JPS6041214B2 - Throttle positioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deceleration control device that temporarily holds a throttle valve at a position slightly open from the idling opening position during deceleration to suppress an increase in the amount of HC in exhaust gas. In particular, the present invention relates to a deceleration control device that provides different operating times depending on the operating state at the start of engine deceleration.

If you decelerate the car while the car is running (release the accelerator pedal and suddenly close the throttle valve to the idling position, the air supply will be rapidly throttled and the increased intake pipe Fuel adhering to the intake pipe rapidly evaporates due to air pressure and is sucked into the engine cylinder, resulting in incomplete combustion of the rich air-fuel mixture and a large amount of HC being discharged into the exhaust system. .

To deal with this problem, when the throttle valve is suddenly closed while the engine is running, a diaphragm device operated by negative pressure in the intake pipe is generally used to move the throttle valve to a position slightly open from the idling opening position. That is, various adjustable throttle positioners have been proposed that hold the throttle valve at the controlled opening position during deceleration and then close the throttle valve to the idling position. a time period during which the throttle valve is held in the deceleration control position by a throttle positioner during deceleration;
In other words, it is preferable that the throttle positioner operating time be substantially constant regardless of the engine operating state or deceleration state at the start of deceleration. The longer the better.

On the other hand, in conventional throttle positioners, the operating time is generally determined by a negative pressure delay valve (throttle element) installed in the middle of the conduit that leads the intake pipe negative pressure to the diaphragm chamber of the diaphragm device. The throttle positioner operating time becomes shorter as the engine decelerates from a high-speed operating state where a large negative pressure in the intake pipe occurs, which tends to have a time characteristic that is opposite to the above-mentioned preferred time characteristic.

SUMMARY OF THE INVENTION The present invention aims to provide a throttle positioner which sets the throttle positioner operating time in a preferable manner in consideration of the operating state of the vehicle cocoon at the start of deceleration and the deceleration state.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

The attached FIG. 1 is a schematic diagram showing one embodiment of a throttle positioner according to the present invention.

In the figure, reference numeral 1 denotes a throttle valve, which is supported by a throttle shaft 2 and rotated in directions to open and close an intake passage 3 of the carburetor. As is well known, the opening and closing operation of the throttle valve 1 is performed by an accelerator system (not shown), and the throttle valve 1 is always visibly biased in the closing direction by a tassel spring (not shown). There is. A throttle lever 4 is fixedly connected to the throttle shaft 2, and a stopper arm (throttle positioner arm) 5 is rotatably attached thereto. A contact 7 having an adjusting screw portion 6 is screwed onto the throttle lever 4.
The tip of the stopper arm 5 comes into contact with the contact surface 81 of the stopper arm 5. The stopper arm 5 contacts the throttle lever 4 when the throttle valve 1 is at or near the idling position, and prevents the throttle valve 1 from returning to the idling position, thereby reducing the idling position. The throttle shaft 2 is located at the first position that guarantees that the deceleration control position is a predetermined amount wider than the position (reference position 8d in the figure) or higher, that is, from the position shown in the figure. between the position where the throttle valve is rotated in the clockwise direction in the predetermined angle diagram using the rotation fulcrum and the second position that allows the throttle valve to return to the idling position, that is, the position shown by the solid line in the diagram. It's starting to move. The rocker of the stopper arm 5 is pivotally connected to one end of the rod 11 of the diaphragm device IQ by a pivot pin 9.

