JPS6117238Y2 - - Google Patents

Description

[Detailed explanation of the invention] The compound vaporizer fulfills its functions by combining both the primary side and the secondary side.The secondary is a mechanism that follows the primary, and the secondary throttle valve is opened effectively. Although the degree changes automatically, it is common for the secondary throttle valve to begin or be able to open when the primary throttle valve reaches 50% to 70% of its full opening. be. Also, the primary throttle valve is fully opened when the accelerator pedal is fully depressed.
At this time, if the engine is rotating at high speed, the secondary throttle valve must be fully open, and if the engine is rotating at low speed, the secondary throttle valve must be closed. There are two methods for opening and closing the secondary throttle valve: negative pressure type and mechanical type.The present invention relates to a negative pressure type secondary throttle valve opening/closing mechanism, and aims to simplify the mechanism of the boost lock prevention part. There is.

The conventional negative pressure secondary throttle valve opening/closing mechanism for compound vaporizers is shown in Figures 1 and 2.
It is configured as shown in the figure. That is, 1 is the primary side bore, 2 is the secondary side bore, 3 is the primary throttle valve, 4 is the secondary throttle valve, 5 is the primary throttle valve shaft, 6 is the secondary throttle valve shaft, 7
Reference numeral 8 indicates a cam-shaped throttle valve lever attached to the shaft end of the primary throttle valve shaft 5, and reference numeral 8 indicates a throttle lever lever attached to the secondary throttle valve shaft 6 in the shape of a lever, with an engaging hook portion 9 formed at the tip. , a connecting pin 10 is provided protruding from the lower end.
Reference numeral 11 denotes a secondary throttle valve which is loosely fitted onto a pin 10 corresponding to the primary throttle valve lever 7 and engaged with the hook part 9 by a notch groove 12 formed at the tip and having a relief width when the throttle valve is fully closed. A secondary throttle valve operating lever is connected by a lever 8 and a spring 13. A roller 14 is provided at one corner of the tip of the secondary throttle valve operating lever, which contacts the cam-shaped surface of the primary throttle valve lever 7, and a pin 10 that passes through this operating lever 11
An actuating rod 17 attached to a diaphragm 16 of a negative pressure device 15 operated by ventilated negative pressure is connected to the outer end of the actuator via a boost lock prevention function.

With this structure, when the primary throttle valve 3 starts to open, negative pressure is generated by the air flowing through the ventilate section, which acts on the diaphragm chamber 18 of the negative pressure device 15, but the cam surface of the primary throttle valve lever 7 is throttle valve 3
The lever 11 is shaped to suppress movement of the lever 11 so that the secondary throttle valve 4 does not open until the opening reaches 50% to 70%, so the secondary throttle valve 4 does not open.
When the primary throttle valve 3 exceeds the above range, the cam is released and the secondary throttle valve 4 opens due to the negative pressure in the ventilate, and even if the primary throttle valve 3 opens further, if the negative pressure in the ventilary is small, The diaphragm chamber 18 cannot be opened due to the force of a spring 19 provided within the chamber 18, but as the rotational speed increases, the air flow rate increases, and the negative pressure increases, the force of the diaphragm 16 overcomes the force of the spring 19. As shown in FIG. 2, the secondary throttle valve 4 is opened.
When the accelerator is released from the fully open state of both the primary and secondary throttle valves 3 and 4, the primary throttle valve 3 is forcibly closed, and the secondary throttle valve 4 is also closed. However, if the air cleaner becomes clogged,
Negative pressure for this acts on the diaphragm 16, and the operating rod 17 and levers 8, 11 are both locked, so the primary throttle valve lever 7 is locked on its cam surface, and the primary throttle valve 3 cannot be closed either. , resulting in so-called boost lock.

In order to prevent this, a boost lock prevention mechanism is provided between the operating rod 17 and the secondary throttle valve operating lever 11 as described above. That is, as shown in FIG. 3, the conventional boost prevention mechanism includes an operating rod 17 and a sub-operating rod 2 formed in the shape of a hacksaw support frame.
A coil spring 22 is compressed and interposed between the hook-shaped portion 21 and the lower end of the actuating rod 17 under a set load, and the tension of the spring 22 causes the actuating rod to function as an actuating rod. A rod-shaped connecting body formed by connecting a connecting part 10a formed at the other end of the sub-actuating rod 20, which is designed to maintain a predetermined length, to the pin 10 of the secondary throttle valve lever 8. 16 does not move, the auxiliary actuating rod 20 moves to the second
As shown by chain lines in the figure, by compressing and expanding the spring 22, the primary throttle valve lever 7 and the secondary throttle valve operating lever 11 are rotated, and as a result, the primary and secondary throttle valves 3 and 4 are rotated. They can be closed together.

