JPH04125664U - fuel injection pump - Google Patents

Abstract

(57) [Summary] (with amendments) [Purpose] With a simple configuration, both the pilot injection amount Qpilot and the interval △A between pilot injection and main injection can be varied according to the load (fuel injection amount), and the engine To provide a fuel injection pump capable of appropriately responding to requests. [Structure] A pilot spill slit 32 communicating with the fuel intake/discharge hole 26 of the plunger 5 is formed on the outer surface of the plunger 5, and a control sleeve 18 located axially opposite to the pilot spill slit 32 is provided for pilot injection. The cut-off port 33 is formed separately from the main injection cut-off port 30, and the angle of inclination of the pilot spill slit 32 from the horizontal state, or the mutual inclination angle of its upper edge 32A and lower edge 32B, is adjusted. I made it.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention applies to fuel injection pumps used in internal combustion engines such as diesel engines. In particular, it is a variable pre-stroke type and a pilot injection type. The present invention relates to a fuel injection pump.

0002

[Conventional technology]

Conventionally, fuel injection pumps have a pre-stroke to make the pre-stroke variable. Some have a variable stroke mechanism, generally plungers that reciprocate up and down. Adjusting the relative positional relationship between the control sleeve and the control sleeve fitted over the plunger. This makes the prestroke variable.

0003 Examples of such variable pre-stroke mechanisms include Utility Model Application No. 118936/1986. The disclosure is required.

0004 Furthermore, in general, diesel engines reduce ignition delay and eliminate nitrogen oxides. In order to prevent the occurrence of combustion noise and reduce combustion noise, pilot injection (initial There are some that perform a main injection (primary injection) followed by a main injection (primary injection).

[0005] For example, Utility Model Application No. 48-5116, Utility Model Application No. 61-167470, No. 63-83458, JP-A No. 62-261667, Publication No. 15398-1983 , Special Publication No. 29-2502, Special Publication No. 5863-1974, etc.

[0006] However, in conventional fuel injection pumps, the pilot injection amount and and the interval (cam angle interval) between pilot injection and main injection. It was not possible to make it variable depending on the load (fuel injection amount).

[0007] Therefore, over the entire load range from low to high loads, the engine Difficult to select appropriate pilot injection amount and interval on request Met.

[0008] In particular, the ignition delay period of the engine differs depending on the load. Therefore, from the point of view of adjusting the ignition delay period, the above pilot injection amount and It is desirable to make the interval between lot injection and main injection variable. It is.

[0009]

[Problem that the idea aims to solve]

This invention was developed in consideration of the above problems, and has a simple structure. The pilot injection amount and the pilot injection and main injection amount are compared to the load (fuel injection amount). Responds appropriately to requests from the engine by making the interval between engine injection and injection variable. An object of the present invention is to provide a fuel injection pump that can perform the following steps.

0010

[Means to solve the problem]

In other words, the present invention improves the shape of the pilot spill slit formed in the plunger. The pilot injection amount and interval can be made variable by changing the conditions appropriately. The plunger barrel with a fuel pressure chamber and this plan It reciprocates inside the bellows barrel and enters the fuel pressure chamber from the fuel storage chamber through the fuel intake and exhaust hole. A plunger that sucks in fuel and pumps this fuel, and a plunger that can slide freely on this plunger. an externally fitted control sleeve, and the control sleeve and the plunger The fuel injection port is designed to adjust the prestroke by changing the relative position in the axial direction. A control inclined groove communicating with the fuel intake/discharge hole of the plunger is connected to the plunger. It is formed on the outer surface of the plunger, and is compatible with this control inclined groove in the axial direction. A cut-off port for main injection is formed in the control sleeve at a position opposite to the above, and The pilot spill slit that communicates with the fuel intake and exhaust hole of the plunger is installed above. It is formed on the outer surface of the plunger, and a shaft is formed in this pilot spill slit. A cut-off port for pilot injection is attached to the control sleeve at the opposite position on the side. A cut-off port is formed separately from the main injection cut-off port, and the pilot cut-off port is formed separately from the main injection cut-off port. The angle of inclination of the spill slit from the horizontal state, or its upper and lower edges. This fuel injection pump is characterized in that mutual inclination angles are adjusted.

