JPH0454829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is characterized in that a timing gear driven by a crankshaft via an idler gear is fitted to a pump shaft via a key and is tightened by a nut. The present invention relates to a method for removing a fuel injection pump having a structure such as that described above from an engine.

(Prior Art) As is well known, when performing maintenance and inspection work on a fuel injection pump, when removing it from the engine, it is necessary to set the timing gear so that the injection timing relative to the crank rotation when reinstalling the pump will not be out of order. A commonly used method is to attach alignment marks to landmarks.

FIGS. 8 and 9 show an example of a conventional pump removal method. That is, an opening 32 is formed in the gear case 30 through which the pump timing gear 31 can pass, and this opening 32 is
A retainer 33 provided on the pump side is attached to the gear case 30 so as to cover the fuel injection pump 3.
In order to remove the timing gear 32 from the engine, the retainer 33 is removed from the gear case 30, and the timing gear 32 is removed from the opening 32 while remaining integral with the pump shaft 35. When the pump 34 is removed, a marking is attached to the timing gear 31 through a hole 36 provided in the gear case 30 to confirm the meshing position with respect to the idler gear 37, thereby serving as a mark for reinstallation.

In addition, if the retainer 33 described above cannot be attached due to the layout of the engine, etc., the gear case cover 38 can be removed from the gear case 30.
At the same time, remove the timing gear 31 from the pump shaft 35, and then remove the fuel injection pump 3.
4 is generally removed from the engine, and at that time markings are attached to the timing gear 31 and the idler gear 37 to confirm the meshing position, and are used as marks for reinstallation. Note that 39 in the figure is a crank gear.

(Problems to be Solved by the Invention) However, in the case of the former method using a retainer, there is a problem that it is difficult to mark accurately when reinstalling, and sometimes the marks disappear. The structure becomes complicated due to the installation. On the other hand, the latter method of removing the gear case cover 38 has a problem in that it requires a great deal of time and effort.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method for disengaging a fuel injection pump that can accurately maintain the meshing of a timing gear with an idler gear and has good workability.

(Means for Solving the Problems) In order to solve the above problems, the present invention is constructed as follows. That is, the timing gear, which is driven by the crankshaft via an idler gear when attached to the engine and meshes with the idler gear, is fitted to the pump shaft via a key and fastened to the pump shaft by a gear fixing nut. A method for removing a fuel injection pump configured such that the idler gear, timing gear, etc. are housed in a gear case and covered by a gear case cover, the method comprising: attaching the gear fixing nut to a screw of the pump shaft; By separating the pump shaft from the timing gear, the pump shaft can be removed from the timing gear. On the other hand, after the timing gear is fixed to the gear case cover via the gear fixing tool, the timing gear is left in mesh with the idler gear. The pump shaft is removed from the timing gear when

(Function) By performing the above operation, the fuel injection pump is removed from the engine, but at this time, the timing gear remains in place, fixed to the gear case cover and meshed with the idler gear, so maintenance and When reinstalling the pump after inspection work, the injection timing of the pump can be maintained accurately by fitting the pump shaft and timing gear at a specific position via a key.

(Example) Hereinafter, an example of the present invention will be specifically described based on the drawings. The fuel injection pump 1 (hereinafter simply referred to as pump in the embodiments) is equipped with a pump bracket 1A at the rear lower part and a pump flange 1B at the front end for mounting, and the pump bracket 1A is fixed to the engine 2. The pump flange 1B is fixed to the bracket 3 by a mounting bolt 1a, and the pump flange 1B is fixed to a gear case cover 4 formed at the front end of the engine 2 by a mounting bolt 1b. The gear case 4 accommodates a crank gear 6 attached to a crankshaft 5, a timing gear 7 for a pump, an idler gear 8 that meshes with both gears 6 and 7, and other gears (not shown). The timing gear 7 is fitted to the end of the pump shaft 9 at a specific position in the circumferential direction via a half-moon key 10, and a gear fixing nut 11 screwed into a threaded portion formed at the tip of the pump shaft. Furthermore, the timing gear 7 has two screw holes 1 for fixing the gear.
2 are installed parallel to the axial direction with a phase difference of 180 degrees in the circumferential direction. Note that the timing gear 7 and the pump shaft 9 are fitted in a tapered manner so that they can be easily attached and detached.

Reference numeral 13 denotes a gear case cover, the peripheral edge of which is fastened to the gear case 4 with an appropriate number of bolts 14. The central outer surface of the portion of the gear case cover 13 that covers the timing gear 7 is formed into a substantially diamond-shaped flat surface, and a tool through hole 15 for removing and removing the gear fixing nut 11 is provided in the center thereof. A screw hole 16 for attaching a tool, which has a diameter larger than the screw hole 12 for fixing the gear, is provided on both sides of the tool through hole 15, which is concentric with the timing gear 7. The through hole 15 and the tool mounting screw hole 16 are normally closed by an auxiliary cover 18 that is fastened to the flat surface with bolts 17.

Therefore, the centers of the gear fixing screw hole 12 of the timing gear 7 and the tool mounting screw hole 16 of the gear case cover 13 coincide when the timing gear 7 is placed at a certain position in the circumferential direction. In this embodiment, the positioning adjustment function is provided in the crank pulley 19 attached to the end of the crankshaft 5 (projecting from the front surface of the gear case cover 13). This is done by aligning a positioning mark (engraved) 20 with a pointer 21 protruding from the gear case cover 13.

