JPH1082356A - Accumulator fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection device which can be mounted on a wide range of engines from large to small sizes by making it possible to minimize an outside diameter of an injector and which improves workability at the time of assembly and maintainability at the time of maintenance and inspection. SOLUTION: It is possible to minimize an outside diameter of an injector 1 by providing a recovery connecting part 19 and a connector 30 on an injector head 46 and piping the connecting part 19 eccentrically from a central shaft of a solenoid valve 22 and a needle valve 5. Consequently, it is possible to generalize the injector 1 against various engines and to reduce its cost. As the connecting part 19, a supply connecting part 41 and the connector 30 are exposed out of an engine head cover, workability is favourable and a manhour reduction effect at the time of maintenance and inspection is high. As a channel to communicate a space in a valve housing 21 and a low pressure fuel passage 18 to each other is formed, bubbles and excess fuel in the valve housing 21 are speedily discharged, and it is possible to reduce an unfavorable effect on an injection characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention accumulates high-pressure fuel in an accumulator pipe (hereinafter referred to as a common rail), which is a kind of surge tank, and injects the accumulated high-pressure fuel from an electrically controlled injector. The present invention relates to a fuel injection device.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 1-253562, there is known a fuel injection device in which high-pressure fuel is injected into a diesel engine by an electrically controlled injector. In this type of fuel injection device, an example in which both a fuel recovery pipe connection for recovering surplus fuel and a connector for supplying power to and controlling the solenoid valve are provided at the non-injection side end of the injector is disclosed in Japanese Unexamined Patent Publication (Kokai) No. Heisei. 5-
No. 133296. An example in which both a fuel supply pipe connection for supplying high-pressure fuel and a connector for supplying power to and controlling an electromagnetic valve are provided at the non-injection side end of the injector is disclosed in Japanese Patent Application Laid-Open No. 1-224457. It has been disclosed.

[0003] A fuel injection device in which a fuel recovery pipe connection or a fuel supply pipe connection and a connector are provided at the opposite end of the injector on the opposite side of the injector has few protruding portions on the side of the injector and can reduce the injector outer diameter. When mounted, there is an advantage that interference between the valve operating system components such as the camshaft and the rocker arm and the injector can be avoided. Also, with the injector mounted on the cylinder head and the head cover covered, connect the fuel recovery pipe or fuel supply pipe and the power connector to the fuel recovery pipe connection or fuel supply pipe connection and connector exposed on the cover, respectively. This is advantageous in that the number of assembling steps can be reduced.

[0004]

However, in order to provide both the fuel recovery pipe connection portion and the connector at the opposite end of the injector on the non-injection side, it is necessary to avoid the fuel recovery pipe connection portion located on the center axis of the injector. Need to be placed. The structure that ensures airtightness so that there is no fuel leakage while maintaining the electrical insulation of the connector occupies an area larger than the diameter of the connector, and if it tries to prevent interference between this structure and the connection of the fuel recovery pipe, This results in an increase in the injector outer diameter. In addition, when the fuel collection pipe connection is eccentric, there is a problem that the surplus fuel discharge passage is bent in a complicated manner, thereby preventing fuel outflow. Further, there is a concern that air bubbles may remain in the middle of the discharge passage, adversely affecting the injection characteristics.

[0005] When both the fuel supply pipe connection and the connector are provided at the opposite end of the injector on the non-injection side, the fuel supplied to the fuel supply pipe connection is supplied to the throttle located on the injection side of the solenoid valve. Need to send, pressure is 100MPa
In order to send the fuel to the injection side, measures must be taken such as newly installing a sturdy thick pipe on the outer periphery of the electromagnetic two-way valve, or arranging the electromagnetic two-way valve eccentrically from the center of the nozzle needle. Must. Therefore, not only is the size of the injector increased, but there is also a problem of an increase in cost due to the need for complicated processing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is capable of reducing the outer diameter of an injector without deteriorating the injection characteristics, so that the injector can be mounted on a wide range of engines from large to small. It is an object of the present invention to provide a fuel injection device which can greatly improve workability at the time of assembly and maintenance at the time of maintenance and inspection.