[0011]

[Effect]

In the fuel injection pump according to the present invention, the conventional main injection control Control inclined groove formed on the plunger and main injection formed on the control sleeve. In addition to the cut-off port for pilot spill, the plunger has a slit for pilot spill. At the same time, a cut-off port for pilot injection is formed in the control sleeve. By this, the engagement between the control inclined groove and the main injection cut-off port At the same time, the pilot spill slit and pipe are closed. Pilot injection can be terminated by engagement with the cut-off port for lot injection. That's what I mean.

0012 Therefore, the amount of pilot injection and the interaction between pilot injection and main injection are The shape of the pilot spill slit, which is an element that determines the tarval, is variable. Therefore, the change in the shape of this pilot spill slit is due to its inclined state. It is easy to create a pie because all you have to do is change the slope of the top and bottom edges. Set lot injection amount and interval between pilot injection and main injection be able to.

[0013] Also, depending on the position and length of the pilot spill slit, it is possible to Pilot injection in the high speed range, or in the entire range from low load to high load. can be realized.

[0014]

【Example】

Next, a fuel injection pump 1 according to an embodiment of the present invention will be explained based on FIG. Ru.

[0015] FIG. 1 is a longitudinal sectional view of the fuel injection pump 1 with a variable prestroke mechanism. Therefore, the number of vertical holes 3 corresponding to the number of cylinders of the engine is formed in the pump housing 2. The lower plunger barrel 4 is inserted and fixed into the pump housing 2 within this vertical hole 3. The plunger 5 is rotatably and reciprocatably inserted into the lower plunger barrel 4. be.

[0016] The upper end of this plunger 5 is connected to the pump housing via the lower plunger barrel 4. This is inserted into the upper plunger barrel 6 fixed to the ring 2. This upper plunge A delivery valve 7 is provided in the barrel 6, and the delivery valve 7 and the plunger A fuel pressure chamber 8 is formed between the delivery valve 7 and the fuel pressure chamber 8, and a fuel outlet is provided above the delivery valve 7. 9 is formed.

[0017] Further, the lower end of the plunger 5 is connected to a cam 11 provided on a camshaft 10 with a tappet. It is in contact with this through the contact 12. This camshaft 10 is connected to the engine. are connected to each other, are rotationally driven by the same engine, and work together with the spring 13 to rotate the cover. The plunger 5 is brought into contact with the circumferential edge of the plunger 11, and is reciprocated in the vertical direction in the figure. It is now possible to

[0018] Furthermore, a driving face 14 is formed on this plunger 5, and this drive face 14 is formed on this plunger 5. The living face 14 is engaged with the injection amount adjusting sleeve 15. Also, A protrusion 16 is engaged with the injection amount adjustment sleeve 15, and the injection amount that is engaged with the protrusion 16 is The injection amount adjustment rod 17 is adjusted according to the amount of depression of the accelerator pedal (not shown). By driving in the angular direction, this injection amount adjusting sleeve 15 moves the plunger 5. It is now possible to rotate. In other words, the effective stroke of the pressure feed for fuel injection is determined by the injection amount adjustment rod. This can be adjusted by rotating the plunger 5 using the rod 17. Ru.

[0019] Further, a control sleeve 18 is slidably fitted over the upper part of the plunger 5. There is. This control sleeve 18 has a longitudinal guide groove 19 on the left side in the figure. A horizontal engagement groove 20 is formed on the right side. This guide groove 19 has a lower plate. The guide pin 21 provided on the plunger barrel 4 is engaged, and the timing control is inserted into the engagement groove 20. The engaging portion 23 of the control rod 22 is inserted.

[0020] This timing control rod 22 is formed in the pump housing 2. This is inserted into the side hole 24 and connected to the pump housing via a bearing (not shown). 2, it is supported rotatably. In addition, in the case of an electronic control system, this timing control rod 22 is connected to an actuator (not shown) such as a step motor, and this actuator This is rotated by a motor.

[0021] Note that the pre-stroke is defined by the timing control rod 22 as described above. This can be adjusted by moving the control sleeve 18 up and down by rotation. It is something that can be done.

[0022] That is, the timing control rod 22 is moved clockwise or counterclockwise in the figure. When rotated forward and backward in the clockwise direction, the timing control rod 22 and the timing The engaging portion 23 of the timing control rod 22 rotates together, and this timing The control sleeve 18 moves up and down due to the rotation of the engaging portion 23 of the control rod 22. However, the relative position of the plunger 5 and the control sleeve 18 in the vertical direction may change. It becomes.

[0023] Therefore, the control sleeve 18 and the fuel intake/discharge hole at the bottom dead center of the plunger 5 The pre-stroke of the plunger 5 defined as the dimension between the position 26 (described below) can be adjusted.

[0024] In other words, the dimension from the bottom dead center of the plunger 5 to when the fuel intake/discharge hole 26 is closed. is the prestroke of the plunger 5, and the time when the fuel intake/discharge hole 26 is closed is the combustion The injection of fuel will begin.

[0025] Specifically, the control is performed by rotating the timing control rod 22 clockwise. When the sleeve 18 is moved upward, the prestroke becomes larger, and at the start of injection The timing is delayed (retarded), and the high injection speed is suitable for the low engine speed range where the engine speed is low. injection rate (ratio of fuel injection amount to unit rotation angle of the camshaft 10, that is, (temporal change rate of injection amount) can be obtained.

[0026] Conversely, rotate the timing control rod 22 counterclockwise to remove the control slide. When the valve 18 is moved downward, the prestroke becomes smaller and the injection timing becomes earlier. (advance angle), it is possible to obtain a lower injection rate suitable for the high speed rotation range. Ta However, the absolute amount of injection increases.

[0027] Furthermore, the plunger 5 slidably inserted into the lower plunger barrel 4 is The rotational driving force of the engine (not shown) is transmitted through the camshaft 10 and the cam 11. By receiving the inside of the lower plunger barrel 4 and the upper plunger barrel 6, It reciprocates, sucks the fuel in the fuel reservoir chamber 25 into the fuel pressure chamber 8, and further Then, the fuel in this fuel pressure chamber 8 is fed under pressure from a fuel outlet 9 through an injection pipe (not shown). The liquid is injected from an injection nozzle (not shown).

[0028] That is, this plunger 5 connects to a fuel intake port that opens into the fuel reservoir chamber 25. A diametrical fuel intake/discharge hole 26 which is a A central communication hole 27 formed in the central axis direction so as to communicate with the The control inclined groove 28 and the opening of the control inclined groove 28 and the fuel intake/discharge hole 26 It has a vertical communication groove 29 that communicates between the sections.

[0029] Furthermore, the control sleeve 18 that is slidably fitted onto the plunger 5 has a , and a main injection cut-off port 30 is formed therethrough in the radial direction. This main injection cut-off port 30 is connected to the vertical movement of the plunger 5. According to shall be

[0030] The fuel reservoir chamber 25 is connected through the horizontal hole 24 formed in the pump housing 2. and communicates with the fuel inlet 31.

[0031] Furthermore, the control inclined groove 28 of the plunger 5 and the control sleeve 18 described above are In addition to the main injection cutoff port 30, the pilot injection For this purpose, a pilot spill slit 32 is formed in the plunger 5. In addition, a cut-off port 33 for pilot injection is formed in the control sleeve 18. Ru.

[0032] The pilot spill slit 32 communicates with the fuel intake and exhaust hole 26 of the plunger 5. In order to horizontally on the outer surface on the same side as 28, with a constant width and over a predetermined circumferential length. form.

[0033] As will be described later, the pilot spill slit 32 as shown in FIG. When forming the jet horizontally and with a constant width, the pilot injection amount and and the interval between main injection and pilot injection is not variable depending on the load. This is a case of a design in which this is constant.

[0034] The pilot injection cut-off port 33 is connected to this pilot spill slip. This is applied to the control sleeve 18 at a position opposite to the plunger 5 in the axial direction. It forms the

[0035] However, this pilot injection cut-off port 33 is not connected to the main injection cup. This is formed closer to the lower end of the control sleeve 18 than the to-off port 30 is.

[0036] The operation of the fuel injection pump 1 configured as above will be explained. First, when the plunger 5 initially rises from the bottom dead center, the fuel intake/discharge hole 26 opens into the fuel reservoir chamber 25, and this fuel reservoir chamber 25 and the fuel pressure chamber 8 are used for fuel intake and discharge. Because they communicate through the hole 26 and the center communication hole 27, the fuel in the fuel pressure chamber 8 is The pressure does not increase and the delivery valve 7 remains closed.

[0037] When actually delivering fuel, the plunger 5 rises and its fuel intake/discharge hole 26 The fuel in the fuel pressure chamber 8 is closed by the lower end of the control sleeve 18. When the pressure increases and the injection pressure exceeds the delivery valve opening pressure, the delivery valve 7 Open the fuel outlet 9 to send fuel from the fuel outlet 9 (pressure feeding of fuel), and pilot injection starts. It will be done.

[0038] Next, the pilot spill slit 32 of the plunger 5 and the control sleeve By communicating with the pilot injection cut-off port 33 of No. 18, the fuel pressure The pilot injection is caused by the fuel in the chamber 8 spilling into the fuel storage chamber 25. finish.

[0039] When the plunger 5 further rises, the pilot spill slit 32 and the pipe The fuel pressure chamber 8 is cut off by cutting off the communication with the lot injection cutoff port 33. is closed again and main injection begins.

[0040] The interval from the end of the above pilot injection to the start of this main injection is the interval. It is △A.

[0041] By engaging the control inclined groove 28 with the main injection cut-off port 30, Main injection ends.

[0042] In other words, the plunger 5 further rises and the control valve communicates with the fuel intake/discharge hole 26. The inclined groove 28 communicates with the main injection cutoff port 30 of the control sleeve 18. , a main injection cut-off port 30, a control inclined groove 28, a communication vertical groove 29, Main injection cut-off port via fuel intake/discharge hole 26 and center communication hole 27 30 and the fuel pressure chamber 8, the fuel in the fuel pressure chamber 8 flows into the fuel reservoir chamber. 25, the pressure of the fuel in the fuel pressure chamber 8 decreases, and the delivery valve 7 is closed. , injection (pumping of fuel) is completed.

[0043] Note that FIG. 3 is a graph showing the injection amount with respect to the rotation angle of the cam 11, The pilot injection described above starts first (pilot injection amount Qpilot), and the pilot The spill slit 32 faces the pilot injection cut-off port 33, and both Interval △A is formed only while in communication state, and then main injection is performed. (main injection amount Qmain).

[0044] Note that when the plunger 5 descends, the fuel flows from the fuel reservoir chamber 25 into the fuel pressure chamber 8. Fuel is sucked through the fuel intake/discharge hole 26 due to the negative pressure of the fuel.

[0045] Furthermore, by rotating the timing control rod 22, the control speed is Move the leaf 18 up and down to control the prestroke, that is, the timing of fuel injection. can be controlled.

[0046] Next, FIG. 4 shows the lift of the plunger 5 relative to the position of the injection amount adjusting rod 17. 2 is a graph showing the relationship between the amount of lift (cam lift).

[0047] The pilot spill slit 32 is formed horizontally on the outer surface of the plunger 5. Therefore, the pilot injection amount Q is adjusted regardless of the position of the injection amount adjustment rod 17. pilot is constant, and the main injection amount Qmain depends on the position of the injection amount adjustment rod 17. It increases and decreases depending on the time.

[0048] In addition, since the pilot spill slit 32 is formed with a constant width, The interval ΔA is constant regardless of the position of the radiation amount adjustment rod 17.

[0049] Therefore, the factors that determine the pilot injection amount are as follows: A distance L1 from the fuel intake/discharge hole 26 of the carrier 5 to the pilot spill slit 32; From the lower end of the control sleeve 18 to the lower end of the pilot injection cut-off port 33. The three factors are the distance L2 at , and the axial width W of the pilot spill slit 32. be.

