JPH1162762A - Distributing type fuel injection pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distributing type fuel injection pump capable of preventing the fretting corrosion of a close-fitted part of a cylinder and a support member by maintaining the smooth rotating operation of a distributor rotor. SOLUTION: A valve body 58 is inserted closely into a through hole 12a provided in a cylinder 12 at a specified clearance so as to realize the smooth rotating operation of a distributor rotor 13. Also the valve body 58 is provided with an inlet side fuel path 72a communicated to a high pressure fuel chamber 71, an outlet side fuel path 72b communicated to a fuel gallery 14, a pressure balance hole 65 opposed in radial direction to the inlet side fuel path 72a, an annular groove 66 formed in circumferential direction so that it is communicated through the inlet side fuel path 72a and pressure balance hole 65, and a slit 79 formed in the outer peripheral surface at the end part on the side opposite to a needle valve, i.e., on the side opposite to a distributor rotor. By this, a pressure balance between the inner wall of the through hole 12a and the outer wall of the valve body 58 is improved, thus preventing the fretting wear.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine (hereinafter referred to as "internal combustion engine").
The present invention relates to a distribution type fuel injection pump for an "internal combustion engine".

[0002]

2. Description of the Related Art Conventionally, an overflow valve is mounted on a distribution head which accommodates a cylinder rotatably supporting a distribution rotor together with a housing, and an inner cam provided with a valve seat on the distribution head on which a valve member of the overflow valve can be seated. 2. Description of the Related Art A distribution type fuel injection pump is known. In such a structure in which the overflow valve is attached to the distribution head containing the cylinder and the valve seat is provided, the length of the overflow passage from the fuel pressurizing chamber to the overflow valve is increased, so that the fuel pressurization volume is increased and the plunger is increased. The fuel pressurization efficiency is reduced. In addition, when the length of the overflow passage from the fuel pressurization chamber to the overflow valve is increased, the pressure loss in the overflow passage increases, so that when the fuel overflows, the amount of overflow fuel per unit time decreases, and the fuel is injected. There is a problem that cutting becomes worse.

[0003]

For this reason, in a recent distribution type fuel injection pump, various techniques have been considered to minimize the useless pumping volume and improve the pumping efficiency of the pump. As one of them, there is a technique in which a valve member of an overflow valve is directly disposed on a cylinder rotatably supporting a distribution rotor. According to this technique, the opening / closing portion of the overflow passage by the valve member can be brought closer to the distribution rotor, and the overflow passage can be shortened.

However, when the valve member of the overflow valve is directly disposed on the cylinder as described above, the cylinder tends to be distorted when the overflow valve is fastened and fixed. There is a possibility that the clearance between the rotor and the rotor is lost, resulting in poor rotation. Also, when the cylinder and the support member that supports the valve member are integrated, the pressure balance between the cylinder and the support member is poor,
The support member receives side pressure due to the high-pressure fuel inside the distribution rotor, and the support member is repeatedly pressed to one side at the fitting portion between the cylinder and the support member, causing fretting wear due to oil film breakage, and the fitting portion is fixed. There was a problem.

The present invention has been made to solve such a problem, and it is an object of the present invention to maintain smooth rotation of a distribution rotor and prevent fretting wear of a fitting portion between a cylinder and a support member. It is an object of the present invention to provide a distribution-type fuel injection pump capable of performing the above-described steps.

[0006]

According to a first aspect of the present invention, there is provided a distribution type fuel injection pump which rotates in synchronization with an internal combustion engine and supports a plunger so that the plunger can reciprocate in a radial direction. An overflow passage that rotatably supports the rotor and allows high-pressure fuel in the fuel pressurization chamber to overflow into the low-pressure chamber, a cylinder having a hole crossing the overflow passage, and an overflow passage formed in the cylinder; By providing an overflow valve having a valve member capable of intermittently interposing the valve member, and a support member that is inserted into a hole formed in the cylinder and slidably supports the valve member, from the fuel pressurization chamber to the overflow valve. The fuel passage length is shortened. For this reason, the fuel pressurization volume is reduced, and the fuel pressurization efficiency of the plunger is improved. Furthermore, the pressure loss at the time of overflow is reduced by shortening the length of the fuel passage from the fuel pressurizing chamber to the overflow valve, so that the fuel overflows quickly and the fuel injection is improved.

