JP2008169746A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent shortage of fuel supplied to a high pressure pump even in low speed rotation. <P>SOLUTION: Fuel is supplied to the high pressure pump 20 and a cam chamber 13 by a low pressure pump 25 driven by an internal combustion engine and a passage area of a passage hole 51 leading fuel to the cam chamber 13 from the low pressure pump 25 is changed by a control valve 60 according to delivery pressure of the low pressure pump 25. Passage area of the passage hole 51 is made small by a control valve 60 to reduce fuel supply quantity to the cam chamber 13 in low speed rotation of the internal combustion engine including idling speed. The quantity of fuel delivered toward a fuel pressurizing chamber 22 is increased thereby. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel supply device having a pump driven by an internal combustion engine, and is suitable, for example, for a fuel supply device used in a pressure accumulation fuel injection device for a diesel engine.

A conventional fuel supply device is driven by an internal combustion engine to rotate, a high-pressure pump that pressurizes fuel by following a cam provided on the cam shaft, and a high-pressure driven by the internal combustion engine via the cam shaft. And a low-pressure pump for supplying fuel to the pump. In addition, a part of the fuel discharged from the low pressure pump is guided to the cam chamber through a lubricating fuel passage (for example, see Patent Document 1).
JP 2002-322968 A

  However, in the conventional fuel supply device described above, the passage area of the lubricating fuel passage is constant in the rotation region of the internal combustion engine except during cranking, while the discharge amount and discharge pressure of the low-pressure pump increase the rotational speed of the internal combustion engine. It increases with. For this reason, the ratio of the fuel supplied to the cam chamber out of the fuel discharged from the low-pressure pump is higher during low-speed rotation than during high-speed rotation, and there is insufficient fuel supplied to the high-pressure pump during low-speed rotation. End up. As a result, the fuel pressure in the common rail is reduced, and the rotation of the internal combustion engine may become unstable or the internal combustion engine may stop.

  Further, in the fuel supply device in which the fuel filter is installed on the downstream side of the low-pressure pump, since a part of the fuel is returned from the fuel filter to the fuel tank, the fuel supplied to the high-pressure pump is more likely to be insufficient. The above problem becomes more prominent.

  In view of the above points, an object of the present invention is to prevent fuel supplied to a high-pressure pump from running out even during low-speed rotation.

  The present invention is driven by an internal combustion engine to supply a high pressure pump (20) and a cam chamber (13) with a low pressure pump (25), and lubrication for guiding the fuel from the low pressure pump (25) to the cam chamber (13). And a passage area control means (60) for changing the passage area of the fuel passage (51, 54, 644, 645), and a lubricating fuel passage (51, 54, 644, 645) is made smaller than the passage area of the lubricating fuel passages (51, 54, 644, 645) when the internal combustion engine rotates at high speed.

  In this way, the amount of fuel supplied to the cam chamber (13) decreases and the amount of fuel supplied to the high-pressure pump (20) increases during low-speed rotation of the internal combustion engine. Problems caused by the shortage of supplied fuel can be solved.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view of a fuel supply apparatus according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  The fuel supply device of this embodiment is used in an accumulator fuel injection device for an internal combustion engine (more specifically, a diesel engine), and pressurizes and supplies fuel to a common rail that accumulates high-pressure fuel.

  As shown in FIGS. 1 and 2, the housing of the fuel supply apparatus includes an aluminum housing body 11 and a pair of iron-based metal cylinder heads 12. A cam chamber 13 to which fuel is supplied from a low-pressure pump, which will be described later, is formed in the housing body 11, and both ends of the cam chamber 13 are closed by the cylinder head 12. The cam chamber 13 is connected to a fuel tank (not shown).

  The cam shaft 14 is made of iron-based metal, is rotatably supported by the housing body 11 via a journal 15, and is rotated by being driven by a diesel engine (not shown). The cam shaft 14 and the housing body 11 are sealed with an oil seal 16.

  A cam 17 having a circular cross section is formed eccentrically with respect to the cam shaft 14 at an intermediate portion in the axial direction of the cam shaft 14.

