improved moldability, reduced costs, increased freedom in installation, miniaturization, etc., while detecting the intake air temperature with high accuracy.

[0069] FIG. 15 is a schematic diagram of a throttle device according to a fifth embodiment, which is the same as the second embodiment except that an intake discharge passage 117b communicating with the middle of the bypass passage 14 is adopted instead of the intake discharge passage 17b. The same components are assigned the same reference numerals and will not be described. In the throttle device of the fifth embodiment, the intake discharge passage 117b is connected to the middle of the bypass passage 14 (upstream passage 14a) upstream of the adjustment valve 50, and the discharge outlet 14b1 of the bypass passage 14 also serves as the discharge outlet of the intake discharge passage 117b.

[0070] As a result, since the outlet 14b1 of the intake discharge passage 117b is downstream of the throttle valve 30, the pressure difference between the inlet 17a1 and the outlet 14b1 becomes larger, and the flow rate of intake air led into the sensor accommodating recess 62 can be increased. According to the throttle device of the fifth embodiment, as in the previously described embodiments, it is possible to achieve improved moldability, reduced costs, increased freedom in installation, miniaturization, etc., while detecting the intake air temperature with high accuracy.

[0071] FIG. 16 is a schematic diagram of a throttle device according to a sixth embodiment, which is the same as the fifth embodiment except that the bypass passage 14 (part of the upstream passage 14a) upstream of the region connected to the intake discharge passage 117b has been eliminated. The same components are denoted by the same reference numerals and will not be described. The throttle device according to the sixth embodiment includes an upstream passage 114a to which an intake lead-out passage 117b is connected, and a downstream passage 14b to which the upstream passage 114a is connected. The intake air introduced through the inlet 17a1 is guided through the intake air introduction passage 17a into the sensor accommodating recess 62, and then passes through the intake air discharge passage 117b, the upstream passage 114a, and the downstream passage 14b, before being discharged from the discharge port 14b1 into the main passage 12. That is, the intake air introduction passage 17a, the sensor accommodating recess 62, and the intake air discharge passage 117b also serve as a bypass passage that branches off from the main passage 12 to introduce intake air and discharge it to the main passage 12, bypassing the throttle valve 30.

[0072] According to this, because the outlet 14b1 of the intake air outlet passage 117b is located downstream of the throttle valve 30, the pressure difference between the inlet 17a1 and the outlet 14b1 increases, thereby increasing the flow rate of the intake air led into the sensor accommodating recess 62. In particular, because the flow rate of the intake air flowing through the bypass passage flows into the sensor accommodating recess 62, the flow rate of the intake air to which the temperature sensor 80 is exposed increases. According to the throttle device of the sixth embodiment, as in the previous embodiments, it is possible to achieve improved moldability, reduced costs, increased freedom in installation, miniaturization, etc., while detecting the intake air temperature with high accuracy.

[0073] Figure 17 is a schematic diagram of a throttle device according to the seventh embodiment, which is the same as the sixth embodiment except for the addition of the second intake discharge passage 217b. The same components are given the same symbols and will not be described. In the throttle device of the seventh embodiment, compared to the configuration of the sixth embodiment, a second intake discharge passage 217b is provided which opens into the main passage 12 at a discharge port 217b1 located downstream of the inlet 17a1 of the intake introduction passage 17a and immediately upstream of the throttle valve 30, and which discharges intake air from the sensor accommodating recess 62 to the main passage 12.

[0074] According to this, because the outlet 14b1 of the intake air outlet passage 117b is located downstream of the throttle valve 30, the pressure difference between the inlet 17a1 and the outlet 14b1 increases, thereby increasing the flow rate of the intake air led into the sensor accommodating recess 62. In particular, because the flow rate of the intake air flowing through the bypass passage flows into the sensor accommodating recess 62, the flow rate of the intake air to which the temperature sensor 80 is exposed increases. Furthermore, by providing the second intake discharge passage 217b, the discharge outlet 217b1 is located immediately adjacent to the throttle valve 30, where the intake air flow rate is high, thereby further enhancing the effect of suctioning intake air from the second intake discharge passage 217b, and increasing the flow rate of intake air led into the sensor accommodating recess 62. According to the throttle device of the seventh embodiment, as in the previously described embodiments, it is possible to achieve improved moldability, reduced costs, increased freedom in installation, miniaturization, etc., while detecting the intake air temperature with high accuracy.