FIG. 6 shows a gear fixing tool 22 for fixing the timing gear 7 to the gear case cover 13 when the pump 1 is removed. a first bolt 23 that can be screwed into 12;
A second bolt 24 that can be screwed into the tool mounting screw hole 16 of the gear case cover 13, and both bolts 2
Tightening nut 2 for fixing 3 and 24 to each other
It is composed of three members: 5. The first bolt 23 is a stepped bolt without a head, and the smaller diameter side is used for tightening the tightening nut 25.
On the other hand, the second bolt 24 is a bolt with a head, and is formed into a cylindrical shape through which the first bolt 23 can penetrate over its entire length (including the head).

Next, the operation of attaching and detaching the pump 1 to the engine 2 for maintenance and inspection work will be explained.

First, rotate the crank pulley 19 (manually)
By aligning the positioning mark 20 with the pointer 21, the gear fixing screw hole 12 of the timing gear 7 is aligned with the tool attaching screw hole 16 of the gear case cover 13, and the auxiliary cover is removed from the flat part of the gear case cover 13. By removing 18, the tool through hole 15 and the tool mounting screw hole 16 are formed.
to open. In this state, the tool through hole 1
From 5, for example, a box wrench (not shown)
and remove the gear fixing nut 11 from the pump shaft 9.

Next, two sets of gear fixing tools 22 are used to loosen the timing gear 7 and fix it in place. That is, after screwing the first bolts 23 into the gear fixing screw holes 12 of the timing gear 7 through the tool mounting screw holes 16,
The second bolts 24 are screwed into the tool attachment holes 16 until their tips leave a certain distance from the timing gear 7. Afterwards,
By screwing the tightening nut 25 into the first bolt 23 until it contacts the head of the second bolt 24, and then tightening both nuts 25 at the same time, the timing gear 7 is moved slightly toward you via both first bolts 23. By doing so, the timing gear 7 is loosened from the pump shaft 9 and is fixed to the gear case cover 13 while remaining engaged with the idler gear 8.

Therefore, if the pump 1 is moved in parallel to the axial direction of the pump shaft 9 after removing the pump mounting bolts 1a and 1b from the bracket 3 and the gear case 4 in this state, the pump 1 shaft 9 will be connected to the timing gear 7. The pump 1 is removed from the engine 2.

In addition, pump 1 after maintenance and inspection work is completed.
The reinstallation of the engine 2 into the engine 2 is performed by following the operating procedure in the reverse order of the above. That is, while aligning the half-moon key 10 of the pump shaft 8 with the key groove of the timing gear 7, insert the pump shaft 8 into the shaft hole of the gear 7, while loosening the tightening nut 25 of the gear fixing tool 22. , tool hole 15
By inserting the gear fixing nut 11 into the threaded portion of the pump shaft 9 and tightening it, the timing gear 7 is fastened to the pump shaft 9. After that, the pump 1 is fixed by fixing the pump bracket 1A to the bracket 3 with the mounting bolts 1a and the pump flange 1B to the gear case 4 with the mounting bolts 1b, and then removing the gear fixing tool 22, Once the auxiliary cover 18 is attached to the carrier case cover 13, the work of reattaching the pump 1 to the engine 2 is completed.

In this embodiment, when removing the pump 1, the timing gear 7 is loosened from the pump shaft 9 using the gear fixing tool 22, but this work may be performed using a puller if necessary. It doesn't matter if you do that. Also, pump 1
The alignment of the key 10 with respect to the keyway when reinstalling the pump can be made easier by attaching alignment marks to the pump flange 1B and the gear case 4, if necessary.

(Effects of the Invention) As detailed above, according to the method of the present invention, the fuel injection pump can be removed from the engine without removing the gear case cover and with the timing gear still meshed with the idler gear, so it can be reinstalled. By determining the fitting position of the pump shaft and timing gear using a key, assembly can be performed without causing any deviation in the injection timing relative to the crank rotation. Since the pump can be removed without removing it, there are fewer parts to remove and remove, and workability is improved, which is extremely effective in shortening removal and removal time and improving work efficiency.

[Brief explanation of the drawing]

Figure 1 is a schematic side view showing how the fuel injection pump is attached to the engine, Figure 2 is a partially cutaway side view of the gear case and gear case cover, and Figure 3 is a front view with the gear case cover attached. , Fig. 4 is a front view showing the gear train inside the gear case, Fig. 5 is a sectional view taken along the line - - in Fig. 3, Fig. 6 is a perspective view showing the gear fixing tool, and Fig. 7 is a detached fuel injection pump. FIG. 8 is a side sectional view showing a conventional example, and FIG. 9 is a front view similarly shown with the gear case cover removed. 1... fuel injection pump, 2... engine, 4...
... Gear case, 6 ... Crank gear, 7 ... Timing gear, 8 ... Idler gear, 9 ... Pump shaft, 10 ... Half-moon key, 11 ... Gear fixing nut, 12 ... Gear fixing screw hole, 13 ... ...Gear case cover, 15...Tool hole, 16...
Tool mounting screw hole, 20...Positioning mark, 2
1...Pointer, 22...Gear fixing tool, 23
...First bolt, 24...Second bolt, 25...
Tighten nut.

Claims (1)

[Claims] 1 The timing gear, which is driven by the crankshaft via the idler gear when attached to the engine and meshes with the idler gear, is fitted to the pump shaft via a key and is fastened and fixed to the pump shaft by a gear fixing nut. A method for removing a fuel injection pump in which the idler gear, timing gear, etc. are housed in a gear case and covered by a gear case cover, the method further comprising: By separating from the pump shaft, the pump shaft can be removed from the timing gear, while the timing gear is fixed to the gear case cover via the gear fixing tool, and the timing gear remains meshed with the idler gear. How to remove a fuel injection pump by removing the pump shaft from the timing gear.