[0007]

According to the fuel injection device of the present invention, the fuel recovery pipe connecting portion is provided eccentrically from the center axis of the solenoid valve, so that the expansion of the injector outer diameter can be minimized. Both the fuel recovery pipe connection for connecting the fuel recovery pipe and the solenoid valve power supply connector can be provided at the end of the injector opposite to the injection side. Therefore, since the injector has a small outer diameter and a shape with little overhang to the side, it hardly interferes with the intake / exhaust valves and these drive systems, making it possible to apply the same injector to engines of various types and sizes. The manufacturing cost of the injector can be reduced. Further, attachment and detachment of the fuel recovery pipe and the power-side connector are facilitated, so that workability at the time of assembly and maintainability at the time of maintenance and inspection are improved.

According to the second aspect of the present invention, the effect of reducing the diameter can be maximized by making the center axis of the solenoid valve of the injector coincide with the center axis of the needle valve. According to the fuel injection device of the third aspect, by providing the fuel supply pipe connection portion between the camshaft and the engine head cover, the protrusion to the lower side surface of the injector is further reduced, and the engine head can be downsized. Further, since the number of engines to which the same injector can be applied increases, the manufacturing cost of the injector can be reduced.

According to the fourth aspect of the present invention, since the accumulator is provided inside the engine head cover, the fuel supply pipe from the accumulator to the injector can be easily arranged. Further, it is not necessary to provide holes for fuel supply pipes in the engine head cover for the number of injectors, and only one hole for fuel supply pipes connecting the fuel pump and the accumulator to the engine head cover. Can be reduced.

According to the fuel injection device of the fifth aspect, the space between the camshaft and the engine head cover can be reduced by exposing the connection portion of the fuel supply pipe to the outside of the engine head cover, thereby reducing the size of the engine. it can. Further, since the fuel supply pipe can be attached and detached without removing the engine head cover, the maintainability at the time of maintenance and inspection is improved.

According to the fuel injection device of the sixth aspect, the mounting direction of the connector and the fuel recovery pipe is made coincident with the axial direction of the injector, thereby facilitating the mounting of the power-side connector and the fuel recovery pipe, thereby reducing the number of assembly steps. Reduce. After the injector is assembled, the engine head cover can be easily attached. According to the fuel injection device of the present invention, by providing a seal member between the injector and the engine head cover for maintaining airtightness, it is possible to prevent foreign matter and moisture from entering the inside of the engine head cover.

According to the fuel injection device of the present invention, since the cross-sectional shape of each of the injectors in the through hole of the engine head cover is circular, the rotation direction at the time of assembling the injector is not restricted. Can be easily fitted. Further, the space between the injector and the engine head cover can be reliably and easily sealed by the seal member.

According to the fuel injection device of the ninth aspect, the fuel recovery pipe connection is decentered by providing a flow path in the injector, which communicates the space in which fuel and air bubbles easily stagnate with the fuel recovery pipe connection. Thus, in the case of an injector having a complicatedly bent flow path, fuel and air bubbles can be discharged to the fuel recovery pipe without delay. Furthermore, the flow passage is formed vertically above the internal space in the state where the injector is assembled, and is recovered by keeping the horizontal or increasing the height vertically and communicating with the fuel recovery pipe connection portion. When the flow velocity of the fuel is low, stagnation of bubbles inside the injector can be prevented, and adverse effects on the injection characteristics can be reduced.

[0014]

Embodiments of the present invention will be described below. FIGS. 1 to 6 show an accumulator type fuel injection device according to a first embodiment of the present invention. The engine shown in the first embodiment is a DOHC four-cylinder engine, and has two intake valves and two exhaust valves for each cylinder.
High-pressure fuel stored in a pressure storage chamber of a common rail is supplied to an injector 1 attached to each cylinder via a fuel supply pipe 2.

First, the structure of the injector 1 will be described with reference to FIGS. At the lower end of the injector 1, a needle valve 5 for opening and closing an injection hole 4a is housed in a nozzle body 4 of an injection nozzle 3 provided at an injection side end so as to be reciprocally movable. The nozzle body 4 and the injector body 6 are connected by a retaining nut 8 with the distance piece 7 interposed therebetween. A pressure pin 9 and a control piston 10 that is in contact with or connected to the pressure pin 9 on the side opposite to the injection hole is disposed on the side opposite to the injection hole of the needle valve 5. The pressure pin 9 is inserted through the inside of the spring 11, and the spring 11 urges the pressure pin 9 downward in FIG.
A pressure control chamber 26 is provided on the side opposite to the injection hole of the control piston 10. The control piston 10 is reciprocally housed around the axis of the nozzle body 4, and a high-pressure fuel passage 12 and a low-pressure fuel passage 13 for discharging excess fuel are formed around the control piston 10.

