Throttle device and method for manufacturing a throttle device

Abstract

Including a throttle device: a body (10) on which an inlet opening (11) is formed; a throttle valve (31) which is provided in the inlet passage and whose degree of opening is adapted; a shaft (32) which is rotatably carried through the body and to which the throttle valve is attached; an actuator (80) configured to output a drive torque; a valve train (40) comprising a gear section (41) configured to rotate by the drive torque transmitted by the actuator, a hub section (42) provided on the gear section having a cylindrical outer wall (425), and one or more extension sections (45) extending in an axial direction from the gear section on a radially outer side of the hub section to form the gear section, hub section, and extension section integrally; a spiral spring (50) comprising a first hook (51) extrapolated to the outer wall of the hub section of the valve train and provided at an end section on one side of the gear section, and a second hook (52) provided at an end section on the opposite side to the gear section, such that the first hook and the second hook each engage on opposite sides to each other in a circumferential direction of the extension section, and a guide (601-604) with a cylindrical guide main body (65) provided between the outer wall of the hub section and an inner circumference of the spring, and configured to act as a buffer to prevent sliding of the hub section and the spring as a result of rotation of the gear section on at least the side of the gear section in the axial direction, wherein the guide is a component of a valve train subassembly, wherein the valve train sub-assembly (701-704), which is formed by mounting the valve train, the spring and the guide, is received in a valve train receiving chamber (13) of the body, wherein the second hook of the spring engages with the body, and the shaft is attached to the hub section of the valve train.

Description

Cross-reference to related registration

[0001] This application is based on Japanese patent application No. 2018-236469, JP 2020 - 97 908 A, filed on December 18, 2018. Technical field

[0002] The present disclosure relates to a throttle device and a method for manufacturing the throttle device. background

[0003] In a conventional throttle device configured to adjust the opening degree of a throttle valve located in an intake manifold, an extrapolated helical spring generates a compressive force on a valve train, to which a drive torque is transmitted by an actuator, in order to maintain the throttle valve opening at a predetermined degree. During the assembly process of the throttle device, when the valve train and spring are individually housed in a body, one of the two hooks formed at either end of the spring engages with the valve train, while the other engages with the body. After housing the valve train and spring in the body, it is then necessary to temporarily mount them to a shaft while their rotational positions are adjusted.

[0004] Furthermore, in the throttle device disclosed in JP 2003-120335A, a valve train (a throttle gear 107), a spring (a twisted coil spring 113), a guide (a cover 115, 117), and a shaft (a throttle shaft 103) are mounted on a projecting cylinder section (a bearing hub 105) of a body (a throttle body 101). Since the hooks (functional ends 113a and 113b) at both ends of the spring are received in the projecting section of the guide, contact pressure is relieved between the hook and the body closure (a standard hub 119). The descriptions in brackets are part designations and corresponding numbers described in JP 2003-120335A.

[0005] US 8,746,210 B2 describes a spiral torsion return spring and a throttle assembly for forcing a throttle valve of a throttle assembly into a standard position when a throttle motor of the throttle assembly is disabled. The return spring consists of a center section, a first end section, a second end section, a first spring leg, and a second spring leg. The throttle assembly includes a throttle shaft, a first bushing, a second bushing, and the spring described above. A first end section center axis, defined by the first end section, and a second end section center axis, defined by the second end section, are offset from a center section center axis, defined by the center section.

[0006] DE 11 2018 003 440 T5 describes the following: When a rotating body is in a default position due to the absence of a driving force, a first hook section and a second hook section engage with a fixed engagement section and / or a movable engagement section. When the rotating body is turned from the default position by the driving force, the first hook section engages with one section from the fixed engagement section and the movable engagement section, and the second hook section engages with the other section from the fixed engagement section and the movable engagement section. A throttle valve device includes a press section that presses on the first hook section and / or the second hook section to apply a press force in a spiral axial direction towards the center of a spiral section.

