JP2020118093A - Fuel injection pump - Google Patents

Abstract

To provide a technology capable of miniaturizing a fuel injection pump and suppressing occurrence of cavitation in a fuel passage, as one phase of this disclosure.SOLUTION: A plunger 30 of a fuel injection pump pressurizes a fuel sucked from suction passages 210, 212 to a pressurization chamber 200 by reciprocating motion. Suction valves 40, 50, 52 are opened when the plunger is moved in a suction direction for sucking the fuel into the pressurization chamber to permit suction of the fuel from the suction passages 210, 212 to the pressurization chamber, and closed when the plunger is moved in a pressurization direction opposite to the suction direction to pressurize the fuel to block the suction of the fuel from the suction passages to the pressurization chamber. Discharge valves 44, 56, 58 are opened when the plunger is moved in the pressurization direction to discharge the pressurized fuel in the pressurization chamber from discharge passages 216, 218, 222, 224. The suction valves and the discharge valves are coaxially disposed, the suction passages and the discharge passages are passages different from each other, and a passage common to the suction passages and the discharge passages does not exist.SELECTED DRAWING: Figure 2

Description

The present invention relates to a technique of a fuel injection pump that pressurizes and discharges fuel drawn into a pressurizing chamber by reciprocating movement of a plunger.

A technique related to a fuel injection pump that pressurizes and discharges fuel drawn into a pressurizing chamber by reciprocating movement of a plunger is known.
For example, in Patent Document 1 below, a suction valve that opens and closes between a suction passage for supplying fuel to the pressurizing chamber and the pressurizing chamber, a discharge passage for discharging fuel pressurized in the pressurizing chamber, and a pressurizing valve A technique is described in which a discharge valve that opens and closes a chamber is installed coaxially. When the intake valve and the discharge valve are installed coaxially, the size of the fuel injection pump in the direction intersecting the axis can be downsized.

In the technique described in Patent Document 1, a part of the suction passage through which the fuel is sucked into the pressurizing chamber and a part of the discharge passage through which the fuel is discharged from the pressurizing chamber are also used as common passages. ..

International Publication No. 2012-020466

As a result of a detailed study by the inventor, when the intake and the discharge of fuel are performed in the dual-purpose passage, the flow direction of the fuel reverses in the dual-purpose passage when the intake and the discharge of the fuel are switched. The problem that eddies and stagnation occur on the surface was found. Further, it has been found that vortices and stagnation that occur in the fuel flow cause cavitation, and when cavitation collapses, erosion occurs on the wall surface forming the fuel passage.

In one aspect of the present disclosure, it is desirable to provide a technique for reducing the size of the fuel injection pump and suppressing the occurrence of cavitation in the fuel passage.

A fuel injection pump (2) according to one aspect of the present disclosure includes a plunger (30), an intake valve (40, 50, 52, 72, 74, 76, 100) and a discharge valve (44, 56, 58, 80). , 90, 100).

The plunger reciprocates to pressurize the fuel sucked into the pressurizing chamber (200) from the suction passages (210, 212, 230, 232, 234, 260, 262).
The intake valve opens when the plunger moves in the intake direction in which fuel is drawn into the pressurizing chamber, permits the intake of fuel from the intake passage into the pressurizing chamber, and the plunger pressurizes the fuel in the opposite direction to the intake direction. When it moves in the pressure direction, it closes and shuts off the intake of fuel from the intake passage into the pressurizing chamber.

The discharge valve opens when the plunger moves in the pressurizing direction and discharges the pressurized fuel in the pressurizing chamber from the discharge passages (216, 218, 222, 224, 240, 242, 250).
The suction valve and the discharge valve are installed coaxially, the suction passage and the discharge passage are different passages, and there is no common passage between the suction passage and the discharge passage.

With such a configuration, it is possible to reduce the size of the fuel injection pump in the direction intersecting the axis where the intake valve and the discharge valve are coaxially installed.
Furthermore, since the intake valve and the discharge valve can be assembled in the same direction along the shaft when assembled, the intake valve and the discharge valve can be easily assembled. In other words, since the intake valve and the discharge valve can be removed in the same direction, at least one of the intake valve and the discharge valve can be easily replaced.

Further, since the suction passage and the discharge passage are different passages, and there is no common passage between the suction passage and the discharge passage, when the suction and the discharge of the fuel are switched, the suction passage and the discharge passage are somewhere. It is possible to suppress reversal of the fuel flow direction as much as possible.

As a result, it is possible to suppress the occurrence of vortex and stagnation of fuel somewhere in the intake passage and the discharge passage when switching between suction and discharge of fuel, and thus suppress the occurrence of cavitation due to vortex and stagnation of fuel. it can. Therefore, it is possible to suppress the occurrence of erosion on the wall surface forming the fuel passage when the cavitation collapses.

It should be noted that, here, "the suction valve and the discharge valve are on the same axis" is not limited to the same axis in a strict sense, and the suction valve and the discharge valve are strictly defined as long as the same effect as described above can be obtained. It does not have to be coaxial.

Sectional drawing which shows the fuel injection pump by 1st Embodiment. Sectional drawing which shows the structure of the pressurizing chamber periphery of FIG. Sectional drawing which shows the structure of the pressurization chamber periphery by 2nd Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 3rd Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 4th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 5th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 6th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 7th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 8th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 9th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 10th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 11th Embodiment. Sectional drawing which shows the structure of the pressurization chamber periphery by 12th Embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
[1. First Embodiment]
[1-1. Constitution]
The fuel injection pump 2 shown in FIG. 1 is a pump that supplies pressurized fuel to a common rail (not shown). The pump housing of the fuel injection pump 2 includes a housing body 10, a bearing cover 12, a cylinder head 14, and the like.

