JP2002106371A - Drive transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive transmission device capable of generating large torque in conformation to the increase in load by disturbance such as icing or the like even if a motor is miniaturized. SOLUTION: This device comprises a throttle shaft 14; an intermediate shaft 22; a rocking lever 26 rotatable to the throttle shaft and pivotally supporting the intermediate shaft at one end; a first gear 21 fixed to the throttle shaft; a second gear 24 fixed to one end of the intermediate shaft and meshed with the first gear; a third gear 24 fixed to the other end of the intermediate shaft 22; a fourth gear rotatably provided on the throttle shaft so as to mesh with the third gear; a drive means 16 for driving the fourth gear; and a torque limiter 27 for connecting the rocking lever 26 to the throttle shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive transmission device for transmitting a rotational motion, for example, a drive transmission device capable of increasing a rotation torque of a throttle valve as required.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view showing the structure of a conventional electronically controlled throttle body. The throttle body 1
A circular bore 2a is provided at the center of the body 2 and a disc-shaped throttle valve 3 is provided therein. The throttle valve 3 is fixed to a throttle shaft 4 penetrating through the bore 2a with screws 5, and is rotated by approximately 90 ° from a position at which the bore 2a is closed to a fully open position parallel to the center axis of the bore 2a. It is free to move.

[0003] A motor 6 is integrally attached to the throttle body 1, and the axis of the motor 6 is a throttle shaft 4. Then, by changing the direction of power supply to the motor 6, the throttle shaft 4 rotates in the opening direction or in the closing direction. Although a torque motor is used as the motor 6, the torque motor is generally excellent in responsiveness and non-contact, and therefore has a feature of high reliability.

In an electronically controlled throttle valve for controlling a normal engine intake system, the torque of a motor required to open and close the valve is determined by the inertia of the throttle valve 3 and the throttle shaft 4 and the frictional force of a bearing applied to the throttle shaft 4. , The fluid pressure flowing through the bore 2a, etc., which are not so great under normal operating conditions.

However, in practice, the motor 6
Is required to apply a much larger torque to the throttle shaft than the above torque. The reason is to cope with sticking such as icing (freezing) which is likely to occur at a small opening of the throttle valve.

[0006] Under conditions where the temperature is below freezing, if the vehicle is parked outdoors, moisture adhering to the inside of the throttle body may freeze and stick the throttle valve. Even when the engine is not frozen when starting the engine, if the throttle valve is continuously operated in a small opening area, the flow velocity of air passing through the valve is high,
This may lower the temperature around the valve and cause icing. When icing occurs, the throttle valve sticks to the inner peripheral surface of the throttle bore, and rotation control cannot be performed.

In order to prevent such icing,
In general, measures are taken to keep the throttle body warm with hot water for cooling the heater and the engine, and at the same time, to secure a sufficient torque of the motor 6 for rotating the throttle shaft 4 in advance so that the throttle valve 3 can be released from being stuck. Have been.

[0008]

However, in order to increase the torque of the torque motor, it goes without saying that
The size of the motor 6 must be increased, which increases the price of the motor and causes an increase in cost. In addition, a problem arises in that the motor becomes large in size if the motor is enlarged.

The present invention has been conceived in view of the above facts. A drive transmission device capable of generating a large torque when the load increases due to disturbance such as icing even if the motor is downsized. It is intended to provide.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a driven shaft, an intermediate shaft provided at a distance from the driven shaft, and driving means for rotating and driving the intermediate shaft. A swinging lever rotatably supporting the driven shaft and the intermediate shaft, and a first lever fixed to the driven shaft.
A gear, a second gear fixed to the intermediate shaft and transmitting reduced power to the first gear, a torque limiter provided between the swing lever and the driven shaft, A stopper for limiting relative rotation with the drive shaft,
It is characterized by having. The driven shaft may be a throttle shaft that rotates a throttle valve in an opening / closing direction, or the intermediate shaft may be disposed substantially parallel to the throttle shaft.

