JPS6319556Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a control device for a throttle valve in a vehicle carburetor, which controls the opening of the throttle valve of a carburetor according to each temperature, especially in a vehicle deceleration state such as cold or warm. It is related to a device that changes.

After this, the carburetor system became a quiet yoke to reduce exhaust gas or improve fuel efficiency, and the idle speed was lowered. Therefore, in the conventional carburetor, since the throttle valve opening and the throttle valve opening are connected, a decrease in the intake yoke or the idle opening may have a large adverse effect on the low-temperature performance.

Therefore, the present invention opens the throttle valve earlier when cold and prevents the throttle valve opening from using the regular throttle positioner to prevent stalls after racing and stalls after cam drop at low temperatures. The purpose is to contribute to exhaust performance by using it like a throttle positioner.

Next, an embodiment of the present invention shown in the drawings will be described.

Reference numeral 1 denotes a carburetor having a throttle valve 2 and a throttle positioner 6, and a negative pressure sensing port 4 located at the bottom of the throttle valve of the carburetor.
An atmospheric pressure sensing port 5 is provided at the top. Throttle positioner 6 has
There is a lever 3 connected to the throttle valve 2, a built-in diaphragm 8, a shell 9, and a spring 7. Negative pressure in the intake cylinder acts on the rear chamber of the diaphragm, causing the diaphragm 8 to move to the right. throttle valve 2 is opened. Reference numeral 10 designates a negative pressure delay valve, which is a check valve 1 for delaying the negative pressure flowing from the negative pressure sensing port 4 to the rear chamber of the diaphragm and speeding up the reverse flow.
1 and an aperture jet 12. Reference numeral 13 denotes a negative pressure conversion device, which has a bimetal 14 that senses temperature and operates, and the operation of the bimetal 14 causes a passage switching valve 15 connected to the bimetal to be operated up and down, thereby controlling each passage 16, 17, 18, 19 communication,
It's starting to shut down. That is, when the engine water temperature or engine block temperature is sensed and the temperature is low, the bimetal 14 moves up to close the passages 16 and 18 and at the same time close the passages 17 and 19.
If the passage is high, the bimetal 14 moves downward to open and close the passage in the opposite direction. Further, each passage 16, 17, 18, 19 is arranged as shown in the figure.

Next, the operation will be explained.

When the engine water temperature or engine block temperature is low, the bimetal 14 senses this and operates upward as shown in Fig. 1, and the passage switching valve 15 pushed up thereby shuts off the upper passages 16 and 18. The lower passage 17 and the passage 19 are communicated with each other. In this state, the atmospheric pressure sensing port 5 of the carburetor is in the atmosphere, so the lever 3 is pushed to the left by the force of the spring 7 in the throttle positioner 6, increasing the throttle valve opening. The atmospheric pressure sensing port 5 is set at a position where negative pressure is not applied even in this state. In other words, when the engine is cold, it will never reach the idle opening regardless of the throttle valve.

Next, when the engine water temperature or engine block temperature is high, the bimetal 14 senses this and moves downward, thereby lowering the passage switching valve 15.
blocks the passages 17 and 19 and at the same time blocks the passages 16 and 1.
Connect 8. In this state, if negative pressure is generated in the negative pressure sensing port 4 of the carburetor, the passage 16
18, negative pressure is transmitted to the throttle positioner 6 through the throttle jet 12 of the negative pressure delay valve 10 in a delayed manner, and when the negative pressure exceeds the set value, it overcomes the spring 7, pulls the lever 3, and closes the throttle. Reduce the tuttle valve opening (return to idle opening). If the generated negative pressure becomes close to the atmosphere due to the influence of the throttle valve, the flow will be the opposite as described above, but in this case, the check valve 11 causes the flow to occur quickly and there is no delay time.

As mentioned above, by not operating the regular positioner function when the engine is cold, but by providing the regular positioner function via the negative pressure delay valve when the engine is warm, the engine braking effect is improved when the exhaust gas cannot be purified. The characteristic is that the exhaust gas is purified during warm times, and as shown in Figure 3, during cold times,
The throttle valve opening is maintained at a larger opening than the idle opening, and when the temperature is warm, the negative pressure delay valve causes the throttle valve to reach the idle opening with a delay (so-called normal operation of the throttle positioner). That is, during deceleration or gear change, the throttle valve gradually returns to the idle opening position. This prevents incomplete combustion and prevents large amounts of Hc from being emitted into the exhaust gas.
Also, when the negative pressure sensing port 4 reaches atmospheric pressure, the check valve 11 opens and the throttle positioner 6
The rear chamber of the diaphragm can be brought close to high pressure immediately to prepare for preventing Hc discharge during the next deceleration or gear change. Due to this characteristic, it is possible to prevent deterioration of low-temperature performance due to a reduction in idle opening and contribute to exhaust performance.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a sectional view showing operation in cold conditions, FIG. 2 is a sectional view showing operation in warm conditions, and FIG. 3 is a sectional view showing operation in cold conditions and warm conditions. FIG. 3 is a diagram showing the opening degree characteristics of the throttle valve at the time of operation. 1... Carburetor, 2... Throttle valve, 4...
...Negative pressure sensing port, 5...Atmospheric pressure sensing port, 6...Throttle positioner, 8...
Diaphragm, 10... Negative pressure delay valve, 11... Check valve, 12... Throttle jet, 13... Negative pressure conversion device, 14... Bimetal, 15... Passage switching valve, 16, 17, 18, 19 ……aisle.

Claims (1)

[Scope of utility model registration request] Throttle positioner 6 on throttle valve 2
Due to the normal throttle positioner function in which negative pressure is applied to the rear chamber of the diaphragm of the throttle positioner, the opening degree of the throttle valve 2 becomes smaller, and by releasing the negative pressure, the throttle valve becomes more open than when the negative pressure is applied. The diaphragm rear chamber has an opening downstream of the throttle valve 2 via a negative pressure delay valve 10 having a check valve 11 and a throttle jet 12. A first port communicating with the negative pressure sensing port 4
and a second communication path that communicates with the atmospheric pressure sensing port 5 opened upstream of the throttle valve 2. A negative pressure switching device 13 is provided which has a passage switching valve 15 that opens a second communicating passage at the same time it is closed and performs the opposite opening/closing operation when it is warm, so that the normal throttle positioner function is disabled when it is cold. 1. A control device for a throttle valve in a carburetor, characterized in that: