JPH0751895B2 - Intake control device for vehicle engine - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to an intake control device for performing variable intake control in a vehicle engine such as a horizontally opposed or V-type engine in which the cylinder head side is separated into left and right banks from the engine body.

[Prior art]

In recent years, some vehicle engines have adopted a variable intake control device in an intake system in order to always ensure a high intake volume efficiency in a wide range from a low speed range to a high speed range.
When the intake air amount is small and the intake air amount is low, the variable intake control device uses an intake passage having a small diameter and a long length to produce an effect on intake inertia and swirl, thereby improving volume efficiency and combustion. At high speed, a large amount of air is supplied to the intake passage having a large diameter and a short length in a state where the intake resistance is small, thereby improving volume efficiency and engine output. Such an intake control device is mainly used in a two-intake-valve engine in order to fully exert its effect. Conventionally, regarding the intake control device of the variable intake control, for example, there is a prior art disclosed in JP-A-60-224933. Here, the high-speed intake passages are connected to the two intake ports, respectively.
The low-speed intake passage is connected to one intake port. Then, an opening / closing valve is attached to a portion of the high-speed intake passage near the intake port, and the opening / closing valve is closed in the engine low-speed rotation range by an appropriate control means.
It is shown to be configured to open in the high speed range. Further, in the prior art of JP-A-57-105534, there is shown a configuration in which a high-speed intake passage having an opening / closing valve and a low-speed intake passage are connected to two intake ports which are connected by a communication hole. There is.

[Problems to be Solved by the Invention]

By the way, in the prior art, when the engine speed is in the low and medium speed regions, the open / close valve of the high speed intake passage is closed, and one of the intake air is taken into the intake port via the low speed intake passage. Is deviated, the amount of intake air to the other intake port is decreased, and the volumetric efficiency is decreased due to the conduit resistance. Further, there is a problem that torque is reduced when the opening / closing valve of the high-speed intake passage is opened to shift to the high-speed region, and the engine torque characteristics are not well connected. The present invention has been made based on the above circumstances, has a small duct resistance, and evenly inhales the intake port from the low speed region to the high speed region, and also opens and closes the open / close valve of the high speed intake passage. It is an object of the present invention to provide an intake control device for a vehicle, which prevents torque reduction of engine torque characteristics due to the above.

[Means for Solving the Problems]

For this reason, in the present invention, the cylinder head side is divided into left and right banks, a chamber is disposed downstream of the throttle valve approximately in the middle of the left and right banks, and from the left and right of the chamber to each cylinder of the left and right banks from horizontal to vertical. In a vehicular engine having an intake manifold extending in a direction extending to communicate with an intake port of each cylinder, the intake manifold has a large-diameter short on the inner peripheral side in a region bending from a horizontal direction to a vertical direction. Of the high-speed intake passage, a small-diameter long long low-speed intake passage is formed on the outer peripheral side of the high-speed intake passage, and a collection chamber for both intake passages is provided at a position beyond the above region. An opening / closing valve is attached to the communicating portion, and the opening / closing valve is provided with an opening for replenishing the intake air amount of the low speed intake passage in the fully closed state.

[Action]