Also, the intermediate shaft has a third gear fixed to the intermediate shaft, and a fourth gear meshing with the third gear is provided between the third gear and the driving means. A structure in which the gear train of the first gear is a reduction gear train, or a structure in which the fourth gear is rotatably supported by the driven shaft or the throttle shaft may be employed.

Also, one or more of the first to fourth gears may be sector gears, the torque limiter may be a spring joint, the driving means may be a torque motor, and the fourth gear may be mounted on a motor shaft of the torque motor. Can be fixed, or the torque limiter can be constituted by a magnetic circuit.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a throttle body 11 showing an embodiment of the present invention. A circular bore 12 a is provided at the center of the body 12, and a disc-shaped throttle valve 13 is fixed to a throttle shaft 14 with screws 15. The throttle shaft 14 is provided on both sides of the bearing 1.
It is supported by 7, 17 and is rotatable. The upper end side of the throttle shaft 14 in the figure is a small diameter portion 14a.

The driving means 16 is a three-pole torque motor.
It has a hollow motor shaft 19, in which a small diameter portion 14a of the throttle shaft 14 is rotatably penetrated. The main portion of the drive transmission device 20 is provided at the tip of the small diameter portion 14a.

The drive transmission device 20 includes a throttle shaft 14, a first gear 21 fixed to the tip of a small diameter portion 14a thereof, an intermediate shaft 22 arranged in parallel with the throttle shaft 14, and one of the intermediate shafts 22. First gear 2 fixed to the end
A third gear 24 fixed to the other end of the intermediate shaft 22, a fourth gear 25 meshed with the third gear 24 and fixed to the motor shaft 19;
One end is rotatably supported by the throttle shaft 14,
A swing lever 26 rotatably supporting the intermediate shaft 22 at the other end.
And drive means 16 using the above-described torque motor. In the above configuration, the first gear 21, the second gear 23 and the swing lever 26 constitute a planetary gear mechanism. The first gear 21 and the swing lever 26 are connected by a torque limiter 27.

In the embodiment of FIG. 1, the torque limiter 27 uses a spring joint. One end of the spring is locked to the first gear 21 and the other end is locked to the swing lever 26. When the relative rotation occurs between the swing joint and the swing lever 26, the spring of the spring joint is elastically displaced. Because of such a configuration, the swing lever 26 is connected to the throttle shaft 1.
When the rotation is performed around the rotation of the rotation 4, the rotation from the swing lever 26 is transmitted to the first gear 21 via the torque limiter 27. When the load applied to the first gear 21 is small, the spring joint of the torque limiter 27 is hardly elastically deformed.
The rotation of the swing lever 26 is transmitted to the first gear 21 almost as it is. Therefore, the first gear 21 and the swing lever 2
6 rotates substantially integrally with the throttle shaft 14 as a center.

On the other hand, when the load applied to the first gear 21 is large, even if the swing lever 26 rotates, the first gear 21 does not rotate, so that the torque limiter 27 is elastically deformed, and the first gear 21 And the swing lever 26, a relative rotation occurs.

FIG. 2 is a view of the drive transmission device 20 as viewed from FIG. 1A. FIG. 2A shows the third gear 24 and the fourth gear 2.
FIG. 2B is a diagram showing a meshing state of the first gear 21 and the second gear 23 with each other.
Since the rotation range of the throttle shaft 14 is about 90 °, the teeth of each gear need not be formed on the entire circumference, and sector gears are used except for the fourth gear 25 having the largest rotation angle. By using the sector gear in this way, the drive transmission device 20 can be reduced in size and weight.

The operation of the drive transmission device 20 will be described with reference to FIG. FIGS. 3A and 3B show a case where the rotation of the throttle shaft 14 is normal, that is, a case where the load is light, FIG. 3A shows a case where the throttle valve 13 is in the fully closed position, and FIG. Shows when in the fully open state.