[0050] Also, the interval △A between pilot injection and main injection is The above width W of the spill slit 32 and the width W of the pilot injection cut-off port 33 It is determined by the sum with the diameter D1.

[0051] Therefore, the pilot injection amount Qpilot and the interval △A are In order to make it variable depending on the amount of fuel injection, the shape of the pilot spill slit 32 must be changed. Whether the state of formation is horizontal (that is, the inclination angle of the pilot spill slit 32) , and whether the upper edge 32A and lower edge 32B are parallel or inclined (i.e., If the mutual inclination angle of the upper edge 32A and lower edge 32B is determined, this can be done arbitrarily. It can be seen that this can be made variable.

[0052] Next, set the pilot injection amount Qpilot and interval △A to the load (fuel injection Regarding the shape of the pilot spill slit to make it variable depending on the amount of radiation A specific example will be explained.

[0053] First, FIG. 5 shows a first specific example showing the formation state of the pilot spill slit. FIG. 6 is an explanatory diagram showing the plunger 40 according to the invention, and FIG. This is a graph of the injection amount Qpilot, the interval △A, and the main injection amount Qmain. .

[0054] As shown in FIG. 5, the pilot spill slit 41 of the plunger 40 is The upper edge 41A and the lower edge 41B are parallel to each other (that is, the distance between them is (constant), the pilot spill slit 41 as a whole is slightly below the horizontal state. This is formed in an inclined state.

[0055] Therefore, as shown in FIG. As the plunger 40 rotates to the right in the figure, the piston Engagement between the lot spill slit 41 and the pilot injection cut-off port 33 is delayed, so the pilot injection amount Qpilot increases. In other words, as the main injection amount Qmain increases, the pilot injection amount Qpilot also increases. To increase.

[0056] Further, the pilot spill slit 41 has an upper edge 41A and a lower edge 41B. are parallel to each other and the width W between them is constant, so the interval △A is constant. be.

[0057] Next, FIG. 7 shows a second specific example showing the formation state of the pilot spill slit. FIG. 6 is an explanatory diagram showing a plunger 50 according to This is a graph of main injection amount Qpilot, interval △A, and main injection amount Qmain. Ru.

[0058] As shown in FIG. 7, the pilot spill slit 51 of the plunger 50 is The upper edge 51A and the lower edge 51B are parallel to each other, and the pilot spill slit is The entire cut 51 is formed in a state in which it is inclined slightly upward from the horizontal state. It is.

[0059] Therefore, as shown in FIG. Along with this, the pilot spill slit 51 and the pilot injection cut-off Since the engagement with the port 33 becomes faster, the pilot injection amount Qpilot decreases. In other words, as the main injection amount Qmain increases, the pilot injection amount Qpilot decreases.

[0060] Further, the pilot spill slit 51 has an upper edge 51A and a lower edge 51B. are parallel to each other and the width W between them is constant, so the interval △A is constant. be.

[0061] Next, FIG. 9 shows a third specific example showing the formation state of the pilot spill slit. FIG. 10 is an explanatory diagram showing a plunger 60 according to In the graph of jet injection amount Qpilot, interval △A, and main injection amount Qmain. be.

[0062] As shown in FIG. 9, the pilot spill slit 61 of the plunger 60 In this case, the upper edge 61A is formed in a horizontal state, and the lower edge 61B is formed in a high The upper edge 61A and the lower edge 61B are formed so as to be inclined downward in the load state direction. By forming the pilot spill slit 61 in an inclined state, the tip of the pilot spill slit 61 can be The width becomes thicker as it approaches .

[0063] Therefore, as shown in FIG. 10, the upper edge 61A is formed horizontally. The pilot injection amount Qpilot will increase or decrease depending on the position of the injection amount adjustment rod 17. No, constant. In other words, the pilot injection amount Qpilot remains the same regardless of the increase or decrease in the main injection amount Qmain. It is fixed.

