Throttle device

Abstract

To provide a throttle device capable of easily manufacturing a gear of a complicated structure while securing strength of a fixing part with a throttle shaft, and suppressing manufacturing cost.SOLUTION: In a throttle device including a throttle shaft to which a throttle valve is fixed, a motor, and a deceleration mechanism that decelerates and transmits rotation of a drive shaft of the motor to the throttle shaft, the deceleration mechanism has a throttle gear 29 fixed to the throttle shaft, the throttle gear 29 has a cylindrical ring 50 into which the throttle shaft is detachably inserted and a gear body portion 40 having a gear portion 41, and the gear body portion 40 is fixed to the ring 50.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a fixing structure for a throttle shaft and a drive gear in a throttle device that controls the intake of an engine. [Background technology]

[0002] An engine mounted on a motorcycle or the like is provided with a throttle device for controlling the amount of intake air. The throttle device is configured to drive a throttle valve provided in an intake passage of the engine by, for example, a motor.

[0003] For example, Patent Document 1 discloses a throttle device equipped with four throttle valves. The throttle device in Patent Document 1 is used in an in-line four-cylinder engine and includes a throttle shaft on which four throttle valves are fixed in a row, and a motor that rotates and drives the throttle shaft. A reducer consisting of two pairs of gears is installed between the rotary drive shaft of the motor and the throttle shaft.

[0004] The throttle shaft is also equipped with a return spring (rotating spring) that regulates the opening of the throttle valve when the motor is stopped. The return spring is a coil spring installed between the reducer case and a drive gear (driven gear) attached to the throttle shaft, and urges the drive gear to rotate relative to the case. The drive gear and case of the throttle shaft are also equipped with stoppers that restrict the drive gear's rotation angle range above a predetermined value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-53713 Summary of the Invention [Problem to be solved by the invention]

[0006] In the throttle device described above, the drive gear is often made of resin or the like to reduce weight, while the throttle shaft is often made of metal or the like. It is also conceivable to provide a support for the return spring and a stopper on the outer surface of a member (lever) that has a hole in the center into which the throttle shaft is inserted and is formed into a disk shape from metal or the like to ensure strength.

[0007] In this way, in the fixing portion that fixes the resin gear, the lever having the support portion and stopper of the return spring, and the throttle shaft, a cylindrical ring (bush) into which the throttle shaft is inserted is prepared, and a drive gear including a disc-shaped lever is insert-molded, and the ring is fixed to the drive gear including the lever by, for example, crimping.

[0008] However, when the ring is crimped, there is a possibility that the insertion hole for the throttle shaft will be crushed, making it impossible to insert the ring. Therefore, after crimping, the ring must be machined using a reamer or the like so that the throttle shaft can be inserted, which poses the problem of increased manufacturing costs.

[0009] The present invention was made in consideration of these problems, and its purpose is to provide a throttle device that can easily manufacture gears with complex structures while ensuring the strength of the fixed part with the throttle shaft, thereby reducing manufacturing costs. [Means for solving the problem]

[0010] In order to achieve the above object, the throttle device of the present invention is a throttle device comprising a throttle shaft to which a throttle valve is fixed, a motor, and a reducer having a gear fixed to the throttle shaft and transmitting the rotation of the drive shaft of the motor to the throttle shaft at a reduced speed, wherein the gear has a cylindrical ring member into which the throttle shaft is detachably inserted, and a gear main body portion having a gear, the ring member is a cylindrical member made of metal and has a shaft hole at its axis through which the throttle shaft passes, and a fixing hole that passes through the axis and into which a pin extending radially is inserted, the ring member and the gear main body portion are fixed, and the gear and the throttle shaft are detachably fixed by inserting a pin into the fixing hole of the ring member.

[0011] Preferably, the ring member has a chamfered portion formed on the cylindrical outer circumferential surface at a portion that contacts the gear body.

[0012] Preferably, the ring member includes a circumferentially extending groove.

[0013] Preferably, the throttle device further includes a biasing portion that biases the throttle shaft to rotate, and a support member that supports one end of the biasing portion, and the gear is integrally formed by insert processing including the support member and the ring member.

[0014] Preferably, the ring member and the support member are made of metal, and the gear is made of resin.

