JPS608128Y2 - Diesel engine fuel injection timing advance device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an advance device that advances the fuel injection timing as the rotational speed of a diesel engine increases.

An advance angle device for gear transmission is shown in FIG. 6.

A driven gear 54 is pivotally supported on a boss 53 of a timer hub 52 fixed to a fuel injection camshaft 51.
4 is rotated by gear transmission, the journal 55 pushes the pin 57 via the timer weight 56 and the timer hub 52
is rotated, and the camshaft 51 is rotated.

The entire device is then housed within the gear case 58 and properly lubricated.

Currently, there is no advance angle device for belt transmission, so if an advance angle device for gear transmission as shown in Fig. 6 is used, as shown by the imaginary line in the figure, the timing belt driven booby IJ
59 is disposed outside the gear case 58, and is further covered with a dustproof cover 60 to protect the belt transmission device and prevent dust.

For this reason, the axial length D of the advance device becomes long, and the advance device protrudes largely from the fuel injection pump chamber 61.

Therefore, the applicant considered creating a structure as shown in FIG.

That is, the driven pulley 5 is attached to the boss 53 of the timer hub 52.
A drive flange 62 to which numeral 9 is fixed is fitted externally so as to be relatively rotatable.

By adopting such a structure, the axial length D of the advance angle device can be somewhat reduced, but the diameter R of the driven pulley 59 becomes large.

Therefore, the driving pulley (fixed to the crankshaft) and other driven pulleys (fixed to the valve drive camshaft) of the timing transmission must be made larger, resulting in an increase in the size of the engine.

This invention provides a fuel injection timing advance device for belt transmission devices, and eliminates the above-mentioned drawbacks of devices that have been converted from gear transmission types to belt transmission devices and those that were previously conceived. In order to do this, the timing hub is fixed to the base end of the input shaft end of the camshaft, and the drive flange is rotatably supported on an auxiliary case that is fixed relative to the pump housing, and the drive flange is formed into a timer hub. The timing pulley is loosely fitted into the boss in a state where it can rotate by an advance angle or more, and is positioned in the axial direction, and a timing pulley is fixed to the drive flange, and this timing pulley is made to cover the drive flange pivot part from the outside. The axial length of the advance angle device is shortened, and the diameter of the timing pulley is made small, so that the advance angle device can be made compact, and the entire engine can be made compact.

Hereinafter, embodiments of this invention will be described based on the drawings.

FIG. 1 is a longitudinal sectional front view of a forced water-cooled overhead camshaft horizontal diesel engine, and FIG. 2 is a longitudinal sectional side view.

This engine consists of a belt transmission device (■) and a timing belt transmission device (T) arranged front and rear outside the front of an engine body 1 that is visible from a cylinder block 2, cylinder head 3, head cover 4, and crankcase 5. There is.

The timing belt transmission T includes a driving gear 7 fixed to a crankshaft 6 and a driven gear 11 fixed to an overhead valve camshaft 8.
, a driven gear (driven pulley) 12 interlockingly connected to the camshaft 10 of the fuel injection pump 9 via an advance device S, a timing belt 13 wrapped around each gear 7, 11, 12, etc. .

The timing belt transmission T is covered with a dust cover 14 fixed to the front of the engine body 1 with bolts.

The belt transmission device ■ includes a drive boob IJ15 fixed to the crankshaft 6, a cylinder block 2, and a crankcase 5.
A driven pulley 1 fixed to the input shaft of a water pump 17 whose housing is an auxiliary case 16 fixed to the front surface of the water pump 17.
9, a driven pulley 21 fixed to the generator 20, and a belt 22 wrapped around these pulleys 15, 19, 21.

Therefore, the overhead valve camshaft 8 and the fuel injection pump 9 are timed driven by the crankshaft 6, and the water pump 17 and the generator 20 are driven.

In the figure, 23 is a tension pulley, 24 is a flywheel, 25 is a starter, 26 is an oil filter, and 27 is a hydraulic pump. Like the water pump 17, this hydraulic pump 27 has a housing formed by an auxiliary case 16. .

