JPH0322550Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a fuel injection pump used in a diesel engine, and particularly to a fuel injection pump suitable for pressurizing highly viscous fuel such as C heavy oil.

(Prior Art) There are various methods for adjusting the injection amount and injection timing in fuel injection pumps.One method that incorporates adjustment mechanisms for both into the pump body is, for example, the Utility Model No. 58 -There is one shown in Publication No. 129069. In this system, the injection amount is adjusted by rotating a plunger relative to the barrel, while the injection timing is adjusted by moving the barrel up and down. This injection timing adjustment is achieved by inserting a barrel into the pump body so as to prevent the barrel from rotating relative to the pump body, and attaching a timing adjustment control rod to the barrel with threads formed on the inner and outer surfaces. When the control rod is moved, the control sleeve rotates, which is converted into vertical movement of the barrel.

However, in the above conventional example, the type of fuel to be injected is not considered. For example, when injecting something that has high viscosity at room temperature, such as C heavy oil, the fuel may be splashed inside the pump body. There was a risk that the particles would adhere to the sliding parts of the adjustment mechanism, fixing the control system and making it impossible to control it. Therefore, a device disclosed in Japanese Utility Model Application Publication No. 59-131970 was proposed. According to this, a configuration is shown in which a lubricating groove 14 is provided in the housing 1, and lubricating oil supplied from the lubricating groove 14 lubricates between the barrel and the control sleeve.

(Problem to be solved by the invention) However, since the lubricating oil also flows to the control rod side, from the control rod insertion hole,
The problem was that the lubricating oil leaked out.

Therefore, this idea was developed by supplying special oil for lubrication to the sliding part of the adjustment mechanism separately from the fuel oil in a pump body in which the adjustment mechanism for the injection amount and injection timing is built into the pump body as described above. An object of the present invention is to provide a fuel injection pump that can prevent the lubricating oil from sticking and leaking from the control rod insertion hole, and can reliably control the injection amount and injection timing.

(Means for solving the problem) The gist of this invention is to insert the barrel 15 into the pump body 1 in such a way as to prevent the barrel 15 from rotating relative to the pump body 1. , the plunger 19 relative to the barrel 15
The plunger 19 is inserted into the barrel 15 so as to allow both vertical and rotational movement, and the plunger 19
The periodic mechanical pressing force received from below the plunger 19 and the spring 2 disposed in the spring storage chamber 25 formed in the pump body 1
The plunger 1 moves up and down due to the return force of 6.
A first adjustment mechanism 27 for adjusting the relative position of the barrel 15 in the rotational direction with respect to the barrel 15 and a second adjustment mechanism 32 for adjusting the relative position of the barrel 15 in the vertical direction with respect to the plunger 19 are provided. The adjustment mechanism 27 includes a first control rod 28 that is slidably provided on the pump body 1 and a first control sleeve 2 that engages with the first control rod 28 and the plunger 19.
9, and the second adjustment mechanism 32
The second control rod 33 is slidably provided on the pump body 1, and the second control rod 33 is fixed in vertical position with respect to the pump body 1 and is connected to the barrel 15 and the second control rod 33. a matching second control sleeve 34;
Furthermore, a lubricating oil supply passage 3 leading from a lubricating oil inlet 38 formed in the pump body 1 above the first control rod 28 to the spring storage chamber 28 is provided.
7 is provided, and the lubricating oil supply passage 37 is surrounded by the pump body 1, the barrel 15, and the second control sleeve 34, and includes a first lubricating oil reservoir chamber 39 communicating with the lubricating oil inlet 38, Barrel 1
5 and a second control sleeve 34 , and communicates with each other via a threaded portion 45 between the barrel 15 and the second control sleeve 34 , and a lower end of the barrel 15 . A main supply hole 4 formed in the barrel 15 extends upward from a lubricating oil outlet 41a formed in the main supply hole 4.
1, a first horizontal hole 42 that communicates the main supply hole 41 with the second lubricating oil reservoir chamber 40, and sliding movement between the barrel 15 and the first control sleeve 29 from the main supply hole 40. Second horizontal hole 4 extending to the surface
It consists of three things.

