Method of manufacturing a throttle gear for a throttle device

Abstract

The present application provides a method of manufacturing a throttle gear of a throttle device, capable of adjusting the relationship between the full-closed position and the default position with high precision, regardless of the size and posture deviation of the spring of the throttle device. One embodiment is a method of manufacturing a throttle gear (30) of a throttle device, wherein the throttle device is provided with a spring (40) that exerts a force on the throttle gear (30) toward a default position, and the throttle gear (30) is provided with a spring engagement portion (38) that is abutted by the spring (40) when a throttle valve member (20) is opened to above the default position. The method has the following steps: forming the throttle gear (30) by resin molding; and thereafter, forming an abutment surface (38k) of the spring engagement portion (38) by cutting processing on a molded surface (38a) of the spring engagement portion (38).

Description

Technical Field

[0001] The technology disclosed in this application relates to a method for manufacturing throttle gears for throttle valve devices. Background Technology

[0002] The throttle mechanism of an automobile, which regulates the amount of air supplied to the engine, typically opens and closes the intake passage formed in the main body by rotating a shaft fixed to the throttle valve member (disc) using an electric motor. In most cases, such a throttle mechanism includes a mechanism to rotate the throttle valve member to a predetermined default position, ensuring a certain amount of air intake even when the power to the motor is cut off. For example, in the throttle mechanism disclosed in Japanese Patent Application Publication No. 2022-149183, a torsion spring mounted on the throttle gear applies force to the throttle valve member toward the default position. To define this default position, the spring is provided with an intermediate hook that can engage with engagement parts respectively provided on the throttle body and the throttle gear.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-149183 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The aforementioned literature discloses a method that uses a fixture capable of supporting the throttle gear and spring sub-assemblies in a state substantially identical to when assembled onto the throttle body. With the sub-assemblies mounted on this fixture, the contact surface of a predetermined stop is machined a second time to accurately adjust the relationship between the fully closed position and the default position. However, in this method, the stop is machined a second time while the throttle gear and spring are combined. Therefore, due to deviations in the position of the spring's center hook and the spring's posture, the reproducibility when assembled onto the throttle body after machining is sometimes reduced. To avoid this, it is necessary to either set the fixture in a manner consistent with the state of assembly onto the throttle body, or to machine the predetermined dimensions based on an assumed position considering the state of assembly onto the throttle body, which becomes cumbersome. Therefore, a method is desired that can adjust the relationship between the fully closed position and the default position with high precision, unaffected by spring deviations.

[0008] Solution for solving the problem

[0009] One technical solution disclosed herein is a method for manufacturing a throttle gear in a throttle body assembly. The throttle body assembly includes a spring that applies force to the throttle gear toward a default position. The throttle gear has a spring-engaging portion, and when the throttle valve component is opened to a position above the default, the spring abuts against this spring-engaging portion. The method for manufacturing the throttle gear includes the following steps: forming the throttle gear by resin molding; and subsequently, machining the formed surface of the spring-engaging portion to form an abutting surface. This allows for adjusting the relationship between the fully closed position and the default position before assembling the throttle gear with the spring and throttle body, thus enabling high-precision adjustment of the relationship between the fully closed position and the default position without being affected by spring deviation. Furthermore, compared to the formed surface before machining, the abutting surface has higher straightness, resulting in a more stable spring mounting posture and improved reproducibility of the default position of the throttle valve component.

[0010] According to the technical solution, the throttle gear has a gear-side fully closed stop that abuts against a body-side fully closed stop (115) provided on the throttle body of the throttle device when the throttle valve component is in the fully closed position. The abutting surface of the spring engagement portion, formed by the cutting process, is based on the abutting surface of the gear-side fully closed stop. Therefore, a proper relationship between the fully closed position and the default position of the throttle valve component can be achieved with high precision.

[0011] According to the technical solution, the throttle gear is made of resin containing glass fibers, and the cross-section of the glass fibers formed by the cutting process is exposed on the contact surface of the spring engagement portion. Therefore, by inspecting the surface condition of the machined part of the throttle gear, it can be confirmed whether machining has been performed. Attached Figure Description

[0012] Figure 1 This is a perspective view of a throttle valve device according to one embodiment.

[0013] Figure 2 This is viewed from the axial direction of the air passage. Figure 1 Throttle valve device Figure 1 The longitudinal section view at line II-II.

[0014] Figure 3 It is viewed from a direction perpendicular to the axis of the air passage. Figure 1 Throttle valve device Figure 1 The longitudinal section view at line III-III.