  A cam ring 18 that revolves around the cam shaft 14 is fitted to the outer periphery of the cam 17. The cam ring 18 includes a cam ring main body 18a and a bush 18b integrated with the cam ring main body 18a. More specifically, the cam ring body 18a is made of an iron-based metal, has an outer shape of a quadrangular prism, and has a circular through hole. The bush 18b is formed in a cylindrical shape with a copper-based metal or resin, and is press-fitted into a through hole of the cam ring body 18a, so that the bush 18b is slidable with the cam 17. The cam 17 and the cam ring 18 are accommodated in the cam chamber 13.

  On both sides of the cam ring 18, iron-based metal plungers 20 that reciprocate following the revolution of the cam ring 18 are arranged. The plunger 20 includes a columnar portion 20 a that is inserted into the cylinder head 12 so as to be reciprocally movable, and a bowl-shaped plunger head 20 b that is disposed in the cam chamber 13 and is opposed to the cam ring 18. The plunger 20 constitutes the main part of the high-pressure pump of the present invention.

  The plunger 20 is urged toward the cam ring 18 by the spring 21 disposed in the cam chamber 13, and the plunger head 20 b is pressed against the cam ring 18. The contact surface between the cam ring 18 and the plunger head 20b is formed in a flat shape, and this prevents rotation of the cam ring 18, so that the cam ring 18 rotates while sliding with the plunger head 20b as the cam 17 rotates. Revolve without any problems.

  In the cylinder head 12, a fuel pressurizing chamber 22 to which fuel is supplied from the low-pressure pump 25 is formed on one end side (the side opposite to the plunger head 20 b) of the cylindrical portion 20 a of the plunger 20. In addition, in the cylinder head 12, only the flow of fuel from the low pressure pump 25 to the fuel pressurizing chamber 22 and allowing only the fuel flow to the fuel pressurizing chamber 22 and the flow of fuel from the fuel pressurizing chamber 22 to the common rail are limited. A permissible outlet check valve 24 is provided.

  One end of the camshaft 14 is coupled to a low-pressure pump 25 formed by an inner gear trochoid pump. The low pressure pump 25 is housed in the pump cover 26 so as to be rotatable. The low pressure pump 25 is driven to rotate by the camshaft 14 so as to pressurize and discharge the fuel sucked from the fuel tank, and the discharge pressure increases as the rotational speed of the internal combustion engine increases.

  The fuel discharged from the low-pressure pump 25 is supplied to the fuel pressurizing chamber 22 through a fuel passage (not shown) and an inlet-side check valve 23. A metering valve (not shown) for metering the amount of fuel supplied to the fuel pressurizing chamber 22 according to the operating state of the internal combustion engine is provided in the middle of the fuel passage.

  Further, in order to supply a part of the fuel discharged from the low pressure pump 25 to the cam chamber 13, the fuel supply device has the following configuration.

  3 is an enlarged cross-sectional view of a portion B in FIG. As shown in FIG. 3, the housing body 11 has a discharge chamber 50 into which fuel discharged from the low-pressure pump 25 flows, a first passage hole 51 communicating with the discharge chamber 50, and a first passage hole 51. The passage area is large, and the second passage hole 52 that communicates the first passage hole 51 and the cam chamber 13, and the tapered valve seat 53 that is located at the connection between the first passage hole 51 and the second passage hole 52. Is formed. The first passage hole 51 corresponds to the lubricating fuel passage of the present invention.

  The second passage hole 52 is provided with a control valve 60 as passage area control means capable of continuously changing the passage area of the first passage hole 51. The control valve 60 includes a spherical valve body 61 that contacts and separates from the valve seat 53, a spring 62 that biases the valve body 61 toward the valve seat 53, and a second passage hole 52 that is press-fitted into the control valve 60. And a cylindrical stopper 63 for supporting one end.

  When the discharge pressure of the low-pressure pump 25 reaches the set pressure, the control valve 60 opens the valve body 61 away from the valve seat 53, and the opening degree (that is, as the discharge pressure of the low-pressure pump 25 increases) The passage area of the first passage hole 51 is continuously increased. Note that the passage area of the first passage hole 51 when the control valve 60 is fully open is equal to the minimum passage area in the lubricating fuel passage in the conventional fuel supply apparatus.

  Next, the operation of the fuel supply device will be described.

