JP3559878B2 - Multi-cylinder V-type engine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multi-cylinder V-type engine provided with an idle control valve in an intake system.
[0002]
[Prior art]
For example, some engines mounted on a vehicle include an idle adjustment valve in an intake system and adjust an intake air amount at idle when the throttle is fully closed to improve idle performance.
[0003]
As described above, in the apparatus provided with the idle control valve, a spacer provided with a hot water passage is inserted, or the idle control valve is warmed by a heater or the like so as to intake air at a predetermined temperature to improve atomization of fuel.
[0004]
[Problems to be solved by the invention]
By the way, if a spacer provided with a hot water passage is inserted, it is not easy to secure a space for inserting the spacer. In addition, an apparatus that heats the idle control valve with a heater or the like is expensive. Moreover, it is necessary to add an electronic control device for controlling the heater and the like.
[0005]
As described above, in the intake system, the surge tank and the throttle body are connected to the downstream side of the idle adjustment valve. The structure is such that they can be easily attached and detached during maintenance of these components and vehicle parts, and the intake efficiency is improved. Such a structure is desired.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a multi-cylinder V-type engine that improves idle performance at a predetermined intake temperature, facilitates maintenance, and improves intake efficiency. And
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems and to achieve the object, the invention according to claim 1 has a set of cylinder banks that branch at an angle, and the intake air is introduced into an intake passage of a cylinder head attached to each of the cylinder banks. In a multi-cylinder V-type engine in which a system is connected and a throttle body having an idle adjustment valve is arranged in the intake system,
A hot water passage is formed in a part of the intake system to which the idle adjustment valve is attached, and the hot water passage is communicated with a cooling system of the engine,
The throttle body is joined to and integrated with a connection intake pipe,
The connection intake pipe is attached to the surge tank in a divisible manner via a rubber member,
The surge tank is disposed above a cylinder head cover that covers the cylinder head,
A control body is fixed to a valley of each cylinder bank and communicates with an intake passage of each cylinder head,
Connecting the control body via an intake pipe divided on the downstream side of the surge tank,
The divided intake pipe is mounted separately on the surge tank side and the cylinder head side, and the two are connected via an elastic member,
The surge tank and the surge tank-side intake pipe are integrally detachable from the elastic member and the rubber member .
A hot water passage is formed in a part of an intake system to which the idle adjustment valve is attached, and a predetermined intake air temperature can be achieved by flowing hot water that has cooled the engine, so that atomization of fuel is good and idle performance is improved. In addition, a hot water passage is formed by using a part of the intake system, and a spacer having a conventional hot water passage or a heater for warming an idle adjustment valve is not required. It is.
In addition, for example, during maintenance of a vehicle component such as an ignition plug, by detaching the surge tank located above, the vehicle component such as the ignition plug can be easily attached and detached. Further, the control body remains on the engine side, so that entry of foreign matter into the cylinder head can be prevented, and it is not necessary to remove vehicle parts such as control links.
[0009]
A multi-cylinder V-type engine according to a second aspect of the invention is characterized in that the intake system inlet of the evaporative purge gas is opposed to the flow of air in the intake system. By causing the intake system inlet of the evaporative purge gas to face the flow of air, the evaporative gas is uniformly mixed with the intake air, and the variation in A / F among the plurality of cylinders is reduced, thereby improving the intake performance.
[0010]
A multi-cylinder V-type engine according to a third aspect of the invention is characterized in that the intake system of the EGR gas is opposed to the flow of air in the intake system. By causing the intake system inlet of the EGR gas to face the flow of the air, the EGR gas is uniformly mixed with the intake air, the variation in the EGR rate among a plurality of cylinders is reduced, and the intake performance is improved.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a multi-cylinder V-type engine of the present invention will be described with reference to the drawings. Figure 1 is a side view of a multi-cylinder V-type engine having an intake device, FIG. 2 is a plan view of a multi-cylinder V-type engine having an intake device, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 3, FIG. 6 is a plan view showing a mounting portion between the surge tank and the idle control valve, and FIG. 8 is a sectional view of the idle control valve, FIG. 9 is a front view of the surge tank, FIG. 10 is a plan view of the surge tank, FIG. 11 is a right side view of FIG. 10, and FIG. 12 is XII of FIG. 13 is a cross-sectional view along the line XIII-XIII in FIG. 9, and FIG. 14 is a cross-sectional view along the line XIV-XIV in FIG.
