CN112343721B - Throttle device of engine - Google Patents
Throttle device of engine Download PDFInfo
- Publication number
- CN112343721B CN112343721B CN202010789445.8A CN202010789445A CN112343721B CN 112343721 B CN112343721 B CN 112343721B CN 202010789445 A CN202010789445 A CN 202010789445A CN 112343721 B CN112343721 B CN 112343721B
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- throttle
- idle
- arm portion
- bracket
- fitting
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/02—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning induction conduits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/02—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning induction conduits
- F02D2009/0201—Arrangements; Control features; Details thereof
- F02D2009/0203—Mechanical governor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/02—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits concerning induction conduits
- F02D2009/0201—Arrangements; Control features; Details thereof
- F02D2009/0218—Details of governor springs
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
Abstract
A throttle device for an engine, capable of ensuring a good idle air inflow regulating function and preventing loosening of an idle regulating screw when an accelerator is returned to an operation. The throttle device includes: a throttle shaft supporting a throttle valve of the valve body; a throttle lever that transmits the closing-side biasing force of the return spring and the accelerator operation of the driver to the throttle valve shaft; and an idle speed adjusting mechanism cantilever-supported from the valve main body via an arm portion of the bracket. The idle speed adjusting mechanism includes: an idle speed adjusting screw for enabling the compression spring to be pressed down and screwed with the female thread of the arm part; and a limiting part of the throttle lever, which is abutted with the idle speed adjusting screw through a return spring and keeps the throttle valve at a prescribed opening degree. The throttle device further includes a fitting attached to the arm portion of the bracket, through holes are provided so as to correspond to the female screw, and a seat surface of the compression spring is inclined with respect to a surface orthogonal to the idle adjustment screw.
Description
Technical Field
The present invention relates to a throttle device of an engine, and more particularly, to a throttle device including an idle adjustment screw that adjusts an intake air amount during idle operation.
Background
In the above-described throttle device, the throttle valve is disposed in an orifice formed in the valve body and supported by the throttle shaft, and the throttle valve is biased to the closing side by the return spring. The throttle of the vehicle is connected to a throttle lever provided at one end of a throttle shaft via a throttle wire, and the throttle valve is opened and closed together with the throttle shaft in accordance with a driver's throttle operation.
In order to adjust the engine rotational speed during idle operation, the throttle device is provided with an idle speed adjusting mechanism that adjusts the idle intake air amount. An idle speed adjusting screw is screwed to one side surface of the valve body, and is biased by a compression spring in a direction away from the valve body. When the throttle lever rotates to the closing side, a limiting portion provided on one side of the throttle lever abuts against the tip of the idle adjustment screw and is limited to rotate, and the minimum opening of the throttle valve is determined in accordance with the rotation angle at that time. Therefore, the amount of intake air to the engine and thus the idle rotation speed can be adjusted by changing the screwed position of the idle adjustment screw.
Since various components attached to the engine are disposed around the throttle device mounted on the vehicle, there are cases where the idle adjustment mechanism interferes with the peripheral components when the idle adjustment mechanism is directly mounted on the valve body. As a countermeasure, there is a throttle device in which an idle adjustment mechanism is disposed apart from a valve main body via a bracket. From the viewpoint of manufacturing cost, the bracket is made of sheet metal formed by bending a steel plate, for example, a base portion of the bracket is fixed to one side surface of the valve main body, and an idle adjustment screw and a compression spring are provided on an arm portion bent at right angles from the base portion. The idle speed adjusting mechanism is cantilever-supported via the arm portion of the bracket separately from the valve main body, thereby preventing interference with the peripheral component.
However, in the throttle device using the bracket as described above, there is a case where a problem occurs in the return operation of the throttle. For example, when the accelerator is quickly returned to be operated in order to rapidly decelerate the vehicle during full-force acceleration, the throttle valve is rapidly closed from full-open due to the urging force of the return spring, and the throttle lever is strongly collided with the idle adjustment screw. Since the impact at this time causes a phenomenon of loosening the idle adjustment screw, a desired idle intake air amount cannot be achieved, and there is a problem that defects such as idle misalignment are caused.
As a countermeasure against the above-described drawbacks, for example, in the technique described in japanese patent application laid-open No. 57-129232, a roll pattern is formed on the outer peripheral surface of the idle adjustment screw, and rubber holders are provided on a bracket that supports the idle adjustment screw, so that the idle adjustment screw is prevented from loosening by contact with each other.
However, the countermeasure described in Japanese patent application laid-open No. 57-129232 has a problem that the function of adjusting the idle intake air amount required by the original throttle device is adversely affected.
