JPS61252865A - Fuel injection pump and manufacture thereof - Google Patents

Abstract

PURPOSE:To facilitate the finishing of a plunger barrel by constituting the plunger barrel from the outside barrel body and the liners fixed onto the inside of the barrel body, thus preventing the deformation of the slidable part with the plunger due to the quenching of the body. CONSTITUTION:As for a plunger barrel 3, liners 3b and 3c are insertion-fitted into the insertion holes 5a and 5b after the material of the barrel body 3a is quenched, and then the barrel body 3a is cold-fitted, and the liners 3b and 3c are fixed. Then, each inside diameter of the plunger insertion holes 6a and 6b is finishing-worked, and fitted with a plunger 7. Therefore, the deformation of the slidable part of the plunger 7 in the quenching of the barrel body 3a can be prevented, and the plunger barrel 3 can be easily finishing-worked. Since, as for the barrel body 3a, the liners 3b and 3c are insertion-fitted and fixed through cold fitting, the manufacture of the plunger barrel 3 is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection pump used in a diesel engine and a method for manufacturing the same.

(Prior art) As this type of fuel injection pump, for example, Utility Model No. 57-1
As shown in Japanese Patent No. 42167, a plunger is slidably inserted into a plunger barrel fixed within a pump body, and a control sleeve is slidably fitted onto the plunger, and the control sleeve and plunger are A type of fuel injection amount and injection timing is controlled by changing the relative position with respect to the fuel injection valve.

The control sleeve is located in a fuel reservoir, and a recess must be formed in the plunger barrel to form this fuel reservoir. Here, hardened steel is usually used as the material for the plunger barrel in consideration of its wear resistance.
Hardened steel has poor machinability, and it is difficult to form four parts by boring the material after hardening. For this reason, in the past, the plunger barrel was divided into two parts, an upper barrel and a lower barrel, a recess was formed in the upper barrel in advance, and the lower end of the upper barrel and the upper end of the lower barrel were fixed by welding. It was then hardened and made into a plunger barrel.

(Problems to be Solved by the Invention) However, in such conventional examples, the plunger barrel undergoes large deformation during hardening, and it is difficult to remove this deformation. There is a problem in that it is difficult to finish the inner diameter of the plunger barrel to a degree that maintains oil tightness.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a structure and a manufacturing method for a fuel injection pump that is based on the quenching deformation of the plunger barrel as described above and that can solve the conventional problems and facilitate the processing of the plunger barrel. is the issue.

(Means for Solving the Problems) Therefore, the first invention of the present application is to slidably insert a plunger into a plunger barrel fixed within a pump body, and to insert the plunger into a recess formed in the plunger barrel. In a fuel injection pump of a type in which a control sleeve is slidably fitted onto the plunger, and the relative position between the control sleeve and the plunger is changed to control fuel injection,
The plunger barrel is composed of a barrel body made of hardened steel arranged on the outside, and an upper and lower liner arranged inside the barrel body and divided into upper and lower parts with the recessed part in between, and the plunger is attached to the liner. The fuel injection pump has a sliding type. Further, a second invention of the present application relates to the method for manufacturing the fuel injection pump, in which the liner is inserted and fitted into the barrel body and then cold-fitted to fix the barrel body and the liner. .

(Function) Therefore, it is the liner that directly slides on the plunger, and since the barrel body made of hardened net is placed outside of this liner, there is no deformation of the liner when the barrel body is hardened. Therefore, the above-mentioned problem can be achieved.

(Example) In the figure, the fuel injection pump is mounted directly on the main body of a diesel engine, and has a pump main body 1 made of, for example, an aluminum alloy, and an assembly insertion hole 2 is formed in the vertical direction in the pump main body 1. A plunger barrel 3 is inserted into the upper part of this assembly insertion hole 2.

The plunger barrel 3 is composed of a barrel body 3a disposed on the outside, and upper and lower liners 3b and 3c fitted and fixed inside the barrel body 3a. The barrel body 3a is made of hardened steel, and a recess 4 is formed in the center of the barrel body 3a, with liner insertion holes 5a located above and below the recess 4.

