JPH11223167A - Fuel injection type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with an operation of a fuel return passage at the time of opening and closing a head cover. SOLUTION: In a fuel injection type engine provided with a lead-out side fuel return passage 61 returning fuel fed from at least one fuel injection nozzle among the fuel injection nozzles 33a, 33b, 33c arranged inside a head cover 52 to the predetermined position on the outside of the head cover 52, the lead- out side fuel return passage 61 includes a through hole passage 65 connecting an inlet opening 63 arranged on a cylinder head wall inside the head cover 52 to an outlet opening 64 formed in a cylinder head wall outside the head cover 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection engine in which fuel is injected by a fuel injector.

[0002]

2. Description of the Related Art Conventionally, a configuration shown in FIG. 5 is known as a fuel supply device for the above-mentioned fuel injection type engine. The fuel injection engine of FIG. 5 is a vertical diesel engine,
The bottom of the fuel tank 153 communicates with the fuel injection pump 155 and the fuel injection nozzle 133 via a fuel supply path 154,
A fuel filter 156 and a feed pump 1 are provided in a fuel supply passage 154 from the fuel tank 153 to the fuel injection pump 155.
57 and the auxiliary filter 158 are provided in this order, and the fuel tank 1
The 53 fuel is filtered by both filters 156 and 158 to remove dust, and the fuel is pumped to the fuel injection pump 155 by the feed pump 157 so that the fuel can be injected from the fuel injection nozzle 133 into each combustion chamber. .

[0003] An introduction-side fuel return passage 159 communicating from the fuel injection pump 155 to each fuel injection nozzle 133.
And the fuel from each fuel injection nozzle 133
By providing an outlet-side fuel return passage 161 for returning the fuel to the fuel tank 53, the excess fuel of the fuel injection pump 155 and each fuel injection nozzle 133 is returned to the fuel tank 153. Here, in the engine in which the fuel injection nozzle 133 is accommodated in the engine head cover 152, the introduction-side fuel return passage 159 and the discharge-side fuel return passage 1
61 are provided penetrating the head cover 152, respectively.

[0004]

However, the above-mentioned conventional fuel injection type engine has the following problems. (A) Since each of the fuel return passages 159 and 161 is provided to penetrate the head cover 152, when the head cover 152 is opened and closed, each of the fuel return passages 159 and 161 is opened.
It is necessary to remove 9.161 from the through hole,
Poor operability. (B) To improve the operability, each fuel return passage 1
It is conceivable that the head cover 152 can be divided at the position of the head cover 152 through which the 59.161 penetrates. However, by making the head cover 152 a split type, the manufacturing cost increases, and even if the split type is used. However, it is still necessary to provide a sealing device so that blow-by gas or the like does not leak at a position where each of the fuel return passages 159 and 161 penetrate, and in any case, there is a problem that the configuration becomes complicated.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection engine that can solve the above problems. An example of a specific purpose is as follows. (a) To provide a fuel injection type engine which does not need to operate a fuel return passage when opening and closing a head cover. It should be noted that the problems of the invention other than those described above and the means for solving the problems will be described in detail in the following specification.

[0006]

The present invention will be described below with reference to, for example, FIGS. 1 to 4 showing an embodiment of the present invention. In the first invention, as shown mainly in FIGS. 1A and 1B, at least one fuel injector 33 is provided in a head cover 52, and fuel from the fuel injector 33 is transferred to a predetermined location outside the head cover 52. In the fuel injection type engine provided with a return-side fuel return passage 61, the discharge-side fuel return passage 61 is configured to include a hole 65 that penetrates the cylinder head 3. In the second invention, FIG.
As shown in (C), at least one fuel injector 33
Is provided in the head cover 52, a fuel injection pump 55 for supplying high-pressure fuel to the fuel injector 33 is provided outside the head cover 52, and an introduction-side fuel return passage 59 of the fuel injection pump 55 is introduced into the head cover 52. In the fuel injection type engine, the introduction side fuel return passage 59 is
It is characterized by including a through hole passage 69 penetrating the cylinder head 3.