That is, the above measures are to prevent loosening by a strong friction generated between the roll marks and the rubber holder, but the above friction hinders smooth rotation of the idle adjustment screw when adjusting the idle intake air amount, and thus it is difficult to perform the adjustment work. Further, since the elasticity of the rubber holder always acts on the idle adjustment screw in a direction of obstructing rotation, the idle adjustment screw which has been adjusted to the optimum screwed position is caused to slightly return, and there is a problem in that precise adjustment is difficult.
Disclosure of Invention
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a throttle device for an engine capable of securing a good idle intake air amount adjusting function and preventing loosening of an idle adjusting screw at the time of returning an accelerator.
In order to achieve the above object, a throttle device of an engine according to the present invention includes: a throttle valve provided to the valve main body; a throttle shaft supporting the throttle valve; a throttle lever that transmits the closing-side biasing force of the return spring to the throttle shaft and transmits the accelerator operation of the driver to the throttle shaft; and an idle speed adjusting mechanism fixed to the valve main body and supported via an arm cantilever of the bracket, the idle speed adjusting mechanism including: an idle speed adjusting screw inserted through the compression spring and screwed into the female screw of the arm portion in a state in which the compression spring is compressed and contracted; and a stopper portion of the throttle lever, which is brought into contact with a tip end of the idle adjustment screw by a biasing force of the return spring and holds the throttle valve at a predetermined opening, wherein the throttle device of the engine includes a fitting that is attached to the arm portion of the bracket and has a through hole penetrating therethrough in correspondence with a female screw of the arm portion, and a seat surface of the fitting, which is brought into contact with one end of the compression spring, is formed obliquely with reference to a surface orthogonal to an axis of the idle adjustment screw.
As another aspect, the attachment may be formed with a holding portion that engages with the arm portion of the bracket, and an abutment restricting portion that restricts engagement of the holding portion by abutment with the bracket.
In another aspect, the holding portion may be a holding groove formed between a pair of legs each having a key-shaped tip, and when the holding groove is fitted into the arm portion of the bracket, the pair of legs are held and elastically sandwiched between the arm portions, and the tip of each leg is hooked to the arm portion.
In another aspect, the through hole of the fitting may coincide with the female screw of the arm portion when the contact limiting portion of the fitting contacts the bracket.
According to the throttle device of the engine of the present invention, the idle adjustment screw can be prevented from loosening during the return operation of the accelerator, while ensuring a good idle intake air amount adjustment function.
Drawings
Fig. 1 is a perspective view showing a throttle device of an engine according to an embodiment.
Fig. 2 is a sectional view taken along line II-II of fig. 1.
Fig. 3 is a view in the a direction of fig. 1.
Fig. 4 is an exploded perspective view of the throttle lever and the idle adjustment mechanism separated from the throttle device.
Fig. 5 is an exploded perspective view showing the idle speed adjusting mechanism.
Fig. 6 is a sectional view taken along line VI-VI of fig. 5 showing the inclination of the seating surface and the biased state of the compression spring.
Fig. 7 is also a cross-sectional view taken along line VII-VII of fig. 5.
Fig. 8 is a cross-sectional view corresponding to fig. 6 showing another example in which the inclination direction of the seat surface is 90 ° different from that of the embodiment.
Fig. 9 is a cross-sectional view corresponding to fig. 7 showing another example.
Fig. 10 is a cross-sectional view corresponding to fig. 7 showing another example of the gasket as a seating surface.
(Symbol description)
1 Throttling device
2.3 Valve body
6 Throttle valve
8 Throttle valve shaft
14 Return spring
15 Throttle lever
15B limit part
20 Idle speed regulating mechanism
21 Bracket
21B arm
21C female screw
23 Fitting
24A seat surface
24B through hole
25 Feet
25A front end
26 Contact limiting part
27 Holding groove (holding part)
29 Idle speed adjusting screw
30 Compression spring
Detailed Description
An embodiment of the present invention will be described below with reference to a four-cylinder engine for a motorcycle.
As shown in fig. 1 and 2, the throttle device 1 of the present embodiment is formed by coupling a first valve body 2 and a second valve body 3 each including a pair of throttle holes 2a and 3 a. Although not shown, in a state mounted on a motorcycle, a hose from an air cleaner is connected to one end of each of the orifices 2a and 3a corresponding to the right side in fig. 1, and an intake manifold of the engine is connected to the other end on the opposite side. During engine operation, intake air filtered by the air cleaner flows through the respective orifices 2a, 3a and is guided to the intake manifold, and the amount of intake air is regulated by a throttle valve 6 in each of the orifices 2a, 3a described below.