  When the camshaft 14 is driven and rotated by the diesel engine, the low pressure pump 25 is driven by the rotation of the camshaft 14, and the low pressure pump 25 sucks fuel from the fuel tank, pressurizes it, and discharges it.

  Further, the cam 17 rotates with the rotation of the cam shaft 14, the cam ring 18 revolves without rotating with the rotation of the cam 17, and the plunger 20 reciprocates with the rotation of the cam ring 18.

  When the plunger 20 at the top dead center moves toward the bottom dead center with the revolution of the cam ring 18, the fuel discharged from the low pressure pump 25 passes through the discharge chamber 50, the metering valve, and the inlet side check valve 23. It flows into the fuel pressurizing chamber 22.

  When the plunger 20 that has reached the bottom dead center moves again toward the top dead center, the inlet side check valve 23 is closed, and the fuel pressure in the fuel pressurizing chamber 22 rises. When the fuel pressure in the fuel pressurizing chamber 22 rises, the outlet side check valve 24 opens and high pressure fuel is supplied to the common rail.

  On the other hand, part of the fuel discharged from the low pressure pump 25 is supplied to the cam chamber 13 through the discharge chamber 50, the first passage hole 51, and the second passage hole 52. At this time, the passage area of the first passage hole 51 is controlled by the control valve 60 as follows, and the relationship between the rotational speed of the internal combustion engine and the discharge pressure of the low-pressure pump 25 is controlled as shown in FIG. In addition, the broken line in FIG. 4 has shown the characteristic of the conventional fuel supply apparatus. FIG. 5 is a cross-sectional view showing the operating state of the control valve 60.

  First, at the rotational speed of the internal combustion engine when starting the internal combustion engine, that is, the cranking rotational speed N1, the discharge pressure of the low-pressure pump 25 is extremely low, so that the control valve 60 is shown in FIG. Is smaller (that is, the passage area of the first passage hole 51). For this reason, the amount of fuel supplied from the low pressure pump 25 to the cam chamber 13 is smaller than before, and the discharge pressure of the low pressure pump 25 is higher than before. And since the discharge pressure of the low pressure pump 25 becomes higher than before, the amount of fuel discharged toward the fuel pressurizing chamber 22 becomes larger than before.

  Further, after the internal combustion engine is started, when the idling rotational speed is N2, the discharge pressure of the low-pressure pump 25 is higher than that during cranking. Therefore, as shown in FIG. Has increased from the time of cranking. However, since the opening degree of the control valve 60 at this time is about half open, the amount of fuel supplied from the low pressure pump 25 to the cam chamber 13 is smaller than before, and the discharge pressure of the low pressure pump 25 is higher than before. . And since the discharge pressure of the low pressure pump 25 becomes higher than before, the amount of fuel discharged toward the fuel pressurizing chamber 22 becomes larger than before.

  Furthermore, as the rotational speed of the internal combustion engine becomes higher than the idling rotational speed N2, the discharge pressure of the low-pressure pump 25 increases and the opening degree of the control valve 60 increases. When the rotational speed of the internal combustion engine reaches the first predetermined rotational speed N3 that is higher than the idling rotational speed N2, the control valve 60 is fully opened as shown in FIG. In the high-speed rotation range where the engine speed is equal to or higher than the first predetermined rotation speed N3, the amount of fuel supplied from the low-pressure pump 25 to the cam chamber 13, the discharge pressure of the low-pressure pump 25, and the fuel discharged toward the fuel pressurization chamber 22 The amount will be the same as before.

  In the present embodiment, when the internal combustion engine is rotated at a low speed including the idling rotational speed N2, the control valve 60 reduces the passage area of the first passage hole 51 to reduce the amount of fuel supplied to the cam chamber 13, thereby increasing the fuel supply. Since the amount of fuel discharged toward the pressure chamber 22 is increased, the fuel is sufficiently supplied toward the fuel pressurizing chamber 22 when the internal combustion engine rotates at a low speed. As a result, it is possible to prevent a decrease in fuel pressure in the common rail, and to solve the problem that the rotation of the internal combustion engine becomes unstable or the internal combustion engine stops.

