JPH0774629B2 - Idle rotation control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an idle speed control device that controls an idle speed of a vehicle to a set speed according to an operating state of an engine, and relates to an actuator that can be electronically controlled. .

[Conventional technology]

This kind of idle rotation control device is as proposed in Japanese Patent Application No. 61-88009, but the valve is fully closed and the supply air is stopped when the solenoid is not energized or the coil is broken.

[Problems to be solved by the invention]

In the prior art configured as described above, when the valve is stuck or the coil is broken, the valve is fully closed and the air supply is stopped, so that the required idle speed cannot be maintained and the engine stops. .

It is an object of the present invention to provide an idle rotation control device which eliminates sticking of a valve and can obtain a required idle rotation speed even if the valve actuator stops functioning.

[Means for solving problems]

The above-mentioned object is achieved by providing a valve drive compensating device which operates when the current of the electromagnetic force-mechanical force converting means is low and the coil is broken, such as a solenoid.

[Action]

By reducing the pressure difference that acts on the diaphragm of the valve drive mechanism when the solenoid current is low and the coil is broken, the spring force overcomes the diaphragm force and pushes the valve in the valve opening direction. Therefore, when the current of the solenoid is low and the coil is broken, the valve is in a slightly opened state, the valve does not stick, and a certain amount of air can be supplied.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a vertical cross-sectional view of this embodiment, showing a state in which the solenoid 1 is non-conductive and the coil 15 is broken. Reference numeral 2 is an inlet for ventilation, which is connected to the atmosphere, and 3 is an outlet, which is connected to the intake manifold of the engine. Reference numeral 4 denotes an intake cylinder having a valve seat and controlling an air amount according to the position of the valve 6. Inside, a shaft 7 integrated with the valve 6 is installed so as to operate left and right, and a diaphragm 8 is provided at the left end.
Fixed to the right end, sliding the guide hole 9 at the right end,
It is in contact with rod 12, which is integrated with 1. Reference numerals 13 and 14 are lids forming a chamber, 15 is a coil, 16 is a plunger, and 17 to 20 are return springs. Pressures P ₁ , P ₂ , P ₃ in which pressure chambers are formed by the communication passages 21, 22, 23 and the introduction holes 24, 25, 26 are transmitted.
The pressure P ₃ is determined by both the fixed orifice 27 and the variable orifice formed by the orifice 28 and the needle valve 29.

Here, the balance of pressure and force is as follows.

B) Pressure (indicated by absolute pressure) When the engine is stopped (when the solenoid is not conducting and the coil is in cross section) P ₁ = P ₂ = P ₃ = 760 mmHg (atmospheric pressure) (1) When the engine is operating (when the solenoid is off and the coil is disconnected) ) 0 <P ₁ <P ₂ = P ₃ ≈760mmHg (2) When the engine is operating (when the solenoid is energized) When the coil 15 of the solenoid 1 is energized, an electromagnetic force is generated against the spring 18 and the plunger 16 is attracted to the right. The integrated needle valve 29 reduces the opening area of the orifice 28, and the pressure P ₃ becomes as shown by the dotted line in FIG. 4 by the orifice 28 and the fixed orifice 27. For the purpose of explanation of operation, the pressures at 0 ampere, a ampere, and maximum ampere are P ₃ ′, P ₃ ″, and P ₃ respectively.

B) Balance of spring force S S ₁₉ (Spring 19)> S ₁₇ (Spring 17) + S ₂₀ (Spring 20)
(3) C) When the balance pressure P ₃ with the spring force S, the diaphragm force F (pressure difference × pressure receiving area) and the closing force V (pressure difference × pressure receiving area) acting on the valve itself is P ₃ ′ (P ₃ ′ ＝ P ₂ ≒ 760m
mHg) S ₁₉ ＞ V ₆ ＋ S ₁₇ ＋ S ₂₀ ＋ FC _C (4) (F _A ＝ F _B = 0) When pressure P ₃ is P ₃ F _A ＝ V ₆ ＋ S ₁₇ … (5) F _A −V _{6 -S 17 = S 19 + F C} -S 20 -F B ... (6) F a> V 6 + S 17 when the pressure P ₃ is _{P 3 ... (7) F B} > S 19 + Fc-S 20 ... (8) V ₆ : Valve closing force (valve 6) F _A : Diaphragm force (diaphragm 8) F _B : 〃 (〃 10) F _C : 〃 (〃 11) To explain the operation in Fig. 1, first, the pressure when the engine is stopped (3) is balanced by the spring force of (3). The spring 19 pushes the diaphragm 10 to the stop 30 to the left,
The shaft 9 that abuts 12 also moves to the left. For this reason,
There is a gap between the valve 6 and the valve seat 4, and the valve is open.