[0012]
The multi-cylinder engine 1 including the intake device is an 8-cylinder V-type engine, and uses a double overhead camshaft type. The engine 1 has a crankcase 2, and further has an oil pan 3 at a lower portion of the crankcase 2 and a cylinder block 4 at an upper portion. The cylinder block 4 has a set of cylinder banks 5 and 6 that branch off at an angle. Four cylinders 5a, 6a are formed in the cylinder banks 5, 6 of each cylinder. The cylinder 5a of the left cylinder cylinder bank 5 in the figure and the cylinder 6a of the right cylinder cylinder bank 6 are arranged at an angle, and in the embodiment shown this angle is approximately 60 degrees. .
[0013]
A V-type engine such as engine 1 has a central valley between which is formed by an outwardly diverging cylinder bank 5 and a cylinder bank 6. The inner side of each cylinder bank 5 or cylinder bank 6 is the side adjacent to the valley, while the outer side is the side not facing the valley. However, certain aspects described herein are also useful for other arrangements of engines and engines having other numbers of cylinders in each cylinder bank except for an angle of 60 degrees between the cylinder banks.
[0014]
The engine 1 is generally arranged with a crankshaft 9 transverse to the longitudinal axis of the vehicle, in an engine room 7 of the vehicle and below an inclined engine hood 8. The radiator 10 is located at a front end of a vehicle to which the engine 1 is attached.
[0015]
The cylinders 5a. A piston 11 provided on 6 a is connected to a crankshaft 9 via a connecting rod 12, and the crankshaft 9 is rotated by the piston 11. A flywheel 13 is fixed to one end of the crankshaft 9, and a drive pulley 14 is fixed to the other end.
[0016]
The crankshaft 9 is rotatably supported in the crankcase 2 disposed below the cylinder block 4. The belt 15 extends around the drive pulley 14 and around the drive pulleys of a plurality of coplanar engine units. In particular, the belt 15 drives an air condition compressor or a drive pulley 17 of a power steering pump 16, a drive pulley 19 of a fuel pump 18, and a drive pulley 21 of an AC generator 20. In addition, a plurality of idle pulleys 22 are disposed between the drive pulleys of the aforementioned device to maintain the tension of belt 15 and the desired path of belt 15.
[0017]
The right cylinder head 26 is mounted on top of the right cylinder bank 6, while the left cylinder head 24 is mounted on top of the left cylinder bank 5. Each cylinder bank 5 and 6 includes a respective row of cylinders 5a and 6a on which the piston 11 is supported so as to reciprocate. Each of the cylinder heads 24 and 26 has a concave cavity 25 formed to face each of the cylinders 5a and 6a. Each of the cylinders 5 a and 6 a, the piston 11, and the concave cavity 25 form a combustion chamber 27 of the engine 1.