The housing body 10 and the bearing cover 12 bear the camshaft 20 via metal bushes 16 and 18, respectively. The cylinder head 14 supports the plunger 30 so as to be capable of reciprocating. A pressurizing chamber 200 is formed on the opposite side of the plunger 30 to the cam ring 24 described later.

The camshaft 20 is provided with a cam 22 having a circular cam profile and eccentric with respect to the central axis of the camshaft 20. The cam ring 24 has a quadrangular outline, and a metal bush 26 is press-fitted and fixed to the inner peripheral wall of the cam ring 24. The cam ring 24 is fitted into the cam 22 via a metal bush 26.

The outer peripheral surface of the cam ring 24 and the plunger head 30a are in flat contact with each other. The plunger head 30a is pressed against the cam ring 24 by the load received from the spring 32.

With such a configuration of the cam shaft 20, the cam 22, and the cam ring 24, when the cam shaft 20 rotates, the cam 22 rotates within the cam ring 24 while revolving around the central axis of the cam shaft 20. Then, the cam ring 24 revolves around the central axis of the cam shaft 20 without rotating as the cam 22 revolves and rotates. The plunger 30 reciprocates according to the revolution of the cam ring 24.

FIG. 2 shows the configuration around the pressurizing chamber 200. The intake valve seat 40, the valve packing 42, and the discharge valve seat 44 are housed in the valve holder 48 toward the cylinder head 14 in this order. The intake valve seat 40 and the valve packing 42 are positioned by a knock pin 46 in their rotational directions. The valve holder 48 is screwed to the cylinder head 14 to press the intake valve seat 40, the valve packing 42, and the discharge valve seat 44 against the cylinder head 14.

On the pressurizing chamber 200 side of the intake valve seat 40, a fuel chamber 202 that forms a part of the pressurizing chamber 200 is formed by a disc-shaped recess that connects the pressurizing chamber 200 and a fuel passage 216 described below. Has been done.

The intake valve seat 40 supports a valve member 50, which will be described later, so as to be capable of reciprocating, by an inner peripheral surface 40a forming a through hole penetrating the intake valve seat 40 in the central axis direction. A valve seat 40b on which the valve member 50 is seated is formed around the inner peripheral surface 40a on the end surface of the intake valve seat 40 on the pressurizing chamber 200 side. On the end surface of the intake valve seat 40 on the valve packing 42 side, a spring seat 40c is formed around the inner peripheral surface 40a to support one end of a spring 52 described later.

A spring chamber 204 that accommodates the spring 52 is formed on the intake valve seat 40 side of the valve packing 42. The spring chamber 204 is formed on the side opposite to the pressurizing chamber 200 with respect to the valve seat 40b. The spring chamber 204 is isolated from the pressurizing chamber 200 in both the state where the valve member 50 is seated on the valve seat 40b and the state where the valve member 50 is separated from the valve seat 40b.

The valve member 50 is a needle-shaped valve member, and has a needle portion 50a and a head portion 50b having a diameter larger than that of the needle portion 50a. The needle portion 50a is supported on the inner peripheral surface 40a of the suction valve seat 40 so as to be capable of reciprocating. The head portion 50b is formed on the pressurizing chamber 200 side of the needle portion 50a. The head portion 50b is seated on the valve seat 40b of the intake valve seat 40 by moving in the pressing direction of the plunger 30, that is, in the upward direction of FIG.

A washer 54 that supports the other end of the spring 52 is fitted on the opposite side of the needle 50a from the head 50b. The valve member 50 receives a load from the spring 52 in the direction toward the valve seat 40b, that is, in the pressing direction of the plunger 30. The intake valve seat 40, the valve member 50, and the spring 52 correspond to an intake valve.

The valve member 56 is a ball-shaped valve member, and receives a load from the spring 58 in a direction toward the valve seat 44a of the discharge valve seat 44, that is, a direction opposite to the direction in which fuel is discharged. The end of the spring 58 opposite to the valve member 56 is supported by the stopper 60. The discharge valve seat 44, the valve member 56, and the spring 58 correspond to the discharge valve.

The valve member 50 and the valve member 56 are installed coaxially. That is, the suction valve and the discharge valve are installed coaxially.
An annular fuel chamber 210 is formed on the outer peripheral side of the intake valve seat 40 while the cylinder head 14 and the valve holder 48 face each other. The intake valve seat 40 is formed with a fuel passage 212 that penetrates the intake valve seat 40 in the radial direction and connects the valve member 50 side and the fuel chamber 210. Fuel is supplied to the fuel chamber 210 from a feed pump (not shown), and the fuel whose flow rate is adjusted by a metering valve (not shown) is supplied through the fuel passage 214.

In the intake valve seat 40 and the valve packing 42, a plurality of fuel passages 216 and 218 are formed at equal angular intervals in the circumferential direction, penetrating the intake valve seat 40 and the valve packing 42 in the pressurizing direction of the plunger 30. Has been done. The intake valve seat 40 and the valve packing 42 are rotated by a knock pin 46 so that the fuel passage 216 and the fuel passage 218 communicate with each other such that the opening positions of the fuel passage 216 and the fuel passage 218 coincide with each other. Has been positioned.