[0007] DE 10 2015 105 642 A1 describes an actuator and an assembly method thereof. In an electric actuator, an end section of a return spring is hooked onto a first slot formed in a radially outer guide of a delivery gear, so that the return spring is rotated by a predetermined angle (α) that is slightly smaller than an initially set angle. An inclined slot section is formed at an opening of a second slot formed on a covering wall of a spring installation part to rotate the return spring to a predetermined, initially set angle. This rotates the return spring by the initially set angle simultaneously with the assembly of a valve shaft with the delivery gear. This simplifies the assembly process of the electric actuator. Literature on the state of the art Patent literature JP 2003 - 120 335 A US 8 746 210 B2 DE 11 2018 003 440 T5 DE 10 2015 105 642 A1 Summary

[0008] In the configuration described in patent document 1, it is necessary to mount the guide and the spring after the valve train and shaft have been integrated. Therefore, the shaft must be aligned in a specific direction of rotation so that the valve can be mounted, and the valve train must also be aligned in the direction of rotation with the body closure in a specific position. Furthermore, the guide (cover 115) on the side of the valve train and the hook (functional end 113a) of the spring must be rotated and mounted in a position where they engage with the valve train, thus positioning the spring at a predetermined position in the direction of rotation. Therefore, the assembly process is complex.

[0009] One object of the present disclosure is to provide a throttle device and a method for manufacturing the throttle device which improve the mounting characteristics of a valve train and a spring on a body.

[0010] A throttling device of the present disclosure comprises a body in which an inlet passage is formed, a throttle valve which is provided in the inlet passage and whose degree of opening is adjusted, a shaft which is rotatably supported by the body and to which the throttle valve is attached, an actuator which is configured to output a drive torque, a valve train and a coil spring.

[0011] The valve train comprises a gear section configured to rotate by the drive torque transmitted by the actuator, a hub section provided on the gear section having a cylindrical outer wall, and one or more extension sections extending axially from the gear section on a radially outer side of the hub section to integrally form the gear section, hub section, and extension section.

[0012] The spring is placed externally onto the outer wall of the hub section of the valve train. The spring includes a first hook located at an end section on one side of the gear section and a second hook located at an end section on the opposite side to the gear section, such that the first hook and the second hook engage on opposite sides in a circumferential direction of the extension section.

[0013] A valve train sub-assembly, formed by mounting the valve train and spring, is received in a valve train receiving chamber of the body, with the second hook of the spring engaging with the body. The shaft is attached to the hub section of the valve train.

[0014] In the throttle device of the present embodiment, the first and second hooks of the spring engage with the extension section of the valve train, with the valve train subassembly configured with the valve train and spring already assembled. The operator places the valve train subassembly into the valve train receiving chamber of the body and engages the second hook of the spring with the body. The operator then crimps the tip section of the shaft, which penetrates the shaft insertion hole of the hub section, and secures the shaft to the hub section of the valve train.

[0015] Accordingly, the spring, in which the hooks at both ends engage with the valve train, and the body generate a compressive force, thus maintaining the throttle valve's opening at a predetermined degree. In the present disclosure, it is not necessary to temporarily mount the valve train and spring while adjusting their rotational positions after the body is inserted, thereby improving assembly. Furthermore, unlike the conventional technique described in patent document 1, the valve train and shaft are not integrated, resulting in trouble-free assembly.

[0016] In the valve assembly step, the throttle valve and the shaft are mounted to the body. In the sub-assembly step, the valve train and the spring are mounted to form the valve train sub-assembly. After the valve assembly and the sub-assembly steps, in the insertion step, the valve train sub-assembly is inserted into the valve train receiving chamber of the body, and the second hook of the spring engages with the body. Following the insertion step, in a shaft fixing step, the shaft is fixed to the hub section of the valve train in a state where the rotational position of the throttle valve is adjusted. Brief description of the drawings

[0017] The preceding and further tasks, features, and advantages of the following disclosure will become more apparent from the detailed description below, with reference to the accompanying drawings. It shows: Fig. 1 a cross-sectional view showing an overall configuration of a throttle device of a first embodiment; Fig. 2 a perspective view of each component before assembly of a valve train sub-assembly of the first embodiment; Fig. 3 a schematic external view of the valve train sub-assembly of the first embodiment; Fig. 4 a schematic cross-sectional view of the valve train sub-assembly of the first embodiment; Fig. 5 a flowchart of a method for manufacturing the throttle device according to the present embodiment; Fig. 6 a cross-sectional view showing a state after a valve assembly process; Fig. 7 a schematic cross-sectional view of the valve train sub-assembly of a second embodiment; Fig. 8 a schematic cross-sectional view of the valve train sub-assembly of a third embodiment; and Fig. 9 Schematic cross-sectional view of the valve train sub-assembly of a fourth embodiment. Detailed description