The high-pressure fuel passages 12 and 14 form a fuel supply passage.
High-pressure fuel is supplied to the high-pressure fuel passage 12 through the filter 15 and the high-pressure fuel passage 14. A fuel reservoir 16 provided annularly around the needle valve 5 from the high-pressure fuel passage 12.
Is supplied with the high-pressure fuel, and the pressure of the high-pressure fuel acts in a direction to lift the needle valve 5. The low-pressure fuel passage 13
Discharges excess fuel leaking from the sliding portion of the injector 1 to the low-pressure fuel passages 17 and 18, and this excess fuel is connected to a fuel recovery pipe connection (hereinafter, referred to as a “recovery connection”) 19.
The fuel is collected in the fuel tank via a fuel collection pipe 20 connected to the fuel tank.

The valve housing 21 is a member for holding the solenoid valve 22. The valve housing 21 sandwiches the solenoid valve 22, the distance pieces 23a and 23b, and
4 is connected to the injector body 6. First
In the embodiment, the retaining nut 24 has a shape that covers the side surface of the core 35 of the electromagnetic valve 22 so that the outer diameter of the head portion 25 is reduced. However, the structure of the head section 25 is not limited to this. Distance Piece 2
The aforementioned low-pressure fuel passage 17 communicating with the low-pressure fuel passage 13 is formed in 3a and 23b. Further, the high pressure fuel passage 12 and the pressure control chamber 26 are provided in the distance piece 23a.
Is formed to supply high-pressure fuel to the pressure control chamber 26, and to the distance piece 23b, the outflow restrictor 2 capable of discharging the high-pressure fuel in the pressure control chamber 26 to the low-pressure side.
8 are formed.

A low pressure fuel passage 18 communicating with the low pressure fuel passage 13 and opening to the recovery connection portion 19 is formed in the valve housing 21. In addition, a flow path 18a is provided inside the valve housing 21 for communicating the low pressure fuel passage 18 with the space accommodating the spring 33 and the shim 33a for adjusting the set load of the spring 33. The flow path 18 a is formed vertically upward as approaching the low-pressure fuel passage 18. Therefore, the valve housing 2
Bubbles and excess fuel inside 1 are quickly discharged into the low-pressure fuel passage 18.

The valve member 31, the pressure pin 32 and the valve cylinder 36 are formed with low-pressure fuel passages 37, 38 and 39 which communicate with the low-pressure fuel passage 13 and reach the low-pressure fuel passage 18 formed in the valve housing 21. I have.
In particular, the valve member 31 is provided with 4 to 20 low-pressure fuel passages 40 in order to reduce inertia during opening and closing movement of the valve member 31 and to speed up sliding.

The solenoid valve 22 is an electromagnetic two-way valve that closes an outflow restrictor 28 that can discharge high-pressure fuel in the pressure control chamber 26 to a low-pressure side. It is stored in. The recovery connection portion 19 is disposed eccentrically from the central axes of the solenoid valve 22 and the needle valve 5, and is disposed on the injector head 46 while minimizing the outer diameter of the valve housing 21 and the retaining nut 24.

The valve member 31 blocks the communication between the outflow restrictor 28 and the low pressure side, and is urged in the valve closing direction by a spring 33 via a pressure pin 32 which is in contact with or coupled to the valve member 31. I have. Coil 3 of solenoid valve 22
4 is wound in a core 35 and supplied with power from a terminal 30 a embedded in a connector 30 for connecting a power-side connector 29 for supplying electricity to the solenoid valve 22.