A disc-shaped fuel chamber 220 is formed on the valve packing 42 side of the discharge valve seat 44. An opening of the fuel passage 218 opposite to the fuel passage 216 communicates with the fuel chamber 220. A fuel passage 222 that penetrates the discharge valve seat 44 in the central axis direction and connects the fuel chamber 220 and the fuel passage 224 is formed at the center of the discharge valve seat 44.

The fuel passage 224 passes through the central axis of the valve holder 48 and is formed from the valve member 56 side toward the discharge port 48a side of the valve holder 48. The fuel passage 224 accommodates the spring 58 and the stopper 60 described above. A fuel passage 226 is formed in the stopper 60 so as to penetrate the stopper 60 in the central axis direction.

[1-2. Fuel intake and discharge]
Next, the suction and discharge of fuel by the reciprocating movement of the plunger 30 will be described.
When the plunger 30 descends downward in FIG. 2 and the pressure in the pressurizing chamber 200 decreases, the valve member 50 receives the load from the spring 52 due to the force received from the fuel pressure supplied from the feed pump to the fuel chamber 210 side. The valve seat 40b is separated from the seat. As a result, the intake valve is opened, and the fuel is sucked into the pressurizing chamber 200 through the fuel passage 214, the fuel chamber 210, and the fuel passage 212.

When the plunger 30 moves upward in FIG. 2 and the pressure of the pressurizing chamber 200 increases, the valve member 50 is seated on the valve seat 40b by the force received by the pressure of the pressurizing chamber 200 and the load received by the spring 52. .. As a result, the intake valve is closed.

Further, when the plunger 30 moves upward in FIG. 2 and the pressure in the pressurizing chamber 200 increases, the valve member 56 is separated from the valve seat 44a by the force received from the pressure on the pressurizing chamber 200 side. As a result, the discharge valve opens. Then, the fuel pressurized in the pressurizing chamber 200 passes through the fuel passages 216 and 218, the fuel chamber 220, and the fuel passages 222 and 224, and is supplied from the discharge port 48a of the valve holder 48 to a common rail (not shown).

In the first embodiment, the fuel chamber 210 and the fuel passage 212 correspond to the suction passage for sucking fuel into the pressurizing chamber 200, and the fuel passages 216, 218, 222, 224 and the fuel chamber 220 are It corresponds to a discharge passage for discharging the fuel pressurized in the pressure chamber 200.
The spring chamber 204 corresponds to the low pressure chamber.

The discharge passage is formed along the pressurizing direction in which the plunger 30 moves upward in FIG. 2 to pressurize the fuel in the pressurizing chamber 200.
The suction passage and the discharge passage are different passages, and there is no common passage between the suction passage and the discharge passage.

[1-3. effect]
According to the first embodiment described above, the following effects can be obtained.
(1a) Since the intake valve and the discharge valve are installed on the same axis, it is possible to reduce the size of the fuel injection pump 2 in the direction intersecting the axis where the intake valve and the discharge valve are installed.

(1b) Since the suction valve and the discharge valve are installed coaxially, the suction valve and the discharge valve can be assembled in the same direction along the axis when assembled. Therefore, the intake valve and the discharge valve can be easily assembled. In other words, since the intake valve and the discharge valve can be removed in the same direction, at least one of the intake valve and the discharge valve can be easily replaced.

(1c) The suction passage for sucking fuel into the pressure chamber 200 and the discharge passage for discharging the fuel pressurized in the pressure chamber 200 are different passages, and are common to the suction passage and the discharge passage. There is no passage.

This makes it possible to suppress reversal of the flow direction of the fuel somewhere between the intake passage and the discharge passage when the fuel is switched between the suction and the discharge, so that when the fuel is switched between the suction and the discharge, It is possible to suppress the generation of vortices and stagnation somewhere in the suction passage and the discharge passage. As a result, it is possible to suppress the occurrence of cavitation in the fuel due to the vortex and the stagnation, so that it is possible to suppress the occurrence of erosion on the wall surface forming the fuel passage when the cavitation collapses.

(1d) When the pressurized fuel flows through the discharge passage, the discharge passage for discharging the fuel pressurized in the pressurizing chamber 200 is formed along the pressurizing direction in which the plunger 30 pressurizes the fuel. It is possible to reduce as much as possible the flow passage resistance of the fuel cell, and it is possible to reduce dissociation of the fuel flow from the fuel passage wall surface and the difference in the flow passage resistance in the discharge passage as much as possible.

As a result, the fuel flows through the discharge passage with a flow path resistance that is as low as possible. Further, it is possible to suppress the generation of eddies and stagnation in the fuel flow due to the dissociation of the fuel flow from the wall surface of the fuel passage and the difference in the flow path resistance. As a result, it is possible to suppress the occurrence of cavitation in the fuel due to the dissociation of the fuel flow, the vortex, and the stagnation. Therefore, it is possible to suppress the occurrence of erosion on the wall surface forming the discharge passage when the cavitation collapses.

(1e) The spring chamber 204 that houses the spring 52 that applies a load to the valve member 50 is isolated from the pressurizing chamber 200.
As a result, high pressure at the time of pressurizing fuel is not applied to the spring seat 40c of the intake valve seat 40 that supports the end of the spring 52 and faces the spring chamber 204. Concentration of high-voltage stress can be suppressed. Therefore, it is not necessary to increase the strength of the spring seat 40c. Further, since it is not necessary to process the corner portion of the spring seat 40c into a curved surface in order to reduce the stress concentration, the spring seat 40c can be easily processed.

Further, since the fuel is sucked into the pressure chamber 200 without passing through the spring chamber 204 at the time of fuel suction, the fuel sucked into the pressure chamber 200 and the spring 52 do not interfere with each other. Therefore, the flow path resistance of the fuel sucked into the pressurizing chamber 200 can be reduced as much as possible.

[2. Second Embodiment]
[2-1. Differences from the first embodiment]
Since the basic configuration of the second embodiment shown in FIG. 3 is the same as that of the first embodiment shown in FIG. 2, differences between the second embodiment and the first embodiment will be described below. The same reference numerals as those in the first embodiment indicate the same configurations, and refer to the preceding description.

The second embodiment differs from the first embodiment in that a ball-shaped valve member is used as the valve member 74 of the intake valve. The valve member 74 receives a load from the spring 76 toward the valve seat 72a of the intake valve seat 72.

The suction valve seat 72, the valve member 74, and the spring 76 correspond to a suction valve. The valve member 74 and the valve member 56 are coaxially installed. That is, the suction valve and the discharge valve are installed coaxially.

The valve packing 70, the suction valve seat 72, and the discharge valve seat 44 are housed in the valve holder 48 toward the cylinder head 14 in this order, and are pressed against the cylinder head 14. The valve packing 70 and the intake valve seat 72 are positioned in the rotational direction of each other by a knock pin 46.

A fuel passage 216 is formed in the valve packing 70, and a fuel passage 218 is formed in the intake valve seat 72. The intake valve seat 72 is formed with a valve seat 72a on which the valve member 74 is seated. The valve seat 72a is formed on the side opposite to the pressurizing chamber 200 with respect to the valve member 74.

The spring 76 is installed on the pressurizing chamber 200 side with respect to the valve seat 72 a, and is housed in a spring chamber 234 formed inside the valve packing 70 and the suction valve seat 72. The spring chamber 234 communicates with the pressure chamber 200.

One end of the spring 76 is supported by a spring seat 70 a formed on the valve packing 70. The spring 76 applies a load to the valve member 74 toward the valve seat 72a.

An annular fuel chamber 230 is formed between the outer peripheral surface of the intake valve seat 72 and the inner peripheral surface of the valve holder 48. The intake valve seat 72 is formed with a plurality of fuel passages 232 that penetrate the intake valve seat 72 in the radial direction and connect the valve member 74 side and the fuel chamber 230.

[2-2. Fuel intake and discharge]
When the plunger 30 descends downward in FIG. 3 and the pressures of the pressurizing chamber 200 and the spring chamber 234 decrease, the valve member 74 receives the force from the fuel pressure supplied from the feed pump to the fuel passage 232 and causes the spring 76 to move. It separates from the valve seat 72a against the load received from. As a result, the intake valve is opened, and the fuel is sucked into the pressurizing chamber 200 through the fuel passage 214, the fuel chambers 210 and 230, the fuel passage 232, and the spring chamber 234.

When the plunger 30 moves upward in FIG. 3 and the pressures of the pressurizing chamber 200 and the spring chamber 234 increase, the valve member 74 receives a force from the pressure on the pressurizing chamber 200 side and a load received from the spring 76 to cause the valve seat to move. Sit at 72a. As a result, the intake valve is closed. Further, when the plunger 30 moves upward in FIG. 3 and the pressure on the pressurizing chamber 200 side increases, the valve member 56 separates from the valve seat 44a.

As a result, the discharge valve opens. Then, the fuel pressurized in the pressurizing chamber 200 passes through the fuel passages 216 and 218, the fuel chamber 220, and the fuel passages 222 and 224, and is supplied from the discharge port 48a of the valve holder 48 to a common rail (not shown).

In the second embodiment described above, the fuel chambers 210, 230, the fuel passage 232, and the spring chamber 234 correspond to the suction passage for sucking fuel into the pressurizing chamber 200.
[2-3. effect]
According to the second embodiment described above, the following effects can be obtained in addition to the effects (1a) to (1d) of the effects of the first embodiment described above.

(2a) Since the valve member 74 is a ball-shaped valve member, the structure of the valve member 74 is simple.
[3. Third Embodiment]
[3-1. Differences from the first embodiment]
Since the basic configuration of the third embodiment shown in FIG. 4 is the same as that of the first embodiment shown in FIG. 2, differences between the third embodiment and the first embodiment will be described below. The same reference numerals as those in the first embodiment indicate the same configurations, and refer to the preceding description.

The third embodiment is different from the first embodiment in that the intake valve seat 40 and the valve packing 42 are not positioned in the rotational direction by the knock pin 46.
An annular fuel passage 240 is formed on the end surface of the intake valve seat 40 on the valve packing 42 side. The fuel passage 216 on the intake valve seat 40 side and the fuel passage 218 on the valve packing 42 side communicate with each other via an annular fuel passage 240.

In the third embodiment described above, the fuel passages 216, 218, 222, 224, 240 and the fuel chamber 220 correspond to the discharge passage. The discharge passage is formed along the pressurizing direction in which the plunger 30 pressurizes the fuel in the pressurizing chamber 200.

