JPH0210287Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a distribution type fuel injection pump for an internal combustion engine, and more particularly to a distribution type fuel injection pump equipped with a load timer.

(Technical background of the invention and its problems) A distribution type fuel injection pump that injects fuel to a diesel engine has a configuration as shown in FIG. 1, for example, and is installed through the rear part of the pump housing 1. A feed pump 3 consisting of a vane pump is attached to the drive shaft 2 connected to the output shaft of an engine (not shown).
A rotor 4 is fitted therein. The rotor 4 receives fuel pumped by the pump 5 through a filter 6 and a passage 5 formed in the pump housing 1.
0 and 7 and pressurized by vanes (not shown) engaged with the rotor 4, that is, fuel at a pressure related to the engine speed is supplied to the cover which also serves as a part of the housing of the feed pump 3. Part 9
The pump chamber 11 in the pump housing 1 is supplied through a through hole 10 formed in the pump housing 1 .

A flange 13 in which a plurality of pawls 12 are formed is integrally provided on the right end of the drive shaft 2, and the pawls 12 are formed in a plurality of notch grooves 1 formed in the middle plate 14.
5, a plurality of other notch grooves 16 (only one is shown) are formed in the middle plate 14, and a plurality of pawls 19 (of a cam disk 18 fixed to the plunger 17) are formed in this groove (only one is shown) are engaged.

With this configuration, the relative position of the cam disk 18 and therefore the plunger 17 with respect to the drive shaft 2 is always constant in the rotational direction, that is, in the circumferential direction, but is made to be displaced in the axial direction.

Furthermore, a plurality of rollers 2 are provided on the outer periphery of the intermediate plate 14.
A roller holder 21 that supports a roller holder 21 (only one is shown) and is allowed to rotate through a limited angle is provided concentrically with the drive shaft 2, and the cam disk 18 has ridges corresponding to the number of engine cylinders. Since a cam surface 22 is formed and the cam surface 22 of the cam disk 18 is pressed against the roller 20 of the roller holder 21 by a spring (not shown), the cam disk 18, and therefore the plunger 17, are not affected by the rotation of the drive shaft 2. Accordingly, as is well known, rotation for distributing fuel and reciprocating motion for sucking and pumping fuel are performed simultaneously.

A servo valve timer 23 is disposed below the roller holder 21. The servo valve timer 23 has a casing 24 in which a hydraulically responsive piston 25 is slidably disposed. This piston 25 and the roller holder 21 are connected to the connecting lever 2 through a ball 26.
7. The left side of the piston 25 is a low pressure chamber 28, and the right side is a high pressure chamber 29. A hole 30 is formed in the axial direction of the piston 25 from the low pressure chamber 28 side, and a small diameter hole 31 is further formed in the deep part of this hole 30. has been done. A passage 32 is formed in the piston 25 and communicates the circumferential surface of the hole 31 with the high pressure chamber 29.
A servo valve 34 is slidably fitted inside and biased by a coil spring 33 to close the passage 32 at all times. This servo valve 34
A communication hole 35 is formed in the chamber, and when the communication hole 35 matches the passage 32, the low pressure chamber 28 and the high pressure chamber 29 communicate with each other. Further, the low pressure chamber 28 communicates with the passage 7 via a passage 36 formed in the pump housing 1.

A mechanical governor 40 is provided above the cam disk 18 and has a flyweight 39 engaged with a governor sleeve 38 that is fitted onto the governor shaft 37 so as to be slidable in the axial direction. The tip is the plunger 1
The start lever 41 is connected to a control sleeve 17' which is fitted onto the outside of the control sleeve 7.

A passage 46 is provided at the axis of the governor shaft 37, and one end of this passage 46 is connected to the low pressure side, for example, the inlet side of the feed pump 3, through a passage 42 communicating with the spring chamber of the regulating valve 44.
0, the other end is open through a port on the outer peripheral surface, and is provided in the governor sleeve.
When the governor sleeve 38 moves to the right in the figure as the engine speed increases and the port of the passage 46 of the governor shaft 37 and the control port 47 of the governor sleeve 38 are aligned,
The pressure inside the pump chamber 11 is reduced to the low pressure side, that is, the passage 50.
A load timer 48 is provided to return the timer 23 to the delay side by refluxing the water to lower the pressure.