When the energization of the coil 34 is turned off, the valve member 31 is seated on the valve seat 23c of the distance piece 23b and cuts off the communication between the outflow restriction 28 and the low pressure side. High pressure. This pressure control chamber 26
Due to the sum of the force received from the fuel pressure and the urging force of the spring 11, the force received by the needle valve 5 in the downward direction of FIG. Since the pressure is larger than the force received in the upward direction of FIG. 2, that is, in the direction of opening the injection hole, the injection hole 4 a is closed by the needle valve 5 and no fuel injection is performed.

When energization of the coil 34 is turned on, the valve member 31 separates from the valve seat 23c against the urging force of the spring 33 due to the magnetic force generated in the core 35, whereby the outflow restrictor 28 and the low-pressure fuel passage 39 are separated. When communicating, the pressure control chamber 2
The high-pressure fuel No. 6 flows out of the outflow restriction 28 into the low-pressure fuel passage 39. Since the flow passage area of the inflow restriction 27 is smaller than the flow passage area of the outflow restriction 28, the fuel pressure in the pressure control chamber 26 decreases. The force that the needle valve 5 receives in the opening direction of the injection hole from the donut-shaped pressure receiving area by the high-pressure fuel is applied to the pressure control chamber 2.
When the needle valve 5 is larger than the force received in the injection hole closing direction by the sum of the force received from the fuel pressure of 6 and the biasing force of the spring 11, the needle valve 5 is lifted in the upward injection hole releasing direction, and the fuel is discharged from the injection hole 4a. Is injected.

A fuel supply pipe connection (hereinafter, referred to as a "supply connection") for suppressing the overall height of the engine while avoiding interference with valve train components.
) Is formed on the injector body 6 so as to extend obliquely to the non-injection side with respect to the injector center axis. Accordingly, in the present invention, it goes without saying that the supply connection portion can be formed at right angles to the injector center axis. Injector 1 is cylinder head 4
2 is fitted coaxially with the fuel chamber 44a in the mounting hole 43 provided in the engine head cover 45.
The injector head 46 protrudes out of the engine head cover 45 from 5a. Injector head 4
The collection connection portion 19 and the connector 30 provided in 6 are exposed outside the engine head cover 45. By attaching an annular seal member 47 made of an elastic member having excellent heat resistance and oil resistance to the inner peripheral edge of the through hole 45a, the space between the injector 1 and the engine head cover 45 is hermetically sealed. Since the cross-sectional shape of the injector 1 at the contact portion with the through-hole 45a and the seal member 47 is circular, even if the mounting rotation direction of the injector 1 is slightly deviated due to an assembly error or the like, the engine 1 is passed through the through-hole 45a. The head cover 45 can be easily covered, and the seal 1
And the engine head cover 45 can be sealed well. After covering the engine head cover 45, the fuel recovery pipe 20 is attached to the recovery connection portion 19, and the connector 30 is connected.
Can be connected to the power supply side connector 29.

The supply connection part 41 is connected to the engine head cover 4 through a through hole 45b formed in the engine head cover 45.
5 is exposed outside. An annular and cylindrical seal member 48 made of an elastic member having excellent heat resistance and oil resistance is attached to the inner peripheral edge of the through hole 45b, and a space between the supply connection portion 41 of the injector 1 and the engine head cover 45 is provided. It is hermetically sealed. Since the cross-sectional shape of the supply connection portion 41 of the injector 1 at the contact portion between the through hole 45b and the seal member 48 is circular, a good seal can be provided between the supply connection portion 41 of the injector 1 and the engine head cover 45. . Also, the engine head cover 4
After covering, the fuel supply pipe 2 can be attached to the supply connection part 41.

The connection between the recovery connection 19 and the fuel recovery pipe 20 is made via a union 56. As shown in FIG. 5, the union 56 has a cylindrical shape, is provided with a hole 56 a at the center thereof for fitting with the recovery connection portion 19, and has a pipe 56 b for fitting with the fuel recovery pipe 20 provided on the side surface. It communicates with the fuel passage. The fitting depth of the recovery connection portion 19 and the union 56 is smaller than the hole 56a, and the low-pressure fuel passage 18 is not blocked by the fitting of the recovery connection portion 19 and the union 56. An annular groove 19 provided on the outer periphery of the collection connection portion 19
An annular seal member 57 made of an elastic material having excellent heat resistance and oil resistance is disposed at a to prevent fuel from leaking from a gap between the collection connection portion 19 and the union 56.