In a normal load, that is, when the load is light, when the driving means 16 rotates, the fourth gear 25 fixed to the motor shaft 19 rotates. The fourth gear 25 transmits this rotation while reducing the speed from the third gear 24 to the second gear 23, whereby the first gear 21 rotates by the reduced speed. When the first gear 21 rotates, the swing lever 26 is also rotated by the same rotation angle as the first gear 21 by the torque limiter 27. When the swing lever 26 rotates in the same direction as the first gear 21, the second gear 23 also rotates
With the first gear 2
The reverse rotation is transmitted from 1 to the second gear 23. This is transmitted in the opposite direction from the third gear 24 to the fourth gear 25.

However, since the fourth gear 25 is actually rotated by the driving means 16 and cannot be reversed, the rotation corresponding to the reverse rotation is transmitted from the third gear 24 to the first gear 21 again as forward rotation. As a result, the first gear 21
3 to the fourth gear 25 and the entire swing lever 26 are glued.
The throttle shaft 14 is rotated by rotating an arbitrary angle to the fully open position (b). That is, when the load on the throttle shaft 14 is small, the fourth gear 2
If 5 is rotated 90 °, the throttle shaft 14 will also be 9
0 °, (rotation angle of the fourth gear 25) =
(Rotation angle of the throttle shaft 14).

Next, the case where the throttle valve 13 freezes and the throttle shaft 14 is stuck will be described. When the fourth gear 25 is rotated by the rotation of the driving means 16 in the fully closed state of FIG. 3A, the rotation is transmitted to the fourth gear 25 → the third gear 24 → the second gear 23 → the first gear 21. . However, the first gear 21 is integral with the throttle shaft 14 and cannot rotate because the throttle shaft 14 is fixed by freezing. Therefore, the second gear 23
Attempts to revolve around the first gear 21 around the small diameter portion 14a. Due to this revolution, the swing lever 26 rotates about the small diameter portion 14a, and a relative rotation occurs between the first gear 21 and the swing lever 26 against the elastic force of the torque limiter 27. When the rotation angle reaches a predetermined value, the rotation angle comes into contact with a stopper (not shown), and the swing lever 26 is forcibly stopped so as not to rotate any more.

Then, rotation is transmitted by the gear train of the fourth gear 25 → the third gear 24 → the second gear 23 → the first gear 21. Then, as shown in FIG. 3 (c), the swing lever 26 does not rotate, and the third gear 24 rotates with respect to the fourth gear 25 as shown in FIGS. 3 (a) to 3 (c). The first gear 21 rotates with respect to the second gear 23. At this time, the first gear is decelerated by the fourth gear 25 and the third gear 24, and the second gear is reduced by the second gear 23 and the first gear 21. Is decelerated to a large torque which is transmitted to the first gear 21 to break freezing and rotate the throttle shaft 14.

In the above configuration, the third gear 24 and the fourth gear 24
The gear 25 is not essential. That is, the intermediate shaft 22 is directly or indirectly rotated by the driving means 16 and the second gear 2
When the throttle shaft 14 is rotated, if the throttle shaft 14 is in a normal (non-freezing) state, the first gear 21 and the swing lever 26 rotate integrally and the throttle shaft 14 freezes. In this case, the torque is increased by the reduction ratio between the second gear 23 and the first gear 21 to break the icing.

The intermediate shaft 22 and the throttle shaft 1
4 may be parallel as in the above embodiment, but is not limited to being parallel. For example, the first gear 21 and the second gear 21
If the gear 23 is a bevel gear, the intermediate shaft 22 can be arranged at right angles to the throttle shaft 14. The use of helical gears allows non-parallel arrangements other than right angles. However, when the arrangement is parallel as in the embodiment, the size of the apparatus can be reduced.

Further, generally, when the throttle valve 13 is rapidly closed, the throttle valve 13 vigorously hits an idle adjustment stopper (not shown), and an impact load at that time is applied to the idle adjustment stopper and the driving means 16. However, according to the present invention, the impact load generated when contacting the idle adjustment stopper is
When the torque becomes equal to or more than the predetermined torque, the torque limiter 27 acts to reduce the impact force.