(Second Embodiment)
A second embodiment of the present invention will be described. FIG. 6 is a cross-sectional view showing the configuration near the control valve 60 in the fuel supply apparatus according to the second embodiment of the present invention, and FIG. 7 is a characteristic diagram showing the relationship between the rotational speed of the internal combustion engine and the discharge pressure of the low-pressure pump 25. is there. In addition, the broken line in FIG. 7 has shown the characteristic of the conventional fuel supply apparatus. The same or equivalent parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 6, the housing main body 11 is formed with a bypass passage hole 54 that is arranged in parallel to the first passage hole 51 and always communicates the discharge chamber 50 and the second passage hole 52. The sum of the passage area of the first passage hole 51 and the passage area of the bypass passage hole 54 when the control valve 60 is fully opened is equal to the minimum passage area in the lubricating fuel passage in the conventional fuel supply apparatus. The first passage hole 51 and the bypass passage hole 54 constitute the lubricating fuel passage of the present invention.

  The control valve 60 of the present embodiment starts to open when the rotational speed of the internal combustion engine reaches the first predetermined rotational speed N3. Accordingly, when the rotational speed of the internal combustion engine is in the range of the cranking rotational speed N1 to the first predetermined rotational speed N3, the first passage hole 51 is closed by the control valve 60, and the first passage hole 51 and the bypass passage hole 54 Fuel is supplied to the cam chamber 13 only through the bypass passage hole 54. Accordingly, the amount of fuel supplied from the low pressure pump 25 to the cam chamber 13 is smaller than before, the discharge pressure of the low pressure pump 25 is higher than before, and the amount of fuel discharged toward the fuel pressurization chamber 22 is reduced. More than before.

  Further, when the rotational speed of the internal combustion engine reaches the first predetermined rotational speed N3, the control valve 60 starts to open and fuel is supplied to the cam chamber 13 via the first passage hole 51 as well. For this reason, when the rotational speed of the internal combustion engine exceeds the first predetermined rotational speed N3, the degree of increase in the discharge pressure of the low-pressure pump 25 once becomes moderate. When the rotational speed of the internal combustion engine reaches the second predetermined rotational speed N4, the control valve 60 is fully opened, and in the high speed rotational region where the rotational speed of the internal combustion engine is equal to or higher than the second predetermined rotational speed N4, the low pressure pump 25 The amount of fuel supplied to 13, the discharge pressure of the low-pressure pump 25, and the amount of fuel discharged toward the fuel pressurizing chamber 22 are the same as in the prior art.

  In the present embodiment, when the internal combustion engine rotates at a low speed including the idling rotational speed N2, the control valve 60 closes the first passage hole 51 to reduce the amount of fuel supplied to the cam chamber 13, thereby Since the amount of fuel discharged toward the engine is increased, the fuel is sufficiently supplied toward the fuel pressurizing chamber 22 when the internal combustion engine rotates at a low speed. As a result, it is possible to prevent a decrease in fuel pressure in the common rail, and to solve the problem that the rotation of the internal combustion engine becomes unstable or the internal combustion engine stops.

  Further, in the case of the first embodiment, when the spring constant of the spring 62 becomes small due to secular change or the like, compared with the case where the spring constant is the initial value, in the region where the rotational speed of the internal combustion engine is equal to or lower than the first predetermined rotational speed N3. Since the discharge pressure of the low-pressure pump 25 decreases, the rotational stability of the internal combustion engine during idling may slightly decrease.

  On the other hand, in the case of this embodiment, even when the spring constant of the spring 62 becomes small due to secular change or the like, the internal combustion engine when the control valve 60 starts to open is compared with the case where the spring constant is the initial value. Since the rotational speed (in this example, the first predetermined rotational speed N3) only decreases, the discharge pressure of the low-pressure pump 25 at the idling rotational speed N2 does not change, and the rotational stability of the internal combustion engine during idling decreases. Never do.

(Third embodiment)
A third embodiment of the present invention will be described. FIG. 8 is a cross-sectional view showing the configuration in the vicinity of the control valve 60 in the fuel supply apparatus according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same or equivalent part as 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 8, the control valve 60 includes a valve body 64 having first to third cylindrical portions 641 to 643. The first through hole 644 is formed in the first cylindrical portion 641 having the smallest diameter, the second through hole 645 is formed in the second cylindrical portion 642 having a larger diameter than the first cylindrical portion 641, and the second cylindrical portion 642 is formed. A third through hole 646 is formed in the third cylindrical portion 643 having a large diameter.

