JPH10288111A - Distributor fuel injection pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent thermal deformation of a slidly contacting surface, also the sticking of a rotation member, and concurrently suppress playing in the axial direction of the rotation member, by unifying the temperature distribution as much as possible in a rotation member or in a member supporting the rotation member. SOLUTION: A space 28, facing the end part of a rotation member 6, is provided on a distributor head part, and fuel in a fuel chamber 5 is overflowed via the space 28. A groove 55, to be filled with the fuel in a pump inside, is provided on a housing 2b constituting the distributor head part. The space 28 or the groove 55 is filled with fuel, having temperature nearly same as that of fuel in the fuel chamber, to eliminate the deviation of temperature distribution in a rotor 6 or a valve part 7. An orifice 37 and a check valve 36 are provided on a communication path 47, for communicating the fuel chamber 5 and the space 28, to lower the fuel pressure in the space 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head in which a rotatable member is rotatably inserted into a distributor head, compressed fuel is pressure-fed through the rotatable member, and compressed fuel is cut off at the time of cut-off. For example, a plunger is provided slidably in a radial direction on a rotating member that rotates in synchronization with the engine, and the plunger is formed on the rotating member by reciprocating with a cam ring. It is used as a so-called VR type injection pump that changes the volume of the compression chamber.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed a VR type fuel injection device disclosed in Japanese Patent Application Laid-Open No. 8-61180 for the purpose of preventing seizure of a sliding portion between a rotating member and a distributor head portion supporting the rotating member. doing.

[0003] The interior of the housing is defined by a low-pressure fuel region 5 formed from a fuel inlet 49 to a suction side of the feed pump 4 and a high-pressure fuel region 6 filled with fuel pressurized by the feed pump 4. , Rotating member (rotor 1
In order to cool the sliding contact portion between 6) and the member supporting the same, a flow path in which fuel flows from the high pressure fuel region 6 to the low pressure fuel region 5 is formed.

More specifically, a low-temperature low-pressure fuel in the low-pressure fuel region 6 flows from a space facing the tip of the rotating member (rotor 16), and a fuel flow path formed from the high-pressure fuel region 6 to the low-pressure fuel region 5. Are formed by passages 51 and 52 formed between a rotating member (rotor 16) and a member supporting the rotating member, and by moving fuel from the high-pressure fuel region 6 to the low-pressure fuel region 5 with the rotation of the rotating member. A configuration in which a sliding portion between a rotating member and a member supporting the rotating member is cooled, and a space in which high-pressure fuel flows is extended to around the tip of the rotating member, and is formed from a high-pressure fuel region 6 to a low-pressure fuel region 5. The orifices 57, 60, etc., which communicate the space formed around the tip of the rotating member with the low-pressure fuel region, and the like, are located near the sliding contact between the rotating member and the member supporting the same. Configuration so as to promote the cooling by causing fluidized actively fuel has been considered.

[0005]

However, in the pump configuration proposed above, the high-pressure side fuel region and the low-pressure side fuel region include a rotating member and a distributor head portion (a barrel or a member supporting the same) for inserting the rotating member. It can be said to be a very effective means when formed in close proximity to the sliding contact portion with the above. However, if such a configuration must be adopted, the degree of freedom in design is reduced, and In some cases, it is difficult to realize a simple configuration. For this reason, even in an injection pump in which the low-pressure fuel region is not provided close to the sliding portion between the rotating member and the distributor head, the rotation member and the member supporting the same (distributor head) are similarly connected. A configuration that suppresses image sticking is desired.

Further, according to the study of the present inventors, the cause of seizure between the rotating member and the member that supports the rotating member is that the oil film is broken due to the increased heat generation at the sliding contact portion or the discharge of the oil film. It has been found that not only the bias of the pressure but also the biased temperature distribution of the rotating member and the member supporting the rotating member.