[0064] In addition, as the position of the injection amount adjustment rod 17 becomes high load, the pilot Engaged state of tospilling slit 61 and pilot injection cutoff port 33 is maintained for a long time, the interval △A increases as the main injection amount Qmain increases. It increases.

[0065] Finally, FIG. 11 shows a fourth example showing how the pilot spill slit is formed. An explanatory diagram showing a plunger 70 according to an example, FIG. Graph of lot injection amount Qpilot, interval △A, and main injection amount Qmain It is.

[0066] As shown in FIG. 11, the pilot spill slit 71 of the plunger 70 In this case, the upper edge 71A is formed horizontally, and the lower edge 71B is elevated. The upper end edge 71A and the lower end edge 71B are formed to be inclined upward in the load state direction. The tips of the pilot spill slits 71 are formed so that they are inclined to each other. The width tapers as it approaches the bottom.

[0067] Therefore, as shown in FIG. 12, the upper edge 71A is formed horizontally. The pilot injection amount Qpilot will increase or decrease depending on the position of the injection amount adjustment rod 17. No, constant. In other words, the pilot injection amount Qpilot remains the same regardless of the increase or decrease in the main injection amount Qmain. It is fixed.

[0068] In addition, as the position of the injection amount adjustment rod 17 becomes high load, the pilot Engaged state of tospil slit 71 and pilot injection cutoff port 33 As the time becomes shorter, the interval △A increases as the main injection amount Qmain increases. It decreases.

[0069] In short, the inclination of the pilot spill slit 32 (41, 51, 61, 71) Oblique angle, its upper edge 32A (41A, 51A, 61A, 71A), and lower edge 32B (41B, 51B, 61B, 71B) in a predetermined combination of mutual inclination angles By selecting with , pilot injection amount Qpilot, interval △A, main The injection amount Qmain can be set arbitrarily, depending on the request from the engine. can be set selectively.

[0070] However, in this invention, the pilot injection amount and the input An engine that has a variable terval that corresponds to the reciprocating speed of the plunger. For the rotation speed, the pilot injection amount Qpilot and interval △A are variable. It's not something you do.

[0071] In addition, in this invention, the pilot spill slit is formed to a predetermined length. As a result, the pyrotechnic force is reduced at both prestroke values in the low and high load ranges. Although it is possible to perform a jet injection, pilot spill occurs due to the rotation of the plunger. By taking advantage of the change in the end position of the slit in the circumferential direction, By limiting the circumferential position of the pilot spill slit, the pilot It is also possible to limit the load range in which injection occurs. In other words, pilot injection should not be performed at low loads, or vice versa. It is also possible not to perform pilot injection at high loads.

[0072] Furthermore, in this invention, the fuel intake/discharge hole formed in the plunger, the control The relative position of inclined grooves or vertical communication grooves, etc., or directly to any of these positions. Regarding whether to connect and connect to form a pilot spill slit, and whether the pilot Various modifications can be made to the shape of the tosspilling slit, etc.

[0073] Of course, the control sleeve has a main injection cover located opposite to the control inclined groove. In addition to forming a cut-off port, the position opposite to the pilot spill slit is A pilot spill slit shall be formed at the position.

[0074]

[Effect of the idea]

As explained above, according to the present invention, it has a mechanism that makes the prestroke variable. For fuel injection pumps that use Each control sleeve has a cut-off port for pilot injection. It is possible to perform pilot injection even at these prestroke values. At the same time, by changing the shape of the pilot spill slit, Pilot injection amount relative to load (fuel injection amount), and pilot injection and main injection amount The interval between injections can be easily adjusted and set.

[0075]

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a fuel injection pump 1 with a variable prestroke mechanism according to an embodiment of the present invention.

FIG. 2 is a front view of main parts of the plunger 5 and control sleeve 18 in the same embodiment.

FIG. 3 is a graph showing the injection amount versus the rotation angle of the cam 11.

FIG. 4 is a graph showing the relationship between the lift amount (cam lift) of the plunger 5 and the position of the injection amount adjusting rod 17.

FIG. 5 is a plunger 4 according to a first specific example showing the formation state of a pilot spill slit 41 in the present invention.
FIG.