Next, when the engine is not running and the solenoid is not conducting and the coil is broken, the pressure is (2) and the balance is (4). It is then supplied to the engine.

Next, referring to FIG. 2, as shown in FIG. 4, the current flowing through the solenoid 1 is in the state of a ampere and the pressure is P ₃ ″. The balance in this state is Equation (6) is obtained, and the left side, which is the force pulled to the left by the diaphragm 8, and the right side, which is the force pulled to the right by the diaphragm 9, are equal, and the balance of the elements of the force pulled to the left is (5).
The valve 6 is seated on the valve seat 4 and is in a fully closed state.

In FIG. 3, as shown in FIG. 4, the current flowing through the solenoid 1 is at the maximum ampere-hour, and the pressure is P ₃ . In this state, the diaphragm force F _A , which is the force pulled to the left by the diaphragm 8, and the diaphragm force F _B, which is the force pulled to the right by the diaphragm 10, are given by equations (6) and (7), so a gap δ is created at the abutting portion. . Since F _A is set to be maximum when the current is maximum, the gap between the valve 6 and the valve seat 4 is maximum, and the maximum valve open state is achieved.

The movement of the valve 6 under the three conditions of the current flowing through the solenoid 1 has been described above. However, when the current is continuously changed, the movement of the valve 6 linearly changes between the three points, and vice versa when lowering the current. Change. Due to the movement of the valve 6, the flowing air of the air supplied from the inflow port 2 through the outflow port 3 to the engine is as shown by the solid line in FIG.

Although the operation and the flow rate of the air supplied to the engine have been described above, the normal idle rotation control uses the current a to the maximum, and proper idle rotation can be obtained. Further, even if the solenoid coil is broken, the engine does not stall because the required amount of air can be supplied to the engine without fully closing the valve.

In addition, the atmosphere and engine blowback gas contain sticky substances that adhere to the valve and valve seat, but even if the engine is stopped for a long period of time, the valve remains open, so sticking of the valve The problem that the valve cannot be opened does not occur.

Further, according to the present embodiment, the needle valve 29 formed by the variable orifice is configured to be separated from the fixed orifice 28 when the solenoid is not conducting, so that the needle valve 29 does not stick even if the engine is stopped for a long time. Moreover, since the pressure P ₃ can be controlled by the small fixed orifice 27 and the orifice 28, the influence of the pressure acting on the needle valve 29 can be neglected so that the solenoid can be downsized.

FIG. 5 and FIG. 6 show a modified example of the present invention, showing the same condition state as in FIG. 1, the same parts are given the same numbers, and the explanation of the same functions is omitted.

FIG. 5 shows an example in which the solenoid 31 is used to control the pressure P ₃ acting on the diaphragm 10. The rod 32 is provided with the communication hole 33 and the fixed orifice 34, and the communication hole 35, the solenoid 31, and the fixed orifice 36 are provided. Lid 37. Similar to FIG. 1, a contact surface 38 is provided between the rod 32 and the shaft 7. In this case, P ₃ is determined by the fixed orifice 34 and the variable orifice formed by the orifice 36 and the needle valve 29, and the same function as the above-described embodiment can be obtained, but a device for controlling the pressure acting on the diaphragm 10 is separately provided. Since it is provided, in the case of this modification, the pressure acting on the diaphragm 9 and the diaphragm 10 can be changed. Further, if the electromagnetic force of the solenoid 31 is changed in a quadratic curve rather than proportionally, as shown in FIG. 7, in addition to the flow rate characteristic shown by the solid line, the flow rate characteristic shown by the dotted line is obtained. is there.

FIG. 6 shows a modification in which the plunger 12 is operated by the electromagnetic force of the solenoid 37 instead of the diaphragm 10 to move the rod 12. In this case, since the diaphragm force F _B and the electromagnetic force of the solenoid 37 are made equal, the same function as the above-mentioned embodiment can be obtained. Also in this modification, if the electromagnetic force of the solenoid 37 is changed in a quadratic curve rather than proportionally, the flow rate characteristic shown in FIG. 7 can be obtained as in the modification shown in FIG.