That is, this type of fuel injection pump is usually
When the fuel is cut off, the compressed fuel flows out of the cut-off port of the rotating member into the fuel chamber swiftly. Higher than the high-pressure fuel region. At first, it was thought that this spilled fuel was stirred or convected and there was little variation in temperature.However, when we measured the temperature distribution of the fuel, the temperature around the sleeve of the rotating member was lower than that of other parts. It has been confirmed that the temperature of the rotating member is unbalanced between the portion exposed to the fuel chamber and the portion inserted into the distributor head, and However, it was recognized that temperature deviation occurred between the side facing the fuel chamber and the other part, and deformation occurred in the sliding contact surface between the rotating member and the member supporting the rotating member, causing seizure.

Therefore, the present invention can be applied to all fuel injection pumps having a basic structure for inserting a rotary member into a distributor head and spilling fuel at the time of cut-off inside the pump. It is an object of the present invention to prevent the thermal deformation of the sliding contact surface between the rotating member and the distributor head by making the temperature distribution of the rotating member and the member supporting the same as uniform as possible, and to prevent the stick of the rotating member.

In addition, in the case where a mechanism for suppressing the backlash in the axial direction of the rotating member is provided, it is required to achieve the above-mentioned object so as not to impair the function of the mechanism. .

[0010]

To achieve the above object, a distribution type fuel injection pump according to the present invention comprises a rotating member which rotates in synchronization with an engine, and a distributor head into which the rotating member is rotatably inserted. Part, a pump mechanism that varies the volume of the compression chamber with the rotation of the rotating member, and a sleeve that is slidably fitted to the rotating member inside a pump filled with fuel. A pressure oil supply passage for supplying fuel compressed in the compression chamber to a discharge passage of the distributor head portion, and a port connected to the pressure oil supply passage and opening on a peripheral surface covered with the sleeve, Is adjusted relative to the rotating member to adjust the opening timing of the port, so that the compressed fuel passes through the port when the fuel is cut off. In the premise of spilling inside the pump, a space facing the end of the rotating member is provided in the distributor head portion, and a path for allowing fuel inside the pump to overflow through the space is provided. Item 1).

In particular, when used as a VR type injection pump, a rotary member inserted through a barrel fixed to a housing is provided slidably in a radial direction of the rotary member, and a compression member formed on the rotary member is provided. A plunger for changing the volume of the chamber; and a cam ring provided concentrically around the rotating member and reciprocating the plunger in the radial direction of the rotating member with the rotation of the rotating member. It is assumed that the fuel injection pump is configured such that a portion of the member before the barrel insertion portion is exposed to the fuel chamber and a control sleeve is externally fitted to the exposed portion.

Therefore, in the case where the above-mentioned claim 1 is applied to the VR type injection pump, the distributor head is constituted by a pump housing, a barrel fixed to the pump housing, and the like, and compressed fuel is supplied to these members. Thus, a discharge passage for sequentially injecting the fuel through the rotating member and an overflow passage for discharging excess fuel are formed. Further, the space formed in the distributor head portion may be configured as a space surrounded by a housing and a barrel, and a pump mechanism is a plunger that reciprocates a compression chamber formed in a rotating member by a cam ring. It is configured to compress.

[0013] The port of the rotating member which is opened on the peripheral surface covered with the sleeve, even if it is used only as a cut-off port, is provided with a fuel intake port for guiding the fuel in the fuel chamber to the compression chamber during the intake process. It may be a dual purpose. In addition, as a configuration in which the fuel inside the pump overflows through the space of the distributor head, the fuel is not agitated or convected in the fuel chamber, so that the lower part of the fuel chamber where the heat is likely to be trapped and the distributor head are formed. The space may be communicated with the space, and the fuel in the portion of the fuel chamber that tends to become hot may be led to the space of the distributor head.

Therefore, even if the fuel inside the pump becomes high temperature due to the spill fuel at the time of cut-off, this fuel is sent to the space of the distributor head and overflows therefrom. The supporting member is exposed to the high-temperature fuel from the fuel chamber side inside the pump and the space side of the distributor head portion, and it is difficult for the rotating member and the member supporting the rotating member to have a biased temperature distribution. Therefore, the deformation of the rotor and the like due to the temperature difference is suppressed.