(Function) According to such a configuration, the first adjustment mechanism 27
By moving the first control rod 28 in the first control sleeve 29, the plunger 19 rotates, and the effective stroke of the plunger 19 changes to adjust the injection amount. By moving the second control rod 33 of the adjustment mechanism 32, the barrel 15 moves up and down via the second control sleeve 34, and the pre-stroke of the plunger 19 changes to adjust the injection timing.
In this case, smooth sliding between the barrel 15, the first control sleeve 29, and the second control sleeve 34 is required, but these sliding parts are provided with a lubricating oil supply passage 37, that is, It is surrounded by the pump body 1, the barrel 15 and the second control sleeve 34, and has a lubricating oil inlet 3.
The first lubricating oil reservoir chamber 39 communicates with the barrel 15 and the second control sleeve 34 through a threaded portion 45 between the barrel 15 and the second control sleeve 34. The second lubricating oil reservoir chamber 40 and the barrel 15
A main supply hole 41 formed in the barrel 15 so as to extend upward from a lubricant outlet 41 a formed at the lower end of the barrel 15 , and a first lubricant reservoir chamber 40 that communicates with the main supply hole 41 and the second lubricant reservoir chamber 40 . It flows into the horizontal hole 42 and is lubricated, but does not flow toward the first and second control rod insertion holes, so that the above object can be achieved.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

1 and 2, an embodiment of this invention is shown, in which a pump body 1 is formed with vertical holes 2 of a number corresponding to the number of cylinders penetrating from the upper end to the lower end of the pump body 1, A valve device 3 is provided to close the upper end opening of the vertical hole 2.

This valve device 3 is fixed via a plurality of mounting bolts 6 inserted from the vertical hole 2 side so that the upper valve holder 4 and the lower valve seat 5 are in contact with each other.
Also, a plurality of tightening bolts 7 inserted from above
A valve holder 4 is fixed to the upper end of the pump main body 1 via. A fuel outlet 8 is formed at the upper end of the valve holder 4, and an injection pipe 9 is connected to the fuel outlet 8. Further, a fuel discharge passage 10 that opens into a fuel pressure chamber 20 (described later) is formed in the valve seat 5, and the fuel outlet 8 and the high pressure fuel passage 10 are connected to each other.
The fuel discharge passage 11 and the fuel return passage 12 are connected to each other via a bifurcated fuel discharge passage 11 and a fuel return passage 12, respectively. Valves 13 and 14 are arranged in the fuel discharge passage 11 and the fuel return passage 12, respectively, and constitute equal pressure valves.

The barrel 15 is slidably inserted into the vertical hole 2 of the pump body 1. A barrel positioning bolt 16 is attached to the pump body 1 so as to pass through the vertical hole 2 from the side, and a locking groove 17 is formed in the vertical direction slightly in front of the upper end of the barrel 15.
The barrel positioning bolt 16 engages with this rotation prevention difference, preventing the barrel 15 from rotating relative to the pump body 1, and only allowing the barrel 15 to move up and down relative to the pump body 1. Further, a plunger insertion hole 18 is formed in the center of the barrel 15 so as to pass through from the upper end to the lower end of the barrel 15. A plunger 19 described below is inserted, and a fuel pressure chamber 20 is constituted by being surrounded by the valve seat 5, the plunger insertion hole 18, and the plunger 19. This fuel pressure chamber 2
0 includes the high pressure fuel passage 10 of the valve seat 5 mentioned above.
One end is open, and the fuel intake/discharge hole 21
One ends of a and 21b are open. The other ends of the fuel intake/discharge holes 21a, 21b open into a fuel reservoir chamber 22 surrounded by the pump body 1 and the barrel 15, and a fuel inlet (not shown) communicates with the fuel reservoir chamber 22.