The diaphragm device 10 includes a diaphragm 1 that supports the other end of the rod 11 and cooperates with the diaphragm casing 2 to define a diaphragm chamber 13 on the right side in the figure.
4, and a compression coil spring 15 which flexibly biases the diaphragm 14 toward the left side in the figure, that is, the stopper arm 5 toward the first position. The diaphragm chamber 13 is located downstream of the throttle valve 1 in the deceleration control function, and is an intake pipe negative pressure takeoff port located upstream of the throttle valve 1 when the throttle valve 1 is opened beyond the deceleration control function. 16 via a conduit 17, and the negative pressure or atmospheric pressure appearing in the intake pipe negative pressure take-out boat 16 is introduced. Further, a throttle element 18 is provided in the middle of the conduit 17. The compression coil 15 of the diaphragm mounting 10 is the throttle valve 1.
When the opening is closed toward the idling opening position by the spring force of a tuft spring (not shown in the figure), it can be stopped at the deceleration control opening position against the returning spring force. It is composed of a spring with spring force,
When substantial intake pipe negative pressure is introduced into the diaphragm chamber 13 during engine operation, the diaphragm 14 moves to the right in the figure against the spring force of the compression coil 16 due to the negative pressure. It's becoming more eccentric. Further, the diaphragm chamber 13 of the diaphragm device 10 is selectively opened to the atmosphere by a negative pressure control valve 19.

The negative pressure control valve 19 is connected to a boat 21 which is connected to the diaphragm chamber 13 of the diaphragm device 10 via a conduit 20.
The valve element 23 selectively opens to the atmosphere via an air release boat 22 including an air filter element, and a valve seat 24 corresponding to the valve element 23. The valve element 23 is connected via a valve rod 25 to a diaphragm 26, by which it is driven. The diaphragm 26 cooperates with the casing 27 to define a first diaphragm chamber 28 on the left side and a second diaphragm chamber 29 on the right side in the figure, and the spring force of the compression coil spring 30 delimits the first diaphragm chamber 28 and the second diaphragm chamber 29 in the figure. The valve element 23 is operably biased toward the right side, that is, toward the side that presses the valve element 23 against the valve seat portion 24 . Further, the diaphragm 26 is provided with a throttle passage 31 that allows the first diaphragm chamber 28 and the second diaphragm chamber 29 to intersect with each other. The first diaphragm chamber 28 is connected via a conduit 32 to the intake manifold pressure take-off boat 16 and is adapted to receive the negative or atmospheric pressure present therein. in this case,
The negative pressure control valve 19 operates when the negative pressure in the first diaphragm chamber 28 becomes greater than the negative pressure in the second diaphragm chamber 29 by a predetermined value, that is, the negative pressure in the first diaphragm chamber 28 increases. When the pressure difference between the second diaphragm chamber 29 and the negative pressure becomes larger than the set pressure of the compression coil spring 30, the valve element 23 moves to the left in the figure, thereby opening the boat 21 to the atmosphere. Connect to port 22,
On the other hand, when the negative pressure in the first diaphragm chamber 28 is not greater than the negative pressure in the second diaphragm chamber 29 by more than a predetermined value, that is, the differential pressure between the negative pressures in both the diaphragm chambers is When the pressure is lower than the set pressure, the valve element 23 moves to the right in the figure, thereby cutting off the boat 21 from the atmosphere-opening boat 22. The throttle positioner constructed as described above operates as follows.

When the throttle valve 1 is in a certain load operating position or in which the intake manifold pressure take-off boat 16 is opened beyond the intake manifold pressure take-off boat 16, said intake manifold pressure take-off boat 16 is subjected to substantial atmospheric pressure; The pressure is transmitted to the first diaphragm chamber 18 of the negative pressure control valve 19 through the conduit 32, but since the pressure is atmospheric, the diaphragm 26 does not move, and the valve element 23 seats on the valve seat 24, opening the boat 21 to the atmosphere. Maintain a state of isolation from the Also, at this time, the atmospheric pressure appearing in the intake pipe negative pressure extraction boat 16 is introduced into the diaphragm chamber 13 of the diaphragm device 10 through the conduit 17 with a slight time delay due to the throttling effect of the throttling element 18. The diaphragm 14 is moved to the left in the figure by the spring force of the compression coil spring 15, and the stopper arm 5 is rotated clockwise to locate it at the first position. In this state, when the accelerator pedal is released in order to decelerate the engine, the throttle valve 1 rotates counterclockwise in the figure due to a return action (not shown), and the throttle valve 1 rotates counterclockwise in the figure. The lever 4 is closed until the contact 7 contacts the contact surface 8 of the stopper arm 5, and is temporarily held at the deceleration control opening 8d.

As mentioned above, the throttle valve control opening ad during deceleration
, the intake pipe negative pressure extraction boat 16 is located downstream of the throttle valve and is subjected to a large intake pipe negative pressure during deceleration. When the negative pressure exerted on this intake pipe negative pressure extraction boat 16 is transmitted to the first diaphragm chamber 28 of the negative pressure control valve 19 through the conduit 32, and the inside of this first diaphragm chamber 28 also becomes high negative pressure, The diaphragm 26 moves to the left in the figure against the spring force of the compression coil spring 30, pulling the valve element 23 away from the valve seat 24 and opening the boat 21 to the atmosphere via the atmosphere opening boat 22. Become. Then, the diaphragm chamber 13 of the diaphragm device 10 is opened to the atmosphere via the conduit 17, the conduit 20, the boat 21, and the atmosphere opening boat 22, while the stopper arm 5 is held at the first position and the throttle valve 1 is opened. During deceleration, the throttle positioner is maintained at the throttle position and continues to operate. The negative pressure introduced into the first diaphragm chamber 28 of the negative pressure control valve 19 is transmitted to the second diaphragm chamber 29 through the throttle passage 31, so that after a predetermined period of time, the first diaphragm chamber 28 and The pressure difference with the second diaphragm chamber 29 decreases and eventually becomes less than a predetermined value. Then, the diaphragm chamber 26 moves to the right by the spring force of the compression coil spring 30, and the valve element 2
3 is again seated on the valve seat portion 24, and the boat 21 is moved from the atmosphere-opening boat 22. Then, the negative pressure appearing in the intake pipe negative pressure extraction boat 16 is gradually transmitted to the diaphragm chamber 13 of the diaphragm device 10 through the throttle element 18, and the diaphragm I4 moves to the right against the spring force of the compression coil spring 15. Then, the stopper arm 5 is rotated counterclockwise in the figure to locate it at the second position. Therefore, at this time, the throttle valve is returned to the idling opening position as the stopper arm 5 moves to the second position.
The operation of the rent pressure control valve 19 is based on the operation of the first diaphragm chamber 2.
8 and the second diaphragm chamber 29 is Ap, and the time during which the valve element 23 is separated from the valve seat 24 and the boat 21 is connected to the atmosphere opening boat 22 is t, then t=Q△p.
(However, Q=constant).

Therefore, the larger the negative pressure difference Δp is, the longer the throttle positioner operating time is when the vehicle is decelerated from a high-speed operating state. This operating time characteristic is determined by the pressure receiving area of the diaphragm 26 of the negative pressure control valve 19, the spring force of the compression coil spring 30,
It can be arbitrarily set depending on the amount of restriction of the restriction passage 31, the volume of the second diaphragm chamber 29, etc. A throttle element 18 provided in the middle of the conduit 17 removes the pressure of the intake pipe member 16 during momentary accelerator operation (racing operation).
This prevents the atmospheric pressure from being immediately transmitted to the diaphragm chamber 13 of the diaphragm device 10 and activating the throttle positioner, and also ensures that the atmospheric pressure from the member pressure control valve 19 is transmitted to the diaphragm chamber 13, and further releases the throttle positioner. At times, the throttle valve acts to gradually close from the deceleration control opening position to the idling position. The degree of aperture of this aperture element turtle 8 may be set according to engine-specific requirements. Further, for example, in order to activate the throttle positioner early and release it gradually, a negative pressure delay valve 33 as shown in FIG. 2 may be incorporated in the middle of the conduit 17 instead of the throttle element 18. This negative pressure delay valve 3
3 is a check valve 3 that only allows fluid to flow from the intake pipe negative pressure extraction boat 16 toward the diaphragm chamber 13;
4 and a first throttle element 35 in a parallel relationship, and a second throttle element 36 in series with the check valve 34. Even if the throttle valve is opened and the intake manifold pressure take-off boat becomes atmospheric pressure, atmospheric pressure does not immediately act on the diaphragm chamber 13 of the diaphragm device IQ due to the throttling effect of the throttling element 18, so that the throttle valve immediately As mentioned in the above embodiment, the throttle positioner does not operate when the throttle valve is closed, that is, when the throttle valve is instantaneously opened or closed. is transmitted to the first diaphragm chamber 28 of the negative pressure control valve 19, and atmospheric pressure is transmitted from the negative pressure control valve 19 to the diaphragm device 1.
0 into the diaphragm chamber 13, and the throttle valve 1 may be opened to the deceleration control opening position.