[0015] Figure 4 yes Figure 1 A side view of the throttle body.

[0016] Figure 5It constitutes Figure 1 An exploded perspective view of the throttle gear and spring of the throttle body.

[0017] Figure 6 It is a three-dimensional view showing the throttle valve gear and spring, as well as the stop of the throttle valve body, in the default position of the throttle valve components.

[0018] Figure 7 This is a top view showing the throttle valve gear and spring, as well as the stop of the throttle valve body, with the throttle valve components in their default position.

[0019] Figure 8 It is a three-dimensional view showing the throttle valve gear and spring, as well as the stop of the throttle valve body, when the throttle valve components are in the fully closed position.

[0020] Figure 9 This is a top view showing the throttle valve gear and spring, as well as the stop of the throttle valve body, in the fully closed position.

[0021] Figure 10 It is a side view of a throttle gear with an abutment surface of a gear-side spring engagement portion formed by cutting, with only the gear-side spring engagement portion shown in cross section.

[0022] Explanation of reference numerals in the attached figures

[0023] 10. Throttle body; 11h. Air passage; 11. Passage forming part; 12. Gear housing part; 13. Motor housing part; 14. Motor; 20. Throttle valve component; 21. Throttle shaft; 30. Throttle gear; 31. Gear; 31z. Spring locking part; 32. Cylindrical part; 33. Flange part; 35. Connecting plate; 37. Fully closed stop; 37m. Abutment surface; 38. Gear side spring engaging part; 38a. Formed surface; 38k. Abutment surface; 40. (Torsion) spring; 43. Return spring part; 43f. End; 45. Opening spring part; 45b. End; 47. Intermediate hook; 115. Stop (body side spring engaging part, body side fully closed stop); 115f. Abutment surface; 116. Spring locking part. Detailed Implementation

[0024] Next, various embodiments will be described with reference to the accompanying drawings.

[0025] Throttle body assembly

[0026] Figures 1-4This refers to a throttle valve device as one embodiment installed in a vehicle such as an automobile and regulating the amount of air entering the engine. The throttle valve device includes a throttle valve body 10, which has a passage forming portion 11, which is formed into a generally cylindrical air passage (hole) 11h that is part of the air intake passage of the engine.

[0027] A rotatable, circular throttle valve member 20, which regulates the flow rate through the air passage 11h, is disposed within the air passage 11h of the throttle body 10. The throttle valve member 20 is supported within the air passage 11h and is able to rotate between a fully closed position and a fully open position. A throttle shaft 21, extending transversely through the air passage 11h, is provided in the throttle body 10. The throttle shaft 21 is fixed at the center of rotation of the throttle valve member 20 in a non-rotatable state. The throttle shaft 21 is supported on both sides of the air passage 11h by bearings 11r and 11j mounted on the throttle body 10, allowing it to rotate.

[0028] The throttle body includes a motor 14 as a drive source for driving the throttle valve member 20. The rotation output from the motor 14 is transmitted to the throttle shaft 21 via a transmission mechanism. In one embodiment, the transmission mechanism consists of a drive gear 14w fixed to the output shaft of the motor 14, an intermediate gear 16 rotatably supported on the throttle body 10 via an intermediate shaft, and a throttle gear 30 coaxially fixed to the throttle shaft as a driven gear. The motor 14 and the transmission mechanism are respectively housed in a gear housing portion 12 and a motor housing portion 13 integrally formed with the passage forming portion 11 of the throttle body 10. The gear housing portion 12 and the motor housing portion 13 are enclosed by a cover member (not shown). The intermediate gear 16 has a large-diameter tooth 16r and a small-diameter tooth 16s. The large-diameter tooth 16r meshes with the drive gear 14w, and the small-diameter tooth 16s meshes with the tooth 31 of the throttle gear 30. The opening degree of the throttle valve component 20 is adjusted by controlling the rotation direction and amount of the motor 14.

[0029] [Throttle gear]

[0030] The throttle gear 30 can be made of resin. The resin can be a fiber-reinforced resin containing fibers such as glass fibers. For example... Figure 5 As shown, the throttle gear 30 has, for example, a cylindrical portion 32 and a flange portion 33 extending outward from the end of the cylindrical portion 32. The teeth 31 of the throttle gear 30 are disposed on a portion of the outer periphery of the flange portion 33.

[0031] like Figure 2As shown, the end of the throttle gear 30 protruding into the gear housing portion 12 of the throttle body 10 of the throttle shaft 21 is mounted in a manner that prevents relative rotation. The throttle gear 30 includes a connecting plate 35 fixed to a cylindrical portion 32 (e.g., an inner flange portion 34). The connecting plate 35 can be fixed, for example, by embedding its outer periphery into the cylindrical portion 32 of the throttle gear 30 using an insert forming method. The connecting plate 35 has a through hole 35k. The end of the throttle shaft 21 passes through the through hole 35k of the connecting plate 35 and is fixed by appropriate methods such as riveting, threading, or welding. Thus, the throttle shaft 21 and the throttle gear 30 are kept in a position where they cannot rotate relative to each other.

[0032] like Figure 4 , Figure 5 As shown, the throttle gear 30 has a fully closed stop 37 that can abut against the stop 115 provided on the throttle body 10. The fully closed position of the throttle valve component 20 is defined by the contact surface 37m of the fully closed stop 37 of the throttle gear 30 and the contact surface 115f of the stop 115 of the throttle body 10. Figure 3 double-dotted lines and Figure 8 ).

[0033] [spring]

[0034] like Figures 5-9 As shown, the throttle valve assembly has the capability to orient the throttle valve component 20 toward the default position ( Figure 3 solid lines and Figure 6 A torsion spring 40 applies force. The default position is a predetermined position that is opened by a small angle relative to the fully closed position. When the motor 14 is energized, the throttle valve component 20 can be rotated to any position between the fully closed and fully open positions by overcoming the force of the spring 40. When the energization of the motor 14 is cut off, the throttle valve component 20 can be automatically rotated to the default position by the force of the spring 40, supplying a certain amount of air to the engine through the air passage 11h.

[0035] The spring 40 can be configured as a spring consisting of a return spring portion 43 and an opening spring portion 45 wound in opposite directions and connected in series, and is installed between the throttle body 10 and the throttle gear 30 (around the cylindrical portion 32 of the throttle gear 30). Figure 2 The two ends 43f and 45b of the spring 40 are bent in a radially outward manner, and one end 43f is locked to the spring locking part 116 provided in the throttle body 10. Figure 4 The other end 45b is locked to the spring locking part 31z provided on the throttle gear 30.

[0036] The connection between the reset spring part 43 and the opening spring part 45 forms a U-shaped fold-back portion, which bends outward in a radially outward manner. This bent fold-back portion acts as an intermediate hook 47, abutting against the contact surface 38k of the gear-side spring engagement portion 38 provided on the throttle gear 30 and the stop member (body-side spring engagement portion) 115 provided on the throttle body 10. Figure 4 The gear-side spring engagement portion 38 can be formed, for example, to protrude from the flange portion 33 of the throttle gear 30 in the vicinity of the spring locking portion 31z in the same direction as the cylindrical portion 32.

[0037] With the throttle gear 30 in the default position ( Figure 6 , Figure 7 When the throttle body is in operation, the intermediate hook 47 engages with the gear-side spring engagement part 38 provided on the throttle gear 30 and the stop member 115 provided on the throttle body 10. At this time, both the reset spring part 43 and the opening spring part 45 are in a state of being preloaded by twisting from their natural state in the direction of diameter reduction (a state of accumulating elastic energy).

[0038] When the throttle gear 30 is driven by the motor 14 to move from the default position to the fully closed position ( Figure 8 , Figure 9 When the throttle gear 30 rotates, the intermediate hook 47 of the spring 40 engages with the stop 115 provided on the throttle body 10, thus deactivating the return spring portion 43, which is constrained at both ends by the throttle body 10. On the other hand, the throttle gear 30 rotates relative to the throttle body 10 with the intermediate hook 47 engaged with the stop 115 on the body side, thus disengaging the gear-side spring engagement portion 38 of the throttle gear 30 from the intermediate hook 47. The throttle gear 30 rotates while holding the end 45b of the spring 40, thus further twisting the opening spring portion 45 in the direction of diameter reduction. If the power supply to the motor 14 is cut off when the throttle gear 30 is in a position closer to the fully closed position than the default position, the throttle gear 30 returns to the default position by the force of the opening spring portion 45.

[0039] When the throttle gear 30 is driven by the motor 14 to rotate from the default position to the fully open position, the intermediate hook 47 remains engaged with the gear-side spring engagement portion 38 of the throttle gear 30. Therefore, the opening spring portion 45, which is constrained at both ends by the throttle gear 30, is deactivated. On the other hand, the throttle gear 30 rotates relative to the throttle body 10 while the intermediate hook 47 is engaged by the gear-side spring engagement portion 38. Therefore, the return spring portion 43 twists further in the direction of diameter reduction. If the power supply to the motor 14 is cut off when the throttle gear 30 is in a position closer to the fully open position than the default position, the throttle gear 30 returns to the default position by the force of the return spring portion 43.