[0018]
A set of intake valves 30 and a set of exhaust valves 31 are located in each recessed cavity 25 to control the flow of combustion gases to and from the combustion chamber 27. An exhaust passage 32 is formed in each cylinder head 24 or the cylinder head 26, and the exhaust passage 32 extends from an opening to the combustion chamber 27 and communicates with each exhaust pipe 33. The exhaust valve 31 is supported by each of the cylinder head 24 and the cylinder head 26 and controls communication between the exhaust passage 32 and the combustion chamber 27. Each exhaust valve 31 is operated in a suitable manner, for example by an exhaust camshaft 35 mounted above via a thimble tappet 34, for example. A cylinder usually has two exhaust valves 31, but the number can vary. The opening of the exhaust passage 32 to the combustion chamber 27 is on the inner side surface of the combustion chamber 27 via the exhaust valve 31 located on the outer side surface of the combustion chamber 27. Each of the cylinder heads 24 and the cylinder head 26 A set of intake passages 41 communicating from 40 is formed. Almost like the exhaust passage 32, the intake passage 41 is selectively opened and closed by the intake valve 30 and extends to the combustion chamber 27. The intake valve 30 is supported in each of the cylinder head 24 and the cylinder head 26, and controls communication between the intake passage 41 and the combustion chamber 27. Each intake valve 30 is operated in a suitable manner, i.e. by an intake camshaft 42 with overhead mounting. The intake camshaft 42 moves the intake valve 30 in a known manner, such as via a thimble tappet 43.
[0019]
There are four valves and two camshafts per cylinder bank 5 and cylinder bank 6. The intake camshaft 42 is disposed on the inner side surface of the cylinder heads 24 and 26 adjacent to the valley between the cylinder bank 5 and the cylinder bank 6, while the exhaust camshaft 35 is disposed outside the cylinder head 24 and the cylinder head 26. Placed on the side.
[0020]
The engine 1 incorporates an intake device 40, which allows for a more compact engine layout and two different intake passages 41 in each cylinder for different engine speed ranges. The intake device 40 includes a single surge tank 50 mounted on a cylinder head cover 44 on the cylinder head 24, an intake pipe 51, 52 generally formed by a plurality of runners, and a fuel injection device 54 in a control body 53. Including a fuel injection system. The central position of the intake device 40 and the fuel injection system is inside the intake passage 41, so that the intake camshaft 42 is located inside and the exhaust camshaft 35 is located outside. The fuel passage 55 supplies fuel to the fuel injection device 54.
[0021]
Engine 1 utilizes an eccentric balance shaft 60, such as a shaft, to counterbalance the unbalanced pressure created by crankshaft 9, piston 11 and related components. The balance shaft 60 is rotatably supported at a valley between the cylinder banks 5 and 6 of the engine 1. The balance shaft 60 is rotatably supported using a set of bearings 61 provided on the cylinder block 4. The balance shaft 60 extends into a space 62 in front of the front bearing 61, in which a drive sprocket 63 is mounted. The drive sprocket 63 is connected to the drive sprocket 69 of the crankshaft 9 by a flexure transmitter 64 such as a timing chain, and the balance shaft 60 is driven at the same speed as the crankshaft 9 in the opposite direction. The central portion of the balance shaft 61 rotates in a valley space 65 of the cylinder block 4 between the crankcase 2 and the intake device 40.
[0022]
Blow-by gas exiting the cylinder can circulate through the crankcase 2 and pass through the balance shaft 60. The oil separator 66 is arranged in a valley between the cylinder banks 5 and 6 and below the intake device 40. The oil is supplied to the oil separator 66 by a novel arrangement for recovering vaporized hydrocarbons generated by ventilating the crankcase 2, and oil can be separated inside the oil separator 66.
[0023]
The lower wall 66a of the oil separator 66 causes all the oil condensed therein to flow back to the space 65 of the balance shaft 60 through the opening 66b, and from the space 65 to the crankcase 2, the upper wall 67 not shown. Backflow through the opening of. The ventilation gas of the crankcase 2 is re-introduced to the combustion chamber 27 via a conduit 68 extending from the rear of the oil separator 66. The space 65 of the balance shaft 60 communicates with the intake device 40 in this manner. The released vaporized hydrocarbons can be recycled and reburned in the intake system 40 through space 65 and conduit 68.
[0024]
The valve train drive assembly includes a flexure transmitter 64 that not only drives the balance shaft 60 but also includes one of a set of camshafts 35,42 in each cylinder bank 5 and cylinder bank 6. The camshaft driving device drives these camshafts. The camshaft drive includes a drive sprocket 69 rotatably mounted on the crankshaft 9, a flexure transmitter 64, a set of driven sprockets 70 fixed to the front ends of two of the four camshafts, and a balance shaft 60. The drive sprocket 63 is included.