The fixing of the collection connection portion 19 and the union 56 is performed by a C-shaped circlip 58 shown in FIG. A two-sided width 19b for fixing the union 56 by fitting with the C-shaped circlip 58 is provided at a position on the side surface of the collection connection portion 19 closer to the injector than the seal member 57. There is a groove 56c on the side surface of the union 56 for engaging with the C-shaped circlip 58. The groove 56c is configured such that the interval L1 is smaller than the interval L2 of the two-sided width 19b, and a portion thereof is formed to penetrate the wall surface of the union 56.

The C-shaped circlip 58 is made of a material having excellent elasticity such as spring steel, and is configured such that the width L3 is smaller than the interval L2 of the two-sided width 19b before being attached. Therefore, when the C-shaped circlip 58 is assembled to the collection connection portion 19, the union 56
Securely and detachably without rattling. Width L4 is width L3
It is even narrower and serves to fix the C-type circlip 58 so that it does not fall off due to vibration of the injector 1 or the like. Further, a plurality of through-holes 58a are formed at one end of the C-shaped circlip 58, and a tool is hooked on the through-holes 58a to improve workability at the time of attachment and detachment.

The camshafts 49 and 51 rotate synchronously with the crankshaft of the engine (crankshaft 2).
(One rotation per rotation), and a plurality of cams 50 and 52 are provided in the axial direction, respectively. As the camshafts 49 and 51 rotate in synchronization with the crankshaft, the exhaust valve 53 and the intake valve 54 reciprocate, and the intake and exhaust of the combustion chamber 44a is performed.

In the injector 1 corresponding to each cylinder, a part of the injection nozzle 3 and the injector body 6, which are the injection side ends, are fitted into mounting holes 43 provided in the cylinder head 42, and have a bifurcated shape. The cylinder 55 is fixed to the cylinder head 42 by a fixing member 55. The two-face width 6a for positioning the injector 1 in the rotation direction via the fixing member 55 is equal to the width of the injector body 6.
Are formed by cutting out both side surfaces in the radial direction.

Next, the procedure for assembling the injector 1 will be described. The exhaust valve 53, the intake valve 54, and the camshafts 49 and 51 are already assembled before mounting the injector 1 on the engine. The injector 1 is fitted into the mounting hole 43, and the injector 1 is fixed so that the injector 1 is pressed against the cylinder head 42 by the fixing member 55. Thus, the injector 1 attached to the cylinder head 42 is disposed coaxially with the combustion chamber 44a. Engine head cover 4 with seal members 47 and 48 attached
5 is covered from the injector head 46 side.

Next, the fuel supply pipe 2 is attached to the supply connection 41, and the fuel recovery pipe 20 is attached to the recovery connection 19. By connecting the power supply side connector 29 to the connector 30, the assembly of the injector 1 to the engine is completed. In the first embodiment, the solenoid valve 2 is mounted on the valve housing 21.
2, a connector 30 for connecting a power-side connector 29 for supplying power to the solenoid valve 2 is provided.
The recovery connection 19 and the connector 30 are arranged on the injector head 46 while keeping the outer diameters of the valve housing 21 and the retaining nut 24 to a minimum by being eccentrically arranged from the center axis of the needle valve 5, that is, the center axis of the needle valve 5. be able to. Such miniaturization of the injector outer diameter can be achieved not only by a general OHV or OHC engine but also by a DO having a complicated mechanism as shown in the first embodiment.
Application to HC engines becomes possible. Therefore, the accumulator type fuel injection device of the present invention can be mounted on a small engine having a small displacement, so that a common injector can be used for various engines, and the cost can be reduced.

Further, since the recovery connection portion 19, the supply connection portion 41 and the connector 30 are exposed outside the engine head cover 45, the fuel recovery pipe 20, the fuel supply pipe 2 and the power supply The side connector 29 can be attached to the collection connection 19, the supply connection 41, and the connector 30. Therefore,
The workability is good, and the fuel recovery pipe 20, the fuel supply pipe 2, and the current-side connector 29 can be attached and detached without removing the engine head cover 45 during maintenance and inspection.

A flow passage 18a is provided for communicating the space inside the valve housing 21 with the low-pressure fuel passage 18, and the flow passage 18a is formed vertically upward as approaching the low-pressure fuel passage 18. Therefore, bubbles and excess fuel inside the valve housing 21 are quickly discharged to the low-pressure fuel passage 18. Therefore, it is possible to prevent bubbles from stagnating inside the injector, and to reduce adverse effects on the injection characteristics.

In the present invention, the fuel pipe connection is located above the camshaft, so that the pipe connection can be easily performed.
Further, since the fuel pipe connection portion is located on the side surface of the injector, a large space above the injector is not required. Further, since only the upper end face of the injector and the electrical connector are exposed outside the engine head cover, the appearance of the engine is neat. In addition, if the injector needs to be repaired or checked for some reason and it becomes necessary to remove the injector, the injector can be removed without removing the camshaft, and the workability during assembly is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a pressure accumulating fuel injection device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the injector according to the first embodiment of the present invention.

FIG. 3 is an enlarged view of a portion IV in FIG. 2;

FIG. 4 is a view taken in the direction of arrow A in FIG. 1;

FIG. 5A is a front view showing the union according to the first embodiment of the present invention, and FIG. 5B is a longitudinal sectional view of FIG.

FIG. 6 is a plan view showing a C-type circlip according to the first embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injector 2 Fuel supply pipe 3 Injection nozzle 4 Nozzle body 5 Needle valve 6 Injector body 10 Control piston 12, 14 High pressure fuel passage 13, 17, 18 Low pressure fuel passage 19 Recovery connection part (fuel recovery pipe connection part) 20 Fuel recovery pipe 21 Valve Housing 22 Solenoid Valve 26 Pressure Control Chamber 27 Inflow Restrictor 28 Outflow Restrictor 29 Power Connector 30 Connector 31 Valve Member 41 Supply Connection (Fuel Supply Pipe Connection) 42 Cylinder Head 45 Engine Head Cover 46 Injector Head 47, 48 Seal Member 49, 51 Camshaft 50, 52 Cam 53 Exhaust valve 54 Intake valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F02M 51/06 F02M 51/06 Z

Claims (9)

[Claims] 1. A common rail for accumulating high-pressure fuel, a fuel supply pipe for leading high-pressure fuel from the common rail,
An injector that is provided for each cylinder, receives fuel supplied from the fuel supply pipe, and controls the fuel injection timing by an electromagnetic valve to inject fuel into the diesel engine; and the non-injection side end of the injector is an engine. A fuel recovery pipe connecting portion that is exposed to the outside of the engine head cover through a through hole provided in the head cover and that discharges excess fuel from the injector, and a connector that supplies power to a solenoid valve of the injector, the injector anti-injection A pressure-accumulation type fuel injection device provided at a side end, wherein the fuel recovery pipe connection portion is provided eccentrically from a central axis of a solenoid valve of the injector. 2. The accumulator-type fuel injection device according to claim 1, wherein a center axis of the solenoid valve coincides with a center axis of a needle valve of the injector. 3. A pressure-accumulating fuel injection according to claim 1, wherein a fuel supply pipe connecting portion connecting the fuel supply pipe to the injector is provided between a camshaft and the engine head cover. apparatus. 4. The accumulator type fuel injection device according to claim 1, wherein the common rail is provided inside the engine head cover. 5. A pressure-accumulation type fuel injection device according to claim 1, wherein a fuel supply pipe connecting portion for connecting the fuel supply pipe to the injector is exposed outside an engine head cover. 6. The accumulator according to claim 1, wherein the mounting direction of the power-side connector and the fuel recovery pipe connected to the connector coincides with the axial direction of the injector. Type fuel injection device. 7. The accumulator according to claim 1, wherein a seal member is provided between the injector and the engine head cover to maintain the airtightness between the injector and the engine head cover. Fuel injection device. 8. The accumulator-type fuel injection device according to claim 1, wherein the injector has a circular cross section in the through hole. 9. A flow path for communicating an internal space of an injector provided for each cylinder of an engine with a fuel recovery pipe connection for discharging excess fuel from the injector, wherein the flow path is larger than the internal space. A pressure-accumulation type fuel injection device formed vertically above the injector in an assembled state and connected to the fuel recovery pipe connection portion while maintaining the horizontal level or increasing the height vertically.