JPS6332352Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an idle speed control device for a vehicle engine.

Conventional car air conditioning systems, as shown in the circuit diagram in Figure 1,
5, the relay 16 for the fan motor 3 is excited by the power battery 14, and the relay contact 1
9 is closed, and the fan switch 20 is set to L (low speed).
If you turn it on, the power battery 14 will connect to the fuse 1.
8. A fan motor 3 is driven via a fan switch 20 and resistors 21 and 22, and a fan (not shown) blows air at a low speed. Even when the fan switch 20 is set to M (medium speed) or H (high speed), voltage is applied to the fan motor 3 only through the resistor 22 or without going through the resistors 21 and 22, and the fan rotates at medium or high speed. become. Here, 23 is an air conditioner switch, which simultaneously controls the on/off of a magnetic clutch 27 of a compressor (not shown).
An idle speed control solenoid valve 28 connected in parallel with the magnetic clutch 27 is controlled to be turned on or off. 24 is a thermostat that prevents the cooling heat exchanger from freezing, and 13 is a pressure switch that turns off the magnetic clutch 27 to protect the refrigeration cycle when the pressure of the refrigeration cycle becomes abnormally high. .

If the air conditioner switch 23 is closed, the thermostat 24 is closed, and the pressure switch 13 is closed, the magnetic clutch relay 25 is energized, the relay contact 26 is closed, and the magnetic clutch 27 is connected to the compressor and rotates. . on the other hand,
How the idle speed control solenoid valve 28 is turned on and the idle speed increases will be explained with reference to the system diagram in Figure 2. 28a is a power supply coil, 28b is a negative pressure side valve, 28c is an atmospheric side valve,
d is a negative pressure port, 28e is an output port, 28f is an atmospheric port,
29 is the engine intake manifold, 30
31 is a throttle valve, 31 is a throttle valve shaft, 32 is a throttle lever, 33 is a manifold negative pressure outlet, and 34 is a negative pressure actuator which is connected to the throttle lever 32 by a rod 34f and operates in conjunction with the throttle valve. On the other hand, the negative pressure port 34b is connected to the output port 28e of the solenoid valve 28 described above with a rubber hose 36.

When the electromagnetic coil 28a of the solenoid valve 28 is excited, the negative pressure port 28d opens and the atmospheric port 28f closes, and the negative pressure port 34b of the vacuum actuator 34 and the negative pressure outlet 33 of the manifold 29 are connected to the rubber hose 35. , 36, and the diaphragm 34d of the actuator 34 and the negative pressure chamber 34c.
Negative pressure acts on and overcomes the spring 34a,
The rod 34f is attracted to the right, and the throttle valve 30 is slightly opened via the throttle lever 32 to increase the amount of fuel and increase the idle speed.

Next, when the electromagnetic coil 28a is de-energized, the negative pressure port 28d of the solenoid valve 28 is closed, and the atmospheric port 28 is closed.
8f is opened, and the negative pressure port 3 of the actuator 34 is opened.
4b, and the atmospheric chamber 34e is filled with the atmosphere, the rod 34f moves to the left due to the return of the spring 34a, and the throttle valve 3
0 returns to the original position, fuel decreases, and the idle speed decreases. Note that the rotation speed can be adjusted by changing the stroke of the rod 34f, but this is normally only done when the air conditioner is installed.

Therefore, such a device has the following drawbacks. In other words, as shown in Figure 3, when the cooling load changes depending on the outside air temperature, the throttle opening is constant, so during high loads such as summer, the compressor power is large and the engine speed is reduced significantly, and during the middle season and winter. At equal low load times, the power of the compressor becomes smaller, resulting in a smaller reduction in engine rotation. Originally, when the load is high, it is necessary to increase the engine speed (compressor speed) to produce compressor capacity, but when the load is low, the compressor capacity may be small, so the engine speed may also be low. In this sense, conventional devices exhibit completely opposite characteristics, which causes problems in terms of fuel consumption and noise.

The present invention was proposed in view of the above circumstances, and is an idle rotation speed control device for a vehicle engine that aims to improve fuel consumption and noise during low cooling load idling operation and increase cooling capacity during high cooling load idling operation. The purpose is to provide an air conditioner with a compressor driven by the vehicle drive engine, and to control the idle speed by controlling the throttle valve via a negative pressure actuator that introduces negative pressure in the intake manifold. The engine for driving a vehicle is equipped with a negative pressure actuator for switching a throttle valve of the engine in two stages, and a means for automatically switching the negative pressure actuator depending on the magnitude of the cooling load of the air conditioner. It is characterized by

An embodiment of the present invention will be explained with reference to the drawings.
Fig. 4 is its control circuit diagram, Fig. 5 is a system diagram showing the operation procedure of the solenoid valve for controlling the idle speed shown in Fig. 4, and Fig. 6 is a diagram showing the throttle opening and idle speed according to this device. , FIG. 7 is a diagram showing a modification of FIG. 6.

First, in FIGS. 4 and 5, the same reference numerals as in FIGS. 1 and 2 indicate the same members as in FIGS.
7 is connected in parallel with a solenoid valve for idle rotation speed control, 39 is a pressure switch for idle rotation speed control that switches according to the high pressure side refrigerant pressure, and when the high pressure side refrigerant pressure is above a set value, the contact 39a is connected to the solenoid valve 38. If it is less than the set value, the solenoid valve 37 is switched in the direction of turning on the solenoid valve 37.

37a, 38a are electromagnetic coils, 37b, 38b
is a negative pressure side valve, 37c and 38c are atmospheric side valves, 37
d and 38d are negative pressure ports, 37e and 38e are output ports to the actuator 42, which will be described later, and 37f and 38f.
is the atmosphere release port, 37g and 38g are filters, 40
a, 40b 40c, 40d, 40e are rubber or metal tubes, 41 is a three-way branch joint, 42 is an actuator, diaphragms 42a, 42b, a rod 42c connected to the throttle lever 32, a spring 42d, plates 42e, 42f, a second The nipple 42g communicates with the negative pressure chamber 42k, the nipple 42h communicates with the first negative pressure chamber 42j, the snap ring 42i, the first negative pressure chamber 42j, and the second negative pressure chamber 42k, and the stroke of the diaphragm 42a is larger than that of diaphragm 42b.

In such a device, air conditioner switch 2
3 is turned on and the thermostat 24 and pressure switch 13 are closed, the relay 25 is energized, its contact 26 is closed, the magnetic clutch 27 is turned on, and the compressor rotates. When the cooling load increases and the high-pressure refrigerant pressure rises above a predetermined set value, the contact 39a of the changeover switch 39 is turned on in the direction that turns on the idle speed control solenoid valve 38, and the relay coil 38a is energized.
The negative pressure side valve 38b opens (the atmospheric side valve 38c closes),
The negative pressure of the intake manifold 29 causes the negative pressure outlet 33, the rubber or metal tube 40a, the three-way branch joint 41, the rubber or metal tube 40c, the negative pressure port 38d of the solenoid valve 38, the output port 38e, the rubber or metal tube 40e, and the actuator. 42 nipples 42
h, the diaphragm 42 passes through the first negative pressure chamber 42j.
a is attracted to the right, and the rod 42c connected to the diaphragm 42a also moves in the same direction.
Therefore, the shaft 3 via the throttle lever 32
1. The throttle valve 30 rotates counterclockwise, the amount of fuel sent to the intake manifold 29 is increased, and the idle speed increases.

When the cooling load decreases and the high pressure side refrigerant pressure decreases below a predetermined setting value, contact 3 of the changeover switch 39
9a turns off the solenoid valve 38 and turns on the solenoid valve 37. As a result, the relay coil 38a of the solenoid valve 38
is de-energized, the negative pressure side valve 38b is closed, and negative pressure from the intake manifold 29 is cut off. On the other hand, the atmosphere side valve 38c is opened, and the atmosphere is introduced into the first negative pressure chamber 42j through the filter 38g, the atmosphere port 38f, the output port 38e, the rubber or metal tube 40e, and the nipple 42h, and the diaphragm 4
2a, the rod 42c moves to the left and returns to its original position due to the return of the spring 42d.

The relay coil 37a of the solenoid valve 37 is excited, the negative pressure side valve 37b is opened, and the atmospheric side valve 37c is opened.
is closed, and the air in the second negative pressure chamber 42k flows through the nipple 42g, the rubber or metal pipe 40d, the output port 37e of the solenoid valve 37, the negative pressure side port 37d,
It is sucked into the intake manifold 29 through the rubber or metal tube 40b, the three-way branch joint 41, the rubber or metal tube 40a, and the negative pressure outlet 33. As a result,
Diaphragm 42b and rod 4 connected to it
2c moves to the right and via the throttle lever 32,
The shaft 31 and throttle valve 30 rotate counterclockwise, the amount of fuel sent to the intake manifold 29 is increased, and the idle speed increases.