[0025]
The single surge tank 50 of the intake device 40 is disposed above the cylinder on the rear side of the vehicle, has an inlet opening 50a at the upstream end of the surge tank 50, and takes in air from the inlet opening 50a. As shown in FIG. 3, the single surge tank 50 has a triangular cross-section, and is arranged with one side facing the seat surface along the cylinder head cover 44 of the cylinder. As described above, the single surge tank 50 has a substantially triangular cross-sectional shape and one side surface is arranged along the cylinder head cover 44 of the cylinder on the rear side of the vehicle, thereby suppressing the engine width and height. However, the capacity of the surge tank 50 can be secured, and satisfactory intake performance can be obtained.
[0026]
The surge tank 50 is provided with a first air horn 80 and a second air horn 81 connected to intake pipes 51 and 52 for sucking air into cylinders of respective cylinders. The first air horn 80 and the second air horn 81 have a divided structure. The divided first air horn 80 and second air horn 81 are separately mounted on a single surge tank 50.
[0027]
The intake pipes 51, 52 connected to the respective cylinder banks 5 and 6 are divided into two parts, a surge tank side and a cylinder side, and mounting parts 51a1, 51a2 are provided on both sides of the surge tank side intake pipe 51a. Attachments 52a1 and 52a2 are formed on both sides of the tank-side intake pipe 52a, attachments 51b1 and 51b2 are provided on both sides of the cylinder-side intake pipe 51b, and attachments 51b1 and 52b2 are provided on both sides of the cylinder-side intake pipes 51b and 52b. Is formed.
[0028]
The surge tank-side intake pipe 51a and the cylinder-side intake pipe 51b are connected to each other by a rubber band, which is an elastic member 91, in which an attachment portion 51a2 and an attachment portion 51b1 are attached. Similarly, the surge tank-side intake pipe 52a and the cylinder-side intake pipe 52b are connected by a rubber band in which the attachment part 52a2 and the attachment part 52b1 are elastic members 93.
[0029]
To install the intake pipes 51 and 52, first, the intake pipe 52 at the lower position is attached, and then the intake pipe 51 at the upper position is attached. The intake pipe 52 has a mounting part 52b2 of the cylinder side intake pipe 52b screwed to the control body 53, and a mounting part 52a1 of the surge tank side intake pipe 52a is applied to the second air horn 81 by screwing a bolt (not shown) to the surge tank 50. It is fastened and fixed.
[0030]
The suction pipe 51 has a mounting part 51b2 of the cylinder side suction pipe 51b screwed to the control body 53, and a mounting part 51a1 of the surge tank side suction pipe 51a is applied to the first air horn 80 by screwing a bolt (not shown) to the surge tank 50. It is fastened and fixed.
[0031]
Thus, the control body 53 is attached to the downstream side of the surge tank 50 via the divided intake pipes 51 and 52. That is, the respective intake pipes 51 and 52 are separately mounted on the surge tank side and the cylinder head side, and the respective mounting portions are connected by the elastic members 91 and 93, so that the inspection of the spark plug provided in the cylinder can be performed. When performing replacement or the like, the surge tanks 51a, 52a of the intake pipes 51, 52 need only be removed from the elastic members 91, 93, and the entire intake system does not need to be removed. The vehicle parts such as the ignition plug can be easily attached and detached. In addition, the control body 53 remains on the engine side, so that foreign substances can be prevented from entering the cylinder head 26, and it is not necessary to remove vehicle parts such as the throttle link.