[0018] A variety of embodiments of the throttle device are described below with reference to the drawings. In the various embodiments, the essentially identical components are indicated by the same reference numerals, without a detailed description of these components. Furthermore, the first to fourth embodiments are collectively referred to as "the present embodiment." The throttle device of the present embodiment adjusts the opening degree of a throttle valve provided in an intake port of an internal combustion engine. (First embodiment)

[0019] The first embodiment is described with reference to the Fig. 1 to 6 are described. First, an overall configuration of a throttle device 100 is described with reference to Fig. 1 described. In the throttle device 100, parts such as a throttle valve 31, a shaft 32, a valve train 40, a spring 50, an actuator 80, and an intermediate gear 82 are mounted on a body 10 in which an inlet passage 11 is formed, and a cover 20 covers the body 10. In the figure, the center of the inlet passage 11 is defined as the x-axis, with a plane orthogonal to the x-axis, i.e., the two axes that would be drawn on a paper surface. Fig. 1. They are orthogonal to each other, defined as the y-axis and z-axis.

[0020] The throttle valve 31 is a disc-shaped butterfly valve provided in the inlet passage 11 to adjust the degree of opening. The shaft 32 is rotatably supported along the z-axis by a shaft support section 12 of the body 10 and a bearing 34 provided on a projecting cylindrical section 14 of the body 10, with the throttle valve 31 being attached to the shaft 32. The valve train 40 comprises a gear section 41, a hub section 42, an extension section 45, and the like. A tip section 325 of the shaft 32 is inserted into a shaft insertion hole 43 of the hub section 42, with the shaft 32 being attached to the valve train 40. The exact configuration of the valve train 40 will be described later.

[0021] The actuator 80, such as a DC motor, is housed in an actuator housing chamber 18 of the body 10 and outputs a drive torque. The intermediate gear 82 can rotate about a bolt or pin 83, which is supported by the body 10 and the cover 20, and reduces the rotation of an output gear 81 of the actuator 80 and transmits the rotation to the gear section 41 of the valve train 40. When the actuator 80 is rotated by excitation, the valve train 40 is rotated by the drive torque transmitted via the intermediate gear 82, and the shaft 32 and the throttle valve 31, which are attached to the shaft train 40, are rotated integrally.

[0022] The spring 50 is extrapolated to an outer wall of the hub section 42 of the valve train 40 and generates a compressive force in one direction of rotation with respect to the drive torque in order to maintain the opening degree of the throttle valve 31 at a predetermined degree. A guide 601 serves as a buffer between the valve train 40 and the spring 50 for sliding when the valve train 40 rotates. The exact configuration of the spring 50 and the guide 601 will also be described later. Here, in the throttle device 100 of the present embodiment, a valve train sub-assembly 701, which is formed by mounting the valve train 40 and the spring 50, is shown in a valve train receiving chamber 13 (see Fig. 6) of the body 10. Next, the configuration of the valve train subassembly 701 of the first embodiment is described with reference to the Fig. 2 to 4 described. Fig. Figure 2 shows each part before the valve train subassembly 701 is assembled. Fig. Figure 3 schematically shows the appearance of the valve train sub-assembly 701 and Fig. Figure 4 schematically shows an axial cross-section of the valve train subassembly 701.

[0023] As in the Fig. As shown in Figures 2 to 4, the valve train subassembly 701 contains the valve train 40, the spring 50, and the guide 601. Fig. Figure 4 shows the positions of the projecting cylinder section 14, the shaft 32 and the bearing 34 of the body 10 by dashed lines in a state in which the valve train sub-assembly 701 is received in the valve train receiving chamber 13 of the body 10.

[0024] The valve train 40 is made of a resin material, such as PA6T (polyamide 6T), with the gear section 41, the hub section 42, and the extension section 45 being integrally formed. The gear section 41 rotates due to the drive torque transmitted from the output gear 81 of the actuator 80 via the intermediate gear 82. Fig. In figure 4, the axis of rotation of the gear section 41 is denoted as z. Only about one-third of the total circumference of the gear section 41 is actually formed with teeth; however, the entire flat plate section, which includes the section without teeth, is referred to as the "gear section 41".