Hereinafter, application examples of the present invention will be described with reference to FIGS. FIG. 8 is a vertical cross-sectional view of this application example, showing the case where the current of the solenoid 81 is high, that is, the valve opening amount is large, and the pressure P ₁ is the lowest. Reference numeral 82 is an inlet for ventilation, which is the atmosphere (atmospheric pressure
P ₀₎ is connected to, 83 are connected to the engine intake manifold at the outlet. Reference numeral 84 is an intake cylinder in which an air amount controlled by the positional relationship between the valve seat 5 and the valve 86 flows in and out. Inside, a shaft 7 integrated with the valve 86 is installed so as to operate left and right, and the left end is Diaphragm
It is fixed to 88 and inserted in the guide hole 89 so that the right end side can slide. The central portion of the shaft 7 is pressure P ₁ from the introduction hole 110.
Is provided at the right end, but a fixed orifice 112 is arranged at the left end.
Plunger 113 with solenoid 81 and orifice 112
The pressure P ₁ is controlled to P ₂ by the variable orifice formed by and the fixed orifice 114, and the control of this P ₂ is controlled by the current applied to the solenoid 1 so that the plunger with valve 11
The variable orifice is changed by sucking 3 to the left.

15 is a guide hole 89, a guide groove 116 of the valve seat 5, a diaphragm 117.
Is a holder having a stopper and a pressure chamber 118, and the atmospheric pressure P ₀ is introduced into the pressure chamber 119 through the introduction hole 120 and the communication passage 121.

The valve seat 85 has a substantially tubular shape, and is provided in the intake cylinder 84,
The spring 123 sliding in the sliding hole 122 is moved to the right by the repulsive force of the spring 123, and the right end leg 124, which penetrates the guide groove 116, is fixed integrally with the diaphragm 117 and contacts the diaphragm plate. Touching. Figure 9 shows IX in Figure 8.
-IX is a cross-sectional view, but four legs 124 of the valve seat 85 are provided, and further, the valve seat 85 is provided with an introduction hole 126 so that the air measured in the bubble 86 part is introduced into the outflow port 3. There is. 1
27 and 128 are return springs, and 129 and 130 are airtight O-rings.

Next, the operation function will be described. As shown in FIG. 8, when the valve opening amount of the valve 86 is large, the valve 86 is moved by the pressure chamber (P ₀ -P ₁ ).
The valve closing force acting on is small enough to be ignored and the pressure difference P ₀ −
The valve opening amount is determined by the diaphragm force of the diaphragm 88 due to P _2, and the ventilation area and the pressure difference P ₀ −P ₁ depending on this valve opening amount.
Determines the amount of air supplied. Here, when the engine condition changes and the pressure P ₁ changes to P ₁ ′ so that it approaches the atmospheric pressure side, P ₂ also changes to the atmospheric pressure side to P ₂ ′, so the pressure difference between P ₀ −P ₂ ′. Becomes smaller and the force of the spring 127 resists the diaphragm force and moves the valve 86 to the right. As a result, the fixed orifice 112 is also separated from the valve-equipped plunger 113, so that the opening area of the variable orifice becomes large and P ₂ ′ to P ₂
The force of spring 127 and diaphragm 88
Depending on the balance with the force of, the valve moves to the left and right, but its average valve opening amount becomes small. On the other hand, since the diaphragm force of the right diaphragm 117 is also reduced, the spring force of the spring 113 overcomes and moves the valve seat 85 to the right, resulting in a large valve opening amount. This correction of the valve opening amount is based on the relationship between the diaphragm 117 and the spring 122 and the spring 123, P _{2 or} P ₂ ′, and the pressure difference P ₀ -P ₁ to P _0.
-Because the pressure is adjusted from P ₀ because it is corrected by adding the amount of valve opening corresponding to the decrease of the supply air amount by -P ₁ ′.
Since the valve opening amount can be increased even if it changes to P ₁ ′, the supply air amount does not change and is constant.

When the valve opening amount of the valve 86 is small, the valve closing force due to the pressures P ₁ to P ₁ ′ changes, but the amount of change is small because the air amount is small.

These relationships are summarized in Fig. 10. Fig. 10 shows the relationship between the current supplied to the solenoid 81 and the supply air amount. Conventionally, when the pressure P ₁ changes to P ₁ ′, the supply shown from the solid line to the broken line. Although it is an air amount characteristic, as is clear from the description of this embodiment, since the position of the valve seat is corrected, even if the pressure P ₁ changes, the supply air amount is almost a solid line, and the current of the solenoid is reduced. It is possible to obtain a constant supply air amount.

In the conventional idle rotation control device, the supply amount is determined by the difference between the diaphragm force and the closing force applied to the valve, but the closing force becomes negligible when the valve opening amount becomes large, and the valve opening amount is determined by the diaphragm force. To be done.

Therefore, when the pressure in the intake passage changes depending on the operating state of the engine, the diaphragm force is constant, so even if the valve opening amount is constant, the supply air amount changes due to the change in the intake passage pressure. , Proper idle rotation control cannot be obtained.