The plunger 19 is inserted into the plunger insertion hole 18 of the barrel 15 so as to allow both vertical and rotational movement, and the lower end of the plunger 19 engages with a plunger guide 23 so that the plunger 19 is inserted upwardly from a cam (not shown) through the plunger guide 23. It is designed to periodically receive mechanical pressing force. Further, a spring storage chamber 25 is provided between the spring receiver 24 that fits into the vertical hole 2 of the pump body 1 and the aforementioned plunger guide 23, and a spring 26 is stored in this spring storage chamber 25. The upper end of the spring 26 contacts the spring receiver 24, the lower end contacts the plunger guide 23, and when the above-mentioned mechanical pressing force on the plunger 19 is released, the plunger 1
Return it to its original position in step 9. Further, a well-known lead (not shown) is formed on the upper peripheral edge of the plunger 19, and the lead and the above-mentioned fuel intake/discharge hole 2 are formed.
Plunger 19 depending on the positional relationship between 1a and 21b.
The effective stroke and pre-stroke of are to be determined.

The first adjustment mechanism 27 is for adjusting the injection amount, and is connected to a first control rod 28 which is slidably inserted in the lateral direction of the pump body 1, and a first control rod 28 which is slidably inserted into the barrel 15 described above. a first control sleeve 29 fitted over the control rod 28 and the control sleeve 2;
9 mesh with each other in the form of a rack and pinion. The first control sleeve 29 engages the spring receiver 24 with a stepped portion, and an engagement groove 30 is formed in the lower part of the sleeve 29, and a face portion 31 formed on the plunger 19 is engaged with this engagement groove 30.
Therefore, when the first control rod 28 is moved, the first control sleeve 29 rotates, and the plunger 19 accordingly rotates relative to the barrel 15, changing the effective stroke of the plunger 19. , whereby the injection amount is adjusted.

The second adjustment mechanism 32 is for adjusting the injection timing, and is similar to the first adjustment mechanism 27 described above.
Similarly, it has a second control rod 33 which is slidably inserted laterally into the pump body 1 and a second control sleeve 34 which engages with the control rod 33 in the form of a rack and pinion. This second control sleeve 34
The upper outer circumferential portion is in close contact with the vertical hole 2 of the pump body 1, the upper inner circumferential portion is engaged with the outer circumference of the barrel 15 with the threaded portion 45 made of a trapezoidal thread, and the central outer portion is in close contact with the vertical hole 2 of the pump body 1, and the central outer portion is in close contact with the vertical hole 2 of the pump body 1. It meshes with the control rod 33 of No. 2, and the lower inner peripheral part is the barrel 15.
The control sleeve 29 is in close contact with the outer periphery of the control sleeve 29, and its lower end surface is in contact with the upper end surface of the first control sleeve 29 described above. Further, an annular groove 35 is formed on the outer circumferential surface of the second control sleeve 34, and a control sleeve positioning bolt 36 is attached to the pump body 1 so as to penetrate from the side into the vertical hole 2. The bolt 36 is connected to the control sleeve 34
The control sleeve 34 is engaged with the annular groove 35 of the control sleeve 34, thereby inhibiting vertical movement of the control sleeve 34. Therefore, the second
When the control rod 33 is moved, the second control sleeve 34 rotates with its vertical position fixed, and the barrel 15 is prevented from rotating by the barrel positioning bolt 16 and the locking groove 17 mentioned above. Therefore, the rotation of the second control sleeve 33 is converted into the vertical movement of the barrel 15, and the prestroke of the plunger 19 changes.
The injection timing is adjusted.

The lubricating oil supply passage 37 is a passage leading from the lubricating oil inlet 38 formed in the pump body 1 to the spring storage chamber 25 described above, and is a passage that connects the first adjustment mechanism 27.
It supplies lubricating oil to the sliding parts of the second adjustment mechanism 32, and its detailed configuration is shown in FIG.