[0032]
A throttle body 120 is attached to an inlet opening 50a at the upstream end of the surge tank 50 via a connection intake pipe 110, and the throttle body 120 is provided with a throttle valve 121. An air cleaner 102 is connected to the upstream side of the throttle body 120 via a heat insulating tube 101 made of rubber. The connection intake pipe 110 is connected to the inlet opening 50a of the surge tank 50 by a rubber member 130, and this connection is insulated by the rubber member 130. In this way, by insulating a part of the intake system, it is possible to achieve a predetermined intake temperature, to achieve good atomization of fuel, and to improve idle performance.
[0033]
The connection intake pipe 110 and the throttle body 120 are joined and integrated, and bypass passages 111 and 122 are formed between the connection intake pipe 110 and the throttle body 120. An idle adjustment valve 140 is disposed between the connection intake pipe 110 and the throttle body 120, and an idle passage 141 provided in the idle adjustment valve 140 communicates with the bypass passages 111 and 122. A body 142 is arranged, and the adjustment valve body 142 adjusts the intake air amount at the time of idling when the throttle is fully closed to improve idle performance. As described above, by insulating a part of the intake system to which the idle adjustment valve 140 is attached, a predetermined intake air temperature can be achieved, fuel atomization is good, and idle performance can be improved.
[0034]
Grooves 112 and 123 are formed at the joint openings between the connection intake pipe 110 and the throttle body 120, respectively, and a hot water passage 150 is formed in a part of the intake system by joining the grooves 112 and 123. The connection intake pipe 110 is provided with a hot water inlet port 113, and a hot water inlet pipe 114 for leading hot water from a cooling system 180 formed by a water jacket or the like on the engine side is connected to the hot water inlet port 113. The throttle body 120 is provided with a hot water discharge port 124, and a hot water discharge pipe 125 for returning hot water to the cooling system 180 on the engine side is connected to the hot water discharge port 124. As described above, the hot water passage 150 is formed in a part of the intake system to which the idle adjustment valve 140 is attached, and the predetermined intake air temperature can be attained by flowing the hot water that has cooled the engine. Performance is improved. In addition, the hot water passage 150 is formed by using a part of the intake system, so that a spacer having a conventional hot water passage, a heater for warming the idle adjustment valve, and the like are not required, and it is easy to secure an arrangement space. It is cheap.
[0035]
Further, since the throttle body 120 including the idle adjustment valve 140 is attached to the surge tank 50 on the downstream side via the splittable connection intake pipe 110, the throttle body 120 is located at the upper part during maintenance of a vehicle component such as a spark plug. By integrally removing the surge tank 50 to be connected from the connection intake pipe 110, attachment and detachment of a vehicle component such as a spark plug becomes easy. Further, the throttle body 120 remains on the engine side, so that intrusion of foreign matter into the cylinder head 26 can be prevented, and there is no need to remove vehicle parts such as the throttle link.
[0036]
In addition, as shown in FIGS. 2, 9 and 14, an intake system inlet 160a of the evaporative purge gas introduction unit 160 is formed in the inlet opening 50a of the surge tank 50 so as to face the intake upstream side. An evaporation purge gas pipe 161 is connected to the introduction section 160. The evaporative purge gas pipe 161 is connected to the fuel tank 181, guides the evaporative purge gas generated in the fuel tank 181 to the evaporative purge gas introduction unit 160, and causes the evaporative purge gas to face the air flow from the intake system inlet 160 a of the evaporative purge gas introduction unit 160. Supplied. In this way, by making the intake system inlet 160a of the evaporative purge gas to face the air flow, the evaporative gas is uniformly mixed with the intake air, and the A / F variation among a plurality of cylinders is reduced, and the intake performance is reduced. Be improved.
[0037]
In addition, as shown in FIGS. 2, 9, 10, 12, and 13, the inlet opening 50a of the surge tank 50 is configured such that the intake system inlet 170a of the EGR gas introduction unit 170 faces the intake upstream side. An EGR gas pipe 171 is connected to the formed EGR gas introduction section 170. The EGR gas pipe 171 is connected to the EGR 182, guides the EGR gas generated in the exhaust system to the EGR gas introduction unit 170, and is supplied from the intake system inlet 170a of the EGR gas introduction unit 170 so as to face the flow of air. . As described above, by making the intake system inlet 170a of the EGR gas opposed to the air flow, the EGR gas is uniformly mixed with the intake air, and the variation in the EGR rate among a plurality of cylinders is reduced, and the intake performance is improved. Is done.
[0038]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the hot water passage is formed in a part of the intake system to which the idle adjustment valve is attached, it is possible to set the predetermined intake air temperature by flowing hot water that cools the engine, Good atomization of fuel improves idle performance. In addition, since the hot water passage is formed by using a part of the intake system, a spacer having a conventional hot water passage and a heater for warming the idle adjustment valve are not required, so that the arrangement space can be easily secured and the cost is low. is there.
In addition, for example, during maintenance of a vehicle component such as an ignition plug, by detaching the surge tank located above, the vehicle component such as the ignition plug can be easily attached and detached. Further, the control body remains on the engine side, so that intrusion of foreign matter into the cylinder head can be prevented, and it becomes unnecessary to remove vehicle components such as control links.
[0040]
According to the second aspect of the present invention, since the intake system inlet of the evaporative purge gas is opposed to the flow of air, the evaporative purge gas is uniformly mixed with the intake air, and the variation in A / F among the plurality of cylinders is reduced, thereby improving the intake performance. Is improved.
[0041]
According to the third aspect of the present invention, since the intake system inlet of the EGR gas is opposed to the air flow, the EGR gas is uniformly mixed with the intake air, the variation in the EGR rate among a plurality of cylinders is reduced, and the intake performance is reduced. Be improved.
[Brief description of the drawings]
FIG. 1 is a side view of a multi-cylinder V-type engine including an intake device.
FIG. 2 is a plan view of a multi-cylinder V-type engine including an intake device.
FIG. 3 is a sectional view taken along line III-III in FIG. 2;
FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1;
FIG. 5 is a sectional view taken along the line VV in FIG. 3;
FIG. 6 is a plan view showing a mounting portion between the surge tank and the idle adjustment valve.
FIG. 7 is a right side view of FIG.
FIG. 8 is a sectional view of an idle regulating valve.
FIG. 9 is a front view of the surge tank.
FIG. 10 is a plan view of a surge tank.
FIG. 11 is a right side view of FIG.
FIG. 12 is a sectional view taken along the line XII-XII in FIG. 9;
FIG. 13 is a sectional view taken along lines XIII-XIII in FIG. 9;
FIG. 14 is a sectional view taken along the line XIV-XIV of FIG. 9;

Claims (3)

A multi-cylinder V having a set of cylinder banks branching at an angle, connecting an intake system to an intake passage of a cylinder head attached to each of the cylinder banks, and arranging a throttle body having an idle control valve in the intake system. In the type engine ,
A hot water passage is formed in a part of the intake system to which the idle adjustment valve is attached, and the hot water passage is communicated with a cooling system of the engine,
The throttle body is joined to and integrated with a connection intake pipe,
The connection intake pipe is attached to the surge tank in a divisible manner via a rubber member,
The surge tank is disposed above a cylinder head cover that covers the cylinder head,
A control body is fixed to a valley of each cylinder bank and communicates with an intake passage of each cylinder head,
Connecting the control body via an intake pipe divided on the downstream side of the surge tank,
The divided intake pipe is mounted separately on the surge tank side and the cylinder head side, and the two are connected via an elastic member,
A multi-cylinder V-type engine, wherein the surge tank and the surge tank side intake pipe are integrally removable from the elastic member and the rubber member . 2. The multi-cylinder V-type engine according to claim 1 , wherein an intake system inlet of an evaporative purge gas is opposed to a flow of air in the intake system. 3. The multi-cylinder V-type engine according to claim 1, wherein an intake system inlet of the EGR gas is opposed to a flow of air in the intake system. 4.

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