Further, the support member has an inlet side fuel passage communicating with the overflow passage, an outlet side fuel passage communicating with the low pressure chamber,
A pressure balance hole formed at a position radially opposed to the inlet side fuel passage, an annular groove formed circumferentially to communicate the inlet side fuel passage with the pressure balance hole, and a hole formed in the cylinder. And a notch formed on the outer peripheral surface facing the inner wall of the portion. For this reason, the radial pressure balance between the inner wall of the bore of the cylinder and the outer wall of the support member is improved by the pressure balance hole, the circumferential pressure balance is improved by the annular groove, and the axial pressure balance is notched. Better in some parts. Therefore, the support member can be prevented from being pressed against the inner wall of the hole of the cylinder, and fretting wear between the inner wall of the hole of the cylinder and the outer wall of the support member can be prevented.

According to the distribution type fuel injection pump of the second aspect of the present invention, the notch is formed at the end of the support member on the side opposite to the valve member and on the outer peripheral surface on the side opposite to the distribution rotor. The pressure balance between the inner wall of the hole and the outer wall of the support member is further improved, and fretting wear between the inner wall of the hole of the cylinder and the outer wall of the support member can be reliably prevented.

According to the distribution type fuel injection pump according to the third aspect of the present invention, a predetermined clearance is provided between the inner wall of the hole of the cylinder and the outer wall of the support member to such an extent that a high-pressure seal can be secured. . Therefore, when the cylinder and the support member are integrally formed, the opening / closing portion of the overflow passage formed by the valve member can be brought closer to the distribution rotor, and the overflow passage can be shortened. Further, in order to insert and support the support member into the hole of the cylinder with a predetermined clearance,
The smooth rotation of the distribution rotor can be maintained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a distribution type fuel injection pump according to an embodiment of the present invention. As shown in FIG. 5, a drive shaft 1 of a fuel injection pump 10 driven by an engine (not shown) is rotatably supported by a pump housing 4 via a bearing 2 and a journal 3. The vane-type feed pump 5 rotates together with the drive shaft 1, sucks and pressurizes fuel through a fuel tank (not shown), a fuel inlet 6, and a suction port 7, and forms a low-pressure chamber through a discharge pipe 8 through an external pipe (not shown). The fuel is delivered to the fuel gallery 14. The suction port 7 and the discharge port 8 of the vane type feed pump 5 are connected via a pressure adjusting valve (not shown) so that the discharge pressure is adjusted.

A cylinder 12 is fixed to the inner wall of the distribution head 11, and a distribution rotor 13 is rotatably supported on the inner wall of the cylinder 12. The distribution rotor 13 is connected to the drive shaft 1 in the axial direction, and rotates together with the drive shaft 1. A pair of sliding holes orthogonal to each other are formed in the distribution rotor 13,
A pair of plungers 20 are slidably supported in an oil-tight manner on the inner wall of the distribution rotor 13 forming the respective sliding holes, and the inner end face of each plunger 20 and the distribution rotor 13 forming the respective sliding holes are formed. A fuel pressurizing chamber 21 is defined by the inner wall.