Therefore, the intake air from the low-speed intake passage or the high-speed intake passage and the low-speed intake passage uniformly flows into the two intake ports branching in the front-rear direction of the engine after flowing into the collecting chamber from above or in the vertical direction. To do. Therefore, the intake air can be distributed evenly in the low, medium speed, and high speed regions of the engine speed, and the intake air flows smoothly, so that high volume efficiency can be obtained in the entire engine operating range. Even if the on-off valve of the high-speed intake passage is closed, a predetermined amount of intake air flows in through the opening and joins with the intake air from the low-speed intake passage in the collecting chamber to increase the intake amount. Therefore, even if the opening / closing valve of the high-speed intake passage is opened, there is no torque reduction, the connection of the torque characteristics is smooth, and the maximum torque can be obtained.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. Referring to FIG. 1, a case where the present invention is applied to a horizontally opposed engine will be described. Here, reference numeral 1 is an engine body, and a cylinder head 4 having a combustion chamber 5 (only one of which is shown) for two cylinders is arranged in the right bank 3 of the crankcase 2. In the combustion chamber 5, as shown in FIG. 3, two intake valves 6a, 6b, 2
Exhaust valves 7a and 7b are provided, and a spark plug 8 is attached at substantially the center. Further, the cylinder head 4 is formed with a branch intake port 9 which branches into a bifurcated shape in the front-rear direction of the engine body 1, and the intake valves 6a, 6a
The b is communicated with the intake ports 9a, 9b corresponding to the intake valves 6a, 6b. In addition, exhaust ports 10a and 10b corresponding to the exhaust valves 7a and 7b are independently formed. The intake valves 6a and 6b and the exhaust valves 7a and 7b are opened and closed by a valve mechanism 11 of a double overhead cam (DOHC) type, for example. Similarly, a left-side bank 3'of the crankcase 2 is also provided with a cylinder head 4'having a similar structure, and the left and right banks 3, 3'and the engine body 1 are combined to form a horizontally opposed four-cylinder engine. Are configured. The combustion chamber in the cylinder head 4 '(only one is shown)
Are designated by the reference numeral 5 '. Exhaust pipes 12, 12 'from left and right banks 3, 3'are catalytic converters.
It is assembled at 13 parts and is further connected to one exhaust pipe 14. Next, describing the intake system, the air cleaner 20 communicates with a throttle body 24 having a throttle valve 23 via a hot wire type air flow meter 21 and an intake pipe 22,
A box-shaped chamber 25 for preventing pulsation and the like is connected downstream of the throttle body 24. The chamber 25 is located above the crankcase 2
The intake manifolds 26, 26 ', which are arranged approximately in the middle of the left and right banks 3, 3', and which bend from the horizontal to the vertical direction, extend from the left and right side surfaces toward the upper side of the left and right banks 3, 3 '. The intake manifolds 26, 26 'are in communication with the intake ports 9a, 9b, 9a', 9b 'of the branch intake ports 9, 9'. And that intake manifold 26,2
6'is of equal length on each side. Above intake manifold 2
Injector mounting portion 27 is integrated at the end of 6, 26 ',
An injector 28 is attached to the injector attachment portion 27 so as to inject fuel toward the intake ports 9 and 9 '. For the throttle valve 23, the idle adjustment screw 29,
Bypass passages 31 and 32 of the idle speed control valve 30 are provided, and the chamber 25 is provided with a positive bypass of blow-by gas.
A crankcase ventilation (PCV) valve 33 is installed. The chamber 25 and the intake manifold 26, 26 'will be described with reference to FIGS. 2, 3, 4 (a), 4 (b) and 5. The chamber 25 has a flange 41 connected to the throttle body 24 at the rear of the main body 40. Further, flanges 42, 42 'are provided on the left and right sides of the main body 40, and the flanges 43, 42' at the end portions of the intake manifolds 26, 26 'are attached to the gaskets 44, 4'.
It is designed to be connected via 4 '. Here, the right intake manifold 26 is
Utilizing the fact that the pipe length on the lower inner circumference side is short and the pipe length on the outer circumference side on the upper side is long, the pipe diameter is large at the lower part D ₁ , and the center line O ₁ drawn with the required radius of curvature A short, high-speed intake passage 45 is provided along the passage. Further, a pipe diameter is a small diameter D ₂ in the upper part, a long low speed intake passage 46 is provided along a center line O ₂ drawn with a required radius of curvature, and the high speed intake passage 45 and the low speed intake passage 46 are The partition wall 47 is interrupted by a predetermined length from the inlet of the manifold 26, and a collecting chamber 26a is formed between the end of the partition wall 47 and the intake manifold outlet end 43a.
As a result, the high-speed intake passage 45 and the low-speed intake passage
The arrangement of the 46 is vertical with respect to the area that is curved from the horizontal direction to the vertical direction (shown on the vertical cross section Y in FIG. 2), while the high-speed intake passage 45 and the low-speed intake passage 46 are arranged. The branching direction of the branch intake port 9 that communicates with each other through the collecting chamber 26a is the front-back direction of the engine body 1 which is 90 degrees out of phase with the arrangement of the high-speed intake passage 45 and the low-speed intake passage 46. (Shown on the horizontal section X in FIG. 2). On the other hand, above and below the right side flange 42 of the main body 40 of the chamber 25, holes 48 and 47 having the same diameter as the low speed intake passage 46 and the high speed intake passage 45, respectively, open and communicate with each other. Four
An on-off valve 50 is installed at the 7th part. The on-off valve 50 has
As shown in FIG. 4 (a), in order to replenish the intake air amount of the low speed intake passage 46 in the fully closed state, the opening / closing valve is provided so as to obtain a predetermined intake air amount through the high speed intake passage 45. Both side portions 50a, 50a 'of the 50, 50' are cut out, and openings 50b, 50b 'are provided at both side portions of the opening / closing valve 50. Similarly, the left-side intake manifold 26 'is also provided with a high-speed intake passage 45' and a low-speed intake passage 46 ', a partition wall (not shown), and a collecting chamber, and a hole 47' of the left flange 42 'of the chamber 25 is also opened. Part 50