[0025] The hub section 42 is provided on the gear section 41 and has a cylindrical outer wall 425. In the present embodiment, the hub section 42 is coaxial with the axis of rotation z of the gear section 41. A shaft insertion hole 43, into which the tip section 325 of the shaft 32 is inserted, is formed inside the hub section 42. The shaft insertion hole 43 can, for example, be formed from a metal element embedded in a resin. The tip section 325 of the shaft 32 penetrates the shaft insertion hole 43 and is exposed on the side of the gear section 41, so that it can be crimped on the side of the gear section 41.

[0026] Since the length of the hub section 42 is shorter than the height of the spring and the guide 601, a mounting space 54, indicated by a thick alternating long and short dashed line, is formed in the section where the hub section 42 is not present inside the spring 50 and the guide 601. The mounting space 54 is a space in which the projecting cylinder section 14 can be mounted when the valve train subassembly 701 is received in the valve train receiving chamber 13.

[0027] The extension section 45 extends axially from the gear section 41 on the radially outer side of the hub section 42. As in Fig. As shown in Figure 3, a first locking section 451 is provided for engaging a first hook 51 of the spring 50 on a base side near the gear section 41 on the left side of the drawing. Furthermore, a second locking section 452 is provided for engaging a second hook 52 of the spring 50 on a tip side farther from the gear section 41 on the right side of the drawing.

[0028] The first detent section 451 and the second detent section 452 absorb the compressive force of the spring 50. Therefore, PA6T or the like is selected as the material for the valve train 40, as it exhibits sufficient strength to withstand the drive torque and the spring load. In the perspective view from Fig. Figure 2 does not show the first locking section 451 and the second locking section 452. Furthermore, in Fig. 3 the outer diameter shape of the extension section 45 is essentially trapezoidal, wherein this is in Fig. 2 is simplified and described as an essentially rectangular shape.

[0029] The spring 50 is provided with the first hook 51 at the end of the spiral body 53 on the side of the gear section 41 in the axial direction. (Hereinafter, the reference numeral "41" is omitted and this is referred to as the "side of the gear section".) Furthermore, a second hook 52 is provided at the end on the side opposite to the gear section 41 in the axial direction (hereafter referred to as the "opposite side of the gear section"). The spiral body 53 is mounted externally on the outer wall 425 of the hub section 52 of the valve train 40. The first hook 51 and the second hook 52 each engage on opposite sides of the extension section 45 of the valve train 40 in the circumferential direction.

[0030] When the valve train sub-assembly 701 is received in the valve train receiving chamber 13 of the body 10, the second hook 52 engages in a body locking section 16, which is indicated by a dashed line in Fig. As shown in Figure 4, the spring 50 generates a pressure force by attaching the shaft 32 to the valve train 40, so that the opening degree of the throttle valve 31 is maintained at a predetermined opening degree.

[0031] The guide 601 is formed in a cylindrical shape from a resin material, for example PA (polyamide), containing PTFE (polytetrafluoroethylene), which exhibits good sliding properties. Since the guide 601 has a thin cylindrical shape, its volume is less than the volume of the valve train 40, and the amount of material used to form the guide 601 is small. Furthermore, the guide 601 is divided into two parts in the axial direction: a first guide 611 and a second guide 621. In the present embodiment, the first guide 611 has a relatively short axial length on the side of the gear section, while the second guide 621 has a relatively long axial length on the opposite side of the gear section. However, the basic shapes of the first guide 611 and the second guide 621 are identical.

[0032] The following describes the identical elements of the first guide 611 and the second guide 621 as the subject of the guide 601. The guide 601 has a cylindrical guide body 65 and an edge section 66 that projects outwards from an axial end section of the guide body 65. The outer diameter of the edge section 66 is configured to be equal to or slightly larger than the outer diameter of the coil body 53 of the spring 50. The first guide 611 and the second guide 621 are shaped such that the ends of the guide body 65 are joined to each other on opposite sides of the edge section 66.

[0033] The main guide body 65 of the first guide 611 is inserted externally in an area covering approximately half of the outer wall 425 of the hub section 42 on the gear section side. Furthermore, a section of the main guide body 65 of the second guide 621 is inserted externally opposite the edge section 66 in an area covering approximately half of the opposite side of the gear section. The section of the first guide 611 and the second guide 621 that is inserted externally on the outer wall 425 of the hub section 42 dampens the sliding of the hub section 42 and the spring 50 due to the rotation of the gear section 41. That is, since the guide 601 lies between the hub section 42 and the spring 50, the valve train 40 and the spring 50 do not slide or rub directly against each other, thus reducing the load due to the sliding resistance.

[0034] The section of the main guide body 65 of the second guide 621 on the side of the edge section 66 is fixed in an outer wall 145 of the projecting cylindrical section 14 of the body 10. The previously described section of the second guide 621 serves as a buffer for the sliding of the projecting cylindrical section 14 and the spring 50 due to the twisting of the spring 50. That is, since the guide 601 lies between the hub section 42 and the spring 50, the body 10 and the spring 50 do not slide directly or rub directly against each other, thus reducing the load due to the sliding resistance.

[0035] Next, a method for manufacturing the throttle device 100 according to the present embodiment is described with reference to the flowchart from Fig. 5 and the Fig. Section 6 is described. In the following flowcharts, a symbol S indicates a step. This flowchart primarily describes the process of receiving the valve train 40 and the spring 50 as subassemblies in the valve train receiving chamber 13 of the body 10. The assembly and inspection processes for other parts are simplified or omitted.

[0036] In valve assembly step S1, the throttle valve 31 and the shaft 32 are mounted to the body 10. Fig. Figure 6 shows a state after valve assembly step S1 and before pickup step S3. In particular, the bearing 34 is held inside the projecting cylindrical section 14 of the body 10 and between the projecting cylindrical section 14 and an outer circumference of the shaft 32. Then the throttle valve 31, which is arranged in the inlet passage 11, and the shaft 32, which is rotatably supported by the body 10, are fastened by screws or the like.

[0037] In a sub-assembly step S2, the valve train 40, the spring 50 and the guide 601 are assembled to form the valve train sub-assembly 701, which is located in the Fig. The process is shown in sections 2 to 4. Either the valve assembly step S1 or the sub-assembly step S2 can be performed first.

[0038] After valve assembly step S1 and sub-assembly step S2, in a receiving step S3 the valve train sub-assembly 701 is placed in the valve train receiving chamber 13 of the body 10 in the state shown in Fig. As shown in Figure 6, the spring 50 is engaged with the body locking section 16 of the body 10. At this time, the projecting cylindrical section 14, in which the bearing 34 is supported internally, fits into the mounting space 54 formed inside the spring 50 of the valve train subassembly 701. In this way, the bearing 34 is held between the outer circumference of the shaft 32 and the projecting cylindrical section 14 in a position that overlaps the spring 50 in the axial direction. Furthermore, the end section 325 of the shaft 32 is inserted into the shaft insertion hole 43 of the hub section 42 by means of a gap fitting, penetrating to the side of the gear section 41.

[0039] Following the insertion step S3, in a shaft fastening step S4, the shaft 32 is connected to the hub section 42 of the valve operation 40 in a state in which the rotational position of the throttle valve 31 is adjusted. In particular, for example, the tip section 325 of the shaft 32, which penetrates the shaft insertion hole 43 of the hub section 42, is crimped.

[0040] Following shaft mounting step S4, in an assembly step for an actuator and a cover S5, the actuator 80 is placed in the actuator receiving chamber 18, the intermediate gear 82 is attached to the pin 83, and then the cover 20 is attached to the body 10. Details of the assembly step for the actuator and the cover S5 are omitted. (Effects)

[0041] The effects of the throttle device 100 and the method for manufacturing the throttle device 100 of the first embodiment are described below.

[0042] (1) In the throttle device 100 of the present embodiment, the valve train sub-assembly 701 is configured with the valve train 40 and the spring 50 pre-assembled, such that the first hook 51 and the second hook 52 of the spring 50 engage on the extension section 45 of the valve actuator. For example, after picking up the valve train sub-assembly 701 in the valve train receiving chamber 13 of the body 10, the operator then crimps the tip section 325 of the shaft 32, which penetrates the shaft insertion hole 43 of the hub section 42, and then fastens the shaft 32 to the hub section 42 of the valve actuator 40.