[0040] In addition, such as Figures 6-9 As shown, the abutting surface 115f of the stop member 115 of the throttle body 10 can be formed such that the portion abutted by the intermediate hook 47 of the spring 40 (the spring engagement portion on the body side) and the portion abutted by the fully closed stop member 37 of the throttle gear 30 (the fully closed stop member on the body side) are on the same plane. However, as another embodiment not shown, the two portions of the abutting surface 115f can also be formed on different planes or disposed at completely different positions on the throttle body 10.

[0041] As an alternative embodiment not shown, the return spring and the opening spring may not be formed as parts of a continuous single spring 40 as described above (i.e., return spring portion 43 and opening spring portion 45), but rather as independent springs. In this case, the portion corresponding to the intermediate hook 47 described above can be configured as a connecting member linking the return spring portion 43 and the opening spring portion 45. Such a structure has been disclosed, for example, in Japanese Patent Application Publication No. 2018-100598.

[0042] [Form of the contact surface of the gear-side spring engagement portion]

[0043] like Figure 10 As shown, the abutment surface 38k of the gear-side spring engagement portion 38 provided on the throttle gear 30 is formed after the throttle gear 30 is formed by resin molding and before it is assembled to the throttle body 10. Specifically, by using a suitable cutting tool to cut the forming surface 38a of the gear-side spring engagement portion 38, the abutment surface 38k is formed at a position that corresponds to a predetermined angle θ from the abutment surface 37m of the fully closed stop member 37 of the throttle gear 30, corresponding to the default opening degree. As a result, the relationship between the fully closed position and the default position can be adjusted before the throttle gear 30 is assembled to the spring 40 and the throttle body 10, so the relationship between the fully closed position and the default position can be adjusted with high precision without being affected by spring deviation. In addition, compared with the forming surface 38a before machining, the straightness of the abutment surface 38k is higher, thereby stabilizing the installation posture of the spring 40 and improving the reproducibility of the default position of the throttle valve member 20. Furthermore, when the throttle gear 30 is made of resin containing fibers such as glass fibers, the cross-section of the glass fibers formed by machining is exposed at the contact surface 38k. Therefore, by inspecting the surface condition of the machined part of the throttle gear 30, it can be confirmed whether machining has been performed.

[0044] [Assembly of spring and throttle gear]

[0045] Next, the spring 40 is assembled onto the throttle gear 30, and the sub-assemblies of the throttle gear 30 and the spring 40 are placed on the throttle body 10. At this stage, the throttle gear 30 and the throttle shaft 21 can still rotate relative to each other. Then, with the fully closed stop 37 of the throttle gear 30 abutting against the contact surface 115f of the stop 115 of the throttle body 10, the throttle valve member 20 fixed to the throttle shaft 21 is held in the fully closed position. Thus, the relative positional relationship between the throttle gear 30 and the throttle valve member 20 (throttle shaft 21) is determined. Then, while maintaining this positional relationship, the throttle shaft 21 and the throttle gear 30 are fixed in a way that prevents relative rotation by means such as riveting.

[0046] The above describes various implementation methods, but this technology is not limited to these implementation methods. If one is skilled in the art, one can make various changes, substitutions and improvements without departing from the spirit of this technology.

Claims

1. A method for manufacturing a throttle gear for a throttle valve device, wherein, The throttle valve assembly includes a spring that applies force to the throttle gear toward a default position. The throttle gear has a spring-engaged portion, and when the throttle valve component is opened to a position above the default position, the spring abuts against this spring-engaged portion. The method for manufacturing the throttle gear of the throttle valve device includes the following steps: The throttle gear is formed by resin molding; and Subsequently, the forming surface of the spring engagement portion is machined by cutting to form the abutment surface of the spring engagement portion.

2. The method for manufacturing the throttle gear of the throttle valve device according to claim 1, wherein, The throttle gear has a gear-side fully closed stop that abuts against a body-side fully closed stop provided on the throttle body of the throttle device when the throttle valve component is in the fully closed position. The abutment surface of the spring engagement portion, formed by the cutting process, is based on the abutment surface of the gear-side fully enclosed stop.

3. The method for manufacturing the throttle gear of the throttle valve device according to claim 1, wherein, The throttle gear is made of resin containing glass fiber, and the cross-section of the glass fiber formed by the cutting process is exposed on the contact surface of the spring engagement part.

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