An on-off valve 50 'with a'is installed. A diaphragm-type actuator 55 is further attached to the rear portion of the main body 40 of the chamber 25. In this actuator 55, a negative pressure chamber 58 is defined in one of the diaphragms 57 of the case 56 as shown in FIG. A return spiring 59a and a full-open positioning spring 59b are urged on both sides, and the actuator 55 is configured to interlock with the on-off valves 50, 50 'via an operating mechanism 60. The operating mechanism 60 connects the diaphragm 57 of the actuator 55 to one end of the valve shaft 51 of the on-off valve 50 arranged on the flange 42 of the chamber 25 via a link 61, and the other end of the valve shaft 51 to the flange 42 ′. On the valve shaft 51 ′ of the provided on-off valve 50 ′, the lever 62
And a rod 63 for connection. And the protrusion of lever 62
62a hits the stopper 64 on the chamber 25 side to perform the fully closed positioning. Referring to the control system in FIG. 5, from the low speed intake passage 46 which is always open in the intake manifold 26,
The negative pressure chamber 58 of the actuator 55 is communicated with each other via a negative pressure passage 68 having a check valve 65, a negative pressure tank 66, and a solenoid valve 67, and the check valve 65 constantly applies a constant negative pressure to the negative pressure tank 66. I'm storing. A crank rotor 1b is fixedly mounted on the crankshaft 1a of the engine body 1 and has a protrusion on its outer periphery that indicates a crank angle position. When the crank rotor 1b rotates, the crank rotor 1b is provided with a protrusion in the outer peripheral direction. A crank angle sensor 69 composed of an electromagnetic pickup or the like for detecting an angle is arranged so as to face each other, and the control unit 70 processes the sensor signal to operate the solenoid valve 67. The control unit 70 has an engine speed calculation means 71 for calculating the engine speed N from the crank angle signal of the crank angle sensor 69. The engine speed N is determined by the engine speed determination means 72 to be, for example, 4200 to 4400 rpm. When compared with the set value N _O and N ≧ N _O or N <N _O , the drive means 73 is configured to energize or de-energize the solenoid valve 67. Next, the operation of the intake control device having such a configuration will be described in the sixth
A description will be given using the flowchart of the figure. First, the engine speed calculation means of the control unit 70 based on the crank angle signal of the crank angle sensor 69 during engine operation.
71 the engine speed N is calculated by (step S1), the are compared with a set value N _O by the engine speed determining section 72 (step S2). Therefore, when the engine speed N and the set value N _O have a relationship of N <N _{O and} the engine speed is low and medium speed, the solenoid valve 67 is switched to the negative pressure tank 66 side by de-energizing (step S3). Since the negative pressure is introduced into the negative pressure chamber 58 of the actuator 55, the diaphragm 57 attracts the link 61. As a result, the valve shaft 51 rotates to one side and the on-off valve 50 closes (step S4). This rotation is also transmitted to the other valve shaft 51 'by the lever 62 and the rod 63, and the on-off valve 50' also closes. In this way, the left and right on-off valves 50, 50 'are both fully closed to shut off the high speed intake passages 45, 45' except for the openings 50b, 50b '. Therefore, the air that has been throttled by the throttle valve 23 and flows into the chamber 25 is a small-diameter long low-speed intake passage.
Openings 50 in 46, 46 'and high speed intake passages 45, 45'
The fuel is sucked into the intake ports 9, 9'of the left and right banks 3, 3'via b, 50b 'and is supplied to the combustion chambers 5, 5'with the fuel injected by the injector 28. Therefore, since the pipe diameter D _{2 of} the low speed intake passages 46, 46 'is smaller than the pipe diameter D ₁ of the high speed intake passages 45, the intake flow velocity is increased, and the pipe length of the low speed intake passages 46, 46' is long. Since it is formed in, the intake inertia effect is generated, so that it is efficiently inhaled and combusts well. In this case, when the on-off valves 50, 50 'are fully closed, the opening 5
Collecting chamber 2 from high speed intake passage 45,45 'through 0b, 50b'
The intake of air to 6a improves the volumetric efficiency in the low and medium engine speed range. With the opening / closing valves 50, 50 ′ of the high-speed intake passage 45 being closed, the relationship between the volume efficiency and the engine speed when the opening areas of the openings 50b, 50b ′ of the opening / closing valves 50, 50 ′ are changed is described below. 7
Shown in the figure. As is clear from FIG. 7, in the vicinity of the engine speed of 1000 to 2000 rpm, there is little change in the volume efficiency due to the change in the opening area of the openings 50b and 50b ', but in the vicinity of the engine speed of 4000 rpm, the volume efficiency changes greatly. . Then, as shown in FIG. 8, when an opening / closing valve having no openings 50b, 50b 'is provided in the high speed intake passage, torque reduction occurs as shown by the dotted line. On the other hand, the on-off valve 50,50 '
When the areas of the openings 50b, 50b 'are properly selected and provided, there is no torque down as shown by the solid line and there is a smooth connection, and when the engine speed is around 4000 rpm, that is, the on-off valves 50, 50'. Torque reduction at the time of shifting from the closed state to the open state is avoided (volume efficiency is improved), and the maximum torque can be obtained when the engine speed is around 4000 rpm. On the other hand, when the relationship between the engine speed N and the set value N _O is N ≧ N _{O at} a high speed, the solenoid valve 67 is energized (step S5) to switch to the atmosphere side, and the negative pressure chamber 58 of the actuator 55 is opened to the atmosphere. . Therefore, the diaphragm 57 links 61
Causes the on-off valves 50, 50 'together with the valve shafts 51, 51' to return to the initial fully open position (step S6), and the high speed intake passages 45, 45 'are also in communication with each other. Therefore, in this case, the high speed intake passages 45, 45 'and the low speed intake passage 4
A large amount of air is supplied to 6,46 'with a smaller intake resistance to increase the output. In the intake manifold 26, 26 ', the high-speed intake passages 45, 45' and the low-speed intake passages 46, 46 'from the chamber 25 to the collecting chambers 26a, 26a' are arranged vertically, while
The main body of the engine, in which the branching direction from the collecting chambers 26a, 26a 'to the intake ports 9a, 9b by the branch intake ports 9 is orthogonal to the arrangement of the high-speed intake passage 45 and the low-speed intake passage 46 (90-degree phase difference). Since it is in the front-back direction of 1, even if the on-off valves 50, 50 'are closed at low and medium engine speeds,
Air is evenly taken into the intake ports 9a, 9b via the collecting chambers 26a, 26a ', and the duct resistance is small, so that high volume efficiency can be obtained. Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Further, it goes without saying that it can be applied to a V-type engine as well. Note that the opening / closing valves 50, 50 'are notched on both sides to open the openings 50b, 50b'.
However, holes may be formed in the on-off valves 50, 50 '.