In order to communicate the inside of the pump with the space of the distributor head, it is desirable to provide a throttle mechanism in this communication path (claim 2). A check valve may be provided in a communication passage communicating with the space (claim 3), or a check valve may be provided at an outflow end where fuel that has passed through the space flows out (claim 4).

The throttle mechanism formed in the communication passage may simply form an orifice in the distributor head, or a plate with an orifice may be interposed at the inlet of the check valve. Further, the check valve may be constituted by a check valve using a ball valve or a flat valve.

Therefore, the fuel inside the pump is decompressed by the throttle mechanism and guided to the space in the distributor head, so that the fuel temperature in the space is not much different from the fuel temperature inside the pump, but is applied to the tip of the rotating member. The pressure will be reduced. Such a throttle mechanism reduces the biasing force more than necessary when a biasing force toward the space side is applied to the rotating member in order to stabilize the behavior of the rotating member, and the behavior of the rotating member is unstable. In addition, it is effective to prevent the pulsation of the fuel pressure generated inside the pump from being transmitted to the space, and to stabilize the rotating member also from this point.

Further, by providing the check valve, it is possible to quickly raise the pressure at the initial stage of starting the injection pump. In particular, the check valve is provided in the middle of the communication passage communicating the inside of the pump and the space of the distributor head. When the check valve is provided, the space in the distributor head is at atmospheric pressure, and in a configuration in which the check valve is provided at the outflow end, the fuel pressure in the space in the distributor head is set equal to the valve opening pressure of the check valve.

As another means for suppressing the variation in the temperature distribution between the rotating member and the distributor head, in the premise of the first aspect, the member constituting the distributor head is provided with a groove for filling the fuel inside the pump. (Claim 5). This groove may be combined with the structure of claim 1, and the above-described V
In the case of the R-type injection pump, an annular groove concentric with the rotating member is formed in the housing constituting the distributor head portion, and the annular groove is closed between the housing and a member to be assembled with the housing, so that the fuel inside the pump is removed. A configuration that satisfies is conceivable. Such a groove is desirably provided in the vicinity of the sliding contact surface between the rotating member and the member supporting the rotating member. However, even if the groove is provided in a somewhat separated place, the heat of the fuel is transmitted to the rotating member or the member supporting the rotating member. If it is done, it does not matter. When combined with the structure of claim 1, it is preferable to connect a groove to a communication passage that communicates the inside of the pump with the space, and to guide the fuel that moves to the space to the groove.

Therefore, the distributor head is provided with a groove, and the groove is filled with the fuel inside the pump. Therefore, the heat of the fuel is transmitted from the inside of the distributor head to the rotating member and the member supporting the same. The bias of the temperature of the rotating member and the supporting member can be reduced, and the deformation of these members due to the temperature difference can be suppressed.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, a main part of an inner-cam type distribution type fuel injection pump is shown. In the distribution type fuel injection pump 1, a drive shaft 3 is inserted into a pump housing 2, and one end of the drive shaft 3 is connected to the pump housing. 2 and receives driving torque from an engine (not shown), and rotates in synchronization with the engine (at half the engine speed). The other end of the drive shaft 3 extends into the pump housing 2.
A feed pump 4 is connected, and the fuel supplied from a tank (not shown) by the feed pump 4 is supplied to the fuel chamber 5 in a slightly pressurized state.

The pump housing 2 includes a housing member 2a into which the drive shaft 3 is inserted, a housing member 2b attached to the housing member 2a and provided with a delivery valve (not shown), and an open end of the housing member 2b. And a housing member 2c provided on an extension of the rotating member 6, and the fuel chamber 5 includes a supporting member 8 integrally formed with a barrel portion 7 fixed to a pump housing 2b. It is formed by a space surrounded by the housing 2 and communicates with the governor storage chamber 24.

The rotating member 6 is arranged so as to cross the fuel chamber 5, and the rotating member 6 is rotatably inserted into the barrel portion 7 of the supporting member 8. The rotating member 6 has a base end 6a connected to the drive shaft 3 via a coupling 9, so that only rotation is allowed in synchronization with the engine. A plunger 10 is slidably inserted in the base end 6a of the rotating member 6 in the radial direction (radial direction).

In this embodiment, two (or four) plungers 10 are provided on the same plane at an interval of, for example, 180 degrees (or 90 degrees), and the tip of each plunger 10 is provided. Faces so as to close the compression chamber 11 provided at the center of the base end of the rotating member 6, and the base end of the plunger 10 slides on the inner surface of the ring-shaped cam ring 14 via the shoe 12 and the roller 13. It has become. The cam ring 14 is provided concentrically around the rotating member 6, and cam lobes corresponding to the number of cylinders of the engine are formed on the inner surface, and when the rotating member 6 rotates,
Each plunger 10 reciprocates in the radial direction (radial direction) of the rotating member 6 to change the volume of the compression chamber 11.

The rotary member 6 has a vertical hole 15 formed in the axial direction thereof and communicating with the compression chamber 11, and communicates with the vertical hole 15.
An inflow / outflow port 16 which is opened on the peripheral surface of the rotating member 6 by the number corresponding to the number of cylinders, and a discharge which enables the vertical hole 15 to communicate with a distribution passage (not shown) formed in the barrel portion 7 and the pump housing 2b. A port 17 is formed. A control sleeve 18 disposed in the fuel chamber 5 is slidably fitted to the rotating member 6 so as to cover the inflow / outflow port 16.

The control sleeve 18 has a lateral groove 19 extending in the circumferential direction thereof, a longitudinal groove 20 formed in parallel with the axial direction of the rotating member 6, and a communication hole capable of communicating with the inflow / outflow port 16 of the rotating member 6. A hole (not shown) is formed. An eccentric engagement portion 23 provided on a shaft 22 of the electric governor 21 is engaged with a lateral groove 19 of the control sleeve 18.
The rotation of the shaft 22 of the electric governor 21 causes the rotating member 6 to relatively displace in the axial direction. Further, the locking portion 26 of the link member 25 which is interlocked with the cam ring 14 in a predetermined relationship is engaged with the vertical groove 20, and when the cam ring 14 is rotated by the timer device 27, the control sleeve 18 also moves in the same direction by a predetermined amount. It is designed to be rotated in a relationship.

From the above configuration, when the rotating member 6 rotates, the plunger 10 reciprocates in the radial direction of the rotating member 6,
Although the inflow / outflow port 16 is sequentially communicated with the through hole of the control sleeve 18, in the suction step in which the plunger 10 moves away from the center of the cam ring 14,
The inflow / outflow port 16 is aligned with the through hole, and the fuel in the fuel chamber 5 is sucked into the compression chamber 11 through the inflow / outflow port 16. Thereafter, when the plunger 10 enters a pressure feeding step in which the plunger 10 moves toward the center of the cam ring 14, the inflow / outflow port 1
The communication between the port 6 and the through hole is cut off, the discharge port 17 and one of the distribution passages are aligned, and the compressed fuel is pumped to the delivery valve via the distribution passage. The fuel delivered from the delivery valve is sent to an injection nozzle via an injection pipe, and is injected from the injection nozzle into a cylinder of the engine. Then, when the next outflow / inflow port 16 communicates with the through hole during the pressure feeding step, the compressed fuel spills into the fuel chamber 5, whereby the fuel pressure is reduced at once, and the injection ends.

Here, the timing at which the inflow / outflow port 16 communicates with the through hole of the control sleeve 18 can be varied depending on the position of the control sleeve 18. That is, the injection amount can be adjusted.

The distal end 6a of the rotary member 6, which passes through the barrel 7 of the support member 8, projects into a space 28 formed between the housing member 2c and the barrel 7, and the projecting portion The washer 29 is a snap ring 29
a. Further, a biasing force toward the space side is applied to the rotating member 6 by a spring 30 elastically mounted between the rotating member 6 and the driving shaft 3.

The space 28 facing the tip 6a of the rotating member 6
Communicates at a position below the rotating member 6 of the fuel chamber 5 and communicates with an outflow end 31 formed at the top of the housing 2b. In the drawing, a link member 25 is provided below the fuel chamber 5 so that the passage formed in the housing 2b and the fuel chamber 5 do not communicate with each other. A hole (not shown) is formed, and the fuel chamber 5 and the passage of the housing are communicated with the offset hole. The passage of the housing communicates with the first hole 32 drilled from the fuel chamber side, the second hole 33 drilled from the space side, and the first hole 32 and the second hole 33. The offset hole communicates with the first hole 32.

