JP2583164Y2 - Mounting structure of torsional viscous damper for fuel injection pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torsional viscous damper which is interposed in a drive system of a fuel injection pump to reduce torsional vibration, torque fluctuation, etc. of the drive system, and more particularly to a technique relating to a mounting structure thereof. .

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for a diesel engine for a small-sized vehicle for long-distance transportation, for higher output, lower fuel consumption and longer life. In particular, due to the trend toward higher output, the average effective pressure has increased, and the vibration torque applied to the crankshaft has been increased.

As a result, the use of a torsional viscous damper (hereinafter simply referred to as a viscous damper) has been regarded as effective for the purpose of reducing the torsional vibration of the crankshaft caused by the gas pressure and the inertial force in the cylinder. This viscous damper has a disk-shaped inertial mass portion,
It consists of a fixed part to the crankshaft, and is constituted by interposing a high-viscosity silicone oil or the like as a viscoelastic body therebetween, and is usually attached to the tip of the crankshaft facing the flywheel.

[0004] A typical structure of the viscous damper is, as shown in FIG. 4, formed by a case 1 and a cover 2 to form a cylindrical closed space, and is positioned inside the closed space by a thrust bearing 3 and a journal bearing 4. The closed space is filled with a high-viscosity silicone oil 6 while accommodating an inertia ring 5 rotatably supported.

[0005] The case 1 and the cover 2 are integrated by crimping after press-fitting with a sealing material therebetween. The case 1 is fixed by bolts to the crankshaft, and the connection between the case 1 and the inertia ring 5 is made only through the silicone oil 6. In a situation where there is no torsional vibration, the case 1 and the inertia ring 5 rotate as if they were an integrated unit. As the engine speed changes to a point that excites torsional vibration, the crankshaft, that is, the case 1 fixed to the crankshaft, exhibits a phenomenon in which torsional vibration is added to the main rotation. Since the inertia ring 5 tries to keep a constant rotation due to its own inertia, a relative rotational vibration change occurs between the case 1 and the inertia ring 5, so that the silicone oil 6 receives the shear force and vibrates. Energy is replaced by heat energy, and vibration of the crankshaft is absorbed.

The viscous damper is significantly different from other rubber dampers and the like in that there is no elastic coupling portion between the inertial ring 5 and the case 1. Therefore, it can be said that the damper does not require tuning. This type of viscous damper is advantageous in that it does not cause additional resonance, whereas a damper that needs tuning generates a new resonance point.

[0007]

[Problems to be Solved by the Invention] By the way, in recent years, exhaust gas regulations of diesel engines have been tightened,
O _X, black smoke and particulate measures are urgently needed.
As a countermeasure, it has been proposed to promote atomization of fuel in order to improve the combustion efficiency of a diesel engine.

For this reason, it has been practiced to increase the injection pressure in the fuel injection pump to inject the fuel at a high pressure. However, as a result of increasing the injection pressure in the fuel injection pump as described above, torsional vibration and torque fluctuation of the drive system of the fuel injection pump increase, and the generation of gear noise becomes remarkable. In particular, the peak torque reaches about 2.5 times the steady torque.

In order to suppress such torsional vibration and torque fluctuation of the drive system of the fuel injection pump, it is necessary to increase the size of the support and bearings and the size of the drive system. It is unfavorable because of increase and enlargement. Therefore, a viscous damper provided solely for the purpose of reducing the torsional vibration of the crankshaft,
It has been found that the arrangement in the drive system of the fuel injection pump reduces torsional vibration and torque fluctuation of the drive system of the fuel injection pump.

However, there has not been proposed in the past how to specifically arrange the viscous damper in the drive system of the fuel injection pump. A proposal for a mounting structure has been desired. Accordingly, an object of the present invention is to provide a structure for effectively attaching a viscous damper to a drive system of a fuel injection pump in view of the above-described conventional problems.

[0011]

Therefore, the torsional viscous damper mounting structure for a fuel injection pump according to the present invention comprises a torsional viscous damper, a drive shaft to which engine driving force is transmitted, and a camshaft of the fuel injection pump. The timer housing of the timer is directly connected to a drive shaft through a coupling device, and the coupling of the timer housing to the coupling device is performed. A case portion that extends in parallel with the timer center axis from the peripheral portion of the side end surface to form an annular shape surrounding the coupling device and forms a cylindrical space of the torsional viscous damper is integrally formed with the timer housing, A cover that seals the cylindrical space of the case is provided, and the thrust is placed inside the sealed cylindrical space. And is positioned by a journal bearing, as well as accommodating the support inertial ring rotatable state, while satisfying the high viscosity liquid within said cylindrical space, said coupling device, a plurality of thin plates
The second formed by polymerization and fastened to the drive shaft
1 and the coupling is tightened.
Arm joint to be connected and the arm joint
And a second laminated coupling to be tied .