A fuel injection valve 4 is attached to the lower sides of the first and second valve bodies 2, 3 in such a manner that the tip ends face the respective orifices 2a, 3a, and pressurized fuel is supplied from a fuel pump, not shown, through a delivery pipe 5. The fuel injection valves 4 are opened and closed in synchronization with the fuel circulation of each cylinder of the engine, and accordingly inject fuel into the intake manifold of the corresponding cylinder.
Since the throttle device 1 of the present embodiment includes the throttle valve 7 for starting in addition to the throttle valve 6 for adjusting the output of the engine, as shown in fig. 2, two throttle shafts 8 and 9 penetrating the respective throttle holes 2a and 3a on the upstream side and the downstream side in the intake air flow direction are rotatably supported by the first valve body 2 and the second valve body 3. In the respective orifices 2a, 3a, the throttle 6 for output adjustment is fixed to the throttle shaft 8 on the downstream side by a screw 10, and the throttle 7 for activation is fixed to the throttle shaft 9 on the upstream side by a screw 11.
On one side surface of the first valve main body 2 corresponding to the left side in fig. 1, one end of each throttle shaft 8, 9 protrudes, and the start-time driving mechanism 12 is connected to the end of the throttle shaft 9 on the upstream side. The throttle valves 7 for starting are kept in a fully open state during the engine operation, and are driven to the closed side by the start-time driving mechanism 12 at the time of engine starting, and are limited to an intake air amount suitable for starting.
As shown in fig. 3 and 4, a return spring 14 is wound around the end of the throttle shaft 8 on the downstream side, a disk-shaped body portion 15a of the throttle lever 15 is fastened by a nut 17 via a washer 16, and a plate-shaped stopper portion 15b is integrally formed on one side of the outer periphery of the body portion 15 a. One end of the return spring 14 is hooked to the first valve main body 2, and the other end is hooked to one side of the throttle lever 15, and biases the throttle lever 15 in a direction corresponding to the closing side of the output-adjusting throttle valve 6.
Although not shown, an accelerator of the vehicle is connected to a connection hole 15c provided in a main body portion 15a of the throttle lever 15 via an accelerator cable. Therefore, the accelerator operation by the driver is mechanically transmitted to the throttle lever 15 via the accelerator cable, and the throttle valves 6 for output adjustment are opened and closed via the throttle shaft 8 in accordance with the rotation of the throttle lever 15 in both the forward and reverse directions. Specifically, the throttle lever 15 rotates about the axis Lth of the throttle shaft 8 between two positions, i.e., an idle position indicated by a solid line and a fully open position indicated by a phantom line in fig. 3 in which rotation is restricted by the idle adjustment mechanism 20 described below. In the idle position, each throttle valve 6 is kept at a minimum opening degree, and in the full-open position, each throttle valve 6 is kept at a maximum opening degree.
An idle speed adjusting mechanism 20 that adjusts the amount of idle speed intake air is provided at the position close to the throttle lever 15 as described above. As shown in fig. 4 and 5, a bracket 21 made of so-called sheet metal, which is formed by bending a steel plate, is disposed on one side surface of the first valve body 2, and a base portion 21a of the bracket 21 is fixed to the first valve body 2 by a pair of screws 22. The arm portion 21b is bent from the base portion 21a to the opposite side of the first valve main body 2 at a right angle, and extends along the throttle axis direction. The arm portion 21b faces the stopper portion 15b of the throttle lever 15, and a female screw 21c is formed to penetrate the tip end of the arm portion 21 b.
The fitting 23 is attached to the arm portion 21b of the bracket 21 from the opposite side of the first valve main body 2. Since the fitting 23 is a feature of the present invention, a side surface opposite to the throttle lever 15 is set as a seat surface 24a, and a through hole 24b corresponding to the female screw 21c of the arm portion 21b is provided through the seat surface 24a, which will be described in detail later.
An idle speed adjusting screw 29 is screwed to the female screw 21c of the arm portion 21b of the bracket 21 from the opposite side of the throttle lever 15 through the through hole 24b of the fitting 23. The idle adjustment screw 29 is composed of a male screw 29a and a head 29b, and the male screw 29a is screwed into the female screw 21c of the arm 21b in a state inserted into the compression spring 30 and the resin washer 31, and the tip end thereof protrudes from the arm 21b toward the throttle lever 15 side. The compression spring 30 is compressed between the seat surface 24a of the fitting 23 and the head 29b of the idle adjustment screw 29, and the urging force acts in a direction to move the idle adjustment screw 29 away from the seat surface 24a of the fitting 23.