[0015] Preferably, the throttle device is provided in an engine of a motorcycle and controls the amount of intake air of the engine. [Effects of the Invention]

[0016] According to the throttle device of the present invention, the gear fixed to the throttle shaft has a cylindrical ring member and a gear body, so the ring member and the gear body can be made of different materials. Therefore, by making the ring member out of a relatively strong metal, the strength of the fixed portion between the throttle shaft and the gear can be ensured. By forming the gear body out of, for example, resin, it is possible to easily form gears with complex shapes, and by forming it out of a light material, it is possible to reduce the weight of the entire gear.

[0017] Furthermore, since the ring member and the gear body are fixed together, deformation of the ring member is suppressed and post-processing after insert processing is unnecessary, which reduces the manufacturing cost of the gear and makes it possible to provide an inexpensive throttle device. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an external view of a throttle device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic diagram illustrating the configuration of a drive unit of the throttle device. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a vertical cross-sectional view of a throttle gear. [Figure 6] FIG. 2 is a perspective view showing the outer shape of the ring. [Figure 7] FIG. 2 is a perspective view showing the outer shape of the lever. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] Fig. 1 is an external view of a throttle device 10 according to one embodiment of the present invention. Fig. 2 is a schematic diagram of a drive unit of the throttle device 10. Fig. 3 is a diagram showing the internal structure of a speed reduction mechanism 20 (speed reducer). Fig. 3 is a cross-sectional view of the AA portion shown in Fig. 1.

[0021] The throttle device 10 of the present invention is a multiple throttle device that is attached to a multi-cylinder engine and controls the amount of intake air. The throttle device 10 of this embodiment is used in an in-line four-cylinder engine 1 mounted on a vehicle such as a motorcycle. The engine 1 has four cylinders (2a, 2b, 2c, 2d) numbered #1 to #4 arranged in order in the vehicle width direction (left-right direction).

[0022] As shown in FIG. 1, the throttle device 10 includes a first segment body 14a in which an intake passage 13a for the #1 cylinder 2a and an intake passage 13b for the #2 cylinder 2b are formed, and a second segment body 14b in which an intake passage 13c for the #3 cylinder 2c and an intake passage 13d for the #4 cylinder 2d are formed.

[0023] A speed reduction mechanism 20 is provided between the first segment body 14a and the second segment body 14b, i.e., between the intake passage 13b of the #2 cylinder 2b and the intake passage 13c of the #3 cylinder 2c. A motor 17 is connected to the speed reduction mechanism 20.

[0024] 1 and 2, the throttle device 10 further includes a throttle shaft 15, throttle valves 16b to 16d, a speed reduction mechanism 20, a return spring 21 (biasing portion), and a throttle position sensor 22. Note that Fig. 2 shows the structure of a drive portion provided inside the throttle device 10, in which throttle valve 16a is provided in intake passage 13a, throttle valve 16b in intake passage 13b, throttle valve 16c in intake passage 13c, and throttle valve 16d in intake passage 13d.

[0025] The first segment body 14a and the second segment body 14b are arranged side by side in the left-right direction (vehicle width direction) in accordance with the corresponding cylinders 2a to 2d to form a unit body 23 (throttle body).

[0026] The intake passages 13a to 13d are formed to extend perpendicularly (front-rear direction in Figs. 1 and 2) to the vehicle width direction (left-right direction). The throttle shaft 15 penetrates the unit body 23, extends in the vehicle width direction, passes through the four intake passages (13a, 13b, 13c, and 13d), and is rotatably supported by the unit body 23.

[0027] The throttle valves 16a to 16d are disk-shaped members with approximately the same diameter as the inner diameter of the intake passages 13a to 13d, and are fixed to the throttle shaft 15 and disposed within the intake passages 13a to 13d. The throttle valves 16a to 16d rotate within the intake passages 13a to 13d as the throttle shaft 15 rotates, and are rotatable by any angle between a closed position where they close the intake passages 13a to 13d and an open position where they open the intake passages 13a to 13d.

[0028] The motor 17 is an electric motor. The motor 17 is fixed to the second segment body 14b, and is disposed so that a rotary drive shaft 24, which is an output shaft, is parallel to the throttle shaft 15.