A check valve 36 is mounted in the valve mounting space 34 via a spacer 35, and an orifice 37 communicating with the first hole 32 is formed in the spacer 35. The check valve 36 is known per se, and a vertical hole 39 communicating with the orifice 37 is formed in the holder 38.
A toilet seat 40 is formed in the middle of the vertical hole 39, and the toilet seat 40
A spring is disposed between the ball valve 41 that contacts the toilet seat and the spring receiver 42 that closes the vertical hole 39, and the spring 44 constantly urges the ball valve 41 in the direction of contacting the toilet seat 40. A groove 46 communicating with the second hole 33 is formed in the valve mounting space 34, and a lateral hole 45 communicating the vertical hole 39 and the groove 46 is formed on a side wall of the holder 38. Therefore, the offset hole, the first hole 32, the valve mounting space 34, the orifice 37, the check valve 36 (the vertical hole 39 and the horizontal hole 45), the groove 46, the second
A communication passage 47 that connects the lower part of the fuel chamber 5 and the space 28 is formed with the hole 33.

A third hole 48 is formed in the housing 2b from the upper end to the space 28, and a holder 50 constituting the outflow end 31 is fixedly mounted in the third hole 48. An outflow passage 53 through which the fuel in the space 28 flows out to the fuel tank is formed by the third hole 48 and the holes 51 and 52 formed in the holder 50.

Further, an annular path 54 is formed between the housing 2b and the support member 8. This ring road 54
Is formed by forming an annular groove 55 substantially concentric with the rotating member 6 in the housing 2b, and is filled with fuel from the fuel chamber 5 which is connected to the first hole 32 and flows into the communication passage. It has become.

In the above configuration, the high-temperature and high-pressure fuel compressed in the compression chamber 11 at the time of cut-off spills into the fuel chamber 5 at once, and the spilled fuel is mixed with the fuel filled in the fuel chamber 5. A part of this mixed fuel is supplied as surplus fuel from the lower part of the fuel chamber 5 to the communication path 47
Through the space 28, and flows out of the outflow passage 53 through the space 28 to the outside.

Therefore, high-temperature fuel is distributed around the rotating member of the fuel chamber.
In this case, the high-temperature fuel is guided through the communication passage 47, so that heat is transmitted not only from the high-temperature fuel in the fuel chamber 5 but also from the high-temperature fuel filling the space 28 to the rotating member 6 and the barrel portion 7. Is done. Thereby, the temperature distribution of the rotating member 6 and the barrel portion 7 can be made substantially uniform, so that the rotating member 6 and the barrel portion 7 are deformed due to the temperature distribution imbalance, and the rotating member 6 sticks. Disappears.

A characteristic feature of this configuration example is that an orifice 37 and a check valve 36 are provided in a communication passage 47 that connects the fuel chamber 5 and the space 28. If only high-temperature fuel is introduced into the space 28, an orifice or a check valve may be provided in the outflow passage 53. However, when these are disposed downstream of the space 28, the fuel pressure in the space 28 is reduced. It becomes almost equal to the fuel pressure of the chamber 5. The rotating member 6 is urged in a direction away from the drive shaft 3 by a spring 30 to thereby suppress backlash in the axial direction. However, when the space 28 is filled with high-pressure fuel, the spring 30
The spring force is offset or weakened. Since the washer 29 is attached to the tip end 6a of the rotating member 6, there is no large play, but at least clearance clearance is inevitable, and there is a disadvantage that the injection characteristics fluctuate. Therefore, in order to stabilize the behavior of the rotating member 6, a structure that does not weaken the spring pressure more than necessary is necessary.
This can be coped with by providing the orifice 37 and the check valve 36 on the more upstream side.