【The invention's effect】

As described above, according to the present invention, the high-speed intake passage and the low-speed intake passage are vertically arranged, and branch in the front-rear direction of the engine via the common collecting chamber to communicate with each intake port. With this configuration, intake air can be distributed evenly in any of low engine speed, medium speed region, and high speed region, and there is no pipe resistance due to uneven flow of intake air, so high volume efficiency is achieved in all engine operating regions. Obtainable. In addition, since the high-speed intake passage has an opening in the on-off valve, there is no torque down when switching the on-off valve, so the connection of engine torque characteristics is smooth, and maximum torque is maintained near the switching of the on-off valve. Obtainable.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of an intake control device for a vehicle engine of the present invention, FIGS. 2 and 3 are exploded perspective views and sectional views of an intake system, and FIGS. 4 (a) and 4 (b). ) Is a plan view and a front view in which a part of the chamber and the intake manifold are cut away, FIG. 5 is a configuration diagram of a control system, FIG. 6 is a flow chart of the action, and FIG. 7 is a relation of the volume efficiency to the engine speed. FIG. 8 is a diagram showing the size of the opening provided in the on-off valve as a parameter, and FIG. 8 is a diagram showing the relationship between engine speed and torque in relation to intake control in the intake manifold. 1 …… Engine body, 3,3 ′ …… Left and right banks, 4,4 ′ ……
Cylinder head, 9 ... Branch intake port, 9a, 9b ... Intake port, 25 ... Chamber, 26, 26 '... Intake manifold, 45, 45' ... High speed intake passage, 46, 46 '... Low speed Intake passage, 50, 50 '... open / close valve, 50b, 50b' ... opening,
55 …… Actuator, 60 …… Operating mechanism.

Claims (1)

[Claims] 1. A cylinder head side is divided into left and right banks, and a chamber is disposed downstream of the throttle valve in the approximate middle of the left and right banks. From the left and right of the chamber to the cylinders of the left and right banks in a horizontal to vertical direction. In a vehicle engine configured to extend a curved intake manifold and communicate with an intake port of each cylinder, in a curved region from the inlet of the intake manifold, a high-speed intake with a large diameter short on the inner peripheral side A small diameter long low-speed intake passage is formed on the outer peripheral side of the passage, and a collecting chamber for both intake passages is provided between the curved region and the intake port of each cylinder. An on-off valve is attached to a place communicating with the intake passage for use, and the open-close valve is provided with an opening portion for replenishing the intake air amount of the low-speed intake passage in a fully closed state. An intake control device for a vehicle engine, characterized in that