  The sum of the passage area of the first through hole 644 and the passage area of the second through hole 645 is equal to the minimum passage area in the lubricating fuel passage in the conventional fuel supply apparatus. The passage area of the third through hole 646 is set sufficiently larger than the passage areas of the first through hole 644 and the second through hole 645. In addition, the 1st through-hole 644 and the 2nd through-hole 645 comprise the lubricating fuel channel | path of this invention.

  In the housing body 11, the first cylindrical hole 55 into which the first cylindrical portion 641 is slidably inserted in the connecting portion between the first passage hole 51 and the second passage hole 52, and the second cylindrical portion 642 are slid. A second cylindrical hole 56 to be inserted movably is formed.

  When the discharge pressure of the low-pressure pump 25 is low, the first cylindrical portion 641 is positioned in the first cylindrical hole 55 and the second cylindrical portion 642 is positioned in the second cylindrical hole 56, and this state Then, the first passage hole 51 and the second passage hole 52 communicate with each other only through the first through hole 644 among the first to third through holes 644 to 646.

  When the discharge pressure of the low-pressure pump 25 increases, the valve body 60 moves against the spring 62 in the valve opening direction. In the state where the first cylindrical portion 641 is pulled out of the first cylindrical hole 55 and the second cylindrical portion 642 is positioned in the second cylindrical hole 56, the first of the first through third through holes 644 to 646 is the first. The first passage hole 51 and the second passage hole 52 communicate with each other through the first through hole 644 and the second through hole 645.

  When the discharge pressure of the low-pressure pump 25 further increases, the second cylindrical portion 642 also comes out of the second cylindrical hole 56, and in this state, the first passage hole 51 and the second passage hole are formed by the first to third through holes 644 to 646. 52 is communicated.

  The control valve 60 of the present embodiment is configured such that the first cylindrical portion 641 comes out of the first cylindrical hole 55 when the rotational speed of the internal combustion engine reaches the first predetermined rotational speed N3 (see FIG. 7). . Therefore, when the rotational speed of the internal combustion engine is in the range of the cranking rotational speed N1 (see FIG. 7) to the first predetermined rotational speed N3, only the first through hole 644 among the first to third through holes 644 to 646 is used. Fuel is supplied to the cam chamber 13. Accordingly, the amount of fuel supplied from the low pressure pump 25 to the cam chamber 13 is smaller than before, the discharge pressure of the low pressure pump 25 is higher than before, and the amount of fuel discharged toward the fuel pressurization chamber 22 is reduced. More than before.

  When the rotational speed of the internal combustion engine reaches the first predetermined rotational speed N3, the first cylindrical portion 641 comes out of the first cylindrical hole 55 and fuel is supplied to the cam chamber 13 via the second through hole 645. It becomes like this. For this reason, when the rotational speed of the internal combustion engine exceeds the first predetermined rotational speed N3, the degree of increase in the discharge pressure of the low-pressure pump 25 once becomes moderate. When the rotational speed of the internal combustion engine reaches the second predetermined rotational speed N4 (see FIG. 7), the first cylindrical portion 641 completely comes out of the first cylindrical hole 55, and the rotational speed of the internal combustion engine becomes the second predetermined rotational speed. In a high-speed rotation region that is N4 or more, the amount of fuel supplied from the low-pressure pump 25 to the cam chamber 13, the discharge pressure of the low-pressure pump 25, and the amount of fuel discharged toward the fuel pressurization chamber 22 are the same as in the past. become.

  If the discharge pressure of the low-pressure pump 25 rises abnormally, the second cylindrical portion 642 also comes out of the second cylindrical hole 56, and fuel flows into the cam chamber 13 via the first to third through holes 644 to 646. It is escaped and further increase in the discharge pressure of the low-pressure pump 25 is prevented, and breakage of the low-pressure pump 25 is prevented.