As described above, the orifice 37 is
And the check valve 36, the fuel filled in the space 28 does not have a great difference in temperature as compared with the fuel in the fuel chamber 5, but the fuel pressure becomes substantially equal to the atmospheric pressure. The bias of the temperature distribution of the rotating member 6 and the barrel portion 7 can be avoided while the behavior of the rotating member 6 is stabilized by suppressing the fuel pressure applied to 6a.

Although the fuel pressure can be reduced by providing only the orifice 37, the reason why the check valve 36 is provided is that the pump chamber pressure rises quickly when the pump is started. is there.

Further, since an annular passage 54 is formed between the housing 2b and the support member 8 so as to fill the high-pressure and high-temperature fuel, the temperature deviation inside the distributor head is reduced, and the distributor head is reduced. The fuel heat is transmitted from the inside to the barrel portion 7 and the rotating member 6, so that the temperature deviation of the barrel portion 7 and the rotating member 6 can be reduced. Such an annular path 54 is desirably provided near the sliding contact surface between the rotating member 6 and the barrel portion 7. However, even if the annular path 54 is provided at a place slightly separated as in the present configuration example, the deviation of the temperature distribution may be reduced. It is effective in reducing it.

FIG. 3 shows another example of the structure. The differences will be mainly described below. The passage of the housing communicating with the offset hole (not shown) of the support member 8 is formed from the fuel chamber side. The first hole 60, the second hole 61 drilled from the space 28 side, and the orifice 62 that connects the first hole 60 and the second hole 61, the offset hole is the It communicates with one hole 60. Therefore, a communication passage 47 that communicates the lower part of the fuel chamber 5 and the space 28 is formed by the offset hole, the first hole 60, the orifice 62, and the second hole 61.

Further, a space 28 is formed from the upper end of the housing 2b.
A check valve 63 having substantially the same configuration as that of the check valve 36 is attached to the third hole 48 drilled. That is, the check valve 63 has the holder 64 inserted into the third hole 48 and the third hole 4
8 is formed, a toilet seat 66 is formed in the middle of the vertical hole 65, and the ball valve 6 abuts on the toilet seat 66.
7 and a spring receiver 68 for closing the vertical hole 65, a spring 70 is provided, and the spring 70
7 is constantly urged in the direction in which it contacts the toilet seat 66. The side wall of the holder 64 is formed with a horizontal hole 71 communicating the vertical hole 65 and the outlet 72. When the fuel in the space 28 becomes higher than the valve opening pressure, the third hole 48 and the vertical hole 65 are formed. , And from the outlet 72 through the horizontal hole 71.

The fuel pressure of the fuel filled in the space 28 is determined by the valve opening pressure of the check valve 63, but the spring pressure of the spring 30 interposed between the rotating member 6 and the drive shaft 3 is increased more than necessary. Needless to say, the pressure is set to be not weakened. Even in such a configuration, the same operation and effect as those of the above configuration example can be obtained, and there is also an advantage that the fuel pressure in the space 28 can be changed by adjusting the valve opening pressure of the check valve 63 if necessary. In other respects, the configuration is the same as that of the above-described configuration example.

[0043]

As described above, according to the first aspect of the present invention, the distributor head is provided with the space in which the end of the rotating member faces, and the fuel inside the pump overflows through this space. Therefore, the heat of the high-temperature fuel is transmitted from the inside of the pump and the space of the distributor head to the rotating member and the member supporting the rotating member. Therefore, a temperature difference is less likely to be formed in the rotating member and the member supporting the rotating member, and deformation due to the temperature difference is suppressed, so that a stick of the rotating member can be prevented. In addition, since the overflow path is also used, the function of the distributor head is enhanced, and it is not necessary to independently form a structure for uniformizing the temperature distribution of the rotating member and the like and an overflow structure, thereby simplifying the structure. Can be planned.

According to the second aspect of the present invention, since the throttle mechanism is provided in the communication path from the inside of the pump to the space of the distributor head, the urging force is applied to the rotating member toward the space. In addition, the urging force is not reduced more than necessary by the fuel pressure in the space, so that the behavior of the rotating member is not unstable, and the behavior of the rotating member can be kept stable. Further, it is possible to prevent the pulsation of the fuel pressure generated inside the pump from being transmitted to the space by the throttle mechanism, and from this point, it is possible to stabilize the rotating member.