FIGS. 4A and 4B are views showing the configuration of a second embodiment of the present invention, in which FIG. 4A is a sectional view, and FIG. 4B is an end view taken along line BB in FIG. The first gear 21 ', the second gear 23' and the third gear 24 'are basically the same as those described in the embodiment of FIG. 1, but in the embodiment of FIG. This embodiment is different from the former in that the gear is a circular gear. The fourth gear 25
Is a circular gear as in the embodiment of FIG. Reference numeral 116 indicates a driving means, and in this example, a separate motor is used.

As shown in FIG. 4 (b), the swing lever 26 'has a boss 26a' centered on the small diameter portion 14a of the throttle shaft 14, and a coil spring as a torque limiter 32 surrounds the boss 26a '. Is fitted. Both ends 32a and 32b of the torque limiter 32 are rotationally displaced in a direction in which the torque limiter 32 is twisted, and both ends 32a and 32b are rotated.
The protrusion 26b 'at the tip of the swing lever 26' is inserted between the pins 32b, and is pressed and held.

On the other hand, the first gear 21 'has a bracket 3
1 is fixed, and an arm 31 a protruding from the bracket 31 is attached to both ends 32 a of the torque limiter 32.
It has entered between 32b.

With the above structure, when the arm 31a rotates, the rotation is transmitted through the torque limiter 32 to the protrusion 26a.
is transmitted to the arm 31a via the torque limiter 32 when the projection 26b 'rotates. That is, when one of the first gear 21 ′ and the swing lever 26 ′ rotates, the corresponding one of the protrusion 26 b ′ and the arm 31 a rotates, and the rotation is transmitted to the other via the torque limiter 32. Is done. When the load applied to the throttle shaft 14 is small, the torque limiter 32 transmits this rotation to the other with little elastic deformation.

However, when the load applied to the throttle shaft 14 is large, the first gear 21 'does not rotate, but the swing lever 26' can rotate. Therefore, the first gear 21 ′ is elastically deformed while the torque limiter 32 is deformed.
And the swing lever 26 'make relative rotation about the small diameter portion 14a. Then, when the relative rotation reaches a predetermined angle, it contacts a stopper (not shown) to forcibly prevent further relative rotation. That is, the torque limiter 32 of the second embodiment can also perform the same operation as the torque limiter 27 of the first embodiment.

FIG. 5 is an enlarged sectional view showing another embodiment of the torque limiter. The torque limiter 37 shown in this embodiment has two arc-shaped projecting sides 14b, 14b formed on the small diameter portion 14a at intervals of 180 °, a rotor 38 of the driving means 16, and two It is composed of arc-shaped magnets 39a and 39b. Magnets 39a, 3
9b both have magnetic poles in the radial direction.
If the inside of a is the south pole and the outside is the north pole, the magnet 39b is arranged so that the inside is the north pole and the outside is the south pole. On the rotor 38, a protruding portion 38a opposed to the protruding sides 14b, 14b with a small gap and a concave portion 38b opposed to a large gap are formed to be orthogonal to each other. The magnetic resistance of the driving means 16 composed of a torque motor, which passes the magnetomotive force of the magnet and the coil, is minimized at the position shown in FIG. It becomes maximum at the position where

FIG. 6 is a sectional view showing the structure of a third embodiment of the present invention, wherein a tension coil spring is used for the torque limiter 127. Explaining the configuration, first, a first gear 121 is fixed to the distal end of the small-diameter portion 14 a at the distal end of the throttle shaft 14. An intermediate shaft 122 is provided in parallel with the small diameter portion 14a. A second gear 123 meshing with the first gear 121 is fixed to one end of the intermediate shaft 122, and a third gear 124 is fixed to the other end. At the base end side of the small diameter portion 14a, a third
A fourth gear 125 meshing with the gear 124 is provided rotatably. The fourth gear 125 is driven by driving means 116 such as a torque motor. A swing lever 126 is rotatably provided on the intermediate shaft 122.
, An intermediate shaft 122 is rotatably mounted.

The first gear 121 has a bracket 1
28 is fixed, and a pin 128a is erected at the tip thereof, and a torque limiter 127 made of a tension coil spring is provided between the pin 128a and the pin 126a erected on the swing lever 126.
Is provided. In the above configuration, all of the first to fourth gears 121 to 125 are ordinary circular gears, and no sector gear is used.