A shoe 2 is provided at the outer end of each plunger 20.
2, a roller 23 is rotatably held by each shoe 22. An inner cam ring 24 having a cam surface having a plurality of cam ridges on the inner peripheral surface corresponding to the number of engine cylinders is disposed outside the roller 23, and the inner ring 23 is rotated based on the rotation of the distribution rotor 13. By sliding on the cam surface on the inner peripheral surface of the roller
Reciprocates in the radial direction of the inner cam ring 24 along the cam surface.
Is transmitted to The plunger 20 is connected to the distribution rotor 13
, The volume of the fuel pressurizing chamber 21 increases, and fuel is sucked into the plunger chamber 21. As the plunger 20 moves radially inward of the distribution rotor 13, the volume of the plunger chamber 21 decreases, and the fuel is pressurized. The inner cam ring 24 is rotatably supported on the inner wall of the pump housing 4, and includes a timer device 40.
Can adjust the rotation angle.

The distribution rotor 13 has a communication passage 17 communicating with the fuel pressurizing chamber 21 and a distribution passage 16 branched from one end of the communication passage 17. An annular groove is formed in the inner wall of the cylinder 12, and the communication passage 17 communicates with an annular gallery 68 formed by the groove and the outer peripheral wall of the distribution rotor 13. The distribution passage 16 communicates with the distribution passages 25 provided in the cylinders 12 by the number of the cylinders of the engine as the distribution rotor 13 rotates. Distribution passage 2
5 is always in communication with a distribution passage 26 provided in the distribution head 11, and high-pressure fuel is supplied from the distribution passage 26 through a delivery valve 30 to an injector (not shown).

A pulsar 41 having projections 41a provided at predetermined intervals is fitted on the outer peripheral wall of the drive shaft 1, and a rotation angle sensor for converting the approach or separation of the projections 41a into a pulse signal on the inner cam ring 24. 42 is fixed.
That is, by counting the number of pulses output by the rotation angle sensor 42, the drive shaft 1 with respect to the inner cam ring 24 is counted.
, That is, the rotation angle of the distribution rotor 13 with respect to the inner cam ring 24 can be detected.

The distribution head 11 has an overflow valve 6
The overflow valve 62 is provided with a passage 63 communicating with the fuel gallery 14 when the electromagnetic spill valve 50 as an overflow valve provided in the pump housing 4 is opened.
It is provided in order to reduce the pressure of a part of the overflow fuel inside and return the fuel to the fuel tank. Next, a detailed configuration of the electromagnetic spill valve 50 will be described with reference to FIGS.

As shown in FIG. 1, the electromagnetic spill valve 50 of this embodiment functions as a normally open valve (normally open valve), and its solenoid 51 is fixedly disposed on the pump housing 4 to adjust the flow rate. The part 52 is arranged so as to penetrate the cylinder 12. Solenoid part 51
, The solenoid housing 53 has a substantially cylindrical shape and is screwed into the screw hole 4a of the pump housing 4. A stop ring 55 is mounted on the bottom surface of the screw hole 4a, and the lower edge of the solenoid housing 53 is received by the stop ring 55. A lift stopper 56 is provided at the lowermost part of the solenoid housing 53.

A stator 44 is provided inside the solenoid housing 53, and a coil 46 is provided in an annular coil insertion groove 45 formed in the stator 44. In the through hole 47 formed in the center of the stator 44,
A high-hardness bush 48 is press-fitted and fixed, and a push rod 60 connected to an armature 49 is disposed in the bush 48 so as to be slidable in the vertical direction in the figure.

Above the armature 49, there is provided a cover 61 which is in close contact with the inner peripheral surface of the solenoid housing 53, and an armature chamber 62 is formed on the lower surface of the cover 61. At the center of the lower surface of the cover 61, a stopper 63 for regulating the movable range of the armature 49 is provided. Armature 49 and cover 61 include
Signal input terminal 64 for inputting an external electric signal
Are provided in a penetrating state, and the signal input terminal 64 is electrically connected to the coil 46 via a lead wire.