In view of the above-mentioned circumstances, FIG. 3 shows an embodiment in which the throttle positioner is more reliably prevented from operating during instantaneous throttle valve opening/closing operations.

In FIG. 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals as in FIG. 1. In this embodiment, another intake pipe negative pressure take-out boat 37 is provided in addition to the intake pipe negative pressure take-off boat 16. This intake pipe negative pressure take-off boat 37 may be provided so as to be always located downstream of the throttle valve 1, and is connected to the first diaphragm chamber 28 of the negative pressure control valve 19 via a conduit 38. The boat 21 of the negative pressure control valve 19 is the throttle element 1
8 is connected to the middle of the conduit 17 of the 16 intake pipe member pressure take-off boats via a conduit 20'. Further, another throttle element 39 is provided at the intake pipe negative pressure extraction boat i6. In this case, the throttle valve is instantaneously opened and closed, and the intake pipe negative pressure appearing in the intake pipe negative pressure extraction boat 37 is transmitted to the first diaphragm chamber 28 of the negative pressure control valve 19, and the negative pressure control valve 19 is activated. Even if an attempt is made to transmit atmospheric pressure to the diaphragm chamber 13 of the diaphragm device 10, the atmospheric pressure will not be immediately transmitted to the diaphragm chamber 13 due to the throttling effect of the throttling element 18. Therefore, in this case, the throttle positioner will not operate. The throttle element 39 reliably transmits the atmospheric pressure from the negative pressure control valve 19 to the diaphragm chamber 13, and together with the other throttle element 18, the throttle valve changes from the deceleration position to the idling opening position when the throttle positioner is released. It acts to gradually close. In order to ensure that the throttle positioner does not operate during instantaneous throttle valve opening/closing operations, in addition to the embodiment described above, a throttle element is installed in the middle of the conduit 20 in the embodiment shown in FIG. It may be provided.

In addition, in the embodiment shown in FIG.
Connect to the middle of the intake pipe, and connect it to the front self-intake pipe negative pressure take-out boat 1.
Another diaphragm element may be provided at the portion 6. FIG. 4 shows an embodiment in which the operation of the throttle positioner is controlled in relation to temperature.

(The parts in FIG. 4 that correspond to those in FIG. 1 are given the same reference numerals as those in FIG. 1.) HC and CO are
When a large amount of liquid fuel is moored in the intake pipe due to poor choke operation and poor fuel atomization, such as during deceleration when the engine is cold, a large amount of liquid fuel is discharged, and a large amount of unburned gas is also discharged from the exhaust system. If the exhaust air purification system is equipped with a secondary air supply system, afterfire will occur.