FIGS. 7A and 7B are views as viewed from C in FIG. 6, wherein FIG. 7A shows a state in which the throttle valve 13 is fully closed, and FIG. 7B shows a state in which the throttle valve 13 is fully open. Reference numeral 131 denotes a fully closed side stopper, and reference numeral 132 denotes a fully opened side stopper. When the throttle valve 13 is fully closed and fully opened, a slight gap is provided between the swing lever 126 and these. Further, as shown in these figures, the torque limiter 127 is usually mounted so that the tension coil spring is the shortest when the bracket 128 and the swing lever 126 are aligned.

The operation of this embodiment when the load applied to the throttle shaft 14 is low will be described with reference to FIGS. The rotation of the driving means 116 is transmitted to the fourth gear 125 → the third gear 124 → the second gear 123 → the first gear 121. When the first gear 121 rotates counterclockwise from the position shown in FIG. 7A, the bracket 128 also rotates counterclockwise, and the swing lever 126 and the bracket 128
Bend in the shape of a letter. Then, the coil spring constituting the torque limiter 127 is extended, and a tensile force is generated to return to the original length. By this pulling force, the swing lever 126
Rotates counterclockwise (in a direction away from the fully closed side stopper 131), and the bracket 128 and the swing lever 126 return to the linearly arranged arrangement. As a result, the first gear 121, the second gear 123, the swing lever 126, and the bracket 128
Rotates as if the whole is glued, and rotates around the small-diameter portion 14a within the range from fully closed in FIG. 7A to fully opened in FIG. 7B. In other words, when the rotation torque of the throttle shaft 14 (small diameter portion 14a) is small, the first gear 121 and the swing lever 126 rotate about the small diameter portion 14a almost integrally.

FIG. 8 is a diagram showing an operation when the throttle shaft 14 is frozen by icing or the like. When the throttle shaft 14 freezes, the small diameter portion 14a cannot rotate. On the other hand, the rotation of the fourth gear 125 is
→ It is transmitted to the second gear 123 and tries to rotate the first gear 121 in the counterclockwise direction. However, since the small diameter portion 14a does not rotate, the first gear 121 cannot rotate, and the second gear 12
3 starts revolving clockwise around the first gear 121, and the swing lever 126 also rotates accordingly. Shortly after the rotation starts, the end of the swing lever 126 is fully closed-side stopper 13.
1 and further rotation of the swing lever 126 is prevented.

Then, the fourth gear 125 and the third gear 124
At the first stage, and the second stage of deceleration is performed between the second gear 123 and the first gear 121. As a result, the torque of the driving means 116 increases due to the deceleration, and the first gear 1
21. With this increased torque, the vehicle escapes from a frozen state.

On the other hand, since the icing is broken by the first gear 121 being slightly rotated, the load on the throttle shaft 14 is sharply reduced. Then, the torque limiter 127 returns to the original length, and the entire swing lever 126 and the torque limiter 127 are arranged in a straight line as shown in FIG. 7A. Thereafter, the whole is glued and rotated to the position shown in FIG.

The fully-open stopper 132 is used when the load applied when the throttle valve 13 is fully opened increases and the throttle valve 13 cannot be rotated in a normal state in which the throttle valve 13 is fully glued. Is the same as

In each of the embodiments described above, the drive transmission device used to rotate the throttle shaft has been described. However, in general, the drive transmission device can be applied to various actuators as a transmission device that amplifies torque only when a load is applied.

In the above embodiment, the torque limiter is provided between the swing lever and the throttle shaft. However, the present invention is not limited to this. The torque limiter may be provided anywhere between the drive means and the throttle shaft.

[0043]

As described above, the present invention provides a throttle shaft for rotating a throttle valve disposed in a bore of a throttle body in an opening / closing direction, an intermediate shaft provided separately from the throttle shaft, Driving means for driving the intermediate shaft to rotate, a swinging lever rotatably supporting the throttle shaft and the intermediate shaft, a first gear fixed to the throttle shaft, and a fixed to the intermediate shaft. And a second gear for transmitting the reduced power to the first gear, and a torque limiter for connecting the swing lever and the throttle shaft, so that the rotational load of the throttle shaft is reduced by the torque limiter. When the value is smaller than the set value, when the second gear is rotationally driven, the first gear, the second gear, and the swing lever rotate integrally, and the response is improved. There can be opened and closed throttle valve. When the rotation load of the throttle shaft increases due to freezing or the like, the second gear rotates the throttle shaft by reducing the speed of the first gear, so that a large torque is transmitted to rotate the frozen throttle shaft. Can be.

When the first to fourth gears are used, the speed can be reduced to two stages, so that a larger rotation torque can be transmitted. When a sector gear is used for one or more of the first to fourth gears, the size of the device can be reduced. If the torque limiter is a spring joint, it is possible to reduce the impact when the throttle valve is suddenly closed. If the torque limiter is configured by a magnetic circuit, the size of the torque limiter can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a throttle body showing an embodiment of the present invention.

FIG. 2 is a view of the drive transmission device as viewed from A in FIG. 1;
Is a diagram showing a meshing state of the third gear and the fourth gear,
(B) is a figure which shows the meshing state of a 1st gear and a 2nd gear.

FIGS. 3A and 3B are diagrams for explaining the operation of the drive transmission device, wherein FIGS. 3A and 3B show the case where the rotational load of the throttle shaft is light; FIG. 3A shows the case where the throttle valve is at the fully closed position; (b) shows a state in which the throttle shaft is fully opened, and (c) shows a state in which the rotational load of the throttle shaft is large.

FIG. 4 is a diagram showing the configuration of a second embodiment of the present invention, wherein (a)
Is a cross-sectional view, and (b) is an end view seen from line BB of (a).

FIG. 5 is an enlarged sectional view showing another embodiment of the torque limiter.

FIG. 6 is a sectional view showing the configuration of a third embodiment of the present invention.

7A is a diagram viewed from C in FIG. 6, wherein FIG. 7A shows a state when the throttle valve is in a fully closed state, and FIG.

FIG. 8 is a view showing an operation when icing or the like is caused by icing when the throttle shaft is fully closed.

FIG. 9 is a sectional view showing a configuration of a conventional electronically controlled throttle body.

[Explanation of symbols]

 Reference Signs List 11 throttle body 12a bore 13 throttle valve 14 throttle shaft 16, 116 driving means 21, 21 ', 121 first gear 22, 22', 122 intermediate shaft 23, 23 ', 123 second gear 24, 24', 124 third Gear 25, 125 Fourth gear 26, 26 ', 126 Swing lever 27, 32, 127 Torque limiter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 1/28 F16H 1/28 35/10 35/10 A

Claims (7)

[Claims] 1. A driven shaft, an intermediate shaft provided at a distance from the driven shaft, a driving means for rotating and driving the intermediate shaft, and the driven shaft and the intermediate shaft being rotatable, respectively. A swinging lever pivotally supported on the driven shaft, and a first lever fixed to the driven shaft.
A gear, a second gear fixed to the intermediate shaft and transmitting reduced power to the first gear, a torque limiter provided between the swing lever and the driven shaft, A stopper for limiting relative rotation with the drive shaft,
A drive transmission device comprising: 2. The drive transmission device according to claim 1, wherein the driven shaft is a throttle shaft that rotates a throttle valve in an opening and closing direction. A third shaft fixed to the intermediate shaft;
A fourth gear having a gear, and a fourth gear meshing with the third gear is provided between the third gear and the driving means, and a gear train from the fourth gear to the first gear is a reduction gear train. Item 3. The drive transmission device according to item 1 or 2. 4. The drive transmission device according to claim 3, wherein at least one of the first to fourth gears is a sector gear. 5. The drive transmission device according to claim 1, wherein the torque limiter is a spring joint. 6. The drive transmission device according to claim 3, wherein said drive means is a torque motor, and said fourth gear is fixed to a motor shaft of said torque motor. 7. The drive transmission device according to claim 6, wherein said torque limiter is constituted by a magnetic circuit.