[0075] FIG. 18 shows the results of measuring the flow rate of intake air flowing through the sensor accommodating recess 62 in the throttle devices according to the first to seventh embodiments, dividing the flow rate into the flow rate at idle opening and the flow rate when the throttle valve 30 is fully open. In FIG. 18, the flow rates in the second embodiment (flow rate Qi at idle opening, flow rate Qf at full opening) are used as the reference (ratio 1), and the flow rates in the first, third to seventh embodiments are shown as ratios to the flow rates Qi, Qf in the second embodiment. According to the measurement results, the intake air flow rates Qi and Qf in the throttle device according to the second embodiment were flow rates that could be detected by the temperature sensor 80. In addition, the intake air flow rates in the throttle devices according to the first, third to seventh embodiments were even greater than the flow rates in the second embodiment, and were flow rates that could be detected by the temperature sensor 80. In addition, the measurement results did not reveal any clear difference in the flow rate Qi at idle opening among the first, third, and fourth embodiments, but theoretically, it is preferable to have the guide wall 12a rather than not having it, and it is also preferable for the intake discharge passage 17b to open immediately upstream of the throttle valve 30. At full opening, as is clear from a comparison between the third and fourth embodiments, the flow rate Qf is increased in the fourth embodiment having the guide wall 12a, and as is clear from a comparison between the first and fourth embodiments, the flow rate Qf is increased in the fourth embodiment in which the intake discharge passage 17b opens immediately upstream of the throttle valve 30.

[0076] In the above embodiment, the communication passage connecting the main passage 12 and the sensor accommodating recess 62 is shown to be a communication passage having an intake air introduction passage 17a, an intake air discharge passage 17b, 117b, and a second intake air discharge passage 217b, i.e., a communication passage consisting of multiple passages, but this is not limited to this. 19 is a schematic diagram of a throttle device according to the eighth embodiment, which employs a main passage 112 that is curved on the upstream side and a communication passage 117 that is made up of a single passage that connects the main passage 112 with the sensor accommodating recess 62. The communication passage 117 is formed so as to open to the mounting surface 16 over the length of the sensor accommodating recess 62. In this configuration, intake air flowing from the upstream side of the main passage 112 is guided into the sensor accommodating recess 62 through the communication passage 117, and then is led from the sensor accommodating recess 62 through the communication passage 117 to the main passage 112.

[0077] According to this, the intake air is actively guided to the communication passage 117 by utilizing centrifugal force in the curved region of the main passage 112 , so that the temperature sensor 80 is exposed to the intake air introduced and discharged through the communication passage 117 . According to the throttle device of the eighth embodiment, as in the previously described embodiments, it is possible to achieve improved moldability, reduced costs, increased freedom in installation, miniaturization, etc., while detecting the intake air temperature with high accuracy.

[0078] In the above embodiment, the sensor unit U is shown as being equipped with a temperature sensor 80 and a pressure sensor 90, but this is not limited to this and the sensor unit may further be equipped with a position detection sensor that detects the rotation angle of the valve stem 20. In this case, a non-contact magnetic sensor including a Hall element or the like embedded in the inner region of the fitting portion 64 may be used as the position detection sensor.

[0079] In the above embodiment, the temperature sensor 80 is arranged to protrude into the sensor accommodating recess 62, with the temperature sensor 81 exposed. However, this is not limited to this, and a configuration may be adopted in which the temperature sensor 81 is covered with a thin resin material or other material with good thermal conductivity.

[0080] In the above embodiment, the main passage 12 is shown as having a conical surface shape, with the passage area expanding from the area where the throttle valve 30 is located toward the upstream side. However, the present invention is not limited to this, and a cylindrical main passage with the same passage area may also be used.