As described above, although the conventional mechanism has a boostlock prevention function, it has a complicated structure, a large number of parts, and requires a lot of effort to assemble, resulting in high costs.

In view of the above points, the present invention has been developed by forming a spring wire tightly spirally wound around the rod-shaped connection body between the diaphragm of the negative pressure device and the secondary throttle valve actuation lever, so as to have an initial tension corresponding to the set load. It uses a rod-shaped spring with a boost lock prevention function, and is characterized by its simple structure, significantly fewer parts, and low cost.

Next, embodiments of the present invention will be described based on the drawings.

The present invention consists of a secondary throttle valve operating lever 11 and a negative pressure device 1.
A fourth diaphragm 16 is attached to the rod-shaped connection body with the diaphragm 16 of No. 5.
As shown in FIG. 5 and FIG. 5, a rod-shaped spring 23 is used, which is made by closely spirally winding a spring wire material into a rod shape, has an initial tension corresponding to the set load, and has a boost lock prevention function. Connect one end of 23 to the diaphragm pin 24
4, the diaphragm pin 24 is provided with a screw 25, and one end of the rod-shaped spring 23 is elastically connected to the threaded portion. The connecting portion 10a at the other end is formed in the shape of a hook so that it fits and locks into the connecting pin 10 or hole for connecting to the secondary throttle valve operating lever 11. However, as shown in FIG. 5, even if the diaphragm side is also formed into a hook shape, the diaphragm pin 24' is provided with a hole 26 instead of a screw, and the hook part is elastically fitted and fixed into this hole. good.

In the negative pressure secondary throttle valve opening/closing mechanism of the present invention in which the rod-shaped spring 23 configured as described above is used as a rod-shaped connection body between the diaphragm 16 and the secondary throttle valve operating lever 11, the rod-shaped spring 23 has a tension lower than the set load. Since it does not expand even when a Due to the increase in the rod-shaped spring 23
By expanding the diaphragm 16, both the primary and secondary throttle valves 3 and 4 can be closed without movement, thereby achieving a so-called boost lock prevention function.

As mentioned above, the present invention is based on a spiral spring wire closely attached to the connecting rod between the secondary throttle valve operating lever that operates in conjunction with the primary throttle valve lever and the diaphragm of the negative pressure device that controls the secondary throttle valve. Using a rod-shaped spring that has an initial tension equivalent to the set load and has a boost-lock prevention function,
Since one end of the spring is fixed to the diaphragm pin and the other end is connected to the secondary throttle valve operating lever, the structure of the mechanism for preventing boost lock, which is common to this type of mechanism, is simpler than conventional mechanisms. The number of parts is greatly reduced and the number of parts is greatly simplified, which simplifies the assembly work and contributes to cost reduction, which brings excellent effects to this type of mechanism.

[Brief explanation of the drawing]

Figures 1 and 2 are front views of the negative pressure secondary throttle valve opening/closing mechanism of a compound carburetor, and Figure 3 is a partially cutaway side view of the conventional boost lock prevention function.
4 and 5 are partially cutaway front views of a connecting rod showing an embodiment of the negative pressure type secondary throttle valve opening/closing mechanism of the compound vaporizer of the present invention. 1: Primary side bore, 2: Secondary side bore, 3: Primary throttle valve, 4: Secondary throttle valve, 5: Primary throttle valve shaft, 6: Secondary throttle valve shaft, 7: Primary throttle valve lever, 8: Secondary throttle valve lever, 10: Connection pin, 10a: Connection portion, 11:
Secondary throttle valve operating lever, 14: Roller, 15: Negative pressure device, 16: Diaphragm, 23: Rod spring (connecting rod), 24, 24': Diaphragm pin,
25: Screw.

Claims (1)

[Scope of utility model registration request] The secondary throttle valve is operated through a secondary throttle valve operating lever that operates in conjunction with the rotation of the primary throttle valve lever attached to the primary throttle valve, and a secondary throttle valve lever that operates in conjunction with the secondary throttle valve operating lever. In a negative pressure secondary throttle valve opening/closing mechanism for a compound vaporizer in which a negative pressure device for opening/closing control is connected by a rod-like connecting body having a boost-lock prevention function, the rod-like connecting body having the boost-lock preventing function is for a spring. It consists only of a rod-shaped spring made of a wire tightly wound in a spiral shape, and when an initial tension corresponding to the set load is applied to the rod-shaped spring, one end is connected to the diaphragm pin of the negative pressure device and the other end is connected to the secondary throttle. A negative pressure type secondary throttle valve opening/closing mechanism for a compound vaporizer, characterized in that each valve operating lever is connected to the valve operating lever.