Now, as shown in FIG. 2, the camshaft 10 of the fuel injection pump 9 is rotatably supported by a bearing 28 on a pump housing 2a that is integrally formed in the upper part of the cylinder block 2.
The input end 10a protrudes outside the pump housing 2a, and an advance angle device S is attached thereto.

The advance angle device S is housed in the auxiliary case 16 like the water pump 17 and the hydraulic pump 27, and does not protrude greatly from the front of the engine.
The mounting surface can be formed on one plane.

The advance angle device S includes a timer hub 29, a drive flange 30, a timer weight 31, and a spring 32.

As shown in FIG. 4, the boss 33 of the timer hub 29 protrudes toward the drive flange 30, and a mounting hole 34 for the camshaft 10 is formed near the proximal end of the boss 33, and a drive flange is formed on the outer periphery near the distal end of the boss 33. Thirty pivot shaft surfaces 35 are formed.

The boss 36 of the drive flange 30 protrudes on the opposite side from the timer hub 29, and is rotatably supported on the auxiliary case 16 via a bearing 28, and is also pivotally supported on a portion near the proximal end of the boss 36. An input section 38 is formed near the tip of the hole 37, and the driven pulley 12 of the timing belt transmission T is fixed to this input section 38 with a bolt 39.

This timing pulley 12 is formed so as to cover the pivot portion of the drive flange 30 from the outside in the assembled state.

Then, the pivot hole 37 of the drive flange 30 is externally fitted onto the pivot shaft surface 35 of the timer hub 29, and a screw hole 50 is formed in the boss 36 of the drive flange 30 from the mounting hole 34 side. 40, and timer hub 2
A drive flange 30 is rotatably supported at 9 in a manner that prevents it from being pulled out.

Since this bolt 40 only positions the drive flange 30 on the timer hub 29 in the axial direction, it may have a small diameter.

Therefore, the boss 36 of the drive flange 30 can have a small diameter, and the driven pulley 12 can have a small diameter.

The spring 32 is connected from the timer hub 29 to the drive flange 3.
It is interposed between a pin 41 that projects toward the 0 side and a journal 42 that projects from the drive flange 30 toward the timer hub 29 side.

The timer weight 31 has a fan shape when viewed from the front and has the timer hub 2 at one end.
A pin 41 of No. 9 passes through the pin 41 so that it can swing around this pin, and a pin 43 protruding from the other end toward the timer hub 29 engages with a locking hole 44 of the timer hub 29 and moves outward. Possibly supported by timer knob 29.

A curved surface 45 is formed in the center of the dome, and the journal 42 is pressed against this curved surface 45 by the spring 32, so that when the engine is stopped, the timer weight 3
1 is biased inward.

The rotation of the crankshaft 6 is transmitted to the driven pulley 12 by the timing belt 13, and the pin 41, that is, the timer hub 29, is rotated via the drive flange 30, journal 42, and timer weight 31, and the camshaft 10 is rotated.

Then, when the rotation speed increases, the timer weight 31 spreads outward due to centrifugal force, and the journal 42
5, the pin 41 is pulled against the sliding waist journal 42, and the timer hub 29 is slightly rotated in the rotational direction relative to the drive flange 30, so that the camshaft 10 is automatically advanced relative to the crankshaft 6. Ru.

Furthermore, in order to assemble the advance angle device S to the camshaft 10, after assembling the entire advance angle device S, the mounting hole 34 of the timer hub 29 is fixed to the input shaft end 10a of the camshaft 10 by interference fit, and then the final angle device S is assembled. This is done by fixing the driven pulley 12 to the drive flange 30.

In the figure, reference numeral 46 is a key, 47 is a centrifugal ball type governor, and 48 is a sealing material.

Another embodiment is shown in FIG.

Similar to the previous embodiment, the axial positioning of the drive flange 30 to the boss 33 of the timer hub 29 is performed using flanged bolts 40. 33 and screwed together with a nut 49.

Instead of using the nut 49, there is a screw hole 50 in the boss 33.
may be formed.

Since this invention is constructed as described above, it has the following effects.

(a) The timing hub is fixed to the base end of the input shaft end of the camshaft, the drive flange is loosely fitted to the timing hub boss, and the drive flange boss is rotatably pivoted to the auxiliary case. Therefore, the advance angle device as a whole is supported on both sides, and the driven pulley fixed to the drive flange is also arranged to cover the drive flange pivot part from the outside, so that the advance angle device is supported in the axial direction. The length of the timing pulley can be reduced compared to when converting a conventional type to a belt-driven type, and since it is supported on both sides and the drive pulley is directly fixed to the input shaft, the diameter of the timing pulley can be reduced. This allows the entire advance angle device to be made smaller.

(b) As mentioned above, since the advance angle device can be made smaller,
The diesel engine to which this advance angle device is attached can also be made smaller.

Furthermore, since the diameter of the timing pulley can be made smaller, the drive pulley and driven pulley of the timing transmission can also be made smaller in diameter and lighter, thereby making it possible to reduce the weight of the engine.

(c) Also, after assembling the advance angle device, the mounting hole of the timer knob is fixed to the input shaft end of the camshaft of the fuel injection pump, so the advance angle device is supported on both sides. However, the advance angle device can be assembled independently as before, and the manufacturing cost of the engine can be reduced.

[Brief explanation of drawings]

The drawings show an embodiment of this invention. Fig. 1 is a longitudinal sectional front view of the diesel engine, Fig. 2 is a longitudinal sectional side view, and Fig. 3 is a longitudinal sectional view of the diesel engine.
4 is a sectional view taken along the line IV-TV in FIG. 3, FIG. 5 is a view corresponding to FIG. 4 showing another embodiment, and FIGS. 4 is a diagram corresponding to FIG. 4. S: Advance angle device, T: Timing belt transmission, 9: Fuel injection pump, 10: Curved camshaft, 10a: Input End, 12...
Driven pulley, 29...Song timer hub, 30...
Drive flange, 33...39 boss, 34...
...Mounting hole, 35, curved, pivot shaft surface, 36...
・30 bosses, 37・song・pivot hole, 38・・song input section,
40...Positioning tool (positioning bolt), 50
...screw hole.

Claims (1)

[Scope of Claim for Utility Model Registration] 1 Camshaft 1 of fuel injection pump 9 of diesel engine
0 is rotatably supported on a pump housing 2a by a bearing 28, an input shaft end 10a of a camshaft 10 projects outside the pump housing 2a, and a timer hub 29 is fixed to this input shaft end 10a. In S, the boss 33 of the timer hub 29 is made to protrude toward the drive flange 30, and the mounting hole 34 is provided near the base end of the boss 33, and the drive flange 30 is provided near the distal end of the boss 33.
The boss 36 of the drive flange 30 forms a pivot shaft surface 35 of the drive flange 30.
protrudes from the side opposite to the timer hub 29, and this boss 36
is rotatably supported on an auxiliary case 16 that is relatively fixed to the pump case, and a pivot hole 37 is formed in a portion near the proximal end of the boss 36 to loosely fit into the pivot shaft surface 35 of the timer hub 29.
The driven pulley 12 of the timing belt transmission T is fixed to the input portion 36 formed near the tip of the boss 36 of the drive flange 30 so as to cover the pivot portion of the drive flange 30 from the outside, and the pivot hole 37 of the drive flange 30 is is rotatably supported on the pivot shaft surface 35 of the timer hub 29 for more than advance angle, and the boss 36 of the drive flange 30 is positioned in the axial direction with a positioning tool 40 with respect to the boss 33 of the timer hub 29. The mounting hole 34 of the fuel injection pump 9 is connected to the camshaft 1 of the fuel injection pump 9.
1. A fuel injection timing advance device for a diesel engine, characterized in that it is fixed to an input end 10a of a diesel engine by interference fitting. 2 Utility Model Registration In the fuel injection timing advance device for a diesel engine described in Claim 1, a positioning bolt is used as the positioning tool 40 and is screwed into a screw hole 50 formed in the boss 36 of the drive flange 30. The boss 36 of the timer hub 29 is positioned in the axial direction.