[0043] Therefore, it is not necessary to temporarily mount the valve train 40 and the spring 50 on the shaft 32 while adjusting the rotational positions of the valve train 40 and the spring 50 after the body 10 has been received, thus improving assembly. Furthermore, in contrast to the conventional method from patent document 1 (JP 2003-120335 A), the valve train and the shaft are not integrated, thus simplifying assembly.

[0044] (2) In the first embodiment, the guide 601 is further provided as a component of the valve train subassembly 701. The guide 601 has the cylindrical guide body 65 between the outer wall 425 of the hub section 42 and the spring 50, serving as a buffer for sliding between the hub section 42 and the spring 50 due to the axial rotation of the gear section 41 on the side of the gear section. That is, since the guide 601 is located between the outer wall 425 and the spring 50, the valve train 40 and the spring 50 do not slide directly against each other, thus reducing the load due to the sliding resistance. Similarly, on the opposite side to the gear section, the body 10 and the spring 50 do not slide directly against each other in the axial direction, thus reducing the load due to the sliding resistance.

[0045] In an embodiment where the valve train 40 and the spring 50, or the body 10 and the spring 50, slide directly against each other without the guide 601, it is necessary to design the valve train 40, for example, with a large volume using a material with good sliding properties, such as PTFE, which results in high material costs. On the other hand, in the first embodiment, which includes the guide 601, it is sufficient to design only the guide 601, which has a cylindrical shape and a small volume and is made of a material with good sliding properties. Therefore, the material costs can be reduced.

[0046] (3) The guide 601 of the first embodiment is divided into two parts in the axial direction: the first guide 611 on the side of the gear section and the second guide 621 on the opposite side of the gear section. Consequently, the first guide 611 and the second guide 621 can rotate, each following the rotation of both ends of the spring 50 on the side of the gear section and the opposite side of the gear section, thus reducing the load due to sliding resistance. Furthermore, it is possible to adjust the positions of both ends in the axial direction of the spring 50 and to prevent the spring 50 from falling down in the subassembled state, since the guide 601 has the edge section 66.

[0047] (4) The valve train sub-assembly 701 has the mounting space 54 inside the spring 50, into which the projecting cylinder section 14 can be mounted when the valve train sub-assembly 701 is received into the valve train receiving chamber 13 of the body 10. Consequently, the valve train sub-assembly 701 and the bearing 34, which is held by the projecting cylinder section 14, overlap in the axial direction, so that the space of the valve train receiving chamber 13 can be reduced. (Second embodiment)

[0048] Next, the second to fourth embodiments, in which the structure of the guide in the valve train subassembly is partially modified compared to the first embodiment, are described. The reference numerals of the guides and the valve train subassemblies of each embodiment are numbered with the third digit following "60" and "70". Furthermore, the reference numerals of the first guide and the second guide, into which the guides are divided into two parts, are indicated by the numbers of the embodiments in the third digit following "61" and "62".

[0049] As in Fig. As shown in Figure 7, the guide 602 in the valve train subassembly 702 of the second embodiment comprises a first guide 612 and a second guide 622, which are divided into two parts in the axial direction. In addition to the edge section 66, the first guide 612 and the second guide 622 have a side wall section 67 that extends from a circumferential edge of the edge section 66 toward the center position in the axial direction. As indicated by an alternating long and short dashed line on the left side of the Fig. As shown in Figure 7, the side wall section 67 is removed at a position where it obstructs the first hook 51 and the second hook 52.