The spring chamber of the regulating valve 44 communicates with the passage 46 of the load timer 48 and also communicates with the passage 50 via the passage 42, and the valve body 42b
The side thereof is communicated with a passage 50 via a passage 43, and the passage 43 and the discharge hole 10 of the feed pump 3 are closed by a valve body 44b set to a predetermined valve opening pressure by a spring 44a.

According to the above-described configuration, if the fuel supplied from the load timer 48 to the regulating valve 44 is contaminated with dust such as metal powder, this dust is transferred from the feed pump 3 to the regulating valve 44. There was a risk that the reflux would cause valve clogging, or that the valve of the servo valve timer would become clogged.

(Objective of the invention) An object of the present invention is to provide a distribution type fuel injection pump that eliminates the drawbacks of the conventional pump described above and that can reliably remove dust from the fuel.

(Summary of the invention) In order to achieve the above purpose, in this invention,
In a distribution type fuel injection pump in which a governor is provided with a load timer having a passage communicating with a regulating valve, the passage communicating between the regulating valve and a feed pump built in the distribution type fuel injection pump. A distribution type fuel injection pump provided with a filter is provided.

(Embodiments of the invention) The invention will be described below with reference to embodiments shown in the drawings. Note that the same components as those of the conventional device described above are designated by the same reference numerals in the drawings, and their explanations will be omitted.

FIG. 2 shows an embodiment of the present invention, showing a fuel tank (not shown) and passages 7, 36, 42,
A step 51 is formed at the lower end of a straight hole 50 that communicates with the passage 36 , and below the step 51 the straight hole 50 communicates with the passage 36 . This straight hole 5
A cylindrical filter 52 is installed inside the
The outer diameter of the intermediate portion of the filter 52 is smaller than the inner diameter of the straight hole 20. The outer diameter of the upper and lower ends of the filter 52 is approximately equal to the inner diameter of the straight hole 50, and reinforcing caps 53, 53 are attached to the upper and lower ends of the filter 52, respectively.

A cap 53 at the lower end of the filter 52
is seated on the stepped portion 51, and a threaded joint 54 is screwed into the straight hole 50 to prevent upward movement of the filter 52. This threaded joint 54 is connected to a fuel tank (not shown). Furthermore, a shielding ring 55 made of, for example, rubber is attached to the outer periphery of the filter 52 at approximately the middle thereof, so that the fuel from the passages 42 and 43 is introduced into the passage 7 after passing through the filter 52. It's getting old.

According to such a configuration, a filter 52 having a large surface area is disposed within the straight hole 50, and the filter 52 has a large surface area.
Since the fuel from Nos. 2 and 43 is introduced into the passage 7 after passing through the filter 52, dirt in the fuel is reliably removed. Further, the filter 52 can be easily attached and detached by attaching and detaching the threaded joint 54.

(Effects of the invention) As explained above, in the distribution type fuel injection pump according to the invention, since the filter is provided in the passage that communicates the regulating valve and the feed pump, it is possible to increase the surface area of the filter. This has the practical effect of being able to reliably remove dust from the fuel.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a general distribution type fuel injection pump, and FIG. 2 is a schematic vertical sectional view of the main parts showing an embodiment of the distribution type fuel injection pump according to the present invention. 1... Pump housing, 2... Drive shaft, 3...
...Feed pump, 17...Plunger, 18...
...Cam disc, 23...Servo timer, 25...
...Piston, 28...Low pressure chamber, 29...High pressure chamber,
34... Servo valve, 39... Fly weight, 40... Mechanical governor, 45... Passage,
46... Penetration path, 47... Control port, 48...
Load timer, 50... straight hole, 52... filter, 53... cap, 54... threaded joint, 55...
shielding ring.

Claims (1)

[Scope of utility model registration request] In a distribution type fuel injection pump in which a governor is provided with a load timer having a passage communicating with a regulating valve, the passage communicating between the regulating valve and a feed pump built in the distribution type fuel injection pump. A distribution type fuel injection pump characterized by being equipped with a filter.