5b is formed, the upper liner 3b is inserted into the upper liner insertion hole 5a, and the lower liner 3C is inserted into the lower liner insertion hole 5b.
are inserted respectively. The liners 3a, 3b are made of, for example, hardened steel, and have plunger sliding holes (3a, 5), respectively.
A plunger 7, which will be described later, is slidably inserted into the plunger sliding holes 6a and 6b. Further, a mounting plate 8 is joined to the upper end of the barrel body 3a by caulking or the like, and this mounting plate 8 is fixed to the upper surface of the pump body 1 via mounting bolts 9.
The barrel 3 is suspended from the pump body 1.

The plunger barrel 3 is constructed by hardening the material of the barrel body 3a and then inserting the liners 3b and 3c into the liner insertion holes 5a and 5.
b, then insert and fit the barrel body 3a into the liner 3b.
, 3c and fix by cold fitting. And after that, the plunger insertion hole 6a.

Finish the inner diameter of 6b and align it with plunger 7.

Therefore, when the barrel body 3a is hardened, the liners 5a, 5b are not deformed, and therefore the plunger barrel 3 can be easily finished.

A fuel pressure chamber 10 is provided above the plunger 7, and this fuel pressure chamber 10 is provided with a plunger sliding hole 5a.

It is surrounded by a plunger 7, a valve seat body 11, and a delivery valve 12. The valve seat body 11 is sandwiched between a valve holder 13 screwed onto the upper part of the barrel body 3a, and a delivery valve 12 is seated on the valve seat body 11. The delivery valve 12 is pressed by a valve spring 14 elastically mounted between it and the valve holder 13. When the pressure in the fuel pressure chamber 10 increases, the delivery valve 12 lifts against the valve spring 14 and presses against the upper end of the valve holder 13. Fuel is discharged from the discharge hole 15 formed therein.

Further, the lower end of the plunger 7 is engaged with a lower spring receiver 16 and is in contact with a tappet 18 via shims 1 and 7. This tappet 18 holds a roller 19, and this roller 19 comes into contact with a cam (not shown) to receive driving force from the engine.

The return spring 20 has a lower spring receiver 16 and an upper spring receiver 21.
The upper spring receiver 21 is in contact with the lower end of the plunger barrel 3, and the return spring 20 applies a return force to the plunger 7.

The injection amount adjusting member 22 is provided at the lower part of the plunger barrel 3, and this injection itgPI node member 22 is connected to the plunger 7.
It engages with the face portion 7a formed on the surface so as to allow movement only in the axial direction. Moreover, this injection amount adjusting member 22 is
It has a ball-shaped protrusion 23 on its upper part, and this protrusion 23 engages with a first control rod 24 that is slidably provided on the pump body 1. By moving this control rod 24, the injection amount is increased. The plunger 7 can be rotated via the adjustment member 22.

The control sleeve 25 is slidably fitted onto the plunger 8 in a fuel reservoir chamber 26 . The fuel reservoir chamber 26 is surrounded by the recess 4 of the plunger barrel 3 except for the negative side, and is surrounded by the fuel reservoir 27 formed in the pump body 1.
and a fuel return port (not shown). Further, the control sleeve 25 has a vertical groove 28 in the axial direction and a horizontal groove n29 in the circumferential direction formed on the outer periphery of the control sleeve 25.
The guide pin 32 fixed to the plunger barrel 3 is
Eccentric pins 31 of a connecting member 30, which will be described later, are respectively engaged with the lateral grooves 29 to determine the positions in the vertical direction and the circumferential direction.

The plunger 7 has a vertical hole 33 whose one end opens into the fuel pressure chamber 10, first and second horizontal holes 34 and 35 connected to the vertical hole 33 and which open on the side surface of the plunger 7. and an inclined groove 3 connecting the openings of the second horizontal holes 34 and 35.
6 is formed.

The first horizontal hole 34 located below is for setting the timing of the start of injection, and the injection starts when the plunger 7 rises and the control sleeve 25 moves in the first horizontal hole 35. . The second horizontal hole 35 is for realizing a no-injection state, and the plunger 7 is rotated in relation to a cut-off boat 37 formed in the control sleeve 25 to open the second horizontal hole 35. When the plunger 7 rises and the control sleeve 25 closes the first lateral hole 35, the second lateral hole 35 and the cut-off boat 37 are placed on the same plane. communicate,
It is designed to be in a non-injection state.