[Figure 6] Pilot injection amount Q by plunger 40
pilot, interval △A, and main injection amount Qmain
This is a graph of

FIG. 7 is a plunger 5 according to a second specific example showing the formation state of the pilot spill slit 51 in the present invention.
It is an explanatory diagram showing 0.

[Fig. 8] Pilot injection amount Q by plunger 50
pilot, interval △A, and main injection amount Qmain
This is a graph of

FIG. 9 is a plunger 6 according to a third specific example showing the formation state of the pilot spill slit 61 in the present invention.
It is an explanatory diagram showing 0.

[Fig. 10] Pilot injection amount Qpilot, interval △A, and main injection amount Qmai by plunger 60.
This is a graph of n.

FIG. 11 is an explanatory diagram showing a plunger 70 according to a fourth specific example showing the formation state of a pilot spill slit 71 in the present invention.

[Fig. 12] Pilot injection amount Qpilot, interval △A, and main injection amount Qmai by plunger 70.
This is a graph of n.

[Explanation of symbols]

1 Fuel injection pump 2 Pump housing 3 Vertical hole 4 Lower plunger barrel 5 Plunger 6 Upper plunger barrel 7 Delivery valve 8 Fuel pressure chamber 9 Fuel outlet 10 Camshaft 11 Cam 12 Tappet 13 Spring 14 Driving face 15 Injection amount adjustment sleeve 16 Protrusion 17 Injection amount adjustment rod 18 Control sleeve 19 Guide groove 20 Engagement groove 21 Guide pin 22 Timing control rod 23 Engagement portion 24 of timing control rod 22 Lateral hole 25 Fuel reservoir chamber 26 Fuel intake/discharge hole 27 Center communication hole 28 For control Inclined groove 29 Communication longitudinal groove 30 Main injection cut-off port 31 Fuel inlet 32 Pilot spill slit 32A Upper edge 32B of pilot spill slit 32 Lower edge 33 of pilot spill slit 32 Pilot injection cut-off port 40 Plunger 41 Pilot spill slit 41A Upper edge 41B of pilot spill slit 41 Lower edge 50 of pilot spill slit 41 Plunger 51 Pilot spill slit 51A Upper edge 51B of pilot spill slit 51 Lower edge 60 of pilot spill slit 51 Plunger 61 Pilot spill slit 61A Upper edge 61B of pilot spill slit 61 Lower edge 70 of pilot spill slit 61 Plunger 71 Pilot spill slit 71A Upper edge 71B of pilot spill slit 71 Lower edge of pilot spill slit 71 Qpilot Pilot injection Quantity Qmain Main injection amount ΔA Interval between main injection and pilot injection L1 Distance L2 from the fuel intake/discharge hole 26 of the plunger 5 to the pilot spill slit 32 From the lower end of the control sleeve 18 to the pilot injection cut-off port 33 Distance to the lower end W Width in the axial direction of the pilot spill slit 32 D1 Diameter of the pilot injection cut-off port 33

Claims (1)

[Scope of utility model registration request] 1. A plunger barrel having a fuel pressure chamber; a plunger that reciprocates within the plunger barrel to suck fuel from a fuel reservoir chamber into the fuel pressure chamber through a fuel intake/discharge hole; A fuel injection pump comprising: a control sleeve slidably fitted onto the plunger; and a pre-stroke of the plunger is adjusted by changing the relative position of the control sleeve and the plunger in the axial direction. A control inclined groove communicating with the fuel intake/discharge hole is formed on the outer surface of the plunger, and a main injection cut-off port is formed in the control sleeve at a position facing the control inclined groove in the axial direction, and A pilot spill slit communicating with the fuel intake/discharge hole of the plunger is formed on the outer surface of the plunger, and a pilot injection cut-off port is formed in the control sleeve at a position axially opposed to the pilot spill slit. The fuel is formed separately from the main injection cut-off port, and further configured to adjust the inclination angle of the pilot spill slit from a horizontal state or the mutual inclination angle of its upper and lower edges. injection pump.