[0007]

According to the first aspect of the present invention, the outlet side fuel return passage includes a through hole passage penetrating the cylinder head and does not penetrate the head cover.
There is no need to operate the outlet fuel return passage when the head cover is attached or detached. Therefore, inspection inside the head cover,
Work such as maintenance can be performed efficiently. According to the second aspect, the introduction-side fuel return passage is configured to include a through-hole passage that penetrates the cylinder head, and does not penetrate the head cover. No need to operate. Therefore, work such as inspection and maintenance inside the head cover can be performed efficiently. Further, according to the first and second aspects of the invention, it is not necessary to form the head cover in a divided form or provide a sealing device in order to improve operability as described in the related art.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view for explaining a fuel injection type engine according to the present invention. FIG. 1 (A) is a schematic configuration diagram thereof, and FIGS. FIG. This fuel injection type engine 1
As shown in FIG. 1A, the cylinder head 3 is assembled to the cylinder block 35, and a valve operating chamber 51 is formed above the cylinder head 3. A head cover 52 is attached to a peripheral wall of the valve operating chamber 51. Also, the fuel tank 53
Is connected to the fuel injection pump 55 and the fuel injection nozzle 33 by the fuel supply path 54, and the fuel filter 5 is connected to the fuel supply path 54 from the fuel tank 53 to the fuel injection pump 55.
6. A feed pump 57 and an auxiliary filter 58 are provided in this order. The fuel in the fuel tank 53 is filtered by the two filters 56 and 58 to remove dust, and the feed pump 57 pumps the fuel to the fuel injection pump 55. Injection nozzle 3
From 3, fuel can be injected into the combustion chamber of each cylinder. In FIG. 1A, a three-cylinder engine is illustrated, and one fuel injection nozzle 33 is provided for each cylinder. The tip of each fuel injection nozzle 33 protrudes from the upper wall of the cylinder head 3 into the combustion chamber of each cylinder.

As shown in FIG. 1A, an introduction-side fuel return passage 59 communicating from the fuel injection pump 55 to the first fuel injection nozzle 33a on the side of the fuel injection pump 55,
An inter-nozzle fuel return passage 60 that communicates the fuel injection nozzles 33a, the second fuel injection nozzles 33b, and the third fuel injection nozzles 33c;
An outlet side fuel return passage 61 for guiding the fuel from c to the outside of the head cover 52 is provided. With this configuration, the surplus fuel of the fuel injection pump 55 can be returned to the fuel tank 53 together with the surplus fuel of the first to third fuel injection nozzles 33a, 33b, and 33c. In addition to the above basic configuration, in the present embodiment, as shown in FIG. 1 (B), the outlet side fuel return passage 61 extends from the inlet opening 63 formed in the cylinder head inner wall 66 in the valve operating chamber 51 through the head cover 5.
Outlet opening 6 formed in outer cylinder head outer wall 62
Since the head cover 52 is configured to include the through hole passage 65 communicating with the head cover 4, it is not necessary to operate the outlet side fuel return passage at least when opening and closing the head cover 52 as in the related art, and the head cover 152 shown in FIG. The opening / closing operation of the head cover 52 can be performed more easily than in the case of the penetrating configuration.

Further, in this embodiment, as shown in FIG. 1 (C), the introduction side fuel return passage 59 extends from the inlet opening 67 formed in the cylinder head outer wall 62 outside the head cover 52 to the inside of the valve operating chamber 51. Since it is configured to include the through hole passage 69 that communicates with the outlet opening 68 formed in the cylinder head inner wall 66, it is not necessary to operate the introduction-side return passage 59 at the time of attaching and detaching the head cover 52. Opening and closing operations can be performed more easily. Further, as shown in FIGS. 1B and 1C, a part of the outlet-side fuel return passage 61 and a part of the inlet-side fuel return passage 59 are constituted by an oil return pipe 70. The positions of the inlet opening 63 of the outlet-side fuel return passage 61 and the outlet opening 68 of the inlet-side fuel return passage 59 can be appropriately set at optimal positions of the valve train chamber 51 and the cylinder head wall. Although FIG. 1 shows a configuration in which both the lead-out fuel return passage 61 and the introduction-side fuel return passage 59 are provided, the introduction-side fuel return passage 59 is not provided, and the fuel injection nozzles 33a, 33b, and 33c are not provided. Excess fuel is supplied to the fuel tank 5 only through the outlet fuel return passage 61.
A configuration returning to 3 can also be employed.

Next, at least the outlet side fuel return passage 61
A description will be given of a configuration in a case where the fuel injection engine 1 provided with the above is applied to a multi-valve engine in which at least one of an intake valve and an exhaust valve is constituted by a plurality of valves in one cylinder. 2 (A) and 2 (B) are views for explaining the direct injection type multi-valve engine, respectively. FIG. 2 (A) is a longitudinal sectional view of a main part of the multi-valve engine, and FIG. 2 (B) shows a head cover. FIG. 3 is a schematic plan view of the cylinder head in a state where it is removed.

FIG. 3 is a longitudinal sectional view of a main part of the multi-valve engine, and FIG. 4 is a schematic plan view for explaining an arrangement relationship of the valve gear. The multi-valve engine 1 described in this embodiment is a multi-cylinder overhead valve type four-valve direct injection diesel engine. First, the configuration of the four-valve direct injection diesel engine will be described. As shown in FIG. 4, this diesel engine has four valve ports 9a, 9b, 10a, and 10b open in a region along the cylinder inner peripheral surface 2 of the cylinder head 3. Also,
A rocker arm shaft 7 is installed in parallel with the front-rear vertical line 5 of the front-rear vertical line 5 and the left-right cross line 6 orthogonal to each other on the cylinder center axis 4. The longitudinal longitudinal line 5 is parallel to the crankshaft center (not shown).

[0013] Four valve ports 9a, 9b, 10a, 10b
Are two intake valve ports 9a and 9b and two exhaust valve ports 10a
10b, two intake valve openings 9a, 9
b, a pair of intake valves 11a and 11b are linked by an intake valve bridge 12, and an intake rocker arm 13 is pivotably supported on the rocker arm shaft 7 as shown in FIG. The end 14 is in contact with the input 15 of the intake valve bridge 12. As shown in FIG. 4, a pair of exhaust valves 16a and 16b provided in the two exhaust valve ports 10a and 10b are linked by an exhaust valve bridge 17, and the same rocker arm shaft 7 is connected to the exhaust rocker arm 18 by the same rocker arm shaft 7.
The output end of the exhaust rocker arm 18 is in contact with the input portion 20 of the exhaust valve bridge 17.

The intake valve bridge 12 and the exhaust valve bridge 17 are not orthogonal to the direction of the rocker arm shaft 7, but are inclined in the same direction.
The positions of 10a and 10b are set. Therefore, the position of the input portion 20 of the exhaust valve bridge 17 is smaller than the position of the input portion 15 of the intake valve bridge 12 in the rocker arm shaft 7.
It is close to. In this configuration, the difference between the arm ratios of the exhaust rocker arm 18 and the intake rocker arm 13 is different, but this difference in the arm ratio is caused by the cam lift of the exhaust valve cam (not shown) and the intake valve cam (not shown). By providing a difference, correction is made so that there is no problem. FIG.
As shown in (A) and (B), a fuel injection nozzle mounting hole 36 reaching the combustion chamber is provided at a position of the cylinder head 3 substantially coincident with the cylinder center axis, and the fuel injection nozzle 33 is protruded from the mounting hole 36. The tip of the fuel injection nozzle 33 faces the combustion chamber.

The intake valve bridge 12 is configured as shown in FIG. That is, in FIG. 3, the intake valve bridge 12 is provided with a vertical guide boss 23 at the center of the elongated arm 22, a pad mounting seat 25 at the upper end of the boss hole 24, and a pad 26 here. The pad 26 is rotatably seated, and the pad 26 is connected to the input portion 15 of the intake valve bridge 12.
There is. The right end of the arm 22 has a concave portion 2 facing downward.
7, and an adjusting screw 28 is provided at the left end. In the intake valve bridge 12, a guide boss 23 is externally fitted to a column 29 erected on the cylinder head 3, an output end 14 of the intake rocker arm 13 is brought into contact with a pad 26 from above, and an intake Intake valve 11a corresponding to valve port 9a
Of the intake valve 11b corresponding to the intake valve port 9b is contacted to the lower end surface of the adjusting screw 28 from below.

The intake valve bridge 12 is moved up and down along the column 29 by the lifting and lowering operation of the push rod 30 and the swinging of the intake rocker arm 13 by the operation of the valve spring 31, and the intake valves 11a and 11b are integrally moved up and down. I do. Note that the exhaust valve bridge 17 has the same configuration. As described above, the difference between the arm ratios of the intake rocker arm 13 and the exhaust rocker arm 18 (see FIG. 4) is to provide a cam lift difference between the exhaust valve cam (not shown) and the intake valve cam (not shown). Is set so that there is no problem. Therefore, unlike the configuration in which the rocker arm shafts for the intake valve and the exhaust valve are separately provided so as to keep the arm ratio constant, only one rocker arm shaft is used. Thus, there is an advantage that the structure in the valve operating chamber can be simplified, and the valve operating device can be reduced in weight by adopting such a configuration.

In this multi-valve engine, FIG.
As shown in the figure, the outlet side fuel return passage 61 is formed by providing a through hole passage 65 in an end cylinder head wall 72 corresponding to the front-rear direction of the engine. The through hole passage 65 forms a stepped surface 74 continuously with the valve operating chamber peripheral wall 73 on the end cylinder head wall 72 side, forms a vertical hole 75 in the stepped surface 74, and further forms the vertical hole 75. It is formed by providing a lateral hole 76 from the end cylinder head wall 72 so as to communicate with the end portion. A connecting member 77 such as a plug is attached to the end of the fuel return passage 61 from the final fuel injection nozzle 33z so as to engage with the vertical hole 75. Although not described with reference to the drawings, the introduction-side fuel return passage may be provided, and a through-hole passage including a vertical hole and a horizontal hole may be formed in the end cylinder head wall or the like.

By providing a through-hole passage or a through-hole passage 65 that penetrates through the cylinder head 3 in the multi-valve engine as described above, excess fuel can be returned. In addition to the effects described with reference to FIG. There are the following advantages. First, in the multi-valve direct injection type engine, the fuel injection nozzle 33 is generally located near the cylinder center axis surrounded by the intake valve and the exhaust valve. This is mainly for improving the uniformity of the spray in the main combustion chamber. In the configuration in which the fuel injection nozzles 33 are erected substantially vertically on the cylinder head 3 as described above, unlike the engine of the type that injects fuel into the sub-chamber type combustion chamber, the fuel injection nozzles 33 are accommodated in the head cover 52. It becomes a configuration. In this case, the fuel injection nozzles 33 are fixed to the cylinder head 3 by the fuel injection nozzle fixture 79 as shown in FIG. 2A. The operation of the introduction-side fuel return passage 59 and the discharge-side fuel return passage 61 due to the attachment / detachment work causes a slight change in the fixing state of the fuel injection nozzle fixture 79, and a slight change in the spray characteristics in the main combustion chamber. Sometimes occurred. However, by causing the fuel return passages 59 and 61 to pass through the cylinder head 3 as shown in FIG. 1, the above problem can be completely prevented.

[Brief description of the drawings]

1 is a schematic explanatory view for explaining a fuel injection type engine according to the present invention, FIG. 1 (A) is a schematic configuration diagram thereof, and FIGS. 1 (B) and 1 (C) are cylinder heads, respectively. It is a principal part longitudinal cross-sectional view.

FIGS. 2 (A) and 2 (B) are views for explaining the direct injection type multi-valve engine, respectively. FIG. 2 (A) is a longitudinal sectional view of a main part of the multi-valve engine, and FIG. () Is a schematic plan view of the cylinder head with the head cover removed.

FIG. 3 is a longitudinal sectional view of a main part of the multi-valve engine.

FIG. 4 is a schematic plan view illustrating a valve train.

FIG. 5 is a schematic configuration diagram of a conventional fuel injection engine.

[Description of Signs] 3 ... Cylinder head, 33 ... Fuel injection nozzle, 52 ... Head cover, 55 ... Fuel injection pump, 59 ... Introduction side fuel return passage, 61 ... Outflow side fuel return passage, 65 ... Punch hole passage, 69 ... Through-hole passage.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuru Ueyama 64 Kubota Sakai Works, Sakai City, Osaka Prefecture (72) Inventor Satoshi Maeya 64 64 Ishizu Kitamachi Town, Sakai City, Osaka Prefecture 72 Kubota Sakai Works, Ltd. ) Inventor Kiyoshi Hataura 64, Ishizukitacho, Sakai City, Osaka Prefecture Inside the Kubota Sakai Factory (72) Inventor Miya ▲ zaki ▼ Manabu 64, Ishizukitamachi, Sakai City, Osaka Prefecture Inside Kubota Sakai Factory, Ltd. (72) Inventor Noki Takii Osaka 64 Ishizu-Kitamachi, Sakai City, Osaka Prefecture Kubota Sakai Works, Ltd.

Claims (2)

[Claims] An at least one fuel injector (33) is provided in a head cover (52), and an outlet-side fuel return passage for returning fuel from the fuel injector (33) to a predetermined location outside the head cover (52). 61), wherein the outlet side fuel return passage (61) is provided with a cylinder head (3).
A fuel injection type engine comprising a through hole passage (65) penetrating through the hole. 2. At least one fuel injector (33) is provided in a head cover (52), and a fuel injection pump (55) for supplying high-pressure fuel to the fuel injector (33) is provided outside the head cover (52). And a fuel injection type engine in which the introduction side fuel return passage (59) of the fuel injection pump (55) is introduced into the head cover (52), wherein the introduction side fuel return passage (59) is provided in the cylinder head (3).
A fuel injection type engine comprising a through-hole passage (69) penetrating through the fuel injection engine.