In the flow rate adjusting section 52, a valve body 58 as a support member having a substantially cylindrical shape is inserted into a through hole 12a as a hole formed in the cylinder 12, and the valve body 58 and the through hole 12a are formed. Has a small clearance of about several μm. Here, the through hole 12a
Extends in a direction substantially perpendicular to the direction of the rotation axis of the distribution rotor 13 and communicates with the fuel gallery 14 and a communication passage 69 formed in the cylinder 12 to be described later. The upper end of the valve body 58 is in contact with the lift stopper 56. A slide hole 70 for slidably holding a needle valve 59 as a valve member is formed in the valve body 58. The slide hole 70 communicates with an annularly formed high-pressure fuel chamber 71. I have.

The valve body 58 has an inlet fuel passage 72a communicating with the high-pressure fuel chamber 71 and an outlet fuel passage 72b communicating with the fuel gallery 14. 2 and 3, a pressure balance hole 65 is formed in the valve body 58 at a position radially opposed to the inlet side fuel passage 72a. Further, an annular groove 66 is formed in the outer peripheral portion of the valve body 58 so as to communicate the inlet side fuel passage 72a and the pressure balance hole 65. At the end of the valve body 58 on the side opposite to the needle valve and on the side opposite to the distribution rotor, that is, at the end farther from the position where the needle valve 59 is slidably supported and on the outer peripheral surface farther from the distribution rotor 13 As shown in FIG. 2 and FIG. 4, a slit 79 is formed as a notch.
Here, the pressure balance hole 65 is provided for improving the radial pressure balance between the outer wall of the valve body 58 and the inner wall of the through hole 12a, and the annular groove 66 is provided with a circumferential pressure balance. The slit 79 is provided to improve the axial pressure balance.

The needle valve 59 is connected to the lower end of the push rod 60 and is always urged by the return spring 73 in the valve opening direction (upward in FIG. 1). The lift stopper 56 is provided with a plurality of notches 56a, and a fuel gallery pressure acts on an upper space of the needle valve 59 (hereinafter, referred to as a needle valve upper chamber 77) via the notches 56a. Further, a small diameter portion 59a is provided in a part of the needle valve 59, and a space below the needle valve 59 (hereinafter, referred to as a needle valve lower chamber 78) is formed by the small diameter portion 59a. Here, the needle valve lower chamber 78 is always in communication with the fuel gallery 14 via the outlet side fuel passage 72b, so that the fuel gallery pressure acts on the needle valve lower chamber 78 as well as the needle valve upper chamber 77. It has become. The state shown (excitation state)
Then, the needle valve 59 is connected to the valve seat 58a of the valve body 58.
, And the electromagnetic spill valve 50 is in a closed state.

As shown in FIG. 1, the axial center of the needle valve 59 exists on an imaginary plane perpendicular to the axial center of the distribution rotor 13, and the axial center of the needle valve 59 and the extension of the axial center of the distribution rotor 13 intersect. I haven't. An annular groove 1 is provided on the inner wall of the cylinder 12 which rotatably supports the distribution rotor 13.
2b are provided, and an annular gallery 68 is formed by the groove 12b and the outer peripheral wall of the distribution rotor 13. Further, the cylinder 12 has an annular gallery 68 and a valve body 58.
Communication passage 6 for communicating with the fuel passage 72a on the inlet side
9 are formed. That is, the high-pressure fuel chamber 71 and the fuel pressurizing chamber 21 are connected to the inlet-side fuel passage 72a and the communication passage 69.
And the annular gallery 68 and the communication path 17 are always in communication.

The operation of the electromagnetic spill valve 50 will be described in detail. In the demagnetized state of the coil 46, a predetermined amount of air gap is held between the upper surface of the stator 44 and the lower surface of the armature 49, The connected needle valve 59 is held at the valve open position. That is, the needle valve 59 is separated from the valve seat 58a of the valve body 58. At this time, the fuel gallery 14 includes an inlet-side fuel passage 72a, an outlet-side fuel passage 72b, and a high-pressure fuel chamber 71.
, The communication passage 69, the annular gallery 68, and the communication passage 17 to communicate with the fuel pressurizing chamber 21.