[0081] As described above, the throttle device of the present invention achieves improved moldability, reduced cost, increased freedom in installation, and compactness, while also being able to detect intake air temperature with high accuracy, making it applicable to motorcycles and other vehicles as well as being useful in other vehicles. [Explanation of symbols]

[0082] 10 Throttle body 12,112 Main aisle 12a Guide wall 14 Bypass Passage 14b1 Bypass passage outlet 16 Mounting surface 17,117 Communication path 17a Intake passage 17a1 entrance 17b, 117b Intake outlet passage 17b1 outlet 217b Second intake outlet passage 217b1 outlet 18 2nd communication passage 30 Throttle valve 50 Regulating valve U Sensor Unit 60 Housing 61 Joint surface 62 Sensor accommodating recess 63 Second sensor accommodating recess 70 Circuit Board 80 Temperature Sensor 81 Thermosensor 90 Pressure Sensor

Claims

1. a throttle body having a main passage through which intake air passes, a mounting surface formed on an outer wall, and a communication passage that opens to the mounting surface and communicates with the main passage; a throttle valve that opens and closes the main passage; a sensor unit joined to the mounting surface, The sensor unit includes a housing having a joint surface joined to the mounting surface and a sensor accommodating recess recessed from the joint surface and communicating with the main passage via the communication passage, a circuit board embedded in the housing, and a temperature sensor electrically connected to the circuit board and disposed so as to protrude within the sensor accommodating recess. A throttle device characterized by:

2. The main passage is formed in a conical shape such that the passage area increases from a region where the throttle valve is disposed toward the upstream side.

2. The throttle device according to claim 1, wherein:

3. the communication passage communicates the main passage with the sensor accommodating recess on the upstream side of the throttle valve; 3. The throttle device according to claim 1 or 2.

4. The sensor accommodating recess is formed in the shape of a long groove extending along the extension direction of the main passage.

4. The throttle device according to claim 1, wherein the throttle device is a throttle valve.

5. The temperature sensor includes a temperature sensing element that is exposed and disposed in the sensor accommodating recess.

5. The throttle device according to claim 1, wherein the throttle device is a throttle valve.

6. the communication passage includes an intake air introduction passage that introduces intake air from the main passage to the sensor accommodating recess upstream of the throttle valve, and an intake air discharge passage that discharges intake air from the sensor accommodating recess to the main passage downstream of an inlet of the intake air introduction passage.

6. The throttle device according to claim 1, wherein the throttle device is a throttle valve.

7. The throttle body has a guide wall near an inlet of the intake air introduction passage that guides the intake air flowing through the main passage toward the intake air introduction passage.

7. The throttle device according to claim 6, wherein:

8. The guide wall is formed by removing a part of the inner wall surface of the main passage so as to allow the intake air flowing through the main passage to collide with the guide wall.

8. The throttle device according to claim 7.

9. an outlet port of the intake air outlet passage opens into the main passage immediately upstream of the throttle valve; 9. The throttle device according to claim 6, wherein the throttle device is a throttle valve.

10. a bypass passage branching from the main passage to introduce intake air and lead the intake air to the main passage by bypassing the throttle valve; an adjusting valve for adjusting a passage area of ​​the bypass passage, the intake discharge passage communicates with a portion of the bypass passage upstream of the regulating valve, and an outlet of the bypass passage also serves as an outlet of the intake discharge passage; 9. The throttle device according to claim 6, wherein the throttle device is a throttle valve.

11. a bypass passage branching from the main passage to introduce intake air and lead the intake air to the main passage by bypassing the throttle valve; an adjusting valve for adjusting a passage area of ​​the bypass passage, the intake air introduction passage, the sensor accommodating recess, and the intake air discharge passage also serve as the bypass passage; 9. The throttle device according to claim 6, wherein the throttle device is a throttle valve.

12. a bypass passage branching from the main passage to introduce intake air and lead the intake air to the main passage by bypassing the throttle valve; an adjusting valve for adjusting a passage area of ​​the bypass passage; a second intake discharge passage that opens into the main passage downstream of the inlet port of the intake introduction passage and immediately upstream of the throttle valve, and that discharges intake air from the sensor accommodating recess into the main passage, the intake air introduction passage, the sensor accommodating recess, and the intake air discharge passage also serve as the bypass passage; 9. The throttle device according to claim 6, wherein the throttle device is a throttle valve.

13. the throttle body includes a second communication passage that opens to the mounting surface and communicates with the main passage, the sensor unit includes the housing having a second sensor accommodating recess recessed from the joint surface and communicating with the second communication passage; and a pressure sensor electrically connected to the circuit board and disposed in the second sensor accommodating recess for detecting the pressure of intake air flowing through the main passage.

13. The throttle device according to claim 1, wherein the throttle device is a throttle valve.

14. the second communication passage communicates the main passage with the second sensor accommodating recess downstream of the throttle valve; 14. The throttle device according to claim 13.

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