Here, since the movement stroke of the diaphragm 42b is set smaller than that of the diaphragm 42a, the rate of increase in the idle rotation speed is smaller than when the high-pressure side refrigerant pressure rises above a predetermined set value. When the air conditioner switch 23 and fan switch 20 are turned off, the thermostat 24 is turned off, or the system protection pressure switch 13 is turned off, the magnetic clutch 27 is turned off and the compressor is stopped. In addition, since both the solenoid valves 38 and 37 are de-energized, the negative pressure side valves 38b and 37b are closed, and the atmospheric side valves 38c and 37c are closed, so that the first and second negative pressure chambers 42j and 42k are closed.
The diaphragms 42a, 42b and the rod 42c connected to the spring 42
By returning d, it moves to the left. Therefore, the throttle lever 32, shaft 31, and throttle valve 30 rotate clockwise, and the fuel flow to the intake manifold 29 decreases, returning to the original idle speed, and the refrigerant pressure and throttle according to the present invention are reduced. The relationship between the opening degree and the engine speed is shown in FIG.

According to such a device, the following effects can be expected. In other words, the throttle opening during idling switches between high and low stages depending on the refrigerant pressure (cooling load), so it is necessary to increase the compressor capacity during high loads with high refrigerant pressure. At times, the increase in engine speed is increased, and when the high-pressure side refrigerant pressure is below a predetermined set value under low load conditions, the idle speed can be further reduced, making it possible to provide a low-noise, fuel-efficient air conditioner. Of course, when the air conditioner is turned off, for example, when the thermostat 24 or pressure switch 13 is activated, the idle speed control device is released, so unnecessary operation can be prevented.

In the above-described example, when the refrigerant pressure on the high-pressure side of the refrigeration cycle rises above a predetermined set value, the idle speed is switched to the higher stage side. However, in addition to the refrigerant pressure, as shown in FIG. Temperature sensors are provided to detect refrigerant temperature, engine cooling water temperature, outside air temperature, and vehicle interior temperature, and it is also possible to switch to the higher stage side when each temperature rises above a set temperature.

In short, according to the present invention, the idle speed can be controlled by controlling the throttle valve via the negative pressure actuator that is equipped with an air conditioner having a compressor driven by the vehicle engine and introduces negative pressure from the air supply manifold. A vehicle driving engine comprising: a negative pressure actuator for switching a throttle valve of the engine in two stages; and means for automatically switching the negative pressure actuator depending on the magnitude of the cooling load of the air conditioner. As a result, the present invention is extremely useful industrially because it provides an idle speed control device for a vehicle engine that achieves low noise and low fuel consumption as well as increases cooling capacity during idling operation.

[Brief explanation of the drawing]

Fig. 1 is a control circuit diagram of a known car air conditioner, Fig. 2 is a system diagram showing the operation procedure of the solenoid valve for controlling the idle speed shown in Fig. 1, and Fig.
Fig. 2 is a diagram showing the throttle opening and idle rotation speed, Fig. 4 is a control circuit diagram of an embodiment of the present invention, and Fig. 5 shows the operation procedure of the solenoid valve for controlling the idle rotation speed shown in Fig. 4. The system diagram, FIG. 6 is a diagram showing the throttle opening degree and idle rotation speed according to the present device, and FIG. 7 is a diagram showing a modification of FIG. 6. 3...Fan motor, 13...Pressure switch,
14...Power battery, 15...Ignition switch, 16...Relay for fan motor, 1
7, 18...Fuse, 19...Relay contact, 2
0...Fan switch, 21, 22...Resistance, 2
3... Air conditioner switch, 24... Thermostat, 26... Relay contact, 27... Magnetic clutch, 29... Intake manifold, 30
...Throttle valve, 31...Throttle valve shaft, 32...Throttle lever, 33...
...Negative pressure outlet, 37, 38... Solenoid valve for idle speed control, 37a, 38a... Electromagnetic coil, 37b, 38b... Negative pressure side valve, 37c,
38c...Atmospheric side valve, 37d, 38d...Negative pressure port, 37e, 38e...Output port, 37f, 38f
...Air release port, 37g, 38g...Filter,
39...Idle rotation speed control pressure switch, 3
9a...Contact, 40a, 40b, 40c, 40
d, 40e...Rubber or metal tube, 41...Three-way branch joint, 42...Actuator, 42a, 42
b...diaphragm, 42C...rod, 42d
...Spring, 42e, 42f...Plate,
42g, 42h...nipple, 42i...snat spring, 42j...first negative pressure chamber, 42k...
Second negative pressure chamber.

Claims (1)

[Scope of utility model registration request] In a vehicle drive engine that is equipped with an air conditioner having a compressor driven by the vehicle drive engine and controls the idle rotation speed by controlling a throttle valve via a negative pressure actuator that introduces negative pressure from an air supply manifold, A vehicle engine characterized by comprising: a negative pressure actuator for switching a throttle valve of the engine in two stages; and means for automatically switching the negative pressure actuator depending on the magnitude of the cooling load of the air conditioner. idle speed control device.