As shown by an arrow a in fig. 3, when the throttle lever 15 rotates to the closing side about the axis Lth of the throttle shaft 8, the stopper portion 15b comes into contact with the tip of the male screw 29a from a direction indicated by an arrow b substantially along the axis Lscw of the idle adjustment screw 29. Thereby, the throttle lever 15 is restricted from rotating at the idle position, and the minimum opening degree of each throttle valve 6 is determined in accordance with the rotation angle at that time. Therefore, the amount of intake air to the engine and thus the idle rotation speed can be adjusted by changing the screwed position of the idle adjustment screw 29.
As described above, the bracket 21 is fixed to one side surface of the first valve main body 2, and the idle adjustment mechanism 20 is cantilever-supported to the first valve main body 2 via the arm portion 21 b. As a result, the idle adjustment mechanism 20 is disposed apart from the first valve body 2, and interference with various components attached to the engine disposed around the throttle device 1 is prevented.
In a general idle adjustment mechanism, a compression spring 30 is interposed between an arm portion 21b of a bracket 21 and a head portion 29b of an idle adjustment screw 29. The biasing force of the compression spring 30 acts in a direction to move the idle adjustment screw 29 away from the arm portion 21b of the bracket 21, and the current screwed position of the idle adjustment screw 29 is maintained by the biasing force. Specifically, friction is generated between the female screw 21c of the arm portion 21b and the male screw 29a of the idle adjustment screw 29 by the biasing force of the compression spring 30, and friction is also generated between one end of the compression spring 30 and the arm portion 21b and between the other end of the compression spring 30 and the head portion 29b of the idle adjustment screw 29, respectively, and rotation of the idle adjustment screw 29 is restricted by the friction, so that the idle adjustment screw 29 is held at the current screwed position.
When the stopper portion 15b of the throttle lever 15 collides with the front end of the male screw 29a of the idle speed adjusting screw 29 as described above due to the return operation of the throttle, the impact thereof is input to the arm portion 21b of the bracket 21 via the idle speed adjusting screw 29. For example, the bracket 21 made of sheet metal is inherently low in rigidity as compared with a bracket made of die-cast aluminum or the like, and the arm portion 21b having one side surface facing the stopper portion 15b and functioning as a cantilever beam is also likely to be deflected in terms of its cross-sectional shape due to an impact input from the stopper portion 15 b.
Therefore, the arm portion 21b is deflected in the tilting direction starting from the base portion 21a, for example. The compression spring 30 is instantaneously contracted by the abrupt positional displacement of the arm portion 21b at this time, and the biasing force to the idle adjustment screw 29, in other words, the original installation load is eliminated or reduced. As a result, friction between the bracket 21 side and the idle adjustment screw 29 side due to the urging force is reduced, and the idle adjustment screw 29 is rotated in the loosening direction.
As a countermeasure for preventing the loosening phenomenon of the idle adjustment screw 29 as described above, the present inventors focused on the compression spring 30.
As described above, the compression spring 30 acts in a direction to separate the idle adjustment screw 29 from the arm portion 21b, and for example, as shown in fig. 6, the axis Lsp of the compression spring 30 substantially coincides with the axis Lscw of the idle adjustment screw 29, and all portions of the inner periphery of the compression spring 30 are separated from the outer peripheral surface of the male screw 29a of the idle adjustment screw 29. When the axis Lsp of the compression spring 30 arranged as described above is intentionally deviated from the axis Lscw of the idle adjustment screw 29, for example, as shown in fig. 7, one side of the inner periphery of the compression spring 30 is brought into pressure contact with the outer peripheral surface of the male screw 29a of the idle adjustment screw 29. The friction generated between each other at this time acts in a direction to suppress the compression spring 30 from shrinking due to the impact input and to suppress the rotation of the idle adjustment screw 29.
Specifically, the compression spring 30 resists the instantaneous reduction in the impact input by friction with the idle adjustment screw 29, and thereby continues to apply the force to the idle adjustment screw 29. Further, friction generated by the compression of the compression spring 30 acts in a direction that blocks the rotation of the idle adjustment screw 29. Hereinafter, the state in which the axis Lsp of the compression spring 30 is deviated from the axis Lscw of the idle adjustment screw 29 as described above may be simply referred to as the deviation of the compression spring 30.
The biasing of the compression spring 30 can be achieved by forming a seat surface on the arm portion 21b against which one end of the compression spring 30 abuts to have an angle with respect to a surface F orthogonal to the axis Lscw of the idle adjustment screw 29. As a result, the seat surface is inclined with respect to the surface F orthogonal to the axis Lscw of the idle adjustment screw 29. When the seat surface is inclined, the distance between the seat surface and the head 29b of the idle adjustment screw 29 is uneven over the entire circumference centered on the axis Lsp of the compression spring 30, and the compression spring 30 is deviated toward the shorter side. As a result, the portion of the inner periphery of the compression spring 30 on the side opposite to the direction of displacement is in pressure contact with the outer peripheral surface of the male screw 29a of the idle adjustment screw 29, and friction therebetween occurs as described above.