That is, in FIG. 2, the lubricating oil supply passage 37
has a first lubricating oil reservoir chamber 39 and a second lubricating oil reservoir chamber 40. The first lubricating oil reservoir chamber 39 is
It is surrounded by the inner circumferential surface of the vertical hole 2, the annularly cut portion of the barrel 15, and the upper end surface of the second control sleeve 34. Further, the second lubricating oil reservoir chamber 40 is surrounded by the barrel 15 and the second control sleeve 34 below the threaded portion 45 of the barrel 15 and the second control sleeve 34 described above.

Furthermore, the lubricating oil supply passage 37 has a lubricating oil outlet 41a that opens at the lower end surface of the barrel 15, and has a main supply hole 41 that extends upward into the barrel 15 from the lubricating oil outlet 41a. The upper end of the main supply hole 41 communicates with the first lubricating oil reservoir chamber 39 via a first horizontal hole 42 formed in the barrel 15 . In addition, this main supply hole 42 has a second horizontal hole 43.
One end of the second horizontal hole 43 is open, and the other end of the second horizontal hole 43 is open.
The lubricating oil reservoir chamber 44 is opened therein. This third lubricating oil reservoir chamber 44 is provided at a sliding portion between the barrel 15 and the first control sleeve 29. The lubricating oil supply passage 37 leads to the spring storage chamber 25 via the engagement groove 30 described above.

In the above configuration, when a mechanical pressing force upward from a cam (not shown) is applied to the plunger 19 from below, the plunger 19 lifts against the spring 26 . When the lift amount of the plunger 19 exceeds a predetermined value (prestroke), the fuel intake and discharge holes 21a and 21b are closed by the plunger 19, and the pressure of the fuel in the fuel pressure chamber 20 increases.
Pushing open the valve body 13 on the discharge side of the valve device 3,
Fuel is sent from the fuel outlet 8 via the injection pipe 9 to the injection valve. Thereafter, when the lift amount of the plunger 19 exceeds a predetermined value (effective stroke), the fuel pressure chamber 20 and the fuel intake/discharge holes 21a, 21b communicate with each other via the lead portion of the plunger 19.
The pressure of the fuel in the fuel pressure chamber 20 drops rapidly, the valve body 13 on the discharge side closes, and fuel injection ends. In this case, when the pressure on the injection pipe 9 side is high, the return side valve body 14 is opened to maintain the post-injection pressure on the injection pipe 9 side at a predetermined value and prevent problems such as secondary injection.

As mentioned above, the injection amount is adjusted by moving the first control rod 27 of the first adjustment mechanism 27 to rotate the plunger 19 via the first control sleeve 28. Also,
The injection timing is adjusted by moving the second control rod 33 of the second adjustment mechanism 32 to rotate the second control sleeve 34, thereby moving the barrel 15 up and down.

If fuel that is highly viscous at room temperature, such as C heavy oil, is splashed and attached to such adjustment mechanisms 27 and 32, it will solidify when the temperature returns to room temperature, and the adjustment mechanism 2
In this embodiment, the sliding parts 7 and 32 are supplied with lubricating oil to prevent fuel from adhering to them.

That is, pressurized lubricating oil is sent to the lubricating oil inlet 38 by a lubricating oil supply pump (not shown), and this lubricating oil is temporarily stored in the first lubricating oil reservoir chamber 39 and then passed through the threaded portion 45. The threaded portion 45 is then lubricated and reaches the second lubricating oil reservoir chamber 40, where it is temporarily stored. A part of the lubricating oil is used to lubricate the sliding portion between the barrel 15 and the second control sleeve 34 below the second lubricating oil reservoir chamber 40, and the other lubricating oil is used to lubricate the sliding portion between the barrel 15 and the second control sleeve 34, and the other lubricating oil is used to lubricate the sliding portion between the barrel 15 and the second control sleeve 34 below the second lubricating oil reservoir chamber 40.
A part of the lubricating oil that enters the main supply hole 41 from the main supply hole 41 through the second horizontal hole 43 passes through the third side hole 43.
The lubricating oil reaches the lubricating oil reservoir chamber 44, where it is used to lubricate the sliding portion between the barrel 15 and the first control sleeve 29, and other lubricating oil passes through the engagement groove 30 of the first control sleeve 29 to accommodate the spring. room 2
5, and is further sent from this spring storage chamber 25 to the crank chamber, where it is recovered.