[0029] The reduction mechanism 20 is disposed between the first segment body 14a and the second segment body 14b. As shown in Figures 2 and 3, the reduction mechanism 20 includes a first intermediate shaft 25, a second intermediate shaft 30, a first gear 26 fixed to the rotary drive shaft 24 of the motor 17, a second gear 27 fixed to the first intermediate shaft 25 and meshing with the first gear 26, a third gear 28 fixed to the first intermediate shaft 25, a fourth gear 31 fixed to the second intermediate shaft 30 and meshing with the third gear 28, and a throttle gear 29 fixed to the throttle shaft 15 and meshing with the fourth gear 31. The first intermediate shaft 25 and the second intermediate shaft 30 are disposed parallel to the rotary drive shaft 24 and the throttle shaft 15 and are rotatably supported by the unit body 23.

[0030] The reduction mechanism 20 transmits the rotation of the rotary drive shaft 24 of the motor 17 through the first gear 26, the second gear 27, the first intermediate shaft 25, the third gear 28, the fourth gear 31, and the throttle gear 29 in that order, thereby reducing the speed and driving the throttle shaft 15 to rotate.

[0031] The return spring 21 is a cylindrical torsion spring that is wound around the throttle shaft 15 several times, with one end supported by the unit body 23 and the other end supported by a throttle gear 29 fixed to the throttle shaft 15. The return spring 21 biases the throttle shaft 15 so that the throttle valves 16c, 16d are in a closed or fully open state.

[0032] The throttle position sensor 22 is provided at one end of the throttle shaft 15 and has the function of detecting the rotation angle of the throttle shaft 15. The throttle position sensor 22 is disposed in, for example, the second segment body 14b.

[0033] Next, the structure of the fixing portion between the throttle shaft 15 and the throttle gear 29 will be described with reference to FIGS.

[0034] Fig. 4 is an outline view of the throttle gear 29. Fig. 5 is a vertical cross-sectional view of the throttle gear 29. Fig. 6 is a perspective view showing the outline of the ring 50. Fig. 7 is a perspective view showing the outline of the lever 55. Fig. 4 shows a side view of the throttle gear 29, and Fig. 5 is a cross-sectional view of the B-B view shown in Fig. 4.

[0035] As shown in FIGS. 4 and 5, the throttle gear 29 includes a gear body 40, a ring 50 (ring member), and a lever 55 (support member).

[0036] The gear body 40 is a disk-shaped gear made of resin or the like, with a gear portion 41, such as a spur gear, formed on part of the outer periphery. A substantially circular ring insertion hole 42 into which the ring 50 is inserted is provided in the center. The ring insertion hole 42 is chamfered parallel to the axis to match the shape of the chamfered portion 52 of the ring 50, which will be described later.

[0037] As shown in Fig. 6, the ring 50 is a cylindrical member made of metal such as stainless steel, and has a shaft hole 51 at its axis through which the throttle shaft 15 passes. The ring 50 also has a pair of chamfered portions 52 formed on its outer circumferential surface, which are parallel to each other on either side of the axis. Furthermore, a groove 53 having a V-shaped cross section is formed around the entire circumference of the outer circumferential surface of the ring 50 in the axially intermediate portion, excluding the chamfered portion 52. The ring 50 also has a fixing hole 54 formed therethrough, parallel to the chamfered portion 52 and passing through the axis.

[0038] On the other hand, as shown in Figure 7, the lever 55 is composed of a semicircular recessed portion 56 that is recessed within the gear main body 40, and a spring support portion 57 that protrudes radially outward from the circumferential center of the recessed portion 56.

[0039] The spring support portion 57 extends radially outward from the outer peripheral end of the recessed portion 56 and protrudes radially outward beyond the gear body portion 40, with the end of the protruding portion being bent vertically and protruding by approximately 1 cm. One end of the return spring 21 is secured to the spring support portion 57 via a ring-shaped support member (not shown). The other end of the return spring 21 is secured to the unit body 23 via a ring-shaped support member 65. The return spring 21 is a cylindrical torsion spring that biases the throttle shaft 15 so that the throttle valves 16a to 16d are in a closed or fully open state. When the motor 17 is operated, the throttle gear 29 rotates against the bias of the return spring 21 via the reduction mechanism 20.

[0040] The unit body 23 is provided with a stopper bolt (not shown), the tip of which abuts against the spring support portion 57, thereby restricting the rotation of the throttle gear 29. In other words, the spring support portion 57 of the lever 55 also functions as a stopper that restricts the throttle shaft 15 from rotating excessively when biased by the return spring 21.

[0041] The recessed portion 56 of the lever 55 is provided with circular alignment holes 58 arranged in the circumferential direction.

[0042] The gear body 40 is provided with a U-shaped groove 43 so that when the ring 50 is inserted into the ring insertion hole 42 and fixed, the fixing hole 54 of the ring 50 is exposed.

[0043] The throttle shaft 15 is provided with a hole at the attachment position of the throttle gear 29, which hole passes through the axis and extends radially, and has the same diameter as the fixing hole 54 of the ring 50.

[0044] The throttle shaft 15 is inserted into the shaft hole 51 of the ring 50 of the throttle gear 29, and with the throttle gear 29 aligned with a predetermined axial position and rotational position of the throttle shaft 15, a pin (not shown) is inserted into the fixing hole 54 of the ring 50, thereby removably fixing the throttle gear 29 and the throttle shaft 15 together.

[0045] Next, a method for manufacturing the throttle gear 29 will be described.

[0046] A metal ring 50 and lever 55 are prepared in advance. The ring 50 may be manufactured by cutting or casting, for example, and the lever 55 may be manufactured by sheet metal processing of a metal plate. Next, the ring 50 and lever 55 are set in a mold, and a material such as resin is filled around the ring 50 and the lever 55 to form the gear main body 40. Note that the mold is provided with a pin having the same diameter as the throttle shaft 15 and a pin to be inserted into an alignment hole 58 in the lever 55, and these pins allow the ring 50 and lever 55 to be aligned. In this way, the throttle gear 29 is manufactured by insert processing.

[0047] In the above embodiment, the spring support portion 57 of the lever 55 functions to support one end of the return spring 21 and also functions as a stopper that restricts the rotation angle range of the throttle gear 29, but a stopper may be provided separately from the spring support portion 57. For example, a stopper having a shape similar to that of the spring support portion 57 may be provided that protrudes radially outward from the recessed portion 56 at a position different from that of the spring support portion 57 in the circumferential direction.

[0048] Alternatively, a stopper lever having a recessed portion 56 similar in shape to the lever 55 and a protruding stopper 60 formed in the same manner as the spring support portion 57 as shown by the two-dot chain line in Figure 3 may be prepared, and the throttle gear 29 may be manufactured by insert machining the stopper lever together with the lever 55 and ring 50. In this case, a protruding portion 61 with which the stopper 60 abuts may be provided on the unit body 23, thereby restricting the rotation angle range of the throttle gear 29.

[0049] As described above, the throttle device 10 according to this embodiment rotates the throttle shaft 15 from the motor 17 via the reduction mechanism 20, and the throttle gear 29 of the reduction mechanism 20 is fixed to the throttle shaft 15.

[0050] The gear body 40 of the throttle gear 29 is made of resin, which allows for a lighter weight. The throttle shaft 15 is fixed to a metal ring 50 provided on the throttle gear 29. The use of the metal ring 50 ensures the strength of the fixed portion between the throttle shaft 15 and the throttle gear 29.

[0051] Furthermore, since the gear body 40 of the throttle gear 29 is made of resin, it is easy to form a complex shape such as the gear part 41. Also, the throttle gear 29 can be easily formed by insert machining, including the ring 50.

[0052] Here, for example, if the ring 50 and the gear body 40 are manufactured separately, and then the ring 50 is inserted into the ring insertion hole 42 of the gear body 40 and fixed to the gear body 40 by crimping, the ring 50 may be deformed by the crimping. Therefore, after the crimping, it was necessary to additionally machine the shaft hole 51 of the ring 50 using a reamer or the like so that the throttle shaft 15 could be inserted.

[0053] In contrast, in this embodiment, the ring 50 and the gear body 40 are fixed together by insert processing, which suppresses deformation of the ring 50. This eliminates the need for post-processing such as reaming, reduces manufacturing costs, and makes it possible to provide an inexpensive throttle device 10.

[0054] Furthermore, although the ring 50 is cylindrical, two chamfered portions 52 are formed on the outer peripheral surface parallel to the axis, and by engaging with the ring insertion hole 42 of the gear main body 40 which is formed to match the shape of these chamfered portions 52, rotation can be reliably transmitted between the ring 50 and the gear main body 40.

[0055] In addition, a groove 53 extending circumferentially around the entire circumference is provided on the outer peripheral surface of the ring 50, and resin is inserted into this groove 53 and fixed therein by insert processing, thereby restricting the movement of the ring 50 and the gear main body 40 in the thrust direction.

[0056] In this way, the chamfered portion 52 and the groove 53 define the rotational position and axial position of the gear body 40 relative to the cylindrical ring 50, and also firmly fix the ring 50 and the gear body 40 together.

[0057] The throttle gear 29 is also provided with a lever 55 having a spring support portion 57 that supports one end of the return spring 21. The lever 55 is placed and fixed in a mold together with the ring 50 when the gear body 40 is formed by insert machining. This makes it easy to form the throttle gear 29 including the lever 55. Furthermore, because the lever 55 is configured to be included in the throttle gear 29, the structure of the vicinity of the support portion for the return spring 21 can be simplified.

[0058] Although the description of the embodiment is now complete, aspects of the present invention are not limited to the above embodiment. For example, in the above embodiment, insert machining is performed on the ring 50 and the lever 55 when manufacturing the throttle gear 29, but the throttle gear 29 may be manufactured by insert machining only on the ring 50. In this case, the lever 55 may be fixed to the throttle gear 29 with a screw or the like.

[0059] Furthermore, in this embodiment, the present invention is applied to the throttle device 10 of the four-cylinder engine 1, but it may also be applied to a throttle device of an engine with multiple cylinders other than four.

[0060] Furthermore, although the throttle device 10 of this embodiment drives the throttle valves 16a to 16d with one motor 17, it may be provided with a plurality of motors, and the number of throttle valves driven by one motor may be other than four. Furthermore, a throttle device may be formed with a plurality of throttle units that drive the throttle valves 16 with the motor 17, and the present invention may be applied to the fixing portion between the throttle shaft and throttle gear in these throttle units.

[0061] The present invention can also be applied to throttle devices for engines used in vehicles other than motorcycles. [Explanation of symbols]

[0062] 1 engine 10 Throttle device 15 Throttle shaft 16a, 16b, 16c, 16d throttle valve 17 Motor 20 Reduction mechanism (reduction gear) 21 Return spring (biasing part) 29 Throttle gear (gear) 40 Gear body 50 Ring (Ring component) 52 Chamfered part 53 Groove 55 Lever (support member)

Claims

1. a throttle shaft to which the throttle valve is fixed; A motor; a reducer having a gear fixed to the throttle shaft, for reducing the rotation of the drive shaft of the motor and transmitting the rotation to the throttle shaft; A throttle device comprising: the gear includes a cylindrical ring member into which the throttle shaft is detachably inserted, and a gear body portion having a gear wheel, The ring member is a cylindrical member made of metal, and has a shaft hole at its axis through which the throttle shaft passes, and a fixing hole that passes through the axis and into which a pin extending in a radial direction is inserted, The ring member and the gear body are fixed together, The gear and the throttle shaft are detachably fixed to each other by inserting a pin into the fixing hole of the ring member. A throttle device characterized by:

2. 2. The throttle device according to claim 1, wherein the ring member has a chamfered portion formed on the cylindrical outer circumferential surface at a portion that contacts the gear body.

3. 3. The throttle device according to claim 1, wherein the ring member has a groove extending in a circumferential direction.

4. The throttle device further comprises: a biasing portion that biases the throttle shaft to rotate; a support member that supports one end of the biasing portion, 4. The throttle device according to claim 1, wherein the gear is integrally formed with the support member and the ring member by insert machining.

5. 5. The throttle device according to claim 4, wherein the ring member and the support member are made of metal, and the gear is made of resin.

6. 6. The throttle device according to claim 1, wherein the throttle device is provided in an engine of a motorcycle and controls the amount of intake air into the engine.

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