Further, the first control rod 2 of the pump body 1
A second control rod 38 is slidably provided on the same side as 4, and the control sleeve 25 is connected to this second control rod 38 via a connecting member 30. That is, an eccentric pin 31 is provided at one end of the connecting member 30, and a ball-shaped second protrusion 39 is provided at the other end.
are respectively provided eccentrically, the eccentric pin 31 engages in the transverse groove 29 of the control sleeve 25 as described above, and the projection 39 engages in the second control rod 38. Therefore, moving the second control rod 38 causes the coupling member 30 to pivot, thereby causing the control sleeve 2
5 moves up and down.

In the above configuration, when the roller 19 receives an upward force from the engine via a cam (not shown) in the state shown in the figure, the plunger 7 returns to the spring 20 together with the lower spring receiver 16, shim 17, tappet 18, and roller 19. rise against it. However, in this case, the first position of plunger 7 is still
The horizontal hole 34 opens into the fuel reservoir chamber 26, and the fuel pressure chamber 10 and the fuel reservoir chamber 26 communicate with each other via the vertical hole 33 of the plunger 7 and the first horizontal hole 34. The pressure does not increase, and the delivery valve 12 remains closed and no fuel is pumped out.

When the plunger 7 further rises, the first
The horizontal hole 34 is closed by the control sleeve 25, communication between the fuel pressure chamber 10 and the fuel reservoir chamber 26 is cut off, the pressure of the fuel in the fuel pressure chamber 10 increases, and the delivery valve 12 resists the valve spring 14. The fuel in the fuel pressure chamber 10 begins to be discharged from the discharge port 15. This is the beginning of injection, and the amount of lift of the plunger 7 up to the beginning of injection is the prestroke.

When the plunger 7 further rises, the inclined groove 36 of the plunger 7 finally reaches the cut-off port 37 of the control sleeve 25, and the fuel pressure chamber 10 and the fuel reservoir chamber 26 are connected to the vertical hole 33 of the plunger 7, the first and second The horizontal holes 34, 35 and the inclined groove 35 of the control sleeve 25 communicate with each other through the cut-off port 37 of the control sleeve 25, and the fuel in the fuel pressure chamber 10 escapes to the fuel reservoir chamber 26 as the plunger 7 rises. The pressure in the fuel pressure chamber 10 decreases and the delivery valve 12 closes, and this time is the injection path, and the lift amount of the plunger 7 from the start of injection to the injection path is the effective stroke.

When the upward stroke of the plunger 7 is completed and the plunger 7 enters a downward stroke, the pressure in the fuel pressure chamber 10 further decreases, and the first horizontal hole 34 of the plunger 7 opens into the fuel reservoir chamber 26, so that the fuel reservoir chamber 26 fuel is sucked into the fuel pressure chamber 10, and the shortage in the fuel reservoir chamber 26 is transferred from the fuel population 27 to the fuel reservoir chamber 2.
6 and returns to its original state.

The injection amount is adjusted by moving the first control rod 24. When the control rod 24 is moved, the injection amount adjusting member 22 engaged with the control rod 24 rotates, and since the face portion 7a of the plunger 7 is engaged with the injection fiJ1 joint member 22, the plunger 7 also rotates at the same time, causing a change in the relative positional relationship in the circumferential direction between the plunger 7 and the control sleeve 25. Therefore, the position where the inclined groove 36 aligns with the cut-off port 37 changes, thereby changing the effective stroke and adjusting the injection amount.

The injection timing is adjusted using the second control rod 3.
This is done by moving 8. When this second control rod 38 is moved, this control rod 38
Since the second protrusion 39 of the connecting member 30 is engaged with, the connecting member 30 rotates, and the eccentric pin 31 of this connecting member 30 is engaged with the lateral groove 29 of the control sleeve 250. The control sleeve 25 is displaced up and down. therefore,
The distance between the lower end of the control sleeve 25 and the first horizontal hole 34 of the plunger 7 when the plunger 7 is at the bottom dead center, i.e.
The injection timing is adjusted by changing the prestroke.

(Effects of the Invention) As described above, according to the present invention, the plunger barrel is composed of an outer barrel body and a liner fixed to the inside of the barrel body, so that the plunger can be easily removed when the barrel body is hardened. Deformation of the sliding part can be prevented, and the plunger barrel can be easily finished. Furthermore, since the liner is inserted and fitted into the barrel body and then cold-fitted to fix the two, manufacturing of the plunger barrel can be made easier.