(Effects of the invention) As described above, according to this invention, a dedicated lubricating oil is used separately from the fuel oil in a fuel injection pump in which a mechanism for adjusting the injection amount and injection timing is built into the pump body. Since the lubricating oil is supplied to the sliding part of the adjustment mechanism, it is possible to prevent fuel from adhering to the sliding part, and the injection amount and timing can be reliably controlled. Since the lubricating oil flows through the lubricating oil supply passage 37, it does not reach the first and second control rods, and there is no risk of it leaking out from the first and second control rod insertion holes.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of this invention, and FIG. 2 is an enlarged sectional view showing the main parts of the same. 1... Pump body, 15... Barrel, 19...
Plunger, 25... Spring storage chamber, 26...
...Spring, 27...First adjustment mechanism, 28...
... first control rod, 29 ... first control sleeve, 32 ... second adjustment mechanism,
33... Second control rod, 34... Second control sleeve, 37... Lubricating oil supply passage, 38... Lubricating oil inlet, 39... First lubricating oil reservoir chamber, 40... Second Lubricating oil reservoir chamber, 41...
...Main supply hole, 42...First horizontal hole, 43...Second
horizontal hole, 45...threaded part.

Claims (1)

[Scope of utility model registration request] The barrel 1 is attached to the pump body 1 in a manner that prevents the barrel 15 from rotating relative to the pump body 1.
5 and insert the plunger 19 into the barrel 1 so as to allow both vertical and rotational movement of the plunger 19 relative to the barrel 15.
Insert the plunger 19 into the plunger 1.
9 is moved up and down by a periodic mechanical pressing force received from below the plunger 19 and a return force of a spring 26 disposed in a spring storage chamber 25 formed in the pump body 1. A first adjustment mechanism 27 that adjusts the relative position of the barrel 15 in the rotational direction and a second adjustment mechanism 32 that adjusts the relative position of the barrel 15 in the vertical direction with respect to the plunger 19 are provided, and the first adjustment mechanism 27 includes a first control rod 28 that is slidably provided on the pump body 1 and a first control sleeve 29 that engages with the first control rod 28 and the plunger 19. , and the second adjustment mechanism 32
The second control rod 33 is slidably provided on the pump body 1, and the second control rod 33 is fixed in vertical position with respect to the pump body 1 and is connected to the barrel 15 and the second control rod 33. a matching second control sleeve 34;
Furthermore, a lubricating oil supply passage 3 leading from a lubricating oil inlet 38 formed in the pump body 1 above the first control rod 28 to the spring storage chamber 28 is provided.
7 is provided, and the lubricating oil supply passage 37 is surrounded by the pump body 1, the barrel 15, and the second control sleeve 34, and includes a first lubricating oil reservoir chamber 39 communicating with the lubricating oil inlet 38, Barrel 1
5 and a second control sleeve 34 , and communicates with each other via a threaded portion 45 between the barrel 15 and the second control sleeve 34 , and a lower end of the barrel 15 . A main supply hole 4 formed in the barrel 15 extends upward from a lubricating oil outlet 41a formed in the main supply hole 4.
1, a first horizontal hole 42 that communicates the main supply hole 41 with the second lubricating oil reservoir chamber 40, and sliding movement between the barrel 15 and the first control sleeve 29 from the main supply hole 40. Second horizontal hole 4 extending to the surface
3. A fuel injection pump comprising: 3.