[3-2. effect]
According to the third embodiment described above, the following effects can be obtained in addition to the effects of the first embodiment described above.

(3a) Since the fuel passage 216 on the intake valve seat 40 side and the fuel passage 218 on the valve packing 42 side communicate with each other through the annular fuel passage 240, the fuel passage 216 and the fuel passage 218 communicate with each other. It is not necessary to position the intake valve seat 40 and the valve packing 42 in the rotational direction with the knock pin 46. As a result, the number of parts and the number of assembling steps can be reduced.

[4. Fourth Embodiment]
[4-1. Differences from the second embodiment]
Since the basic configuration of the fourth embodiment shown in FIG. 5 is the same as that of the second embodiment shown in FIG. 3, differences between the fourth embodiment and the second embodiment will be described below. The same reference numerals as those in the second embodiment indicate the same configurations, and refer to the preceding description.

The fourth embodiment is different from the second embodiment in that the rotation directions of the valve packing 70 and the suction valve seat 72 are not positioned by the knock pins 46.
An annular fuel passage 242 is formed on the end surface of the intake valve seat 72 on the valve packing 70 side. The fuel passage 216 on the valve packing 70 side and the fuel passage 218 on the intake valve seat 72 side communicate with each other via an annular fuel passage 242.

In the fourth embodiment described above, the fuel passages 216, 218, 222, 224, 242 and the fuel chamber 220 correspond to the discharge passage. The discharge passage is formed along the pressurizing direction in which the plunger 30 pressurizes the fuel in the pressurizing chamber 200.

[4-2. effect]
According to the fourth embodiment described above, the following effects can be obtained in addition to the effects of the second embodiment described above.

(4a) The fuel passage 216 on the valve packing 70 side and the fuel passage 218 on the intake valve seat 72 side communicate with each other through the annular fuel passage 242, so that the fuel passage 216 and the fuel passage 218 communicate with each other. It is not necessary to position the valve packing 70 and the intake valve seat 72 in the rotational direction by the knock pin 46. As a result, the number of parts and the number of assembling steps can be reduced.

[5. Fifth Embodiment, Sixth Embodiment]
[5-1. Differences from the first and second embodiments]
The basic configuration of the fifth embodiment shown in FIG. 6 is the same as that of the first embodiment shown in FIG. 2, and the basic configuration of the sixth embodiment shown in FIG. 7 is the same as that of the second embodiment shown in FIG. The same is true. Therefore, differences between the fifth embodiment and the first embodiment, and differences between the sixth embodiment and the second embodiment will be described below. Note that the same reference numerals as those in the first and second embodiments indicate the same configurations, and refer to the preceding description.

In the first embodiment and the second embodiment, the shapes of both sides of the discharge valve seat 44 on which the valve member 56 is seated in the central axis direction, that is, the vertical shape of the discharge valve seat 44 in FIGS. 2 and 3 are asymmetrical. is there.

On the other hand, in the fifth embodiment and the sixth embodiment, the shapes of both sides of the discharge valve seat 80 on which the valve member 56 is seated in the central axis direction, that is, in the vertical direction of the discharge valve seat 80 in FIGS. 6 and 7. The shape is symmetrical. The discharge valve seat 80 is formed with valve seats 80a on which the valve member 56 is seated on both sides of the central axis.

In the fifth and sixth embodiments, the valve member 56, the spring 58, and the discharge valve seat 80 correspond to the discharge valve. The suction valve and the discharge valve are installed coaxially.
[5-2. effect]
According to the fifth embodiment described above, the following effects can be obtained in addition to the effects of the first embodiment described above. According to the sixth embodiment described above, the following effects can be obtained in addition to the effects of the second embodiment described above.

(5a) In the fifth embodiment and the sixth embodiment, the shapes of both sides in the central axis direction of the discharge valve seat 80 on which the valve member 56 is seated, that is, the shapes of both sides in the direction in which the discharge valve seat 80 is assembled are symmetrical. Therefore, the discharge valve seat 80 may be mounted in either direction. Accordingly, the discharge valve seat 80 can be easily assembled, so that the assembling property is improved.

[6. Seventh embodiment]
[6-1. Differences from the third embodiment]
Since the basic configuration of the seventh embodiment shown in FIG. 8 is similar to that of the third embodiment shown in FIG. 4, differences between the seventh embodiment and the third embodiment will be described below. The same reference numerals as those in the third embodiment indicate the same configurations, and refer to the preceding description.

In the third embodiment, the valve packing 42 and the discharge valve seat 44 are separate members, whereas in the seventh embodiment, a member corresponding to the valve packing 42 and the discharge valve seat 44 of the third embodiment is provided. The third embodiment differs from the third embodiment in that it is configured by one common member 90.

The common member 90 is formed with a spring chamber 204 that accommodates the spring 52 of the intake valve and a valve seat 90a on which the valve member 56 of the discharge valve is seated. The valve member 56, the spring 58, and the common member 90 correspond to a discharge valve. The suction valve and the discharge valve are installed coaxially.

In the common member 90, a plurality of fuel passages 250 are formed in the circumferential direction so as to penetrate the common member 90 in the central axis direction. The fuel passage 250 is formed by processing both sides of the common member 90 in the central axis direction. One opening of the fuel passage 250 communicates with an annular fuel passage 240 formed in the intake valve seat 40. The other opening of the fuel passage 250 communicates with the fuel passage 224 when the valve member 56 is separated from the valve seat 90a of the common member 90.

In the seventh embodiment described above, the fuel passages 216, 224, 240, 250 correspond to the discharge passages. The discharge passage is formed along the pressurizing direction in which the plunger 30 pressurizes the fuel in the pressurizing chamber 200.

[6-2. effect]
According to the seventh embodiment described above, the following effects can be obtained in addition to the effects of the third embodiment described above.

(6a) Since the members corresponding to the valve packing 42 and the discharge valve seat 44 of the third embodiment are formed by the single common member 90, the number of parts and the number of assembling steps can be reduced.
(6b) Since the members corresponding to the valve packing 42 and the discharge valve seat 44 of the third embodiment are configured by the single common member 90, the member having the discharge passage through which the pressurized high-pressure fuel flows is one. Diminishes. As a result, in order to prevent the fuel from leaking at the place where the discharge passages through which the high-pressure fuel flows communicate with each other, it is possible to reduce the number of steps for processing the contact surfaces of the members with high accuracy.

[7. Eighth embodiment]
[7-1. Differences from the fourth embodiment]
Since the basic configuration of the eighth embodiment shown in FIG. 9 is the same as that of the fourth embodiment shown in FIG. 5, differences between the eighth embodiment and the fourth embodiment will be described below. Note that the same reference numerals as those in the fourth embodiment indicate the same configurations, and refer to the preceding description.

In the fourth embodiment, the intake valve seat 72 and the discharge valve seat 44 are separate members, whereas in the eighth embodiment, they correspond to the intake valve seat 72 and the discharge valve seat 44 of the fourth embodiment. It is different from the fourth embodiment in that the members are configured by one common member 100.

The common member 100 is formed with a spring chamber 234 that accommodates the spring 76, a valve seat 100a on which the valve member 74 of the intake valve is seated, and a valve seat 100b on which the valve member 56 of the discharge valve is seated. The valve member 56, the spring 58, and the common member 100 correspond to a discharge valve. The valve member 74, the spring 76, and the common member 100 correspond to an intake valve. The suction valve and the discharge valve are installed coaxially.

A plurality of fuel passages 250 are formed in the common member 100 in the circumferential direction so as to penetrate the common member 100 in the central axis direction. One opening of the fuel passage 250 communicates with an annular fuel passage 242 formed on the end surface of the common member 100 on the valve packing 70 side. The other opening of the fuel passage 250 communicates with the fuel passage 224 when the valve member 56 is separated from the valve seat 100b of the common member 100.

In the eighth embodiment described above, the fuel passages 216, 224, 242, 250 correspond to the discharge passages. The discharge passage is formed along the pressurizing direction in which the plunger 30 pressurizes the fuel in the pressurizing chamber 200.

[7-2. effect]
According to the eighth embodiment described above, the following effects can be obtained in addition to the effects of the above-described fourth embodiment.

(7a) Since the members corresponding to the intake valve seat 72 and the discharge valve seat 44 of the fourth embodiment are configured by the single common member 100, the number of parts and the number of assembling steps can be reduced.
(7b) Since the members corresponding to the intake valve seat 72 and the discharge valve seat 44 of the fourth embodiment are configured by the single common member 100, the member having the fuel passage through which the pressurized high pressure fuel flows One less. As a result, in order to prevent the fuel from leaking at a location where the fuel passages through which the high-pressure fuel flows communicate with each other, it is possible to reduce the number of steps for highly accurately processing the contact surface between the members.

[8. Ninth embodiment, tenth embodiment]
[8-1. Differences from Third Embodiment and Fourth Embodiment]
The basic configuration of the ninth embodiment shown in FIG. 10 is the same as that of the third embodiment shown in FIG. 4, and the basic configuration of the tenth embodiment shown in FIG. 11 is the same as that of the fourth embodiment shown in FIG. The same is true. Therefore, differences between the ninth embodiment and the third embodiment and differences between the tenth embodiment and the fourth embodiment will be described below. Note that the same reference numerals as those in the third and fourth embodiments indicate the same configurations, and refer to the preceding description.

In the ninth embodiment, since the outer diameter of the intake valve seat 40 on the plunger 30 side is smaller than the outer diameter on the valve packing 42 side, the step portion 40d is formed on the outer peripheral surface of the intake valve seat 40. ..

The caulking part 48b of the valve holder 48 fixes the intake valve seat 40, the valve packing 42, and the discharge valve seat 44 in the valve holder 48 by caulking and fixing the step portion 40d of the intake valve seat 40. There is.

In the tenth embodiment, since the outer diameter of the valve packing 70 on the plunger 30 side is smaller than the outer diameter of the intake valve seat 72 side, the stepped portion 70b is formed on the outer peripheral surface of the valve packing 70.

The caulking portion 48 b of the valve holder 48 fixes and accommodates the valve packing 70, the suction valve seat 72, and the discharge valve seat 44 in the valve holder 48 by caulking and fixing the step portion 70 b of the valve packing 70. ..

An annular fuel passage 260 communicating with the fuel passage 232 is formed on the inner peripheral surface of the valve holder 48. A plurality of fuel passages 262 that communicate the annular fuel passage 260 and the fuel chamber 210 are formed at equal angular intervals in the circumferential direction of the valve holder 48.

