JP2607565Y2 - Diesel engine fuel injection pump drive - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection pump driving device for a diesel engine.

[0002]

2. Description of the Related Art FIG. 5 is a side view of a conventional fuel injection pump driving device for a diesel engine. Reference numeral 1 denotes an engine crankcase, reference numeral 2 denotes a timing gear case, and reference numeral 3 denotes a crankshaft gear (not shown) via an idle gear (not shown). Injection pump drive gears 4 that are driven in this manner are injection pump drive shafts fixed to the injection pump gear 3 . Reference numeral 5 denotes a fuel injection pump, reference numeral 6 denotes an injection pump shaft, and reference numeral 7 denotes a flexible joint (for example , a laminate coupling) connecting the injection pump drive shaft 4 and the injection pump shaft 6. The flexible joint 7 is usually used to absorb slight eccentricity between the injection pump drive shaft 4 and the injection pump shaft 6.

Incidentally, the torque generated by the fuel injection pump 5 changes very steeply and unsteadyly. FIG. 6 is a graph showing the change, in which the vertical axis shows the generated torque of the fuel injection pump 5, and the horizontal axis shows time. This fuel injection pump 5
The characteristic of the generated torque is that it has a portion (D portion) that generates a steep and large torque at the time of fuel pumping, and a portion (E portion) that generates a negative torque although it changes slowly. . Of course this torque is transmitted to the drive gear 3 via a joint 7 及 beauty drive shaft 4 deflection.

Generally, a backlash is provided between the meshing tooth surfaces of each gear. Therefore, in particular the following problems occur in the driven gear with a torque variation as shown in FIG. 6 (injection pump drive gear 3 in Fig. 5). Immediate Chi,
If negative torque, as E unit occurs, and pressing the drive gear from the driven gear. When a sharp torque is continuously applied to the driven gear as in the portion D, the driven gear is suddenly braked, and collides with the meshing surface of the driving gear while suddenly decelerating during the backlash. And increase noise. The increase in noise due to the collision of the driving gear with the meshing surface due to the torque fluctuation of the injection pump is particularly noticeable on the low rotation speed side of the engine.

[0005] As a countermeasure against the above problem, (also called Damitaima the flyweight or) inertial weight 40 between the joint 7 deflection as shown in Figure 7 and the injection pump shaft 6
A method for inserting the garment was devised. When the inertia weight 40 is added, a sudden brake is not applied to the driven gear due to a large effect of inertia, and a severe collision between the driven gear and the driving gear can be avoided.

[0006]

However, when the inertia weight is added as described above, the drive shaft is generally used with the conventional rigidity. In that case, the natural frequency of the torsional vibration system decreases due to the addition of inertial weight. Figure
8 is a graph showing the situation, the vertical axis represents vibration transmission torque of the drive shaft, the horizontal axis is the vertical axis I Frequency der, the horizontal axis is a logarithmic scale co. The solid line in the figure indicates the case where the inertial weight is added, and the dotted line indicates the case where the inertial weight is not added. As is apparent from the figure, the vibration transmission torque of the drive shaft is changed from T to T
to co and be reduced to o, reduced to fo from the natural frequency f.

When the natural frequency of the torsional vibration of the fuel injection pump drive system decreases, a resonance phenomenon may occur in a wide range where the engine is operated. In particular, if the inertial moment of the inertial weight is excessively increased in order to further reduce the gear impact noise at low engine rotation, the natural frequency further decreases, and the injection pump drive shaft 4 causes torsional vibration resonance. start. When the injection pump drive shaft 4 causes torsional vibration resonance, the injection pump drive gear 3 mounted on the shaft end also starts to vibrate, repeatedly colliding with the meshing surface of the meshing mating gear, and this generates a large noise. In the worst case, the drive shaft and the friction joint may be damaged.

[0008] As recent trend, but to one of effective means of diesel exhaust gas characteristics of the engine (exhaust emission) improvement is high pressure of the fuel injection pressure, the high pressure of the injection pump more, shown in FIG. 6 In addition, the peak value P of the generated torque of the injection pump is increased, and the rattling impact noise of the drive gear due to the sudden torque fluctuation is deteriorated. Therefore, a larger inertia weight is required, and the above-mentioned problem becomes more remarkable.

As a means for solving this problem, there is a method of improving rigidity such as increasing the diameter of the drive shaft to increase the natural frequency. However, the compatibility with the conventional parts is lost, and the problem of vibration and noise newly generated by vibrating the injection pump itself due to excessive torque generated by increasing the pressure of the fuel injection pump is newly generated.

The present invention has been made in view of the above-mentioned problems. Even if the fuel injection pump is increased in pressure or an excessive inertia weight is added, the drive shaft system is compared with the conventional one. It is an object of the present invention to economically provide a fuel injection pump driving device for a diesel engine that can be safely driven with low rigidity and that can achieve low vibration and low noise.

[0011]

In order to achieve the above object,
A first aspect of the present invention relates to a device for reducing the torsional vibration of the drive shaft of a fuel injection pump of a diesel engine, wherein an inertial body having a sufficient moment of inertia between a flexible joint and the shaft of the fuel injection pump is provided. With the joint , the inertial joint is connected around the first joint .
The first annular structure is joined via the elastic damping inclusion ,
In addition, the inertial joint is formed around a first annular structure.
The second elastic damping inclusion at a position different from the position where the
The second annular structure is joined through the first and second annular structures
The bodies are characterized by acting independently of one another as inertial bodies . Secondly, in a device for reducing torsional vibration of a fuel injection pump drive shaft of a diesel engine, a joint between a flexible joint and an injection pump shaft is connected by an inertial joint, and
Joint has sufficient moment of inertia is larger the outer diameter of a portion of its outer periphery, furthermore, the inertial body joint, the outer diameter
Outer diameter approximately equal to the outer diameter of the portion of the large been periphery (22)
A first annular structure through a first elastic damping inclusion in a space surrounded by the space and the remaining portions (23, 24) whose outer diameter is not increased.
The second annular structure is connected to the body through a second elastic damping inclusion.
The structure is joined and the first and second annular structures are independent of each other.
It is characterized by standing up and acting as an inertial body . Third
Is the fuel injection pump drive of the second diesel engine.
In the dynamic system, the first annular structure, the first elastic damping inclusions through the opposite side <br/> surface of the joint side deflection in some larger by perimeter outer diameter <br/> of the inertial body joint The second annular structure
The structure is attached to a part of the outer circumference where the outer diameter of the inertial body joint is increased.
Through the second elastic damping inclusion on the side of the flexible joint
Ing are joined. Fourth is the second diesel engine.
In the fuel injection pump driving device of the first aspect , the first annular structure is provided at the remaining portion where the outer diameter of the inertial joint is not increased.
That deflection is joined to the opposite side upper surface of the joint side through the first elastic damping inclusions, the second annular structures, large outer diameter of the inertial body joint
A second portion is provided on the upper surface of the remaining joint which has not been
Ing is bonded via an elastic damping inclusions.

[0012]

According to the above construction, the following operation is performed. (1) for configuring the flexible coupling for connecting the joint with the injection pump shaft as an inertial body joint with sufficient inertia moment (first configuration), or, axial joint which connects the flexible coupling and the injection pump shaft Is configured as an inertial joint having a sufficient moment of inertia by increasing a part of the outer diameter (second configuration), torsional vibration can be suppressed low. (2) to said inertial body joint, further a first annular structure first
1 Via the elastic damping inclusion, and connect the second annular structure to the second
Because it was mounted via an elastic damping inclusion (first configuration),
Or, the inertial body joint, the greater is the outer periphery an outer diameter one
The first annular structure is connected to the space surrounded by the portion and the remaining portion whose outer diameter is not increased through the first elastic damping inclusion.
And connects the second annular structure via the second elastic damping inclusion.
(Second configuration), and connect the first and second annular structures to each other.
Since they are independently joined (first and second configurations), torsional vibration can be further reduced. (3) The joint connecting the flexible joint and the injection pump shaft is configured as an inertial joint having a sufficient moment of inertia by increasing the outer diameter of a part of the joint in the axial direction. the part and through the first inertia body in a space surrounded the first elastic damping inclusions, and the second inertial body second
Since it is attached to the inertial body joint via the elastic damping inclusion (second configuration), it becomes a compact fuel injection pump drive device for a diesel engine. (4) The first to fourth configurations have a form in which a dynamic vibration-absorbing effect is imparted to the inertial body, if necessary. As a result, the resonance points are dispersed, and the vibration transmission torque of the injection pump drive shaft is greatly reduced. Therefore, specifically, (a) the tooth surface collision noise of the injection pump gear caused by the rapid torque fluctuation of the fuel injection pump is reduced. (B) Since excessive torque can be prevented from being generated in the injection pump drive shaft and the flexible joint, the injection pump drive shaft and the flexible joint do not need to be reinforced, and conventional ones can be used as they are. (C) Since the elastic deformation of the injection pump drive system is used, the torque applied to the injection pump gear and the fuel injection pump becomes smooth, and vibration and noise are reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a diesel engine according to the present invention will be described.
Refer to the drawings for an embodiment of the fuel injection pump drive device.
I will explain. FIG. 1 shows a first embodiment in which an inertial body divided into three parts is inserted between a flexible joint 7 and an injection pump shaft 6, and reference numeral 4 denotes an injection pump drive shaft, and reference numeral 5 denotes a fuel injection pump. 20 is an inertial body, with an inertia weight 22 in the central portion, one end of the inertia body joint 21 provided with the boss portions 23 and 24 at both ends are fastened by bolts 17 to the plate 8 of the flexible coupling 7, the other end Is fastened to the shaft end of the injection pump shaft 6 by a nut 18. 25 is a first annular structure, which is joined by a first elastic damping inclusions 26 of rubber or the like on one side of the inertia weight 22, the second annular structure Dare 27
Ri, which is the second such rubber on the other side of the inertia weight 22
Joined by the elastic damping inclusions 28, the dynamic damping ability of torsional vibration is maintained.

[0014] To explain the details of the next to the merits of the structure, the first
Assuming that the inertial weight of the annular structure 25 is A, the inertial weight of the second annular structure 27 is B, and the inertial weight of the inertial weight portion 22 of the inertial joint 21 is C, the method of selecting the respective inertia moments is as follows. is there. Moment of inertia of inertial weight A: IA Moment of inertia of inertial weight B: IB Moment of inertia of inertial weight C: IC Assuming that IA = IB + IC and IB = IC (1) (1) The effect is greater if the distance is as close to (1) as possible.

[0015] Next, first, second elastic damping inclusions 26,2
8 shows how to select a torsional spring constant. How to choose the torsion spring constant kM of the first elastic damping inclusions 26 to support the inertia weight A is the fuel injection pump driving system shown in FIG. 2, from the natural frequency fx in the case of completely fixed gear (Hz), KM = (2πfx) 2I However I = IA + IB + IC 0.5KM <kM < to satisfy 2KM (2), the choice of the torsion spring constant kN second elastic damping inclusions 28 to support the inertia weight B, the drive system of FIG. 2 The natural frequency f when the gear is in an unconstrained free state with
From o (Hz), the effect is maximized by satisfying the following condition: KN = (2πfy) 2 {IB.IC / (IB + IC)} 0.5 KN <kN <2KN (3)

As a method of selecting the damping characteristics of the first and second elastic damping inclusions 26 and 28, an elastic damping inclusion such as rubber generally has a larger or smaller damping property, and the elastic damping material used in the present proposal is used. The larger the damping coefficient of the damping inclusion, the greater the effect. Therefore, it is better to select the one as large as possible.

The operation will be described.
Inertia weight has a dynamic vibration-absorbing effect.
The vibration characteristics are as shown in FIG. FIG. 3 is a graph showing the vibration characteristics of the present invention, where the vertical axis represents the vibration transmission torque of the drive shaft,
The horizontal axis is frequency and the vertical axis, the horizontal axis is logarithmic scale co. Natural frequency fo with only inertial weight shown by dotted line
In contrast, the case of the present invention has f11, f12,
f13, the vibration transmission torque of the drive shaft is changed from To to T
It is greatly reduced to 11, T12 and T13.

[0018] The first, second annular structure 25, 27 FIG.
As shown in the second embodiment of FIG. 4 , the outer periphery of the bosses 23, 24 of the inertial joint 21 may be joined by first and second elastic damping inclusions 30, 31 such as rubber .

[0019]

[Effect of the Invention] As described above, the present invention has a form in which the dynamic vibration absorbing effect is imparted to the inertial body, the natural frequency of the torsional vibration system changes, the resonance point is dispersed, and the vibration of the injection pump drive shaft is increased. Transmission torque is greatly reduced. Therefore, the following effects are obtained. (A) tooth surface collision noise of the injection pump gear caused by sudden torque fluctuation of the fuel injection pump is reduced. ( B ) Since excessive torque can be prevented from being generated in the injection pump drive shaft and the flexible joint, the injection pump drive shaft and the flexible joint do not need to be reinforced, and conventional ones can be used as they are. ( C ) Since the elastic deformation of the injection pump drive system is used, the torque applied to the injection pump gear and the fuel injection pump becomes smooth, and vibration and noise are reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a first embodiment of a fuel injection pump driving device having three divided inertia bodies according to the present invention.

FIG. 2 is a configuration diagram of a fuel injection pump drive system having three divided inertia bodies according to the present invention;

FIG. 3 is a graph illustrating an effect of the fuel injection pump driving device having three divided inertia bodies according to the present invention;

FIG. 4 is a side view of a second embodiment of the fuel injection pump driving device having three divided inertia bodies according to the present invention;

FIG. 5 is a side view of a conventional injection pump driving device.

FIG. 6 is a graph of generated torque of a fuel injection pump.

FIG. 7 is a side view of a conventional fuel injection pump driving device having an inertial weight.

FIG. 8 is a graph illustrating the effect of the conventional inertial weight.

[Explanation of symbols]

3 : injection pump gear , 4: injection pump drive shaft , 5 : fuel injection pump , 6 : injection pump shaft , 7 : flexible joint , 8 : plate , 20 : inertia body , 21 : inertia body Fittings 2, 5 , 2
7 : Annular structure , 26 , 28 , 30 , 31 : Elastic damping inclusion , 23 , 24 : Boss , 17 : Bolt , 18 : Nut

Claims (4)

(57) [Scope of request for utility model registration] 1. A torsional vibration damping system of the fuel injection pump driving shaft of the diesel engine, joint with flexible coupling (7) and the injection pump shaft (6) inertial body joint having sufficient inertia moment between (21) At the same time, the inertial joint (21) has a first elastic damping inclusion around it.
(26), the first annular structure (25) is joined thereto, and the inertial body joint (21) is connected to the first annular structure (2).
The second elastic damping inclusion is located at a position different from the position where 5) was joined.
The second annular structure (27) is joined via (28), and the first and second annular structures (25 , 27) are independent of each other by the inertia body.
A fuel injection pump driving device for a diesel engine, characterized in that it functions as a fuel injection pump. 2. A device for reducing torsional vibration of a drive shaft of a fuel injection pump of a diesel engine, comprising: an inertia joint (21) between a flexible joint (7) and an injection pump shaft (6 ).
In splicing together Nag, the inertia body joint (21), the outer diameter is larger with a sufficient moment of inertia of a portion of its outer periphery (22), further, the inertial body joint (21) has an outer diameter Part of the outer circumference that has been enlarged
The outer diameter is almost equal to the outer diameter of (22) and the outer diameter is not increased
In the space surrounded by the remaining parts (23, 24), the first annular structure (25) is inserted via the first elastic damping inclusion (26).
Joined to form the second annular structure (27) via the second elastic damping inclusion (28).
The first and second annular structures (25 , 27) are joined and
A fuel injection pump drive device for a diesel engine, which independently operates as an inertia body . 3. The first annular structure (25) includes an inertial joint (21).
Joint deflection in some outer diameter larger by perimeter (22)
The side opposite to the (7) side is in contact with the first elastic damping inclusion (26).
It engaged, the second annular structure (27), increasing the outer diameter of the inertial body joint (21)
On the side of the flexible joint (7) on the part (22) of the outer periphery
The fuel injection pump driving device for a diesel engine according to claim 2, wherein the driving device is connected via a second elastic damping inclusion (28) . 4. The first annular structure (25) includes an inertial joint (21).
Deflection in the remaining portions (23, 24) whose outer diameter was not increased
Joint (7) side of the opposite side (23) first elastic damping inclusions upper surface (30)
It is joined via a second annular structure (27), increasing the outer diameter of the inertial body joint (21)
The flexible joint (7) side (24) at the remaining (23, 24)
Top Second elastic damping inclusions (31) fuel injection pump driving system for a diesel engine according to claim 2, wherein Rukoto such are bonded via the.