Further, according to the invention of claim 3 or 4,
By using the check valve together with the throttle mechanism, the rise of the pressure at the initial stage of starting the pump can be accelerated. In particular, if the check valve is provided at the outflow end of the overflow path, the fuel pressure in the space of the distributor head can be adjusted by the valve opening pressure of the check valve.

According to the fifth aspect of the present invention, since the groove which fills the fuel inside the pump is provided in the member constituting the distributor head, the rotating member and the member supporting the rotating member are provided from the inside of the distributor head. On the other hand, the heat of the fuel is transmitted, the bias of the temperature of the rotating member and the supporting member is reduced, so that the deformation of these members due to the temperature difference can be suppressed, and the stick of the rotating member can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration example of a distribution type fuel injection pump according to the present invention.

FIG. 2 is an enlarged sectional view of a portion of an overflow path of the fuel injection pump shown in FIG.

FIG. 3 is a sectional view showing another configuration example of the distribution type fuel injection pump according to the present invention.

FIG. 4 is an enlarged sectional view of a part of an overflow path of the fuel injection pump shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Distribution type fuel injection pump 2 Housing 2a, 2b, 2c Housing member 6 Rotating member 7 Barrel part 8 Support member 10 Plunger 11 Compression chamber 15 Vertical hole 16 Inflow / outflow port 17 Discharge port 18 Control sleeve 28 Space 36, 63 Check valve 37 , 62 Orifice 47 Communication passage 53 Outflow passage 55 Groove

Continued on the front page (72) Inventor Atsushi Matsubara 3-13-26 Yayumicho, Higashimatsuyama-shi, Saitama Inside of Zexel Higashi-Matsuyama Plant

Claims (5)

[Claims] A rotating member that rotates in synchronization with an engine; a distributor head portion into which the rotating member is rotatably inserted; a pump mechanism that varies a volume of a compression chamber with rotation of the rotating member; And a sleeve which is slidably fitted to the rotating member inside the pump filled with: a pressure-feeding oil passage for supplying fuel compressed in the compression chamber to the rotating member to a discharge passage of the distributor head. And a port connected to the oil supply passage and opening to the peripheral surface covered with the sleeve, and the opening timing of the port is adjusted by displacing the sleeve relative to the rotating member, and the fuel A fuel injection pump that spills the compressed fuel into the pump through the port at the time of cutoff of the distributor; The space facing the end portion of the rotary member to the de section provided, distributor type fuel injection pump, wherein the fuel within said pump provided with a path for overflowing through the space. 2. The distribution type fuel injection pump according to claim 1, wherein a throttle mechanism for narrowing a flow path cross section is provided in a communication path communicating between the inside of the pump and the space of the distributor head. 3. A throttle mechanism for narrowing a flow path cross section is provided in a communication path communicating between the inside of the pump and the space of the distributor head portion, and fuel is allowed to flow only in one direction from the inside of the pump to the space. 2. The distribution type fuel injection pump according to claim 1, further comprising a check valve. 4. A throttle mechanism for narrowing a cross section of a flow path is provided in a communication path communicating between the inside of the pump and the space of the distributor head portion, and an outflow end from which fuel flows out through the space is provided from the space side. 2. The distribution type fuel injection pump according to claim 1, further comprising a check valve for permitting only fuel outflow. 5. A rotating member that rotates in synchronization with an engine, a distributor head portion into which the rotating member is rotatably inserted, a pump mechanism that varies the volume of a compression chamber with rotation of the rotating member, and a fuel. And a sleeve which is slidably fitted to the rotating member inside the pump filled with: a pressure-feeding oil passage for supplying fuel compressed in the compression chamber to the rotating member to a discharge passage of the distributor head. And a port connected to the oil supply passage and opening to the peripheral surface covered with the sleeve, and the opening timing of the port is adjusted by displacing the sleeve relative to the rotating member, and the fuel A distributed fuel injection pump that spills the compressed fuel into the pump through the port at the time of cutoff of the distributor head. And a groove that fills the fuel inside the pump is provided in a member constituting the pump part.