JPS6233429B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a carburetor in which a choke valve is installed on the upstream side of the intake passage and a throttle valve is installed on the downstream side of the intake path, with the bench lily portion where the main fuel nozzle opens as a boundary, and the choke valve and the throttle valve are installed in the carburetor. The present invention relates to a choke valve and throttle valve control device that controls the opening degree of the internal combustion engine according to the operating conditions of the internal combustion engine so as to always maintain an appropriate operating state of the engine.

Conventionally, an auto-choke device is known as this type of device, and this device connects a temperature-sensitive member such as a bimetal to the chi-yoke valve, and controls the opening of the chi-yoke valve by operating the temperature-sensing member in response to changes in engine temperature. On the other hand, the idle opening of the throttle valve is also controlled according to the engine temperature by interlocking the throttle valve and the throttle valve through links and cams, etc., but the structure is complicated and the carburetor cannot be used. In addition to making the throttle valve bulky, since the closing force of the return spring is always acting on the throttle valve, it is difficult to always properly control the idle opening of the throttle valve using only the output of the temperature sensing member. There are drawbacks. In addition, since such an autochoke device uses the engine temperature as a control signal, for example, when auxiliary equipment such as a compressor for a cooler in a car, a hydraulic pump for power steering, or a generator for charging is connected to the engine as a load. The engine does not have a function that increases the idle opening of the throttle valve to maintain the engine's idling speed at a predetermined value. Therefore, in the past, in addition to the auto-choke device, a negative pressure operated throttle opener was connected to the throttle valve, and when auxiliary equipment was connected, the throttle opener operated to open the throttle valve to an opening slightly larger than the normal idle opening. It is also known to provide a load-responsive throttle valve control device such as this. However, since this type of device can only adjust the idle opening of the throttle valve in stages, it is difficult to accurately control the engine's idling rotation to a constant level regardless of the weight of the load on the auxiliary engine. Needless to say, this is extremely difficult and has the disadvantage that the carburetor becomes even bulkier when combined with an autochoke device.

The present invention has been proposed in view of the above, and uses a pulse motor and a rotary cam means directly connected and driven by its rotor shaft to control the opening of the choke valve and the throttle valve according to the engine temperature and the engine temperature of the auxiliary equipment. load on,
By performing stepless control according to other operating conditions of the engine, the operating condition of the engine can always be maintained at an appropriate level. It is an object of the present invention to provide a choke valve and a throttle valve control device that are extremely simple and compact in structure.

In order to achieve the above object, the present invention provides first and second valves connected to the valve shaft of a chiyoke valve so as to be able to rotate integrally therewith, and arranged at regular intervals in the direction of rotation.
a throttle lever having a second arm; a throttle lever connected to the valve shaft of the throttle valve so as to be integrally rotatable therewith and biased by a spring in the closing direction of the throttle valve; a throttle lever rotatable to the valve shaft of the throttle valve; an interlocking lever that is supported and capable of engaging the throttle lever 0- in a manner that allows it to approach and separate from the throttle lever in its rotational direction to regulate the return limit of the throttle lever; provided on the interlocking lever and the first and second arms, respectively; Three cam plates that can be independently connected to a follower, and a pulse motor in which these cam plates are fixed on a rotor shaft in parallel with each other in the axial direction; this pulse motor is used to drive an internal combustion engine. It is characterized by comprising at least a control circuit that applies an actuation pulse according to conditions; and a spring that constantly biases the interlocking lever toward the corresponding cam plate. Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a carburetor main body 1
has a vertical intake passage 2, the upper part of which is connected to an air cleaner, the lower part to an intake pipe of an internal combustion engine (both not shown), and a main fuel nozzle 3 opens in the middle part. It has become a bench lily part 2a. A choke valve 4 is installed on the upstream side (air cleaner side) of the intake passage 2, and a throttle valve 5 is installed on the downstream side (engine side) with this bench lily portion 2a as a boundary. These valves 4 and 5 are both butterfly type, and each has a valve shaft 4 rotatably supported by the carburetor main body 1.
a, 5a.

The valve shaft 4a of the York valve 4 has two arms arranged at a constant interval, that is, first and second arms 6a, 6b.
A return spring 7 is connected to the lever 6, which urges the lever 6 in the opening direction of the valve 4.