On the other hand, by providing a valve opening amount compensator composed of a slidable valve seat, a diaphragm and a spring as in this application example, the diaphragm force can be changed in accordance with the change in pressure acting on the diaphragm. By changing the position of the slidable valve seat according to the difference between the diaphragm force and the spring force, a constant air can be supplied even if the pressure acting on the diaphragm changes.

The embodiments of this application example are listed below.

1. Idle rotation that controls the amount of air passing through the air passage by operating the valve in a direction away from the valve seat according to an electric signal that is provided in the air passage that bypasses the intake pipe and is input to the solenoid. An idle rotation control device comprising a valve opening amount correction device for moving a valve seat according to pressure in the control device.

2. The valve opening amount compensator is composed of a movable valve seat, a spring, a diaphragm, and a pressure chamber, and is installed on the side opposite to the valve opening direction of the solenoid. When the pressure becomes low, the valve seat closes. The idle rotation control device according to the above-mentioned item 1, wherein the idle rotation control device is configured to be controlled in a direction.

〔The invention's effect〕

According to the present invention, the valve can be opened when the current of the solenoid is low and the coil is broken. Therefore, even if the engine is stopped for a long period of time, there is no sticking of the valve and the required amount of air can be supplied.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of one embodiment of the present invention during non-energization and when the coil is broken, FIG. 2 is a vertical cross-sectional view of the current flow aA of FIG. 1, and FIG. 3 is the current flow of FIG. FIG. 4 is a longitudinal sectional view taken along line A in FIG. 4, FIG. 4 is a characteristic diagram showing the relationship between current, pressure, and flow path in this embodiment, and FIGS. 5 and 6 are modifications of this embodiment, which are the same as those in FIG. Sectional view under the condition
Fig. 6 is a characteristic diagram showing the relationship between current and flow rate in the modified example shown in Fig. 6, Fig. 8 is an application example of the present invention, Fig. 9 is a sectional view taken along line IX-IX in Fig. 8, and Fig. 10 is an application. It is drawing which shows the main characteristics of an example. 1 ... Solenoid, 2 ... Inlet, 3 ... Outlet, 6 ...
… Valve, 8 …… diaphragm, 10 …… diaphragm,
12 ... Rod, 17 ... Spring, 19 ... Spring, 27 ... Fixed orifice, 28 ... Orifice, 29 ... Needle valve.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location F16K 31/126 F 7214-3H (72) Inventor Yutaka Fujitsuji Katsuta City, Ibaraki Prefecture Nishiishikawa Nishikonai 3085 Address 5 Hitachi Automotive Engineering Co., Ltd. (56) Reference JP 58-217879 (JP, A)

Claims (5)

[Claims] 1. A shaft is provided in an air passage that bypasses the intake pipe, and a shaft to which a valve is fixed and a diaphragm are integrally locked in accordance with an electric signal input to an electromagnetic force-mechanical force converting means. In the idle rotation control device that operates the on-off valve device to control the cross-sectional area of the air passage to control the amount of air passing therethrough, at the center of the shaft,
A through hole communicating with the low-pressure chamber of the diaphragm and a first orifice are provided at its tip, and a needle valve that moves in the axial direction of the shaft by the electromagnetic force-mechanical force converting means is provided. A drive obtained by installing a second orifice on the wall member that forms the low-pressure chamber by changing the opening area by moving in the axial direction of the shaft, and controlling the second orifice according to the electric signal. A drive mechanism that controls opening and closing of the valve by pressure is generated, and when the electric signal is zero, a drive pressure that controls the valve to a minute opening position is generated against the drive pressure that acts on the diaphragm. An idle rotation control device characterized by comprising a compensating mechanism for 2. The idle rotation control device according to claim 1, wherein the second orifice is separated from the needle valve when the electric signal is zero. 3. The first opening according to claim 1, wherein the opening area of the first orifice changes so as to generate a driving pressure in the low pressure chamber that is substantially proportional to the magnitude of the electric signal. Idle rotation control device. 4. The compensating mechanism includes a diaphragm fixed to the other end of the shaft, a compression spring for causing the diaphragm to stroke a predetermined amount in the opening direction of the valve, and a pressure chamber under the same pressure condition as the low pressure chamber. The idle rotation control device according to claim 1, wherein the idle rotation control device comprises: 5. The compensating mechanism includes a plunger mounted on the shaft center of one end of the shaft shaft, which operates to close the valve when the electric signal is input, and the plunger when the plunger is not operating. The idle rotation control device according to claim 1, further comprising a compression spring that applies a force in the opening direction to the valve.