JPS591073Y2 - Diesel engine intake throttle device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake throttle valve control device that is operated during idling of a diesel engine.

Recently, easel vehicles such as easel passenger cars have been put into practice due to their economic efficiency, but the vibrations and noise generated from the diesel engines installed in them have become a major problem.

In particular, torque fluctuations within one cycle during idling,
That is, the angular velocity fluctuation is large, and this is one of the factors that increases the vibration.

In view of the above-mentioned points, this proposal throttles the intake air during idling, and also maintains the negative intake pressure at a constant level during intake throttle to prevent an increase in noise and harmful exhaust components due to excessive throttling. It is an object of the present invention to provide an intake throttle device for an easel engine, and an embodiment thereof will be described below with reference to the drawings.

Reference numeral 1 denotes an intake passage of a diesel engine, and an intake throttle section 5 is formed in the middle of the intake passage, which is divided into 1st and 2nd passages 3 and 4 by a partition wall 2.

In the first passage 3, an intake throttle valve 6 is rotatably supported by the wall of the intake throttle section 5 with its shaft 7, and
An arm 8 for operating the throttle valve 6 is provided at one outer end of the
is provided.

9 is a negative pressure responsive actuator, and diaphragm 1
The negative pressure chamber 11 is divided into a negative pressure chamber 11 and an atmospheric chamber 12 with the 0 in between.
A return spring 15 that presses 0 is provided.

On the other hand, the atmospheric chamber 12 is provided with a suitable hole or opening (not shown) to communicate with the atmosphere, and is also provided with a rod 16 having one end fixed to the diaphragm 10 and the other end extending outward. The outer end of the rod 16 is connected to the arm 8 directly or via a suitable rod or link.

Reference numeral 17 denotes a vacuum cut-off valve disposed in the middle of the pipe 13, which is divided into a negative pressure chamber 20, an atmospheric chamber 21, and a pressure chamber 22 by a partition plate 18 and a diaphragm 19 installed therein.

The pressure chamber 22 communicates with an exhaust passage 24 of the engine via a suitable pipe 23, so that the exhaust pressure within the exhaust passage 24 can be detected.

25 is a valve fixed to the diaphragm 19 with a shaft 25a, and is activated when a predetermined set exhaust pressure acts on the diaphragm 19 to close the opening 13a of the pipe 13; It is a return spring.

27 is a water temperature sensing valve disposed between the vacuum cutoff valve 17 and the actuator 9, and the water temperature sensing element section 28 is connected to the water jacket of the cylinder body B of the engine.
- It is installed so as to face inside the W, and opens and closes an internal passage (not shown) in accordance with the operation of the water temperature sensing element section 2B.

Reference numeral 29 denotes an intake negative pressure control valve provided in the second passage 4, which is rotatably supported by the wall of the intake throttle section 5 with its shaft 30, and the control valve 29 is provided at one outer end of the shaft 30. An arm 31 is provided for operating the.

32 is a negative pressure responsive actuator, and the diaphragm 3
3 into a negative pressure chamber 34 and an atmospheric chamber 35, and the negative pressure chamber 34 is connected to the downstream side (engine side) 1a of the intake throttle section 5 through an appropriate pipe 36, and is always connected to the downstream side 1a.
The intake negative pressure taken out more effectively.

Further, a return spring 37 is disposed in the negative pressure chamber 34 to push the diaphragm 33 to the left in the figure, that is, in a direction to close the control valve 29, against the intake negative pressure.

On the other hand, the atmospheric chamber 35 is provided with a suitable hole or opening (not shown) to communicate with the atmosphere, and is also provided with a rod 38 having one end fixed to the diaphragm 33 and the other end extending outward. The outer end of the rod 38 is connected to the arm 31 directly or via a suitable rod or link mechanism.

Next, the operation of the embodiment of the present device configured as described above will be explained.

First, when the engine is idling at room temperature, the exhaust pressure in the exhaust passage 24 is low and the water temperature sensing valve is also open, so the vacuum pump 14 works to return the spring 15 to the negative pressure chamber 11 of the actuator 9. Since the diaphragm 10 and the rod 16 are pulled to the right in the drawing against this, the intake throttle valve 6 is rotated clockwise in the drawing via the arm 9, thereby throttling the passing intake air flow.

Therefore, since the amount of intake air is reduced, the angular velocity fluctuation of the engine and the vibration acceleration in the rolling direction are reduced, and the effect of reducing engine vibration and noise during idling can be obtained.

Furthermore, if the throttle ratio of the intake throttle valve 6 becomes large and the intake negative pressure on the downstream side 1a of the intake throttle section 5 is not increased more than necessary, the negative pressure chamber 34 of the actuator 32 is increased in response to the increase in negative pressure. The same negative pressure is applied to the return spring 3.
7, the diaphragm 33 and the rod 3B are pulled to the right in the figure, and the control valve 29 is rotated clockwise in the figure via the arm 31, increasing its opening. Excessive increase in intake negative pressure is prevented.

Next, even in the same idling operation, at cold start, etc., even if the vacuum cut-off valve 17 is open, the internal passage is closed until the water temperature sensing valve 27 reaches the set temperature. Since the actuator 9 does not operate and the intake throttle valve 6 remains open, there is no adverse effect on starting the engine.

Furthermore, regardless of whether the engine is running at room temperature or during a cold start, when the engine is in an operating state other than idling, the exhaust pressure in the exhaust passage 24 increases and high pressure acts on the pressure chamber 20, causing the diaphragm 19 and its integral The valve part 25 returns to the spring 26
the opening 13 of the pipe 13.
a is closed, the operation of the actuator 9 is stopped and the intake throttle valve 6 returns to the open position.

Therefore, the intake throttle in the intake throttle section 5 is released.

Therefore, during normal driving of the vehicle other than idling, there will be no deterioration in performance such as a decrease in engine output.

Further, along with the reduction in vibration during idling of the engine as described above, there is an effect that vehicle body vibration and shift lever vibration are also reduced.

[Brief explanation of the drawing]

The figure is a schematic system diagram showing an embodiment of the present invention. 1; Intake path, 2; Partition wall, 3: First passage, 4; Second passage, 5; Intake throttle section, 6; Intake throttle valve, 9; Actuator, 14; Vacuum pump, 17; Vacuum cut-off valve, 24; Exhaust path, 27; Water temperature sensing valve, 33
;actuator

Claims (1)

[Scope of utility model registration request] A partition wall is provided in the middle of the intake passage to form an intake throttle section divided into a first and second passage, and a negative pressure responsive actuator is operated by introducing negative pressure from a vacuum pump into the first passage. An intake throttle valve that operates in the closing direction is provided, and an intake negative pressure control valve that maintains the intake negative pressure downstream of the intake throttle portion at a constant level is provided in the second passage, and the actuator and vacuum pump are connected to each other. The diesel engine is characterized by a vacuum cut-off valve that detects the set exhaust pressure and closes the valve, and a water temperature sensing valve that detects the temperature of the engine cooling water and closes the valve in the middle of the negative pressure introduction pipe that connects the engine. Engine intake throttle device.