[0012]

In this configuration, in the absence of torsional vibration, the case portion of the viscous damper and the inertia ring rotate as if they were an integrated unit. As the rotational speed of the fuel injection pump changes to a point that excites torsional vibration, the drive shaft and the camshaft, that is, the case fixed to these shafts, seem to have additional torsional vibration on the main rotation. Phenomena. Because the inertia ring tries to keep constant rotation due to its own inertia,
A relative rotational vibration change occurs between the case portion and the inertial ring. Therefore, the high-viscosity liquid is subjected to a shearing force, and the vibration energy is replaced by heat energy. The vibration of the drive shaft and the cam shaft is absorbed, and the torque fluctuation is reduced. Attenuated and relaxed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings. In FIG. 1, the drive system of the fuel injection pump 10 is provided with a fuel injection pump drive gear (not shown).
A fuel injection timing control timer 11 is interposed between the fuel injection pump drive gear unit of the drive system and the fuel injection pump 10, and the timer 11 is provided with a torsional viscous damper (hereinafter, referred to as a target of the present invention). A viscous damper 12) is provided integrally.

A structure in which the viscous damper 12 is provided integrally with the timer 11 will be described. First, the timer 11
Will be described with reference to FIGS. A timer housing 15 is directly connected to a drive shaft 13 guided from the fuel injection pump drive gear via a coupling device 14 described later. The fly weight 16 is incorporated into and held by the press-fit pin 17 of the timer housing 15. The distal end of the camshaft 19 of the fuel injection pump 10 penetrates through the mounting hole 18a of the mounting boss 18A of the flange 18, and the tapered shaft portion 19A provided on the base side of the distal end of the camshaft 19 has the inside of the mounting hole 18a. Fitted on the peripheral surface. A key (not shown) is fitted into the fitting surface.

A male thread (not shown) is formed at the end of the camshaft 19 projecting from the mounting hole 18a. A nut 20 is fitted into the male thread, and the camshaft 19 and the mounting boss 18A are formed. Is concluded. Nut 20
A spring washer 21 is interposed between the mounting boss 18A and the end face of the mounting boss 18A. Thus, the fuel injection pump 10
A curved surface 18B is formed on the inner surface of the flange 18 connected to the camshaft 19 of the curved surface 18.
B is in contact with a roller 23 fitted into the press-fit pin 22 of the fly weight 16.

The surface of the flange 18 and the fly weight 16
The half-moon spring seat 24 fitted to the press-fit pin 17 of the timer housing 15 penetrating the
In the meantime, a timer spring 25 having a setting force is assembled. Flange 18 of timer housing 15
A cover 26 is provided on the side surface, and the cover 26 is fastened to the press-fit pin 17 by bolts 27.

FIG. 3A shows a state in which the flyweight 16 has no centrifugal force and the timer housing 1 has no rotation.
5 with the press-fit pin 17 (point B) as a fulcrum, the flyweight 16 is set by a timer spring 25 having a set force.
Of the press-fit pin 22 (point A)
B pulls and makes contact. Once the engine is started, the timer 11 rotates clockwise, and the press-fit pin 17 (point B) of the timer housing 15 directly connected to the drive shaft 13
The press-fit pin 22 (point A) of the flyweight 16 pushes the curved surface 18B of the flange 18 via the, and rotates the fuel injection pump 10. When the centrifugal force of the fly weight 16 is inferior to the setting force of the timer spring 25, the state shown in FIG. Further, when the rotation of the fuel injection pump 10 rises and the centrifugal force and the set force balance, the advance angle starts, and the advance angle advances as the rotation speed increases thereafter.

FIG. 3B shows the state at the maximum advance angle. When the centrifugal force gradually increases, the fly weight 16 contracts the timer spring 25 with the press-fit pin 17 (point B) of the timer housing 15 as a fulcrum, and moves the flange 18 in the rotational direction while opening outward (FIG. 3 (B)). ) From the dotted line to the solid line).

That is, the flange 18 rotates in the rotation direction by an amount corresponding to the contraction of the timer spring 25, and the camshaft 19 of the fuel injection pump 10 with respect to the drive shaft 13.
A phase shift occurs between the phases, and the advance angle corrects the delay of the injection timing. When the rotation of the fuel injection pump 10 rises and reaches the maximum advance angle, the fly weight 16 hits the inner wall of the timer housing 15, and the advance angle is not performed even if it rotates further.

The timer housing 15 of the timer 11
Coupling device 1 for directly connecting to drive shaft 13
4 is configured as follows. A first laminated coupling 28 formed by stacking a plurality of thin plates and fastened to the drive shaft 13, an arm joint 29 to which the coupling 28 is fastened, and a second joint to which the arm joint 29 is fastened Laminated coupling 30
Are provided.

A substantially cylindrical joint 31 is fixedly attached to an end of the drive shaft 13 by a bolt 32. On both sides of the outer peripheral surface of the joint 31, a pair of mounting plate portions 31A extending along a plane orthogonal to the central axis thereof are formed. An opening is formed in the center of the first laminate type coupling 28, and the peripheral portion of the first
The portions are fastened and fixed to the pair of mounting plate portions 31A by bolts 33 and nuts 34, respectively. In this case, the joint 31 is inserted into the opening of the first laminated coupling 30.
Is penetrated.

An opening is formed at the center of the arm joint 29, and a pair of mounting plate portions 29A extending along a plane orthogonal to the center axis are formed at opposite sides of the opening forming portion. A pair of mounting plate portions 29B are formed on both sides of the formed portion of the opening, which oppose each other in a direction orthogonal to the both sides, and extend along a plane orthogonal to the central axis. That is, the arm joint 29 is formed such that two sets of a pair of mounting plate portions 29A and 29B are provided, and the mounting plate portions 29A and 29B form a cross shape.

Each of the mounting plate portions 29A and 29B is provided with a female screw hole for a bolt at a tip end thereof. Then, the bolt 33 around the periphery of the first laminate type coupling 28 is used.
The two portions opposed to each other in the direction orthogonal to the fastening portion are fastened and fixed to one pair of mounting plate portions 29A of the arm joint 29 by bolts 35, respectively. Two opposing peripheral portions of the second laminate type coupling 30 are fastened and fixed to the other pair of mounting plate portions 29B of the arm joint 29 by bolts 36, respectively.

The head of the bolt 36 is inserted into a groove 37 formed in the end wall of the timer housing 15.
On the other hand, two portions of the periphery of the second laminated coupling 30 which are opposed to each other in a direction orthogonal to the fastening portion by the bolt 36 are connected to the timer housing 1 by the bolt 38.
5 are fastened and fixed to the periphery of the end wall. .

Here, the timer housing 15 has an annular shape extending parallel to the central axis of the timer 11 from the peripheral portion of the end surface of the timer housing 15 connected to the coupling device 14 and surrounding the coupling device 14. A case 38 that forms a space is integrally formed with the timer housing 15. Further, a cover 39 for sealing the cylindrical space of the case portion 38 is provided.

The viscous damper 12 is positioned by a resin-made thrust bearing 40 and a journal bearing 41 in a cylindrical closed space formed by the case 38 and the cover 39, and is supported in a rotatable state. While accommodating the inertia ring 42
The sealed space is filled with silicone oil 43 as a high-viscosity liquid.

In such a configuration, in the absence of torsional vibration, the case 38 and the inertia ring 42 of the viscous damper 12 rotate as if they were an integrated unit. As the rotational speed of the fuel injection pump 10 changes to a point that excites torsional vibration, the drive shaft 13 and the camshaft 19, that is, the case portion 38 fixed thereto, have additional torsional vibration on the main rotation. The phenomenon as described is exhibited. Because the inertia ring 42 tends to continue rotating due to its own inertia, a relative rotational vibration change occurs between the case portion 38 and the inertia ring 42, and therefore,
The silicone oil 43 receives the shearing force, and the vibration energy is replaced by the heat energy, the vibration of the drive shaft 13 and the camshaft 19 is absorbed, and the torque fluctuation is attenuated and reduced.

According to such a configuration, in the fuel injection pump 10 in which the injection pressure is increased, torsional vibration and torque fluctuation of the drive system can be effectively reduced, gear noise can be suppressed, support and bearings can be added, and the drive system can be added. Since it is not necessary to increase the size of the device, the weight does not increase and the device does not increase in size. In particular, according to the above configuration, the viscous damper 12 can be integrally formed with the timer 11 by integrally molding the case portion 38 with the timer housing 15. Therefore, the viscous damper 12 needs to be provided separately from the timer 11. There is no need for mounting tools for mounting the viscous damper 12 and the viscous damper 1
Also, the mounting work of No. 2 is unnecessary, and the timer housing 15 is simply used.
It is only necessary to change the shape, and the production cost can be kept low.

Further, since the case 38 of the viscous damper 12 is formed so as to surround the coupling device 14, the driving system of the fuel injection pump 10 can be provided even if the viscous damper 12 is additionally provided to the driving system of the fuel injection pump 10. Therefore, the drive system can be kept compact as before. In this embodiment, the viscous damper 12 is used.
As a coupling device for connecting the timer and the timer 11,
Since the laminated type couplings 28 and 30 are applied and the fulcrum of the drive side (drive shaft 13) and the fulcrum of the driven side (timer housing 15) are attached in a direction perpendicular to each other, the thin plates of the laminated type couplings 28 and 30 have By the reversibility, the same function as the universal joint of the propeller shaft is performed, and the rotation of the drive shaft 13 can be smoothly transmitted to the timer housing 15.

Although the present invention has been described with reference to a specific embodiment as described above, the present invention is not limited to this, and is attached to the present invention by a person skilled in the art. It should be noted that various changes and modifications can be made without departing from the scope of the claimed utility model registration claim.

[0031]

As described above, according to the torsional viscous damper mounting structure for a fuel injection pump of the present invention, the timer housing of the timer is directly connected to the drive shaft via the coupling device, and the cup of the timer housing is connected. A case that extends in parallel with the center axis of the timer from the peripheral surface of the end face on the side where the ring device is connected and surrounds the periphery of the coupling device to form a cylindrical space for the torsional viscous damper is integrally formed with the timer housing. , A cover that seals the cylindrical space of the case is provided, so that the torsional vibration and torque fluctuation of the drive system in the fuel injection pump can be effectively reduced, the generation of gear noise can be suppressed, and the laminate type coupling can be used. , The rotation of the drive shaft can be smoothly transmitted to the viscous damper case. Furthermore, there is no need to provide a viscous damper separately from the timer, so that the number of parts can be reduced, mounting workability can be improved, manufacturing costs can be reduced, and the drive system can be kept compact as before. It has the advantage of being practically effective.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a mounting structure of a torsional viscous damper for a fuel injection pump according to the present invention.

FIG. 2 is an assembled perspective view showing a configuration of a timer in the embodiment.

FIG. 3 is an internal structure diagram showing the operation of the above timer.

FIG. 4 is a perspective view showing the structure of a typical torsional viscous damper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fuel injection pump 11 Timer 12 Viscous damper 13 Drive shaft 14 Coupling device 15 Timer housing 38 Case part 39 Cover 40 Thrust bearing 41 Journal bearing 42 Inertial ring 43 Silicone oil

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02M 39/02 F02D 1/04 F02M 59/44 F16F 15/16

Claims (1)

(57) [Scope of request for utility model registration] 1. A structure for attaching a torsional viscous damper to a fuel injection timing control timer provided at a connection between a drive shaft to which engine driving force is transmitted and a cam shaft of a fuel injection pump, An annular structure in which the timer housing of the timer is directly connected to a drive shaft via a coupling device, and extends from an end surface peripheral portion of the timer housing on the coupling device connection side in parallel with the timer center axis to surround the coupling device. The case part forming the cylindrical space of the torsional viscous damper is integrally formed with the timer housing, a cover for sealing the cylindrical space of the case part is provided, and a thrust and a thrust are provided inside the sealed cylindrical space. Contains an inertia ring that is positioned by journal bearings and supported in a freely rotatable state While, while satisfying the high viscosity liquid within said cylindrical space, said coupling device, double
It is formed by stacking a number of thin plates and fastened to the drive shaft.
A first laminated coupling to be tied and the cup
An arm joint to which a ring is fastened;
And a second laminated coupling to which the point is fastened.
A torsional viscous damper mounting structure for a fuel injection pump, comprising: