JPH09296766A - Engine unit injector and valve drive system - Google Patents

Abstract

(57) Abstract: In an engine provided with a unit injector, even if the engine has a camshaft for individually driving the unit injector and the intake / exhaust valve, the number of parts is reduced and the overall configuration is improved. Make it simple. SOLUTION: A differential mechanism 63 is provided by a timing gear 54.
The rocker arms 47 and 48 are swingably supported by the unit injector driving cam shaft 34 which is rotatably driven via the intake / exhaust air rotatably driven by the timing gear 54 via the drive gear 64 and the driven gear 65. The rocker arm 42 is swingably supported by the valve driving camshaft 35, and the rocker arm 42 is supported by the camshaft 34.
Driven by the cam 41 of the unit injector 38
And the rocker arms 47 and 48 are driven by the cams of the cam shaft 35 to open and close the intake valve 39 and the exhaust valve 40, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine having a known unit injector in which a fuel injection pump and a fuel injection valve are integrated and the operation of the fuel injection valve is controlled by an electromagnetic actuator. And a device for driving the intake and exhaust valves.

[0002]

2. Description of the Related Art A conventional four equipped with a unit injector.
As shown in FIGS. 5 and 6, a valve-type in-line multi-cylinder diesel engine has a rocker cover 3 attached to a cylinder head 2 on a cylinder block 1, and a rocker cover 3 has a camshaft for driving a unit injector. 4 and the intake / exhaust valve driving camshaft 5 are arranged in parallel and are rotatably supported by a plurality of bearings 6, and the unit injector rocker shaft 7 and the camshafts 4 and 5 are parallel to each other between the camshafts 4 and 5. The intake / exhaust valve rocker shaft 8 is supported by a bearing 6.

A unit injector 10 is provided in each cylinder 9.
The rocker arm 11 supported by the rocker shaft 7 so as to be swingable with respect to each cylinder 9 has the roller 12 at one end rotatably abutting on the cam 13 of the cam shaft 4 and the other end at the other end. It is in contact with the pressing portion 14 of the unit injector 10.

Further, a pair of intake valves 16 and a pair of exhaust valves 17 are arranged for each cylinder 9, and an intake valve rocker arm 18 is swingably supported by the rocker shaft 8.
In the exhaust valve rocker arm 19, the roller 20 at one end is rotatably abutted on the cam 21 and the cam 22 of the cam shaft 5, and the other end is bridge 2 respectively.
It is configured to press the intake valve 16 and the exhaust valve 17 via the valve 3.

On the other hand, the timing gear 2 which is rotationally driven by the idler gear 24 at a speed half the engine speed.
5 is connected to the camshaft 4 via a differential mechanism 26, and the idler gear 24 allows the engine speed 1 to be increased.
The timing gear 27, which is rotationally driven at a speed of / 2, is connected to the camshaft 5, and the camshaft 4 and the camshaft 5 are rotationally driven, respectively.
The unit injector 10 is operated by the cam 13 of the rocker arm 11 via the rocker arm 11, and an appropriate amount of fuel is injected into the cylinder 9 at a predetermined timing.
Intake valves 16 through the bridges 8 and 19 and the bridge 23, respectively.
Also, the exhaust valve 17 is opened and closed at a predetermined timing.

That is, in the above device, in order to retard or advance the fuel injection timing of the unit injector 10 in accordance with the operating condition of the engine, etc., the unit injector driving camshaft with respect to the intake / exhaust valve driving camshaft 5 Since the rotational phase of 4 is appropriately shifted forward and backward by the differential mechanism 26 so that the phase of the cam 13 can be varied, two camshafts 4 for driving the unit injector and the intake / exhaust valve are provided. 5 is required, and rocker arm 11 and rocker arm 18 and 1 are correspondingly required.
Rocker shafts 7 and 8 for swingably supporting 9 and 9 are required.

Therefore, the two cam shafts 4 and 5 and the rocker shafts 7 and 8 must be separately arranged in a narrow space inside the rocker cover 3 attached to the upper surface of the cylinder head 2. There are drawbacks that increase the number of points and complicate the structure.

[0008]

SUMMARY OF THE INVENTION The present invention, in an engine having a unit injector, suppresses an increase in the number of parts even if the engine has a camshaft for individually driving the unit injector and the intake / exhaust valve. Therefore, the present invention intends to provide a device that can greatly simplify the entire configuration.

[0009]

For this reason, the engine unit injector and valve drive system according to the present invention include a unit injector mounted on a cylinder head and a unit injector rotatably supported on the cylinder head. A drive camshaft, an intake / exhaust valve drive camshaft rotatably supported on the cylinder head, and a cam of the unit injector drive camshaft swingably supported by the intake / exhaust valve drive camshaft. A rocker arm that is driven to operate the unit injector, and an intake valve driving rocker arm and an exhaust that are swingably supported by the unit injector driving cam shaft and that are respectively driven by cams of the intake and exhaust valve driving cam shafts. Equipped with rocker arm for valve drive .

That is, the rocker arm for operating the unit injector is swingably supported on the intake / exhaust valve driving camshaft, and the intake valve driving rocker arm and the exhaust valve driving rocker arm are respectively rocked on the unit injector driving camshaft. These rocker shafts are required because there is no need to specially install a rocker shaft that is movably supported and that rockably supports a rocker arm that operates the unit injector and a rocker arm that drives the intake and exhaust valves, respectively. Compared with the conventional device, the number of parts can be reduced, and at the same time, the entire configuration can be greatly simplified.

[0011]

Embodiments of the present invention will be described below. 1 to 3, 4 mounted on the vehicle
In the valve type in-line multi-cylinder diesel engine 30, a rocker cover 33 is attached to a cylinder head 32 on a cylinder block 31, and a unit injector driving camshaft 34 and an intake / exhaust valve driving camshaft 35 are parallel to each other in the rocker cover 33. Are arranged in a plurality of bearings 3
6 are rotatably supported.

Further, a unit injector 38, a pair of intake valves 39 and a pair of exhaust valves 40 are provided for each cylinder 37, and the camshaft 34 serves as the intake / exhaust valve 3.
The camshafts 35 are arranged on the sides of 9, 40.
Are arranged between the camshaft 34 and the intake and exhaust valves 39, 40 and above them.

Further, a cam 41 is formed on the camshaft 34 for each cylinder 37, and the camshaft 3 is formed.
Rocker arms 42 that are swingably supported on the respective 5
The roller 43 at one end is rotatably abutted on the cam 41, and the other end is at the pressing portion 4 of the unit injector 38.
4 abuts.

Further, a cam 45 and a cam 46 are formed on the cam shaft 35 for each cylinder 37, and the rocker arm 47 and the rocker arm 4 are swingably movable on the cam shift cam shaft 34 with the cam 41 interposed therebetween.
8 are supported.

Each of the rocker arm 47 and the rocker arm 48 has a recess 49 formed in the upper surface thereof, and a roller 51 rotatably supported by a pin 50 in the recess 49 is rollable on a cam 45 and a cam 46, respectively. And the tips of the rocker arm 47 and the rocker arm 48 press the intake valve 39 and the exhaust valve 40 via the bridge 52, respectively.

On the other hand, the idler gear 53 rotatably drives the timing gear 54 at a speed half the engine speed, and the input side bevel gear 55 is coaxially fixed to one side surface of the timing gear 54. An output side bevel gear 56 of the same shape, which is fixed to the tip of the cam shaft 34 that loosely passes through the timing gear 54 and the bevel gear 55, and is arranged opposite to the bevel gear 55, and both bevel gears 55. ,
A ring-shaped casing 57 that covers the periphery of 56, and four pinion gears 59 that are pivotally supported on the casing 57 by shafts 58 at equal intervals and that engage with both bevel gears 55, 56.
The camshaft 34 is formed on the outer surface of the casing 57.
A differential mechanism 63 between the timing gear 54 and the camshaft 34 is constituted by a worm wheel 60 having a central axis of the worm, a worm 61 engaged with the worm wheel 60, and a motor 62 for rotationally driving the worm 61. Is configured.

A drive gear 64 is coaxially fixed to the other side surface of the timing gear 54, and the tip end portion of the cam shaft 34 is loosely inserted through the axial center portion of the drive gear 64 and fixed to the tip end of the cam shaft 35. The driven gear 65 is the drive gear 6
4, the camshaft 35 is rotationally driven in the opposite direction at the same speed as the timing gear 54.

In the above apparatus, the cam shaft 34 is rotationally driven from the idler gear 53 through the timing gear 54 and the differential mechanism 63, and the cam 41 of the cam shaft 34 is driven.
Drive the rocker arm 42 to swing it on the camshaft 35, and the rocker arm 42 moves the unit injector 38.
By urging the pressing portion 44 of, the appropriate amount of fuel is injected from each unit injector 38 to each cylinder 37 at a predetermined timing.

At the same time, the idler gear 53, the timing gear 54, the driving gear 64, and the driven gear 65 are sequentially arranged.
The cam shaft 35 is rotationally driven via the rocker arm 47, and the cam 45 and the cam 46 of the cam shaft 35 are respectively rotatably supported in the recesses 49 of the rocker arms 47 and 48 via the rollers 51, respectively. Rocker 48 on camshaft 34 and rocker arms 47, 48
The respective tips press the intake valve 39 and the exhaust valve 40 via the bridge 52, so that the intake valve 39 and the exhaust valve 40 are opened and closed at predetermined timings for a predetermined time.

In this case, when the engine is in idle operation, the motor 62 of the differential mechanism 63 is rotationally controlled by a controller (not shown) to drive the worm 61 and the worm wheel 60 to drive both bevel gears 55 and 56 and the pinion gear. By operating 59, the phase of the camshaft 34 is controlled to delay the oil feed rate pattern of the unit injector 38 from the engine top dead center TDC as shown by the solid line in FIG. The fuel injection timing of the unit injector 38 is set to T
When 1 to T2 is selected and a relatively low oil feed rate α1 to α2 is selected, the fuel injection pressure of the unit injector 38 can be lowered to extend the fuel injection period, and
By delaying the fuel injection timing, slow combustion in each cylinder 37 can be realized, and NOx in the exhaust gas and combustion noise can be significantly reduced.

When the engine is running at high speed, the controller 62 controls the rotation of the motor 62 of the differential mechanism 63 in the opposite direction to that described above, and the worm 61 and the worm wheel 6 are operated.
0 to drive both bevel gears 55, 56 and pinion gear 59.
Is operated to control the phase of the camshaft 34 to advance the oil feed rate pattern of the unit injector 38 as shown by the alternate long and short dash line in FIG. 4, and to control the fuel of the unit injector 38 by the controller. If the injection timing is selected from T3 to T4 and a high oil transfer rate α3 is selected, the fuel injection pressure of the unit injector 38 can be increased and the fuel injection period can be shortened.
Moreover, by advancing the fuel injection timing, high combustion efficiency can be obtained in each cylinder 37, and the engine output can be increased.

That is, since the phase of the camshaft 34 is controlled by the operation of the differential mechanism 63 and the oil feed rate pattern of the unit injector 38 can be appropriately retarded and advanced by a desired amount, the fuel of the unit injector 38 is fueled. Combined with the injection timing control performance, it becomes possible to perform fuel supply control that best matches the engine operating conditions.

Further, by operating the differential mechanism 63 as described above, the oil feed rate pattern of the unit injector 38 can be appropriately retarded or advanced, and the region start point of the high oil feed rate α3 can be set. Since it is easy to match the fuel injection start timing, in the case of the same cam lift, by relatively narrowing the area of high oil transfer rate α3,
It becomes possible to select a cam 41 of a higher oil transfer rate type, and it is possible to increase the degree of freedom in cam design.

Further, in the above apparatus, the rocker arm 42 for operating the unit injector 38 is swingably supported on the intake / exhaust valve driving camshaft 35, and the rocker arm 47 and the rocker arm for driving the intake valve 39 and the exhaust valve 40, respectively. 48 is swingably supported by the unit injector driving camshaft 34, and there is no need to specially install a rocker shaft for swingably supporting each rocker arm 42, 47, 48. Compared with conventional devices that require these rocker shafts, the number of parts can be reduced and the weight can be reduced, and at the same time, the overall configuration can be greatly simplified, and the camshaft 34 can be used as an intake / exhaust valve. The camshaft 35 is disposed on the side of 39, 40, and the camshaft 35 and the intake / exhaust valve Because it is arranged above them with the 9,40, it can be summarized in very compact unit injector and valve train drive of the engine.

In addition, since the space for accommodating the equipment is particularly small on the cylinder head 32 of the vehicle engine 30, the number of parts and the weight are reduced as described above, and the overall structure is simplified and compact. The advantage of being able to do so becomes more prominent in the vehicle engine 30, and the manufacturing cost of the engine 30 can be easily reduced by reducing the number of parts manufacturing and assembling steps.

In the above embodiment, a differential gear is used as the phase varying mechanism of the unit injector driving camshaft, but a helical spline mechanism, a planetary gear mechanism, etc. are attached to the unit injector driving camshaft. By this, the camshaft itself is controlled to rotate appropriately to retard or advance the phase of the camshaft, or a cam whose shape is changed in the axial direction is formed on the unit injector driving camshaft, Even if the phase of the unit injector drive cam is retarded or advanced by appropriately displacing the camshaft itself in the axial direction by a helical spline mechanism or the like attached to the same camshaft, the above-described embodiment example and The same effect can be achieved.

[0027]

In the engine unit injector and valve drive system according to the present invention, the rocker arm for operating the unit injector, the intake valve drive rocker arm, and the exhaust valve drive rocker arm are rockably supported. Since there is no need to install a special shaft, the number of parts can be reduced and the overall configuration can be greatly simplified compared to conventional devices that require these rocker shafts, and the cost can be reduced. And the weight can be easily reduced.

[Brief description of drawings]

FIG. 1 is a plan view of essential parts in an embodiment of the present invention.

FIG. 2 is a view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a diagram illustrating the operation of the embodiment.

FIG. 5 is a plan view of a main part of a conventional device.

6 is a VI-VI arrow view of FIG.

[Explanation of symbols]

 34 unit injector driving camshaft 35 intake / exhaust valve driving camshaft 37 cylinder 38 unit injector 39 intake valve 40 exhaust valve 41 cam 42 rocker arm 45 cam 46 cam 47 rocker arm 48 rocker arm 54 timing gear 63 differential mechanism 64 drive gear 65 covered Drive gear

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F02M 61/14 310 F02M 61/14 310Z

Claims (3)

[Claims] 1. A unit injector mounted on a cylinder head, a unit injector driving cam shaft rotatably supported on the cylinder head, and an intake / exhaust valve driving rotatably supported on the cylinder head. A camshaft, a rocker arm swingably supported by the intake / exhaust valve driving camshaft and driven by a cam of the unit injector driving camshaft to operate the unit injector, and a unit injector driving camshaft, respectively. A unit injector and a valve drive device for an engine having an intake valve driving rocker arm and an exhaust valve driving rocker arm that are swingably supported and driven by the cams of the intake and exhaust valve driving cam shafts. 2. The unit injector driving camshaft according to claim 1, wherein the unit injector driving camshaft is arranged laterally of the intake valve and the exhaust valve, and the intake / exhaust valve driving camshaft is the unit injector driving camshaft and the intake valve. And the intake valve driving rocker arm and the exhaust valve driving rocker arm disposed above the exhaust valve and the exhaust valve, and the intake and exhaust valves are arranged with the cam of the unit injector driving camshaft interposed therebetween. A unit injector and valve operating device for an engine, in which the rocker arm for operating the unit injector is arranged between the intake valve driving cam and the exhaust valve driving cam on the valve driving cam shaft. 3. The unit injector and valve operating system for an engine according to claim 1 or 2, further comprising a cam phase varying mechanism of the unit injector driving camshaft.