The throttle positioner in this embodiment is designed to lengthen the operating time of the throttle positioner under the above-mentioned conditions to improve combustion during deceleration, thereby suppressing HC and CO emissions and occurrence of afterfire. In this embodiment, a temperature sensing valve 40 is provided in the middle of the conduit 32 to open and close the conduit 32 by sensing the state of the engine. This temperature sensing valve senses, for example, the engine cooling water temperature, and establishes the connection of the conduit 32 when the temperature is below a predetermined temperature that prevents the discharge of HC and CO and the generation of afterfire, whereas when the temperature is above a predetermined temperature, Sometimes said conduit 3
It is designed to block the second lotus route. Therefore, in this case, when the engine cooling water temperature is below a predetermined temperature, that is, when the engine is not running, the operation time of the throttle positioner becomes longer due to the use of the negative pressure control valve 19, as in the above-mentioned embodiment.
When the engine cooling water temperature is above a predetermined temperature, that is, HC, C
When the engine is warm, with less O discharged and no afterfire generation hidden, the operation of the negative pressure control valve 19 is canceled, and the operating time of the throttle positioner is determined by the throttling effect of the throttle element 18.
This will be for a shorter time than when it is operating. The temperature sensing valve 40 may be provided not only in the middle of the conduit 32 but also in the middle of the conduit 20 or in the middle of the conduit 38 in the embodiment shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of a throttle positioner according to the present invention, FIG. 2 is a schematic configuration diagram showing one embodiment of a negative pressure delay valve, and FIGS. 3 and 4 are respectively according to the present invention. FIG. 2 is a schematic slow-growth diagram showing another embodiment of the throttle positioner according to the present invention. DESCRIPTION OF SYMBOLS 1... Throttle valve, 2... Throttle koji, 3... Intake passage 4... Throttle lever, 5... Stopper arm, 6... Adjustment screw part, 7... Contact, 8...
...Abutting surface, 9...Pivot pin, 10...Diaphragm device tll...Rod, 12...Diaphragm casing, 13...Diaphragm chamber, 14...Diaphragm, wing 5
. . . Compression coil spring, 16 .・・・
Atmospheric release boat, 23... Valve element, 24... Valve seat portion, 25... Valve rod, 26... Diaphragm, 27... Casing, 28... First diaphragm chamber, 29... Second diaphragm chamber, 38. ...Compression coil spring, 31... Throttle passage, 32... Conduit, 33... Negative pressure delay valve, 34... Check valve, 3
5...First aperture element, 36...Second aperture element, 37
...Intake pipe member pressure take-out boat, 38... Conduit, 39...
- Throttle element, 40...temperature sensing valve. Figure 2 Figure l Figure 3 Figure 4

Claims (1)

[Claims] 1 A throttle lever fixed to a throttle shaft of a throttle valve engages with the throttle lever to prevent the throttle valve from returning to the idling opening position, thereby increasing the throttle valve by a predetermined amount from the idling opening position. The throttle valve has a stopper element that moves between a first position that ensures an opening equal to or greater than the control opening during open deceleration and a second position that allows the throttle valve to return to the idling opening position. a diaphragm device that moves the stopper element to the first position by a spring force when no negative pressure is applied to the diaphragm chamber, and moves the stopper element to the second position when negative pressure is applied; an intake pipe negative pressure outlet port located downstream of the throttle valve at the control opening during deceleration and located upstream of the throttle valve when the throttle valve is opened at the control opening during deceleration or more; A conduit that connects a negative pressure outlet port to the diaphragm chamber of the diaphragm device, a throttle element provided in the middle of the conduit, and a negative pressure control valve that selectively opens the diaphragm chamber of the diaphragm device to the atmosphere. and the negative pressure control valve controls the negative pressure control valve when the negative pressure in the first diaphragm chamber on one side of the diaphragm becomes greater than the negative pressure in the second diaphragm chamber on the other side of the diaphragm by a predetermined value or more. The diaphragm chamber of the diaphragm device is connected to an atmospheric port, and when the negative pressure in the first diaphragm chamber is not larger than the negative pressure in the second diaphragm chamber by a predetermined value or more, the diaphragm chamber of the diaphragm device is isolated from the atmospheric port. , wherein an intake pipe negative pressure is directly introduced into the first diaphragm chamber, and the first diaphragm chamber and the second diaphragm chamber communicate with each other via a throttle passage. Tutle positioner.