A throttle lever 8 is fixed to the valve shaft 5a of the throttle valve 5, and a return spring 9 is connected to the lever 8 for biasing the lever 8 in the closing direction of the throttle valve 5. The throttle lever 8 is fan-shaped and has a guide groove 1 on its outer periphery.
0, and an operating wire 11 connected to an accelerator pedal (not shown) is engaged with the guide groove 10 and connected to the throttle lever 8.

Further, an interlocking lever 12 extending to a portion near the choke lever 6 is rotatably attached to the valve shaft 5a. The interlocking lever 12 and the throttle lever 8 are each integrally provided with a stopper piece 13 and an abutment piece 14 facing each other, and a stopper screw 15 screwed onto the stopper piece 13 is attached to the abutment piece 14.
The contact point can be separated from the contact point.

A follower 6 is provided on the side surface of each tip of the first and second arms 6a and 6b of the chain lever 6 and the interlocking lever 12.
a', 6b' and 12' are provided, and the follower 6
A first rotating cam member _C1 that can engage with a' and 6b' to rotate the chain lever 6, and a second rotating cam member that can engage with the follower 12' and rotate the interlocking lever 12.
C ₂ are arranged coaxially and in parallel with each other as shown below.

That is, as shown in FIGS. 1 and 2, the first rotary cam member _C1 includes two cam plates connected in parallel to each other in the axial direction, namely a leading cam plate 16 and a trailing cam plate 17.
The second rotary cam member C ₂ is composed of 1
It is composed of two cam plates 18. Cam plate 16,1
7 is provided with one flank portion 16a and one 17b, but the cam plate 18 is provided with two flank portions 18b and 18c on both sides with the base portion 18a in between, and the cam plate 18 has one follower 12'. A spring 19 is used to keep the interlocking lever 12 engaged at all times.
connected to.

The three cam plates 16, 17, 18 are fixed at their respective rotation centers to a rotor shaft 21 of one pulse motor M mounted on a fixed support base 20 on the carburetor main body 1. Therefore, all cam plates 16, 17, 18
are driven by one common pulse motor M.

An electronic control circuit 22 is connected to the pulse motor M, and this circuit 22 applies pulses for forward rotation or reverse rotation to the motor M according to an input signal.
The input section 2 includes an engine temperature detector 23 that emits a signal according to the engine temperature such as engine water temperature, an engine rotation speed detector 24 that emits a signal according to the engine rotation speed, and an engine rotation speed detector 24 that emits a signal according to the engine rotation speed. An intake air temperature detector 25 or the like that emits a signal is connected.

Next, the operation of this embodiment will be explained.

Figure 1 shows the state of the carburetor when the engine is idling after warming up.
The yoke lever 6 has leading and trailing cam plates 16,1
7, and the biasing force of the return spring 7 causes the check valve 4 to be fully opened.
On the other hand, the interlocking lever 12 causes the follower 12' to come into contact with the base portion 18a of the cam plate 18 due to the biasing force of the spring 19, and the stopper screw 15 is moved to the throttle lever 8.
This screw 15 supports the stopper piece 13 and therefore the throttle lever 8 to close the throttle valve 5 to the normal idle opening position. The idle opening is
By moving forward and backward by screwing the stopper screw 15,
It can be adjusted arbitrarily.

Now, when an auxiliary machine such as a cooler compressor is connected to the engine as a load, and the engine speed drops below the specified idling speed, the engine speed detector 24 sends a signal indicating the situation to the control circuit 22. The control circuit 22 applies a pulse corresponding to the input signal to the pulse motor M, and thereby the pulse motor M rotates all the cam plates 16, 17, 18 in the direction of arrow A by its rotor shaft 21. let Then, the cam plate 18 engages with the follower 12' through the first flank portion 18b and rotates the interlocking lever 12 in the opening direction of the throttle valve 5, so that the stopper screw 15 and the abutting piece 14 in the abutting state The throttle lever 8 also rotates at the same time against the force of the return spring 9 to increase the idling opening of the throttle valve 5. That is, an appropriate fast idle opening degree is provided. When the throttle valve 5 obtains the fast idle opening and the engine speed returns to the specified idling speed, the engine speed detector 24 stops generating a signal, and the pulse motor M stops.