On the other hand, when the coil 46 is excited, the armature 49 is attracted to the stator 44 and the air gap decreases. Then, the needle valve 59 moves to the valve closing position and sits on the valve seat 58a of the valve body 58. At this time, the fuel gallery 14 and the fuel pressurizing chamber 21 are shut off. A spring seat 75 fixed to the pump housing 4 is provided below the valve body 58, and a pressing spring 74 is provided between the spring seat 75 and the lower end of the valve body 58. The pressing spring 74 has a spring force larger than the sum of the magnetic force when the coil 46 is excited and the spring force of the return spring 73 for urging the needle valve 59 to the open position. The spring chamber 76 of the return spring 73 and the fuel gallery 14 are communicated via a passage 67.

Further, the pump housing 4 is provided with an accumulator 80 for attenuating a pressure pulsation generated at the time of fuel overflow. This accumulator 80
Housing part 8 formed in part of pump housing 4
1, a piston 82 facing the fuel gallery 14, a lid 83 fixed to the upper end of the housing section 81, and a compression coil spring 84 having both ends in contact with the lid 83 and the piston 82, respectively. I have. The piston 82 is supported on the inner wall of the housing portion 81 so as to be able to reciprocate in the vertical direction in the figure. Hereinafter, the operation of the fuel injection pump 10 will be described.

(1) Suction stroke When the power to the solenoid 51 of the electromagnetic spill valve 50 is turned off, the needle valve 59 is separated from the valve seat 58a of the valve body 58 by the urging force of the return spring 73. That is, the electromagnetic spill valve 50 is in the closed position, and the fuel gallery 14 and the high-pressure fuel chamber 71 are in communication. At this time, as the plunger 20 moves radially outward of the distribution rotor 13 with the rotation of the distribution rotor 13, the volume of the fuel pressurizing chamber 21 increases, and the pressure of the fuel pressurizing chamber 21 decreases. Then, the fuel filled in the fuel gallery 14 is supplied to the needle valve 59 and the valve seat 58.
Then, the air is sucked into the fuel pressurizing chamber 21 through a predetermined suction passage. The distribution passage 25 is closed by an outer peripheral wall of the distribution rotor 13. In this case, the inlet side fuel passage 72a, the communication passage 69, and the annular gallery 68
And the communication passage 17 correspond to a fuel suction passage.

(2) Pressure Feeding Process When the distribution rotor 13 further rotates and energization of the solenoid portion 51 of the electromagnetic spill valve 50 is turned on at a predetermined timing, the needle valve 59 is turned on by the magnetic force generated by the solenoid portion 51. It moves to the valve closing position against the urging force of the compression coil spring 73. That is, the needle valve 59 is seated on the valve seat 58a of the valve body 58, and the communication between the fuel gallery 14 and the high-pressure fuel chamber 71 is cut off. The distribution rotor 1
3 further rotates, and the roller 23 is moved to the inner cam ring 24.
When the plunger 20 starts to move inward in the radial direction, the fuel in the fuel pressurizing chamber 21 is pressurized.
The fuel pressurized in the fuel pressurizing chamber 21 becomes a certain pressure or more,
When the distribution passage 16 and the distribution passage 25 communicate with each other, the high-pressure fuel in the fuel pressurizing chamber 21 passes through the communication passage 17, the distribution passage 16,
The fuel is supplied from the delivery valve 30 to the injector via the distribution passage 25 and the distribution passage 26.

(3) Spillover When the power supply to the solenoid 51 of the electromagnetic spill valve 50 is turned off during the pumping stroke, the needle valve 59 is moved from the valve seat 58a of the valve body 58 by the urging force of the compression coil spring 73. The fuel gallery 14 and the high-pressure fuel chamber 71 communicate with each other. Then, the high-pressure fuel in the fuel pressurizing chamber 21 flows through the gap between the needle valve 59 and the valve seat 58a, and further flows into the fuel gallery 14 through a predetermined overflow passage. In this case, the communication passage 17, the annular gallery 68, the communication passage 69, and the inlet fuel passage 72a correspond to a fuel overflow passage. That is, the overflow passage also serves as the suction passage described in the suction stroke.

