JPS6299657A - Vibration and noise reducing method for diesel engine - Google Patents

Abstract

PURPOSE:To enable the vibration and noise of an engine to restrain without producing white smoke by operating an intake throttle valve in the closing direction at the time of idling after warming and at the time of low speed light load condition of the engine, and at the same time sending current to a glow plug. CONSTITUTION:At the time of idling after warming in a Diesel engine 10, the VSVs 34 and 36 are controlled to communicate with the negative pressure leading side by means of an ECU 32 so as to apply a negative pressure to negative pressure chambers 30A, 30B of a diaphragm type driving device 30, and an intake throttle valve 22 is brought into the fully closed state. In this case, to improve ignitability, the ECU 32 inputs a glow electric conduction signal into a glow plug control circuit 42 so as to turn ON and heat a glow plug 12. Further, in a low speed and light load region, the intake throttle valve 22 is brought into the half-opened state to reduce vibration while keeping the air quantity at a constant amount. In this case, the current to the glow plug 12 is turned ON to bring about a heating condition and to assist ignition, thus combustion can be improved.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for reducing vibration and noise in a diesel engine, and is particularly suitable for use in a direct injection, one-way, automatic small diesel engine. Diesel engine vibration and g Relating to a sound reduction method.

[Conventional technology]

Generally, in a diesel engine, if an intake throttle valve is installed in the intake passage and the intake throttle valve throttles the intake air when the engine is idling or when the engine is stopped, it is possible to prevent vibrations when the engine is idle or when the engine is stopped. Are known. Furthermore, this intake throttle valve is also closed during deceleration, and also serves as a fail-safe function to prevent overspeeding of the engine. This intake throttle is effective in suppressing engine vibrations and torque fluctuations at idle or under partial load, and also has a noise reduction effect. [Problems to be Solved by the Invention] However, if the intake air is throttled using an intake throttle valve, the fuel consumption will worsen and the pressure during combustion will reach an upper limit, which will reduce the effectiveness of imaging and noise reduction. It had the problem of being stored away. Such problems are particularly present in the so-called direct Ilnln type diesel engine, which has a large pressure rise ratio and injects fuel directly into the combustion chamber. In addition, this ii! Diesel engines with I direct injection (G) system have a unique phenomenon in which the increase in injection pressure increases adjustment irregularities in the low speed range. On the other hand, from the viewpoint of vibration reduction, it is better to increase the degree of restriction of the intake air, but if the degree of restriction is high, white smoke may be generated, which is not desirable. Furthermore, as something similar to the present invention, the applicant has already proposed in Japanese Patent Application No. 57-227976 that the glow plug is energized when the intake throttling by the intake throttle valve is large during idling. This paper proposes a method for energizing glow plugs in diesel engines. According to this glow plug energization f + IJ On method, when the intake throttle by the intake throttle valve is large during idling, ignition performance can be improved, but as in the present invention, engine vibration and vibration noise can be reduced. However, it has the problem that it is not necessarily suitable for use for this purpose.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned conventional problems, and is therefore a method for reducing vibration and noise in a diesel engine that can effectively suppress engine stoppage, torque fluctuation, and noise without producing white smoke. The purpose is to provide 12 people.

[Means to solve the problem]

The present invention provides a diesel engine that has an intake throttle valve that throttles the intake air during idle or partial load to suppress engine vibration and torque fluctuation, and a glow plug whose energization state is controlled according to the engine operating state. In the vibration/noise reduction method, as shown in Fig. 1, when the engine is idling after warming up and under low speed and light load, the intake throttle valve is moved 1' in the closing direction, and the intake throttle valve is closed. Same as directional operation 1!l] energize the glow plug,
The above object is achieved by improving the ignition 14. Also, implementation of the present invention! ti is such that the temperature of the glow plug is controlled to be constant. Further, in an embodiment of the present invention, the energization of the glow plug described in ifi is canceled when the engine is decelerated. Further, in an embodiment of the present invention, the energization to the glow plug is terminated when the glow plug continues to be idle for a certain period of time. Further, in an embodiment of the present invention, the FF operation of the intake throttle valve and the energization to the glow plug are controlled by an electronic control unit 111-. is to 1γ1 glow plug)
The electric current is controlled using a semiconductor relay.

[Effect]

The present invention provides a diesel engine as described above.
When the engine warms up (after the engine idling and at low speed and light load, the intake throttle valve moves 1' [J: J: in the closing direction).
(It is possible to suppress engine vibrations and torque fluctuations during loading, and reduce noise. Also, the glow plug is energized in synchronization with the closing direction of the intake throttle valve. This improves ignitability and prevents the generation of white smoke when the intake throttle valve is operated in the closing direction, which does not have good ignitability.Furthermore, when the glow plug is controlled at a constant temperature, In addition to saving power, it is possible to extend the life of the glow plug. Also, if the power to the glow plug is turned off when the engine is in the Mm state, the power to the glow plug can be reduced. Useless energization can be prevented.Furthermore, if the energization to the glow plug is turned off when the idle state is idling for a long time, the glow plug and its power source can be laid underground. Furthermore, if the operation of the intake throttle valve and the energization of the glow plug are controlled by a single electronic control unit, time lag in control can be prevented, and the
It is possible to purify the j・1 formation by 11. In addition, when the power supply to the glow plug is controlled using a semiconductor relay, it becomes possible to control the glow plug to a constant temperature, reducing power consumption.
Low) Can reduce the load on the alternator during insects.

【Example】

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a diesel engine employing the noise reduction method according to the present invention will be described in detail below with reference to the drawings. FIG. 2 is a top view, including a partial block diagram, showing the entire 17IS configuration of this embodiment. In FIG. 2, reference numeral 10 denotes a direct-width type diesel engine, which is equipped with a glow plug 12 arranged so that its tip protrudes into the combustion chamber 1QΔ. The intake passage of the diesel engine 10 is a groove bottom including: 1-A cleaner 14, an intake pipe 16, an intake throttle device 18, and an intake manifold 20, and the air taken from the air cleaner 14 is The combustion chamber 10△ via the intake port 10B of the diesel engine 10 in this order.
It is supposed to be inhaled. The intake throttle device 18 includes a main passage 24 in which an intake throttle valve 22 made of a butterfly valve is disposed, and an adjustment screw 26.
It includes a sub passage 28 in which is arranged. The intake throttle valve 22 is driven by a diaphragm type one-drive valve 30. The diaphragm drive device 30 includes first and second negative pressure chambers 30A and 30B, and first and second diaphragms 3.
0C130D @ h-. Therefore, when 9 pressures are added to the first negative pressure m 30 A, the first diaphragm 3
0C is displaced upward in the figure, causing the intake throttle valve 22 to be in a half-open state. On the other hand, when negative pressure is applied to both the first and second negative pressure chambers 30A and 30B, the second diaphragm 30D is displaced upward in the figure, the first diaphragm 30G is also displaced further upward, and the intake throttle Valve 22 is held fully open. The adjustment 5τ screw 26 is for adjusting the intake air rate to the engine when the intake throttle valve 22 is fully open.
By tightening the adjustment screw 26, the air flow rate at idle, when the main passage 24 is fully opened and air is sucked only from the sub passage 28, is adjusted. The opening number of the intake throttle valve 22 is determined by an electronic control unit for engine control (hereinafter referred to as E CtJ) 32.
Three types of negative pressure switching valve (hereinafter referred to as VSV) 34.3
By controlling the energization of 6, an appropriate 4T value is set according to the engine operating conditions, for example, a fully open state during idling, a half open state during partial load, and a fully open state during load operation of a song. The ECU 32 has engine operating conditions 13? As J, accelerator distance f-(EAcc, engine speed 'I>3kN
e. Engine coolant temperature ~ VT, intake temperature 1'in, intake pressure P
l) has been input. Note that the ECU 32 also performs other engine controls, but their explanation will be omitted here. The V S '1/34.36 includes a negative pressure pump (VP) 3 driven by the diesel engine 10.
The negative pressure generated at 8 is supplied through a zero pressure tank (\/T) 40. The energization state of the glow plug 1'2 is controlled by a glow plug control υB circuit 42, and this glow plug control circuit 42 controls the glow plug 1'2 according to an on/off control condition signal supplied from the CU 32. plug 12
It controls the power supply to. The glow plug control circuit 42 also includes a key switch 44, a water supply hinge 46, etc., which determines the glow operating condition 18.
number has been entered. As shown in detail in the third section, the glow plug control circuit 42 constitutes a half-9 body relay G4, and includes a high-power power transistor 50 that turns on and off the current flowing through the glow plug 12, and the power transistor 50. disposed between the power transistor 50 and the glow plug 12 for detecting the glow current now supplied to the glow plug 12;
The temperature of the glow plug 12 is determined based on the glow current sensor 52 that detects the fixed resistance that has been set and the glow current that changes according to the temperature (resistance value) of the glow plug 12, which is detected by the glow current pin sensor 52. , for example, II 1 I for turning off the glow current at high temperatures of 850°C or higher.
The glow plug warmer discriminator 54 generates a + signal (hereinafter referred to as glow current OFF signal) and the glow plug warmer discriminator 54 outputs a glow energization OFF signal for a certain period of time. The timer 56 and the key switch 4
4 is the engine starting position ST, and the starter relay 57
When the engine is started when the switch is turned on, it becomes "1".
13, a timer 62 that is reset by a signal that becomes "1" when the key switch 44 is turned on, and holds the output of the inverter 58 for a certain period of time T2; A hot water discriminator 72 that outputs "1°" in response to a signal inputted from the sensor 46 and substantially inversely proportional to the water temperature TW in a state after the engine has warmed up and the water temperature is equal to or higher than a set value including hysteresis. ,
a timer 78 that outputs a glow current off signal 8 when the idle switch 76 is continuously on for more than four set times, and the inverter 60. 1. Output and voltage regulator (not shown). An AND gate 80 outputs the logical product of the output of the charge lamp relay 64 which is driven by the terminal output and turns on to turn on the charge lamp 66 when the rotation of the engine 10 is stopped; an AND gate 82 that outputs the AND of the outputs of the water temperature Tll separator 72;
an AND gate 84 which outputs the logical product of the ND gate 82 output and the output of the FCU 32 which becomes "0" when the glow plug 12 should be energized; and the logic of the outputs of the timer 56, 62.7B and the AND gate 1-84. OR inputting the sum to the power transistor 50 as a glow energization off signal
The gate 86 is configured as follows. In FIG. 3, 88 is a battery, 90 is a fusible link, 94
is a glow display lamp, 96.98.102 is an inverter, and 100 is to AND game 1. Therefore, when the control number 13 whose condition has been determined by the EC1J32 is input, the signal is transmitted to the power transistor 50 through the AND gate 84 and the OR gate 86. The control (No. 3 (U0'', tt 1 n on/off signal g) is configured to energize the glow plug 12 in the ground state (T level).The AND gate 84 ( , the starter on signal, the engine on signal, and the water temperature discriminator 72 (3 bows are the AND gate 80
. “1” (
311 voltage to the glow plug 12 is turned off. Conversely, when a zero (ground) signal is applied from the OR gate 86 to the power transistor 50, the glow plug 12 is turned on and <'L. The operation of the embodiment will be explained below. The ECU 32 receives the engine operating condition No. 20L, and
The intake throttle valve 22 and the glow plug 12 are controlled according to the engine operating state. Also, when the engine is cold started, glow heating is performed to assist the engine start, similar to conventional glow control. At this time, the intake throttle valve 22 is set in the ↑ gap ffp to prevent the compression pressure from decreasing. Next, when the engine is idling after warming up, the ECI
J321. :VSV34.36 woQ pressure t'3
The negative pressure of the diaphragm drive device 30 is controlled to the oil side.
[Negative pressure is applied to 30A and 30B to close the intake throttle valve 22.] At this time, in order to improve ignitability, ECU3
2 inputs a glow energization signal to the glow plug control circuit 42 to turn on the glow plug 12 and heat it. Note that if the glow plug 12 is left idle for a long time, the power to the glow plug 12 is turned off after a set time has elapsed in order to keep the glow plug 12 and its power source cool. At this time, the intake throttle valve 22 is left half open to maintain the vibration reduction effect. On the other hand, during engine braking as indicated by cusp fQB in FIG. 4, the intake throttle valve 22 is closed in the same way as during idling after the engine is warmed up, in order to improve braking performance. At this time, the glow plug 12 is not energized, thereby saving power and extending the life of the glow plug 12. Furthermore, in a low speed light load region E surrounded by solid lines B and C in FIG. 4, the intake throttle valve 22 is left half open to reduce vibration while ensuring the amount of air between the legs. At this time, the 311+ power to the glow plug 12 is turned on to create a heating state, which improves combustion by assisting ignition, reducing noise, fuel consumption, and exhaust emissions (+-IC
) Revise the performance by 9g. Note that the boundary line C differs depending on the engine, so it can be selected as appropriate. In addition, in Fig. 4, the full load is not shown, and the solid line △ and the solid line B and C
In the high load region F surrounded by
The intake throttle valve 22 is brought to the full [;i state. At this time, since the temperature within the combustion chamber 10Δ is sufficiently high, the energization to the glow plug 12 is turned off. The conditions of each engine operation 4)<phlegm, intake throttle valve, and glow heating are summarized as shown in Table 1 below. Table 1 In this embodiment, the glow plug control circuit 42 is
It is configured using 9 relays and controls the glow plug 12 to a constant temperature, which prevents unnecessary energization and reduces power consumption by 1q, reducing alternator load at low speeds. be able to. In addition, the glow plug system (Le Circuit 42) can be used without using semiconductor relays.
It is also possible to configure the present invention without controlling the glow plug 12 to a constant temperature. Furthermore, in the present embodiment, in J3, the energization to the glow plug 12 is canceled when the engine is decelerated, so that unnecessary 3IT+ electricity can be prevented and power consumption can be reduced. Furthermore, the life of the glow plug can be extended. Furthermore, in this embodiment, the glow plug 12 is de-energized when the idle time reaches 1, so the glow plug 12 and its power source can be protected. Further, in this embodiment, since the operation of the intake throttle valve 22 and the energization of the glow plug 12 are controlled by the L ECU 32 of A-A, a time lag in control is prevented, and control The configuration of the device is simplified. In this embodiment, the present invention is applied to a direct 1'pC injection (1 type diesel engine), so it is particularly effective in suppressing torque fluctuations, engine vibration, and noise. .In addition,
The scope of application of the present invention is not limited thereto, and can be similarly applied to, for example, an indirect zero-liter type diesel engine in which fuel is injected into the subchamber.

[Effects of the invention-]

As explained above, according to the present invention, the intake throttle valve is operated in the closing direction and the glow plug is energized when the engine is warmed up (during idle and low speed 11 load), so that the combustion chamber It is possible to suppress the gas pressure and pressure rise of the engine, suppress idling vibration and noise, and also reduce the torque fluctuation of the output shaft and reduce the vehicle's locking noise.In addition, since idling vibration is suppressed, It is possible to reduce the strength of the brackets, etc. of each part of the engine, making it more convenient.Furthermore, since torque fluctuations are suppressed, force is reduced, and the durability of each part of the drive system can be improved.Also, glow plugs By energizing, the ignitability is improved and the combustion efficiency is increased, so the emission of unburned hydrocarbons can be reduced.Therefore, white smoke can be prevented when the degree of intake throttling is large, and conversely, It is also possible to increase the degree of aperture without producing white smoke.Furthermore, it is possible to suppress sudden increases in torque of 1 to 100 mph when starting or accelerating at low speeds, thereby preventing the vehicle from jerking.Also, it is possible to prevent engine rotation fluctuations. As a result, irregularities in fuel adjustment caused by rotational fluctuations in the injection pump are prevented.This is especially true in the low speed range due to the high injection Q1 pressure.
This has a great effect on n-injection type diesel engines where 4-adjustment suspension irregularities are large.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the gist of the vibration and noise reduction method for a diesel engine according to the present invention, and FIG. 2 shows the entire groove bottom of an embodiment of a direct injection diesel engine to which the present invention is adopted. , location drawing including a partial block diagram, 3rd
The figure is a block diagram showing the 11.1 configuration of the glow plug υ control circuit used in the above embodiment, and FIG. It is a tlO diagram showing an example of the relationship. DESCRIPTION OF SYMBOLS 10... Diesel engine, 12... Glow plug, 18... Intake throttle device, 22... Intake throttle valve, 30... Diaphragm drive 8 device, S2... Electronic controller, control unit ( EC1J), 34.
36... 9-pressure switching valve (\/SV), 42... Glow plug control circuit, 46... Water wetness sensor, 50... Power transistor, 52... Glow current is nana, 54...・Glow plug temperature discriminator, 72...Water (crystal discriminator), 76...Idle switch.

Claims (6)

[Claims] (1) Vibration in a diesel engine that has an intake throttle valve that throttles the intake air during idle or partial load to suppress engine vibration and torque fluctuation, and a glow plug whose energization state is controlled according to the engine operating state.・In the noise reduction method, when the engine is idling after warming up and at low speed and under light load, the intake throttle valve is operated in the closing direction, and the glow plug is energized in synchronization with the operation of the intake throttle valve in the closing direction to improve ignitability. A method for reducing vibration and noise of a diesel engine, which is characterized by improving engine vibration and noise. (2) A method for reducing vibration and noise in a diesel engine according to claim 1, wherein the glow plug is controlled to a constant temperature. (3) A method for reducing vibration and noise in a diesel engine according to claim 1, wherein the glow plug is de-energized when the engine is decelerated. (4) The method for reducing vibration and noise of a diesel engine according to claim 1, wherein the glow plug is de-energized when the glow plug continues to be idle for a long time. (5) A method for reducing vibration and noise in a diesel engine according to claim 1, wherein the operation of the intake throttle valve and the energization of the glow plug are controlled by a single electronic control unit. (6) Claim 1 or 5, wherein energization to the glow plug is controlled using a semiconductor relay.
Diesel engine vibration/noise reduction method described in section.