  In the present embodiment, when the internal combustion engine rotates at a low speed including the idling rotational speed N2 (see FIG. 7), the fuel is supplied to the cam chamber 13 only through the first through hole 644. Since the supply amount is reduced, and thereby the amount of fuel discharged toward the fuel pressurizing chamber 22 is increased, the fuel is sufficiently supplied toward the fuel pressurizing chamber 22 when the internal combustion engine rotates at a low speed. Is done. As a result, it is possible to prevent a decrease in fuel pressure in the common rail, and to solve the problem that the rotation of the internal combustion engine becomes unstable or the internal combustion engine stops.

  Further, when the discharge pressure of the low pressure pump 25 rises abnormally, fuel is released to the cam chamber 13 through the first to third through holes 644 to 646 to prevent further increase of the discharge pressure of the low pressure pump 25. Therefore, damage to the low pressure pump 25 can be prevented.

  Further, even when the spring constant of the spring 62 becomes small due to secular change or the like, the rotational speed of the internal combustion engine when the first cylindrical portion 641 comes out of the first cylindrical hole 55 (compared to the case where the spring constant is the initial value) ( In this example, the first predetermined rotational speed N3) and the discharge pressure of the low-pressure pump 25 when the second cylindrical portion 642 comes out of the second cylindrical hole 56 only decreases, so the low-pressure pump at the idling rotational speed N2 The discharge pressure of 25 does not change, and the rotational stability of the internal combustion engine during idling does not decrease.

(Other embodiments)
In each of the above embodiments, the inner gear trochoid pump is used as the low pressure pump 25, but a vane pump may be used as the low pressure pump 25.

It is sectional drawing of the fuel supply apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which expands and shows the B section of FIG. It is a characteristic view which shows the relationship between the rotational speed of an internal combustion engine, and the discharge pressure of a low pressure pump. It is sectional drawing which shows the operating state of a control valve. It is sectional drawing which shows the structure of the control valve vicinity in the fuel supply apparatus which concerns on 2nd Embodiment of this invention. It is a characteristic view which shows the relationship between the rotational speed of an internal combustion engine, and the discharge pressure of a low pressure pump. It is sectional drawing which shows the structure of the control valve vicinity in the fuel supply apparatus which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Housing, 13 ... Cam chamber, 14 ... Cam shaft, 17 ... Cam, 20 ... Plunger (main part of high pressure pump), 25 ... Low pressure pump, 51, 54 ... Passage hole (lubricated fuel passage), 60 ... Control valve (Passage area control means), 644, 645... Through hole (lubricated fuel passage).

Claims (4)

A camshaft (14) that is driven by an internal combustion engine to rotate;
A high-pressure pump (20) that pressurizes fuel by following a cam (17) provided on the camshaft (14);
A housing (11) in which a cam chamber (13) for accommodating the cam (17) is formed;
A low pressure pump (25) driven by the internal combustion engine to supply fuel to the high pressure pump (20) and the cam chamber (13);
Passage area control means (60) for changing the passage area of the lubricating fuel passages (51, 54, 644, 645) for guiding fuel from the low pressure pump (25) to the cam chamber (13),
The passage area control means (60) operates according to the discharge pressure of the low-pressure pump (25), and the lubricating fuel passages (51, 54, 644,) during low-speed rotation including an idling rotation region of the internal combustion engine. 645) is configured to be smaller than the passage area of the lubricating fuel passages (51, 54, 644, 645) when the internal combustion engine rotates at high speed. The passage area control means (60) is configured to continuously increase the passage area of the lubricating fuel passage (51) as the discharge pressure of the low pressure pump (25) increases. The fuel supply device according to claim 1. A plurality of the lubricating fuel passages (51, 54, 644, 645) are provided,
The passage area control means (60) includes a part of the lubricating fuel passages (51, 645) among the plurality of lubricating fuel passages (51, 54, 644, 645) during low speed rotation including an idling rotation region of the internal combustion engine. 2. The fuel supply device according to claim 1, wherein the lubricating fuel passages (51, 645) are opened when the internal combustion engine rotates at a high speed. The passage area control means (60) includes a valve body (64) that operates according to the discharge pressure of the low-pressure pump (25), and a plurality of the lubricating fuel passages (644, 645) are provided in the valve body (64). The fuel supply device according to claim 3, wherein the fuel supply device is formed.

Images