On the other hand, the leading cam plate 16 of the first rotating cam member _C1
is separated from the choke lever 6 by the rotation of the pulse motor M in the direction of arrow A, and therefore, during this period, the fully open state of the choke valve 4 does not change at all.

To switch the engine from idling to output operation, operate the accelerator pedal and connect operating wire 1.
1, the throttle lever 8 can be rotated against the force of the return spring 9 to open the throttle valve 5 to an arbitrary opening degree. In this case, the contact piece 14 moves away from the stopper screw 15, and the interlocking lever 12
does not change the engagement position with the cam plate 18.

Next, we will explain the case where the engine temperature drops below a predetermined value. In this case, the engine temperature detector 23 sends a signal indicating the situation to the control circuit 22, and the control circuit 22 responds to the input signal. A pulse is applied to the pulse motor M, thereby causing the pulse motor M to rotate all the cam plates 16, 17, 18 in the direction of arrow B in the opposite direction. Then, first, the flank portion 16a of the leading cam plate 16 engages with the follower 6a', returning the first arm 6a of the check lever 6 and rotating it against the force of the spring 7, so that the check valve 4 is closed. It's getting worse. FIG. 3 shows this state.

When the rotation of the pulse motor M in the direction of the arrow B reaches a predetermined angle, the leading cam plate 16 is rotated by the follower 6 of the first arm 6a.
By the time the trailing cam plate 17 is separated from a', the flank portion 17a of the trailing cam plate 17 comes to engage with the follower of the second arm 6b, and therefore, the subsequent rotation of the trailing cam plate 17 and the trailing cam plate 17 are prevented. This is then taken over by the second arm 6b (see FIG. 4), and the valve 4 can be moved to the fully closed position. Such two leading and trailing cam plates 16, 17 and two arms 6a, 6
According to the use of b, the check valve 4 can be reliably closed by rotating the check lever 6 largely within the limited rotational angle range of the pulse motor M.

During this time, the cam plate 18 moves toward the second flank 18.
c is engaged with the follower 12', and the interlocking lever 12
The throttle lever 8 is rotated against the force of the return spring 9 via the throttle lever 8, thereby giving the throttle valve 5 a fast idle opening degree corresponding to the degree of closing of the choke valve 4. In this way, the engine can be easily cold started and warmed up properly.

As described above, according to the present invention, the main fuel nozzle 3
The intake passage 2 is bordered by the bench lily part 2a where the
In a carburetor having a chiyoke valve 4 on the upstream side and a throttle valve 5 on the downstream side, the first valves are connected to the valve shaft 4a of the chiyoke valve 4 so as to rotate integrally with each other, and are arranged at regular intervals in the direction of rotation. , second arm 6
a and 6b; a throttle lever 8 which is connected to the valve shaft 5a of the throttle valve 5 so as to rotate integrally therewith and is biased by a spring 9 in the closing direction of the throttle valve 5; an interlocking lever 12 rotatably supported on the valve shaft 5a of the throttle lever 8 and capable of engaging with the throttle lever 8 so as to be able to move towards and away from the throttle lever 8 in its rotational direction to regulate the return limit of the throttle lever 8; 12 and three cam plates 18, 16, 17 that can be independently connected to the followers 12', 6a', 6b' provided on the first and second arms 6a, 6b, respectively.
and; These cam plates 18, 16, 17 are connected to the rotor shaft 2.
1; a control circuit 22 for applying operating pulses to the pulse motor M in accordance with the operating conditions of the internal combustion engine; and the interlocking lever 12; Spring 1 that constantly biases toward the corresponding cam plate 18
9 and;, the opening of the throttle valve and the throttle valve can be controlled by the only pulse motor M and the cam means directly connected to the rotor shaft 21 to control the engine temperature, the load applied to the auxiliary engine, and other engines. can be controlled steplessly according to the operating conditions of
The operating condition of the engine can always be maintained properly.