[0050] The side wall section 67 guides the spring 50 on the outside, or at least at its end in the axial direction. Therefore, the first guide 612 and the second guide 622 have a guiding function for the spring 50 on both the inner and outer sides in the radial direction. In the embodiment described in Fig. As shown in Figure 7, the length of the side wall section 67 corresponds approximately to 1 to 1.5 times the diameter of the wire of the spring, although the side wall section 67 may be set longer. (Third embodiment)

[0051] As in Fig. As shown in Figure 8, a guide 603 in the valve train subassembly 703 of the third embodiment comprises a first guide 613 and a second guide 623, which are divided into two parts in the axial direction. In addition to the edge section 66 and the side wall section 67, the first guide 613 and the second guide 623 project radially outward from the axial end section of the guide main body 65 in a circumferential direction, having a cover section 68 that covers the first hook 51 and the second hook 52. Consequently, the contact area at the contact point between the first hook 52 and the body locking section 16 is increased, thereby reducing the surface pressure and thus decreasing the wear of the body 10. Furthermore, the gap between the first hook 52 and the body locking section 16 at the initial rotational position is reduced, suppressing rattling or wobbling. (Fourth embodiment)

[0052] As in Fig. As shown in Figure 9, a guide 604 in the valve train subassembly 704 of the fourth embodiment comprises a first guide 614 and a second guide 624, which are divided into two parts in the axial direction. The first guide 614 and the second guide 624 consist only of a cylindrical main body section 65 and do not have an edge section 66, a side wall section 67, or a cover section 68 as in the first to third embodiments. Even with this configuration, it is not necessary to design the valve train 40 to be made of a material with good sliding properties, since the valve train 40 and the spring 50 do not slide directly against each other, thus reducing material costs.

[0053] As a modification of the fourth embodiment, the wall section 66 can be provided only at one end of the first guide or the second guide, while the wall section 66 may not be provided at the other end. That is, a single guide can have a wall section 66. Similarly, at least one single guide can have a side wall section 67 and a cover section 68. Furthermore, the guide can be configured as an integral cylindrical shape instead of being divided into two parts. Even if it is an integral guide, it can serve as a buffer for sliding between the valve train 40 and the spring 50 by being made of a material with good sliding properties. By configuring the guide as a single part, the number of parts can be reduced. (Other embodiments)

[0054] (A) The first to fourth embodiments all include the guides 601 to 604. However, if the need to reduce material costs is low, or if a material with good sliding properties can be obtained at low cost, the valve train 40 can be formed from a material with good sliding properties without providing the guide.

[0055] (B) In the previous embodiments, the first hook 51 engages circumferentially on one side of a single extension section 45 of the valve train 40, and the second hook 52 engages circumferentially on the other side of the single extension section 45. In a further embodiment, the valve train 40 can be provided with a first extension section into which the first hook 51 engages and a second extension section into which the second hook 52 engages.

[0056] (C) In the previous embodiments, the mounting space 54, into which the projecting cylinder section 14 can be mounted, is formed in a section in which the hub section 42 is not present inside the spring 50, since the length of the hub section 42 of the valve train 40 is shorter than the height of the spring 50. However, the length of the hub section 42 can be equal to or greater than the height of the spring 50, in which case the mounting space 54 may not be formed inside the spring 50. In this case, the projecting cylinder section 14 of the body 10 and the spring 50 do not slide, with the guide 601 or the like acting as a buffer to prevent the valve train 40 and the spring 50 from sliding over the entire length of the spring 50.

[0057] Furthermore, in this case, the bearing 34 is arranged in a position that does not overlap with the spring 50 in the axial direction. Even if the projecting cylindrical section 14 is fixed in the mounting space 54, the bearing 34 can be arranged in a position that is lower than the end surface of the projecting cylindrical section 14 and does not overlap with the spring 50 in the axial direction.

[0058] (D) The hub section 42 need not be coaxial with the axis of rotation z of the gear section 41, but may be non-centered with respect to the axis of rotation z. Furthermore, the cylindrical outer wall 425 of the hub section 42 may be substantially completely cylindrical and may have grooves, projections or the like formed in part of the outer circumference or the inner circumference.

[0059] The present disclosure is not limited to the embodiment previously described, but various modifications may be made within the scope of the following disclosure.

[0060] The present embodiment was carried out in accordance with the embodiments. However, the present disclosure is not limited to such embodiments and configurations. The present disclosure also includes various modifications and variations within the scope of equivalents. Furthermore, various combinations and configurations, including those containing one, more than one, or fewer than one element, may be included in the present disclosure.

Claims

[1] comprising a throttle device: a body (10) on which an inlet opening (11) is formed; a throttle valve (31) which is provided in the inlet passage and whose degree of opening is adapted; a shaft (32) which is rotatably carried through the body and to which the throttle valve is attached; an actuator (80) configured to output a drive torque; a valve train (40) comprising a gear section (41) configured to rotate by the drive torque transmitted by the actuator, a hub section (42) provided on the gear section having a cylindrical outer wall (425), and one or more extension sections (45) extending in an axial direction from the gear section on a radially outer side of the hub section to form the gear section, hub section, and extension section integrally; a spiral spring (50) comprising a first hook (51) extrapolated to the outer wall of the hub section of the valve train and provided at an end section on one side of the gear section, and a second hook (52) provided at an end section on the opposite side to the gear section, such that the first hook and the second hook each engage on opposite sides to each other in a circumferential direction of the extension section, and a guide (601-604) with a cylindrical guide main body (65) provided between the outer wall of the hub section and an inner circumference of the spring, and configured to act as a buffer to prevent sliding of the hub section and the spring as a result of rotation of the gear section on at least the side of the gear section in the axial direction, wherein the guide is a component of a valve train subassembly, wherein the valve train sub-assembly (701-704), which is formed by mounting the valve train, the spring and the guide, is received in a valve train receiving chamber (13) of the body, wherein the second hook of the spring engages with the body, and the shaft is attached to the hub section of the valve train. [2] Throttle device according to claim 1, wherein the guide is divided into two parts in the axial direction. [3] Throttle device according to claim 1 or 2, wherein the at least one guide (601-603) has an edge section (66) which projects in a radial direction from an axial end section of the guide main body. [4] Throttle device according to claim 3, wherein the at least one guide (602, 603) has a side wall section (67) which extends from a peripheral edge of the edge section towards a central position in the axial direction and guides the spring at least at the axial end section on an outside. [5] Throttle device according to one of claims 1 to 4, wherein the at least one guide (603) has a cover section (68) which covers the first hook and the second hook of the spring and projects outwards in a circumferential direction from an axial end section of the guide main body in a part. [6] Throttle device according to any one of claims 1 to 5, wherein the body is designed with a projecting cylindrical section (14) that projects onto a lower section of the valve train receiving chamber, the valve train subassembly has a mounting space (54) inside the spring in which the projecting cylinder section is mounted when the valve train subassembly is received in the valve train receiving chamber, and a bearing (34) inside the projecting cylindrical section is held in a position which overlaps the spring in the axial direction with an outer circumference of the shaft. [7] Method for manufacturing a throttle device comprising a body (10) on which an inlet opening (11) is formed; a throttle valve (31) which is provided at the inlet passage and whose degree of opening is adapted; a shaft (32) which is rotatably carried through the body and to which the throttle valve is attached; an actuator (80) configured to output a drive torque; a valve train (40) comprising a gear section (41) configured to rotate by the drive torque transmitted by the actuator, a hub section (42) provided on the gear section having a cylindrical outer wall (425), and one or more extension sections (45) extending in an axial direction from the gear section on a radially outer side of the hub section to integrally form the gear section, the hub section, and the extension section; a spiral spring (50) comprising a first hook (51) extrapolated to the outer wall of the hub section of the valve train and provided at an end section on one side of the gear section, and a second hook (52) provided at an end section on an opposite side of the gear section, such that the first hook and the second hook each engage on opposite sides to each other in a circumferential direction of the extension section; and a guide (601-604) with a cylindrical guide main body (65) provided between the outer wall of the hub section and an inner circumference of the spring, and configured to act as a buffer to prevent sliding of the hub section and the spring as a result of rotation of the gear section at least on the side of the gear section in the axial direction, wherein the guide is a component of a valve train subassembly, comprising: a valve assembly step (S1) in which the throttle valve and the shaft are mounted to the body; a sub-assembly step (S2) in which the valve train, spring and guide are assembled to form a valve train sub-assembly (701-704); a receiving step (S3) after the valve assembly step and the sub-assembly step, in which the valve train sub-assembly is received in a valve train receiving chamber (13) of the body, wherein the second hook of the spring engages on the body; and a shaft fastening step (S4) after the receiving step, in which the shaft is fastened to the hub section of the valve train in a state in which the rotational position of the throttle valve is adjusted.

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