In the tenth embodiment described above, the fuel chamber 210, the fuel passages 232, 260, 262, and the spring chamber 234 correspond to the suction passage for sucking fuel into the pressurizing chamber 200.
[8-2. effect]
According to the ninth embodiment described above, the following effects can be obtained in addition to the effects of the third embodiment described above. Further, according to the tenth embodiment described above, the following effects can be obtained in addition to the effects of the fourth embodiment described above.

(8a) The valve holder 48 can be screwed to the cylinder head 14 with the components accommodated therein by caulking and fixing the intake valve seat 40 or the valve packing 70 with the components accommodated therein. Therefore, the valve holder 48 and the parts housed inside the valve holder 48 can be easily assembled to the cylinder head 14.

[9. Eleventh Embodiment, Twelfth Embodiment]
[9-1. Differences from Third Embodiment and Fourth Embodiment]
The basic configuration of the eleventh embodiment shown in FIG. 12 is the same as that of the third embodiment shown in FIG. 4, and the basic configuration of the twelfth embodiment shown in FIG. 13 is the same as that of the fourth embodiment shown in FIG. The same is true. Therefore, differences between the eleventh embodiment and the third embodiment and differences between the twelfth embodiment and the fourth embodiment will be described below. Note that the same reference numerals as those in the third and fourth embodiments indicate the same configurations, and refer to the preceding description.

In the eleventh embodiment and the twelfth embodiment, the chamfer 14a on the pressurizing chamber 200 side of the inner peripheral surface that supports the plunger 30 of the cylinder head 14 so as to be able to reciprocate is different from the third embodiment and the fourth embodiment. Is also formed large. As a result, the inner diameter of the opening of the pressurizing chamber 200 is increased.

As a result, in the eleventh embodiment, as in the third embodiment, a disc-shaped fuel chamber for connecting the pressure chamber 200 and the fuel passage 216 to the pressure chamber 200 side of the intake valve seat 40. There is no need to form 202. The positions of the fuel passages 216 and 218 can be set so that the thickness of the intake valve seat 40 and the valve packing 42 around the fuel passages 216 and 218 can be secured without forming the fuel chamber 202.

Further, in the twelfth embodiment, the positions of the fuel passages 216 and 218 can be set so that the wall thicknesses of the valve packing 70 and the intake valve seat 72 around the fuel passages 216 and 218 can be secured.

[9-2. effect]
According to the eleventh embodiment described above, the following effects can be obtained in addition to the effects of the third embodiment described above. Further, according to the twelfth embodiment described above, the following effects can be obtained in addition to the effects of the fourth embodiment described above.

(9a) In the eleventh embodiment, since the inner diameter of the opening of the pressurizing chamber 200 is large, the wall thickness of the intake valve seat 40 and the valve packing 42 around the fuel passages 216 and 218 is ensured, and the pressure is increased. The positions of the fuel passages 216 and 218 to which high pressure is applied when pressure is applied can be set. This improves the pressure resistance of the intake valve seat 40 and the valve packing 42.

In the twelfth embodiment, since the inner diameter of the opening of the pressurizing chamber 200 is large, the wall thickness of the valve packing 70 and the intake valve seat 72 around the fuel passages 216 and 218 is ensured, and high pressure is applied during pressurization. The positions of the fuel passages 216, 218 to which the pressure is added can be set. This improves the pressure resistance between the valve packing 70 and the suction valve seat 72.

(9b) In the eleventh embodiment, since the inner diameter of the opening of the pressurizing chamber 200 is large, the fuel chamber 202 is formed by the disk-shaped recess on the pressurizing chamber 200 side of the intake valve seat 40, and the pressurizing chamber 200 is heated. It is not necessary to connect the pressure chamber 200 and the fuel passage 216. As a result, it is possible to prevent the step portion from being formed on the pressurizing chamber 200 side of the intake valve seat 40 as much as possible, so that the pressure resistance of the intake valve seat 40 is improved.

[10. Other Embodiments]
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be implemented.

(8a) In the first embodiment, the third embodiment, the fifth embodiment, the seventh embodiment, the ninth embodiment, and the eleventh embodiment, when the valve member 50 separates from the valve seat 40b, the spring chamber 204 is opened. A configuration may be adopted in which the fuel is drawn into the pressurizing chamber 200 through it. In this case, when the valve member 50 is seated on the valve seat 40b, the spring chamber 204 is shut off from the pressurizing chamber 200.

(8b) In each of the third embodiment shown in FIG. 4, the ninth embodiment shown in FIG. 10, and the eleventh embodiment shown in FIG. 12, the annular fuel passage 240 is provided not on the intake valve seat 40 side but on the valve side. It may be formed on the packing 42 side.

In addition, in each of the fourth embodiment shown in FIG. 5, the tenth embodiment shown in FIG. 11, and the twelfth embodiment shown in FIG. 13, the annular fuel passage 242 is provided not on the intake valve seat 72 side but on the valve packing. It may be formed on the 70 side.

(8c) In the fifth embodiment shown in FIG. 6, without using the knock pin 46, the fuel passage 216 and the fuel passage are provided on the end face of the intake valve seat 40 on the valve packing 42 side or the end face of the valve packing 42 on the intake valve seat 40 side. An annular fuel passage communicating with 218 may be formed.

Further, in the sixth embodiment shown in FIG. 7, without using the knock pin 46, the fuel passage 216 and the fuel passage 216 are not provided on the end surface of the valve packing 70 on the intake valve seat 72 side or the end surface of the intake valve seat 72 on the valve packing 70 side. An annular fuel passage communicating with the passage 218 may be formed.

(8d) In the seventh embodiment shown in FIG. 8, the annular fuel passage 240 may be formed not on the end surface of the intake valve seat 40 on the common member 90 side but on the end surface of the common member 90 on the intake valve seat 40 side. Good.

Further, in the eighth embodiment shown in FIG. 9, the annular fuel passage 242 may be formed not on the end surface of the common member 100 on the valve packing 70 side but on the end surface of the valve packing 70 on the common member 100 side.

(8e) In the seventh embodiment shown in FIG. 8, the intake valve seat 40 and the common member 90 are arranged so that the annular fuel passage 240 is not formed in the intake valve seat 40 and the fuel passage 216 and the fuel passage 250 are communicated with each other. The rotation directions of and may be positioned by the knock pin 46.

Further, in the eighth embodiment shown in FIG. 9, the annular fuel passage 242 is not formed in the common member 100, and the valve packing 70 and the common member 100 rotate so that the fuel passage 216 and the fuel passage 250 communicate with each other. The direction may be positioned by the knock pin 46.

Further, in each of the ninth embodiment shown in FIG. 10 and the eleventh embodiment shown in FIG. 12, the annular fuel passage 240 is not formed in the intake valve seat 40, and the fuel passage 216 and the fuel passage 218 communicate with each other. As described above, the knock pin 46 may position the rotation directions of the intake valve seat 40 and the valve packing 42.

Further, in the tenth embodiment shown in FIG. 11 and the twelfth embodiment shown in FIG. 13, the annular fuel passage 242 is not formed in the intake valve seat 72, and the fuel passage 216 and the fuel passage 218 communicate with each other. Further, the rotation directions of the valve packing 70 and the suction valve seat 72 may be positioned by the knock pin 46.

(8f) A plurality of functions of one constituent element in the above-described embodiment may be realized by a plurality of constituent elements, or one function of one constituent element may be realized by a plurality of constituent elements. .. Further, a plurality of functions of a plurality of constituent elements may be realized by one constituent element, or one function realized by a plurality of constituent elements may be realized by one constituent element. Moreover, you may omit a part of structure of the said embodiment. Further, at least a part of the configuration of the above-described embodiment may be added or replaced with respect to the configuration of the other above-described embodiment.

2: Fuel injection pump, 30: Plunger, 40, 72: Intake valve seat (intake valve), 44, 80: Discharge valve seat (discharge valve), 40b, 44a, 72a, 80a, 90a, 100a, 100b: Valve seat , 50, 74: valve member (suction valve), 52, 76: spring (suction valve), 56: valve member (discharge valve), 58: spring (discharge valve), 90: common member (discharge valve), 90, 100: common member (suction valve, discharge valve), 200: pressurization chamber, 204: spring chamber (low pressure chamber), 210, 230: fuel chamber (suction passage), 212, 232, 260, 262: fuel passage (suction) Passages), 216, 218, 222, 224, 240, 242, 250: fuel passage (discharge passage), 220: fuel chamber (discharge passage), 234: spring chamber (suction passage)

Claims (5)

A plunger (30) that pressurizes fuel sucked into the pressurizing chamber (200) from the suction passages (210, 212, 230, 232, 234, 260, 262) by reciprocating;
When the plunger moves in the suction direction for sucking fuel into the pressurizing chamber, the valve opens to allow the fuel to be sucked into the pressurizing chamber from the suction passage, and the plunger applies the fuel in the opposite direction to the suction direction. An intake valve (40, 50, 52, 72, 74, 76, 100) that closes when moving in the pressurizing direction by pressing and shuts off the intake of fuel from the intake passage into the pressurizing chamber;
When the plunger moves in the pressurizing direction, the valve is opened to discharge the pressurized fuel in the pressurizing chamber from the discharge passages (216, 218, 222, 224, 240, 242, 250) to the discharge valve (44, 56, 58, 80, 90, 100),
Equipped with
The suction valve and the discharge valve are installed coaxially,
The suction passage and the discharge passage are different passages, and there is no common passage between the suction passage and the discharge passage,
Fuel injection pump (2). The fuel injection pump according to claim 1, wherein
The discharge passage is formed along the pressurizing direction,
Fuel injection pump. The fuel injection pump according to claim 1 or 2, wherein
The suction valve is
A needle-shaped valve member (50),
An intake valve seat (40) having a valve seat (40b) that closes the intake valve when the valve member is seated and opens the intake valve when the valve member is released;
The valve member is installed on a side opposite to the pressurizing chamber, and is installed in a low pressure chamber (204) that is shut off from the pressurizing chamber when the valve member is seated on the valve seat. A spring (52) for applying a load to the valve member,
With
Fuel injection pump. The fuel injection pump according to claim 3, wherein
The low pressure chamber is shut off from the pressurizing chamber even when the valve member is separated from the valve seat.
Fuel injection pump. The fuel injection pump according to claim 1 or 2, wherein
The suction valve is
A ball-shaped valve member (74),
When the valve member is seated, the suction valve is closed, and when the valve member is separated, the suction valve is opened, and the valve member is formed on the side opposite to the pressurizing chamber. An intake valve seat (72) having a valve seat (72a),
A spring (76) which is installed on the pressurizing chamber side with respect to the valve seat and applies a load to the valve member toward the valve seat;
With
Fuel injection pump.

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