In order to incline the seating surface, it is conceivable to machine the arm portion 21b of the bracket 21 made of sheet metal into a twisted shape, but this is not practical for the following reasons.
In order to deviate the compression spring 30, an inclination angle α of the seat surface of about 10 ° is required, for example, but such an inclination angle α is difficult to be formed by twisting the shorter arm portion 21 b. When the inclination angle α=0 of the seat surface, the female screw 21c to which the idle adjustment screw 29 is screwed may be formed at a right angle with respect to the arm portion 21 b. In contrast, when the seat surface is inclined, the female screw 21c needs to be formed on the arm portion 21b so as to be inclined at an angle corresponding to the above-described inclination angle α, and the processing of the female screw 21c is significantly complicated. In this case, it is practically difficult to impart the inclination angle α to the seating surface by twisting the arm portion 21 b.
In the present invention, therefore, the fitting 23 is attached to the arm portion 21b of the bracket 21, and the inclination angle α is given to the seat surface 24a of the fitting 23, and the fitting 23 will be described in detail below.
First, the inclination direction and the inclination angle α of the seating surface 24a of the fitting 23 will be described. The loosening prevention of the idle adjustment screw 29 is achieved by pressing the compression spring 30 against the outer peripheral surface of the idle adjustment screw 29, but the effect thereof varies depending on the inclination direction of the seat surface 24 a. In the idle adjustment mechanism 20 of the present embodiment, when the stopper portion 15b of the throttle lever 15 collides with the idle adjustment screw 29 from the arrow b direction in fig. 7 due to the accelerator return operation, the arm portion 21b is deflected in the tilting direction indicated by the arrow c starting from the base portion 21a of the bracket 21, and the idle adjustment screw 29 is abruptly displaced in the same direction.
At this time, when the compression spring 30 is displaced downward in fig. 7, the pressure contact with the idle adjustment screw 29 is further enhanced by the deflection of the arm portion 21b, and the looseness preventing effect is enhanced. Therefore, the inclination direction of the seat surface 24a of the present embodiment is set such that the distance between the seat surface 24a and the head portion 29b of the idle adjustment screw 29 is short on the opposite side of the base portion 21a, and as a result, the compression spring 30 is biased downward in fig. 7.
Of course, the present invention is not limited to the above-described inclination direction of the seating surface 24 a. This is because, when the specifications of the throttle device 1, for example, the shape of the bracket 21, the collision angle of the throttle lever 15 with the idle adjustment screw 29, and the like are different, the deflection state of the arm portion 21b at the time of impact input changes, and accordingly, the inclination direction of the desired seating surface 24a also changes.
Further, as for the inclination angle α of the seat surface 24a, the larger the inclination angle α is, the stronger the compression spring 30 is pressed against the idle adjustment screw 29, thereby improving the looseness prevention effect. On the other hand, the larger the impact input from the throttle lever 15, the more likely the loosening phenomenon of the idle adjustment screw 29 occurs, and at this time, the magnitude of the impact varies depending on various conditions such as the urging force of the return spring 14. In the four-port throttle device 1 of the present embodiment, for example, a larger force is applied to the return spring 14 than in the single-port throttle device. Therefore, the deflection of the arm portion 21b increases together with the impact force input to the idle adjustment screw 29, and the inclination angle α of the seat surface 24a needs to be relatively increased for the above-described loosening prevention.
Therefore, in the present embodiment, the inclination angle α of the seat surface 24a is set to be 10 ° large, but the present invention is not limited thereto, and the inclination angle α of the seat surface 24a may be set to be a degree that can prevent rattling in consideration of the specifications of the throttle device 1 and the like.
As shown in fig. 5 to 7, the fitting 23 is constituted by a main body 24 formed with a seat surface 24a of a compression spring 30, a pair of leg portions 25 for fixing the fitting 23 to an arm portion 21b of the bracket 21, and an abutment restricting portion 26 for positioning the fitting 23, and is integrally injection molded from a synthetic resin material such as PP (polypropylene). The material of the fitting 23 is not limited to this, and may be, for example, die-cast aluminum.
A flat seating surface 24a is formed on one side surface of the main body 24, and a pair of leg portions 25 are provided to extend from the other side surface of the main body 24. The front ends 25a of the legs 25 are formed in a key shape, and a holding groove 27 is formed between the legs 25. The fitting 23 is disposed in a posture in which the other side surface of the main body 24 overlaps the arm portion 21b of the bracket 21, and the holding groove 27 between the two leg portions 25 is fitted into the arm portion 21b of the bracket 21. The arm portion 21b is elastically sandwiched by the leg portions 25 on both sides, and is hooked to the front ends 25a of both leg portions 25, thereby preventing the fitting 23 from coming off the arm portion 21b. In the present embodiment, the holding groove 27 functions as a holding portion of the invention.
The holding portion of the present invention is not limited to the groove shape like the holding groove 27, and may be, for example, a holding hole having a hole shape as a holding portion and fitted into the arm portion 21b by connecting the distal ends 25a of the both leg portions 25. But when the holding groove 27 is formed by the pair of the legs 25, the following effects can be obtained: good elasticity can be imparted to each leg portion 25, and the amount of resin required for injection molding of the fitting 23 can be saved as compared with connecting both leg portions 25.
The abutment restriction portion 26 extends from the main body portion 24 toward the base portion 21a of the bracket 21, and the abutment restriction portion 26 has a right-angled cross section and the tip thereof abuts against the base portion 21 a. A through hole 24b is formed in the body 24 so as to pass through the body in correspondence with the female screw 21c of the arm 21b, and opens on the seat surface 24a, a male screw 29a of the idle adjustment screw 29 is screwed into the female screw 21c through the through hole 24b, and one end of the compression spring 30 abuts on the seat surface 24 a. As described above, the inclination direction of the seat surface 24a is set such that the distance between the seat surface 24a and the head portion 29b of the idle adjustment screw 29 is shortened on the opposite side of the seat portion 21a, and the inclination angle α is set to 10 °. As a result, the compression spring 30 is deviated downward in fig. 7.
In the throttle device 1 configured as described above, as shown in fig. 7, when the stopper portion 15b of the throttle lever 15 collides with the tip end of the idle adjustment screw 29 due to the accelerator return operation, the arm portion 21b flexes with the base portion 21a of the bracket 21 as a starting point. The abrupt position displacement of the arm portion 21b at this time acts in a direction to instantaneously contract the compression spring 30, but the contraction of the compression spring 30 can be hindered by friction generated between the compression spring 30 and the idle adjustment screw 29. Accordingly, the idle speed adjusting screw 29 continues to receive the force in the direction of the axis Lscw by the compression spring 30, thereby preventing rotation. Further, friction generated by the compression of the compression spring 30 acts in a direction of obstructing the rotation of the idle adjustment screw 29, which also contributes to the prevention of the rotation.
In addition, in the present embodiment, the inclination direction of the seat surface 24a is set so that the pressure contact with the idle adjustment screw 29 is further enhanced by the deflection of the arm portion 21b caused by the input of the impact. Therefore, the compression spring 30 can be strongly pressed against the idle adjustment screw 29 and further improve the friction therebetween, which also contributes greatly to preventing the idle adjustment screw 29 from rotating. For the above reason, according to the throttle device 1 of the present embodiment, the loosening of the idle adjustment screw 29 can be prevented even when the accelerator pedal is operated back, and thus, the trouble such as idle imbalance when the desired idle intake air amount cannot be achieved due to the loosening can be prevented. In addition, the throttle device 1 of the present embodiment can ensure a good regulation function of the idle intake air amount, in addition to the effect of preventing rattling as described above.
In addition, the fitting 23 is mounted to the arm portion 21b for biasing the compression spring 30 not only because of the difficulty in twisting the arm portion 21b itself but also because other advantages can be obtained.
That is, there are cases where a plurality of derivative models having different manufacturing specifications are produced in the throttle device 1, and various conditions such as the positional relationship between the idle adjustment screw 29 and the throttle lever 15, the number of orifices, and the like are different among the derivative models. In the former case, the collision angle between the throttle lever 15 and the idle adjustment screw 29 is different, and in the latter case, the magnitude of the impact input to the idle adjustment screw 29 is different due to the difference in the urging force of the return spring 14. Since the deflection state of the arm portion 21b at the time of impact input is different in any case, the inclination direction and the inclination angle α of the desired seating surface 24a are also different.
Therefore, when the bracket 21 is manufactured separately in accordance with the seating surface 24a required in each derived model, the manufacturing cost increases. In the present embodiment, it is possible to manufacture only the fitting 23 corresponding to the seat surface 24a required in each of the derivative models, and the bracket 21 can be shared by the derivative models. Therefore, the manufacturing cost of the throttle device 1 can be reduced by combining the inexpensive sheet metal manufacturing of the bracket 21 itself.
On the other hand, the pair of leg portions 25 and the abutment restriction portion 26 of the attachment 23 play a specific role in the assembly operation of the idle adjustment mechanism 20, and the respective roles will be described below together with the assembly sequence.