When the fuel overflows, the fuel pressure in the fuel pressurizing chamber 21 and the distribution passage 26 decreases, and the delivery valve 3
0 closes, thereby terminating the fuel supply to the injector. That is, the fuel injection ends. By repeating (1) the suction stroke, (2) the pumping stroke, and (3) the spillover stroke, the fuel injection amount and the fuel injection timing can be accurately controlled.

Hereinafter, the fuel injection pump 1 according to this embodiment will be described.
The effect of 0 will be described. Since the valve body 58 is inserted into the through hole 12a of the cylinder 12 with a predetermined clearance, unlike the case where the valve body 58 is press-fitted or caulked and fixed, for example, when the valve body 58 is tightened and fixed. The distortion of the cylinder 12 can be eliminated. As a result, a smooth rotation operation of the distribution rotor 13 can be realized. Further, the length of the fuel passage from the fuel pressurizing chamber 21 to the electromagnetic spill valve 50 is reduced. For this reason,
Since the fuel pressurization volume decreases, the fuel pressurization efficiency of the plunger 20 improves. Further, since the pressure loss at the time of overflow is reduced by shortening the length of the fuel passage, the fuel overflows quickly and the fuel injection is improved.

The high pressure fuel chamber 71 is provided in the valve body 58.
An inlet side fuel passage 72a communicating with the fuel gallery 14;
The fuel passage 72b communicates with the outlet and the fuel passage 7 on the inlet side.
A pressure balance hole 65 radially opposed to 2a, and an annular groove 66 communicating the inlet side fuel passage 72a and the pressure balance hole 65 in the circumferential direction are formed, and are far from the position where the needle valve 59 is slidably supported. A slit 79 was formed in the outer peripheral surface on one end and farther from the distribution rotor 13. For this reason, the radial pressure balance between the inner wall of the through hole 12a of the cylinder 12 and the outer wall of the valve body 58 is improved by the pressure balance hole 65, and the circumferential pressure balance is improved by the annular groove 66. Pressure balance becomes better due to the slit 79. Therefore, the valve body 58 can be prevented from being pressed against the inner wall of the through hole 12a, and fretting wear between the inner wall of the through hole 12a and the outer wall of the valve body 58 can be prevented.

A pressing spring 74 is provided at the lower end of the valve body 58, and the valve body 58 is pressed against the lift stopper 56 by the urging force of the pressing spring 74. Therefore, the material of the pump housing 4 (for example, aluminum) and the material of the cylinder 12 (for example, iron)
The valve body 58 is always kept in contact with the lift stopper 56 even if the distance between the pump housing 4 and the cylinder 12 changes due to the difference in temperature characteristics due to the difference in the thermal expansion coefficient between the valve body 58 and the pump housing 4. That is, when the dimensions of the pump housing 4 or the cylinder 12 change due to temperature characteristics or the like, the valve body 58 is displaced as an integral structure of the electromagnetic spill valve 50, and no distortion occurs in the cylinder 12 at that time. Therefore, it is possible to always realize the optimal injection amount control without causing a problem that the needle valve lift amount fluctuates and an adjustment error occurs.

Valve body 58 and needle valve 59
Are arranged in the fuel gallery 14 in a immersed state, and the fuel pressure in the fuel gallery 14 acts equally on the needle valve upper chamber 77 and the needle valve lower chamber 78.
Therefore, when fuel pressure pulsation occurs at the time of fuel overflow, the pressure pulsation acts on the needle valve upper chamber 77 and the needle valve lower chamber 78 almost without delay, and the appropriate opening / closing operation of the needle valve 59 is maintained. can do. Therefore, the vertical pressure balance of the needle valve 59 can be maintained in a stable state. Further, the bounce accompanying the opening / closing operation of the needle valve 59 can be attenuated early. As a result, running out of fuel by the electromagnetic spill valve 50 can be improved, and a highly accurate fuel injection operation can be realized not only in the low engine speed range but also in the high engine speed range.

Since the annular gallery 68 is provided by forming the groove 12b on the inner wall of the cylinder 12, the distribution rotor 13
The direction of the overflow fuel flow due to the rotational movement of the distribution rotor 13 is reduced as compared with the case where a groove is formed in the annular gallery. Therefore, fuel overflows stably regardless of the rotational position of the distribution rotor 13. In the embodiment of the present invention described above, the distribution type fuel injection pump in which the axial center of the valve member exists on an imaginary plane perpendicular to the axial center of the distribution rotor has been described. May be a distribution type fuel injection pump parallel to the axis center of the distribution rotor, or an overflow valve may be provided at a position intersecting a virtual plane perpendicular to the axis center of the distribution rotor.

In the embodiment of the present invention, the distribution type fuel injection pump for returning the overflow fuel to the fuel gallery has been described. However, in the present invention, it is possible to return the overflow fuel to the fuel tank. Further, in the embodiment of the present invention, the inward-opening type overflow valve which opens when the valve member is lifted is described. However, in the present invention, an outward-opening overflow valve which closes when the valve member lifts may be used. It is possible.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line II of FIG. 5, showing a distribution type fuel injection pump according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is a sectional view showing a distribution type fuel injection pump according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 drive shaft 4 pump housing 10 fuel injection pump (distribution type fuel injection pump) 12 cylinder 12a through hole (hole) 13 distribution rotor 14 fuel gallery (low pressure chamber) 16 distribution passage 17 communication passage 20 plunger 21 fuel pressurization chamber 50 Electromagnetic spill valve (overflow valve) 56 Lift stopper 58 Valve body (support member) 59 Needle valve (valve member) 65 Pressure balance hole 66 Annular groove 68 Annular gallery 71 High-pressure fuel chamber 72a Inlet side fuel passage 72b Outlet side fuel passage 73 Return spring 74 Pressing spring 75 Spring seat 79 Slit (notch)

Claims (3)

[Claims] 1. A distribution type fuel injection pump for pressurizing and feeding and distributing fuel drawn into a fuel pressurizing chamber from a fuel gallery via a suction passage by a plunger reciprocating according to a profile of a cam, and comprising: A distribution rotor which rotates in synchronization with the plunger and supports the plunger so as to be able to reciprocate in a radial direction; and an overflow which rotatably supports the distribution rotor and allows high-pressure fuel in the fuel pressurization chamber to overflow into the low-pressure chamber. A cylinder formed with a passage and a hole crossing the overflow passage; an overflow valve having a valve member capable of intermittently connecting the overflow passage formed in the cylinder; and communicating with the overflow passage. An inlet-side fuel passage, an outlet-side fuel passage communicating with the low-pressure chamber, a pressure balance hole formed at a position radially opposed to the inlet-side fuel passage, and the inlet-side fuel passage and the pressure balance hole. An annular groove formed in the circumferential direction so as to pass therethrough, and a notch formed on an outer peripheral surface facing an inner wall of the hole formed in the cylinder, and the notch is inserted into the hole and A distribution type fuel injection pump, comprising: a support member that slidably supports a valve member. 2. The distribution type fuel injection pump according to claim 1, wherein the notch is formed at an end of the support member on the side opposite to the valve member and on the outer peripheral surface on the side opposite to the distribution rotor. . 3. The distribution type fuel injection pump according to claim 1, wherein a predetermined clearance is provided between the inner wall of the hole and the outer wall of the support member, so that a high-pressure seal can be secured. .