[Brief explanation of the drawing]

The figure is a sectional view showing a fuel injection pump in one embodiment of the present invention. 1...Pump body, 3...Plunger barrel, 3a
... Barrel body, 3b, 3c... Liner, 7...
Plunger, 25...control sleeve. Procedural amendment (voluntary) April 4, 1985 Michibu Uga, Commissioner of the Patent Office, 1985 Patent Application No. 72439 2, Name of invention Fuel injection pump and its manufacturing method 3, Person making the amendment Related Patent Applicant Address 3-6-7 Shibuya, Shibuya-ku, Tokyo Name (333
) Diesel Kiki Co., Ltd. Representative: Mochizuki-Sei 4, Agent address: 5 Shinei Miyamasu Building, 1-8-8 Shibuya, Shibuya-ku, Tokyo
Telephone number: 409-0350 6, Scope of claims subject to amendment Column 7: Detailed description of the invention, Contents of amendment ill The scope of claims will be amended as shown in the attached sheet. (2) Delete "Made of hardened steel" on page 4, line 13 of the specification. (3) On page 5, line 4, the words "quenching preparation" should be deleted. (4) In the 6th line of the same document, "hardened steel" should be corrected to "for example, carbon steel." (6) On page 6, line 13, "quenching" is corrected to "processing." (7) In line 18, "quenching" should be corrected to "processing." (8) On page 9, line 14, ``Dojiru'' is corrected to ``Close.'' (9) Page 14, line 4 ``Quenching'' has been corrected to ``processing.'' 2. Scope of Claims 1. A plunger is slidably inserted into a plunger barrel fixed within a pump body, and a control sleeve is slidably fitted over the plunger within a recess formed in the plunger barrel, and the control sleeve and the plunger are In a fuel injection pump of a type that controls fuel injection by changing the relative position between the plunger barrel and the barrel body, the plunger barrel is arranged between a barrel body disposed on the outside and a barrel body disposed inside the barrel body, and the plunger barrel is vertically disposed between the plunger barrel and the barrel body disposed on the outside. 1. A fuel injection pump comprising an upper and lower liner divided into upper and lower liners, and the plunger is slid on the liner. 2. A plunger is slidably inserted into a plunger barrel fixed within the pump body, and a control sleeve is slidably fitted onto the plunger within a recess formed in the plunger barrel, and the control sleeve and In a fuel injection pump of a type that controls fuel injection by changing the relative position with respect to the plunger, the plunger barrel is fitted into the barrel body by vertically inserting the liner across the recess, and then the barrel body is inserted into the barrel body. A method for manufacturing a fuel injection pump, characterized in that the fuel injection pump is configured by being cold-fitted onto a liner. Procedural Amendment Form) Mr. Michibu Uga, Commissioner of the Patent Office, J.J. 1986.5
: Judgment'・' 1. Indication of the case 1985 Patent Application No. 72439 2. Name of the invention Fuel injection pump and its manufacturing method 3. Person making the amendment Relationship with the case Representative of the patent applicant Mochizuki - Sei Showa There was an error in the amended part of the procedural amendment (voluntary) submitted on April 4, 1961, so we will amend it as follows. The statement "(5) Line 17" on page 2, line 8 of the procedural amendment is amended to read "(5) Line 18."

Claims (1)

[Claims] 1. A plunger is slidably inserted into a plunger barrel fixed within a pump body, and a control sleeve is slidably fitted onto the plunger within a recess formed in the plunger barrel. In a fuel injection pump of a type in which fuel injection is controlled by changing the relative position of the control sleeve and the plunger, the plunger barrel is connected to a hardened steel barrel body disposed on the outside, and the barrel body. 1. A fuel injection pump comprising an upper and lower liner disposed inside the recess and divided into an upper and a lower part with the recess between them, and the plunger is slid on the liner. 2. A plunger is slidably inserted into a plunger barrel fixed within the pump body, and a control sleeve is slidably fitted onto the plunger within a recess formed in the plunger barrel, and the control sleeve and In a fuel injection pump of a type that controls fuel injection by changing the relative position with respect to the plunger, the plunger barrel is inserted and fitted into a barrel body made of hardened steel with a liner vertically sandwiching the recess, A method of manufacturing a fuel injection pump, characterized in that the barrel body is then cold-fitted onto the liner.