First, the bracket 21 is fixed to one side surface of the first valve main body 2 by the small screw 22, and the holding groove 27 of the fitting 23 is gradually fitted into the arm portion 21b. The arm portion 21b is elastically sandwiched by the leg portions 25 on both sides, and is hooked to the key-shaped distal ends 25a of both leg portions 25. When the fitting operation is further continued, the abutment restriction portion 26 of the fitting 23 abuts against the base portion 21a of the bracket 21 at a certain timing, the further fitting operation is restricted, and the through hole 24b of the fitting 23 is made to coincide with the female screw 21c of the arm portion 21b.
Next, the compression spring 30 and the resin washer 31 are inserted through the male screw 29a of the idle adjustment screw 29, and the male screw 29a is screwed into the female screw 21c of the arm 21b through the through hole 24b of the fitting 23. The compression spring 30 is compressed between the seat surface 24a of the attachment 23 and the head 29b of the idle adjustment screw 29, and the tip of the male screw 29a protrudes from the arm 21b toward the throttle lever 15. The compression spring 30 is biased to the opposite side of the base portion 21a by the inclination of the seat surface 24a, and the portion of the inner periphery on the base portion 21a side is pressed against the outer peripheral surface of the male screw 29a of the idle adjustment screw 29, thereby completing the assembly of the idle adjustment mechanism 20.
In this way, when the holding groove 27 of the attachment 23 is fitted into the arm portion 21b, the fitting operation is continued until the fitting operation is restricted by the abutment of the abutment restricting portion 26, whereby the through hole 24b can be automatically aligned with the female screw 21c and the idle adjustment screw 29 can be screwed. Therefore, the fitting 23 can be easily attached to the bracket 21 without performing the fitting operation while confirming the positional relationship between the through hole 24b and the female screw 21c by visual observation.
After the attachment 23 is attached, the compression spring 30 and the resin washer 31 are inserted into the idle adjustment screw 29, and the idle adjustment screw 29 is screwed as a subsequent operation. At this time, if the fitting 23 is likely to come off from the arm portion 21b, it is necessary to perform the subsequent work while holding the fitting 23 in order to prevent the falling off, and this results in a work that is very difficult to perform.
In the present embodiment, since the attached fitting 23 is elastically sandwiched between the arm portions 21b by the pair of leg portions 25, the detachment from the arm portions 21b in the direction opposite to the fitting can be prevented by friction between them. Meanwhile, since the front ends 25a of the legs 25 of the mounted fitting 23 are hooked on both sides of the arm portion 21b, the fitting 23 is prevented from being separated from the arm portion 21 b. As a result, the fitting 23 is kept in the attached state once attached to the arm portion 21b, and is prevented from falling off the arm portion 21b, so that it is not necessary to consider the falling off prevention as described above. The operator can thus leave his hands from the mounted fitting 23 and use his hands for the next work. For the above reasons, it is also possible to obtain a completely different effect that the idle adjustment mechanism 20 can be easily assembled.
As described above, the inclination direction of the seat surface 24a of the fitting 23 is an example, and as described above, if the specifications of the throttle device 1 are different, the deflection state of the arm portion 21b at the time of impact input changes, and the inclination direction of the desired seat surface 24a also changes. Therefore, another example of making the inclination direction of the seat surface 24a different from that of the present embodiment by 90 ° will be described with reference to fig. 8 and 9.
In this other example, it is assumed that the deflection of the arm portion 21b due to the impact input displaces the idle adjustment screw 29 downward in fig. 8. Accordingly, the inclination direction of the seat surface 24a of the attachment 23 is set to be higher in fig. 8, and the distance between the seat surface 24a and the head 29b of the idle adjustment screw 29 is shortened, whereby the compression spring 30 is deviated upward in fig. 8. Therefore, when the idle adjustment screw 29 is displaced in position in association with the deflection of the arm portion 21b by the impact input, the compression of the compression spring 30 is further enhanced, and the loosening of the idle adjustment screw 29 can be further reliably prevented.
The embodiments described above have been described, but the embodiments of the present invention are not limited to the above embodiments. For example, in the above embodiment, the throttle device 1 of the engine for a motorcycle is embodied, but the present invention is not limited to this. For example, the present invention may be embodied as a throttle device for an engine mounted on an ATV (ALL TERRAIN VEHICLE: all terrain vehicle) or an engine for a generator as a power source. In the above embodiment, the idle speed adjustment mechanism 20 is provided on one side surface of the first valve body 2, but the idle speed adjustment mechanism 20 may be provided between the first valve body 2 and the second valve body 3, for example.
In the present embodiment, the flat seating surface 24a is formed in the main body 24 of the fitting 23, but for example, as shown in fig. 10, a stepped portion 41 may be formed in the main body 24, and a washer 42 may be interposed between the stepped portion 41 and one end of the compression spring 30. In this case, the washer 42 is disposed so as to be inclined with respect to the surface F orthogonal to the axis Lscw of the idle adjustment screw 29, and one side surface of the washer 42 is made to function as the seat surface 24a of the compression spring 30.
Claims (4)
1. A throttle device of an engine, comprising: a throttle valve provided to the valve main body; a throttle shaft supporting the throttle valve; a throttle lever that transmits a closing-side biasing force of a return spring to the throttle shaft and transmits a driver's accelerator operation to the throttle shaft; and an idle speed adjusting mechanism fixed to the valve main body and supported by the arm cantilever of the bracket, characterized in that,
The idle speed adjusting mechanism includes: an idle speed adjusting screw inserted through a compression spring and screwed into a female screw of the arm portion in a state where the compression spring is compressed and contracted; and a limiting portion of the throttle lever that abuts against a front end of the idle adjustment screw by a biasing force of the return spring and maintains the throttle valve at a predetermined opening degree,
The throttle device of the engine includes a fitting attached to the arm portion of the bracket and provided with a through hole penetrating in correspondence with the female screw of the arm portion, and a seat surface of the fitting, which is in contact with one end of the compression spring, is formed obliquely with reference to a surface orthogonal to the axis of the idle adjustment screw.
2. A throttle device of an engine according to claim 1,
In the fitting, a holding portion is formed which fits into the arm portion of the bracket, and an abutment restricting portion is formed which restricts fitting of the holding portion by abutment with the bracket.
3. A throttle device of an engine according to claim 2, wherein,
The holding part is a holding groove formed between a pair of feet with key-shaped front ends,
When the holding groove is fitted into the arm portion of the bracket, the pair of leg portions elastically sandwich the arm portion and hook the respective front ends to the arm portion.
4. A throttle device of an engine as set forth in claim 2 or 3, characterized in that,
When the abutment restriction portion of the fitting abuts against the bracket, the through hole of the fitting coincides with the female screw of the arm portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019-145538 | 2019-08-07 | ||
| JP2019145538A JP7330804B2 (en) | 2019-08-07 | 2019-08-07 | engine throttle device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112343721A CN112343721A (en) | 2021-02-09 |
| CN112343721B true CN112343721B (en) | 2024-04-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010789445.8A Active CN112343721B (en) | 2019-08-07 | 2020-08-07 | Throttle device of engine |
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| Country | Link |
|---|---|
| JP (1) | JP7330804B2 (en) |
| CN (1) | CN112343721B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005069210A (en) * | 2003-08-28 | 2005-03-17 | Denso Corp | Throttle device for internal combustion engine |
| JP2005147026A (en) * | 2003-11-18 | 2005-06-09 | Keihin Corp | Intake control device for engine |
| EP1589206A2 (en) * | 2004-04-23 | 2005-10-26 | Keihin Corporation | Idling opening degree control apparatus in intake air control apparatus |
| JP2016145538A (en) * | 2015-02-06 | 2016-08-12 | 株式会社ケーヒン | Intake air amount control device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5851139B2 (en) * | 1978-05-18 | 1983-11-15 | 本田技研工業株式会社 | engine throttle valve device |
| JPH0256846U (en) * | 1988-10-20 | 1990-04-24 | ||
| JP3333315B2 (en) * | 1994-04-15 | 2002-10-15 | 株式会社ミクニ | Vaporizer valve opening control device |
| JP7286535B2 (en) | 2017-03-17 | 2023-06-05 | 住友重機械工業株式会社 | METHOD FOR MANUFACTURING METAL PIPE AND FORMING APPARATUS |
-
2019
- 2019-08-07 JP JP2019145538A patent/JP7330804B2/en active Active
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2020
- 2020-08-07 CN CN202010789445.8A patent/CN112343721B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005069210A (en) * | 2003-08-28 | 2005-03-17 | Denso Corp | Throttle device for internal combustion engine |
| JP2005147026A (en) * | 2003-11-18 | 2005-06-09 | Keihin Corp | Intake control device for engine |
| EP1589206A2 (en) * | 2004-04-23 | 2005-10-26 | Keihin Corporation | Idling opening degree control apparatus in intake air control apparatus |
| JP2016145538A (en) * | 2015-02-06 | 2016-08-12 | 株式会社ケーヒン | Intake air amount control device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112343721A (en) | 2021-02-09 |
| JP2021025491A (en) | 2021-02-22 |
| JP7330804B2 (en) | 2023-08-22 |
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