In particular, the throttle lever 6 can be engaged directly with cam plates 16 and 17 directly connected to the loader shaft 21, while the throttle lever 8 is engaged with a cam plate 18 directly connected to the rotor shaft 21 via the only interlocking lever 12. Therefore, as a whole, the pulse motor M and each valve 4,
The structure of the interlocking mechanism between the parts 5 and 5 is extremely simple and compact, which is advantageous in reducing the cost and making the carburetor more compact. Moreover, the chiyoke valve 4 and the throttle valve 5
Separate cam plates 16, 17 on the rotor shaft 21;
8, it is possible to secure a wider effective cam surface for each cam plate 16, 17; 18 compared to a case where both valves 4 and 5 are opened and closed by a common cam plate. Therefore, as described above, the structure of the interlocking mechanism between each valve 4, 5 and the pulse motor M is extremely simplified, and each valve 4, 5
The operating accuracy of each valve 4,
5, it is possible to perform extremely fine control according to engine characteristics.

Also, a cam plate 1 for operating the chiyoke valve 4.
6 and 17 are provided on the rotor shaft 21, and these can be sequentially engaged with the two arms 6a and 6b of the brake lever 6. Therefore, the brake lever 6 can be operated within a limited rotational angle range of the pulse motor M. The valve 4 can be reliably closed by rotating the valve greatly.

Furthermore, since the interlocking lever 12 for interlocking the throttle lever 8 with the cam plate 18 is always biased by the spring 19 toward the cam plate 18, the interlocking lever 12
The follower 12' of the throttle lever 8 can be kept in contact with the cam plate 18 at all times, so that even when the throttle lever 8 is manually operated, the interlocking lever 12 can follow the throttle lever 8. There is no fear that the cam plate 18 will move and repeatedly collide with the cam plate 18, and the generation of noise caused by such collisions can be prevented. Moreover, the spring 1 for the interlocking lever 12
Since the biasing force 9 is received by the cam plate 18 and is not transmitted to the throttle lever 8, the manual operability of the throttle lever 8 is not impaired even with the special provision of the spring 19 and interlocking lever 12. .

[Brief explanation of the drawing]

FIG. 1 is a side view of a vaporizer equipped with the device of the present invention;
FIG. 2 is a cross-sectional view taken along the line ``-'', and FIGS. 3 and 4 are operational diagrams. M... Pulse motor, 2... Intake path, 2a... Bench lily part, 3... Main fuel nozzle, 4... Chi York valve, 4
a... Valve stem, 5... Throttle valve, 5a... Valve stem, 6... Choke lever, 8... Throttle lever, 9... Return spring,
12... Interlocking lever, 13... Stopper piece, 14... Contact piece, 19... Spring, 15... Stopper screw, 16...
Leading cam plate, 17... Following cam plate, 18... Cam plate,
22... Control circuit, 23... Engine temperature detector, 24...
Engine speed detector, 25...Intake air temperature detector.

Claims (1)

[Claims] 1 Bench lily portion 2a where the main fuel nozzle 3 opens
In this carburetor, a choke valve 4 is installed on the upstream side of the intake passage 2 and a throttle valve 5 is installed on the downstream side of the intake passage 2. a choke lever 6 having first and second arms 6a and 6b lined up at an interval; connected to the valve shaft 5a of the throttle valve 5 so as to rotate integrally therewith, and biased by a spring 9 in the closing direction of the throttle valve 5; the throttle lever 8; the throttle valve 5;
an interlocking lever 12 rotatably supported on the valve shaft 5a of the throttle lever 8 and capable of engaging with the throttle lever 8 so as to be able to move towards and away from the throttle lever 8 in its rotational direction to regulate the return limit of the throttle lever 8; 12 and a follower 1 provided on the first and second arms 6a and 6b, respectively.
2', 6a', 6b', three cam plates 18, 16, 17 which can be independently connected to each other; these cam plates 18,
16 and 17 are fixed on the rotor shaft 21 in parallel with each other in the axial direction;
The pulse motor M is provided with at least a control circuit 22 that applies an operating pulse according to the operating conditions of the internal combustion engine; and a spring 19 that constantly biases the interlocking lever 12 toward the corresponding cam plate 18. A choke valve and throttle valve control device for a carburetor, characterized by: