JPH018671Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an oil seal device for a hydraulic timer, and in particular, an oil seal for a hydraulic timer that prevents oil from flowing out from the joint between a hydraulic timer and a fuel injection pump. Regarding equipment.

[Conventional technology]

In the past, the fuel injection timing of diesel engines was generally adjusted using a flyweight timer whose movement amount varied depending on the engine speed, but in recent years, hydraulic pressure has been used for this timer. A system called a hydraulic timer is beginning to be adopted.

Such a hydraulic timer device was developed, for example, by
It is described in Japanese Patent No. 99026, and its structure will be summarized and explained using figures. That is, as shown in the side sectional view of FIG. 1 and FIG. 2, which is a front sectional view of the same in the C-C direction, it is formed integrally with the driven shaft 1, or rotates integrally with the driven shaft 1. It includes a first eccentric cam 3 fitted into a fixed disc 2, and a second eccentric cam 4 fitted into the first eccentric cam 3.

The disk 2 and these first and second eccentric cams 3
and 4 are shown in the upper half of FIG. 2, in which a pin 6 fixed to the drive shaft disk 5 is engaged with the second eccentric cam, while the first eccentric cam is assembled with the second eccentric cam. 3 is engaged with a pin 8 fixed to the piston 7.

The piston 7 is housed in a cylinder 9 rotatably attached to a driven shaft, and is biased by a spring 10.

The driven shaft 1 is connected to a camshaft of a fuel injection pump (not shown), and pressurized lubricating oil O is supplied from a hydraulic device 14 into a cylinder 9 located on the outer periphery of the driven shaft 1. It is becoming more and more
This hydraulic system 14 pressurizes lubricating oil O in an oil tank 15 with a pump 17 and sends the oil to an oil pipe 13 having a throttle 11.
The controller 12 and the pressure regulating valve 16 can be used to change the injection timing of the fuel injection pump while detecting the load L and the load L.

That is, when the piston 7 moves in the direction A in the figure, it is operated by the hydraulic force of the lubricating oil O, and when it moves in the direction B, it is operated by the return spring 10.
It is designed to be operated by the urging force of
When the piston 7 presses the spring 10 in the direction of arrow A due to hydraulic pressure, the pin 8 moves to the position shown by the broken line, thereby rotating the first eccentric cam, and thereby the second eccentric cam 4 and pin 6 move to the position shown in FIG. , respectively, and the driven shaft 1 is advanced by θ with respect to the drive shaft disc 5.

FIG. 3 shows the overall structure of the hydraulic timer device that operates as described above.
FIG. 2 is a partially cutaway perspective view of the hydraulic timer 20 with different mounting positions.

Similar to the hydraulic timer device shown in FIGS. 1 and 2, in this device also a disk 2' is attached to the driven shaft 1', and a first eccentric cam 3 is mounted in this disk 2'. ' and the second eccentric cam 4' are fitted together in the same manner as described above. 5' is a drive shaft disc, and 6' is a pin that connects the drive shaft disc 5' and the second eccentric cam 4'. A piston 7' is provided which slides within a cylinder 9' provided on the fuel injection pump side of the first eccentric cam 3',
The piston 7' and the first eccentric cam 3' are connected by a pin 8'. 10' is a spring provided outside the cylinder 9' for biasing the piston.

The piston device, cam device, etc. are integrally built into a timer casing 21, and this casing 21 rotates while maintaining the advance angle as the drive shaft disk 5' rotates. . Reference numeral 19 denotes a pulser for detecting injection timing, which is attached to the input side of the casing 21.

Furthermore, since the inside of this casing 21 is filled with lubricating oil for piston operation and low hydraulic oil leaked from the piston device, the timer 20 is
A casing 21 is provided on the output side, that is, on the injection pump side.
A cover 22 is attached to the cover 22, and an annular oil seal rubber 23 is fixed to the inner circumferential surface of the cover 22 to seal the joint interface between the rotating cover 22 and a fuel injection pump (not shown).

The upper half of FIGS. 4 and 5 is a sectional view showing only this oil seal portion. The timer cover 22 attached to the fuel injection pump 30 side of the timer casing 21 has an O-ring 24 encircled at the joint with the casing 21, and an oil seal rubber 23 fixed to the inner peripheral surface.
23a is the lip portion of the oil seal rubber 23; 25
is a pressing ring that urges the lip portion 23a toward the driven shaft 1 side. As shown in FIG. 5, the above-mentioned parts are included in the hydraulic timer 20 and are parts that rotate together with the hydraulic timer 20.

On the other hand, a camshaft 31 is provided on the fuel injection pump 30 side for lifting a plunger (not shown) to forcefully feed fuel, and this is coupled to the driven shaft 1 as shown in FIG. . An annular protrusion 32 is provided at the hydraulic timer side end of the fuel injection pump 30, and an annular wear ring 33 having an L-shaped cross section is fixed to the annular protrusion 32.

The lip portion 23a of the oil seal rubber 23 and the wear ring 33 are in oil-tight sliding contact with each other when the driven shaft 1 and the camshaft 31 are connected, and the lip portion 23a of the oil seal rubber 23 is in oil-tight sliding contact with the camshaft 31. It is designed to prevent leaked lubricating oil from leaking outside. 34 is another oil seal rubber that seals between the annular protrusion 32 and the driven shaft 1.

However, when looking at the oil seal between the timer cover 22 of the hydraulic timer 20 configured as described above and the wear ring 33 on the fuel injection pump 30 side, the oil seal 23 is located on the timer cover 22 side which is constantly rotating. It is fixed and timer 2
The centrifugal force exerted by the zero rotation acts on the lip portion 23a of the oil seal rubber 23 in a direction that causes it to lose its sealing force. In addition, since the oil seal rubber 23 is fixed to the timer cover 22 side, the lip portion 23a is protected against vibrations of the timer 20.
The oil seal had to be sealed while absorbing all the displacement caused by the tilt, and there was a problem with the reliability of the oil seal, and there was a risk that lubricating oil might leak out from this seal.

[The problem that the idea aims to solve]

This invention eliminates the drawbacks of the conventional oil seal provided between the fuel injection pump housing and the rotating timer cover of a hydraulic timer, and provides an oil seal device for a hydraulic timer that is free from the risk of lubricating oil leaking to the outside. It is intended to.

[Means to solve the problem]

The structure of the oil seal device for a hydraulic timer of this invention to achieve the above object is that a first annular wall is provided concentrically with the rotating shaft from the fuel injection pump housing to the hydraulic timer side, and the inner side of the first annular wall is The hydraulic timer is provided with a second annular wall concentrically arranged with a wear ring member on the outer periphery of the timer cover, and a sealing lip that is in sliding contact with the wear ring member is provided between the first and second annular walls. It is characterized by the installation of an oil seal rubber.

[Effect]

The oil seal rubber is attached to the side of the fuel injection pump that does not rotate, so that centrifugal force that reduces the pressure contact force of the lip is not applied, and the lip comes into contact with the wear ring member, so that The lip easily follows vibrations, tilts, etc. of the hydraulic timer, making it possible to maintain seal performance for a long period of time.

〔Example〕

Embodiments of this invention will be described below with reference to the drawings.

The lower half of Figures 4 and 5 is a sectional view of an embodiment of the oil seal device for a hydraulic timer of this invention, and the same parts are designated by the same numbers in contrast to the conventional example shown in the upper half of the figure. It is shown attached.

In this embodiment, an oil seal retainer 36 having a first annular wall 35 concentric with the camshaft 31 is fixed to an annular protrusion 32 provided at the end of the fuel injection pump 30 on the side of the hydraulic timer 20. A pressure retainer 38 is installed on the bottom surface of an annular recess 37 formed by the wall 35 and the retainer 36 continuous thereto. 39 is an O-ring,
The same oil seal rubber 34 as in the conventional oil seal is used for the oil seal between the injection pump 30 and the driven shaft 1 of the hydraulic timer.

The camshaft 3 of the first annular wall 35
The base portion 26b of the oil seal rubber 26 is fixed to the inner peripheral surface of the oil seal rubber 26 so that the lip portion 26a is located within the annular recess 37. 25 is a pressing ring that urges the lip portion 26a toward the camshaft 31 in the same manner as described above.

On the other hand, as shown in FIG. 5, a timer cover 40 is attached to the timer casing 21 of the rotating hydraulic timer 20, and this timer cover 40 has a second annular wall parallel to and concentric with the first annular wall 35. 41 is continuously provided, and a wear ring 42 is fixed to the outer peripheral surface of the second annular wall 41 over the entire circumference. 24 is the same O-ring as the conventional one.

When the hydraulic timer 20 is joined to the fuel injection pump 30 as shown in FIG. let

Since the oil seal device for the hydraulic timer of this invention is constructed as described above, as shown in the comparison diagram with the conventional example (upper half) in FIG. The oil seal rubber 26 is fixed to the fuel injection pump 30 side and does not rotate together with the timer 20. Therefore, in the device of this invention, the centrifugal force generated by the rotation of the timer 20 is applied to the oil seal rubber 26.
Since the sealing force of the oil seal portion is not weakened, the reliability of the seal is improved.

[Effect of idea]

As explained above, the oil seal device for a hydraulic timer of this invention includes a first annular wall provided concentrically with the rotating shaft from the fuel injection pump housing to the hydraulic timer side, and a first annular wall concentrically arranged inside the first annular wall. A second annular wall having a wear ring member disposed on the outer periphery of the timer cover of the hydraulic timer is provided, and an oil seal rubber having a sealing lip that slides into contact with the wear ring member is provided between the first and second annular walls. Since it is configured to be attached, the following effects can be obtained.

In other words, centrifugal force due to the rotation of the timer does not act on the oil seal rubber, and the sealing force of the oil seal rubber is not weakened, eliminating the risk of oil leakage from the seal, increasing the durability of the oil seal rubber, and increasing reliability. It also has the effect of improving sex.

[Brief explanation of the drawing]

Fig. 1 is a schematic side sectional view of a conventional hydraulic timer, Fig. 2 is a schematic front sectional view taken along the line C-C in Fig. 1, and Fig.
The figure is a partially cutaway perspective view showing the overall structure of a conventional hydraulic timer device, and FIG. Partial sectional view, FIG. 5 is a sectional view showing only the hydraulic timer side portion of FIG. 4. 1... Driven shaft, 20... Hydraulic timer, 21...
...Casing, 22...Timer cover, 23,2
6... Oil seal rubber, 23a, 26a... Lip portion, 30... Fuel injection pump, 31... Camshaft, 32... Annular protrusion, 33... Wear ring, 34... Oil seal rubber, 35... First
Annular wall, 36... retainer, 37... annular recess,
38...retainer, 39...O ring, 40...
Timer cover, 41...second annular wall, 42...wear rig.

Claims (1)

[Scope of utility model registration request] A first annular wall is provided concentrically with the rotating shaft from the fuel injection pump housing to the hydraulic timer side, and a wear ring member is disposed concentrically inside the first annular wall and on the outer periphery from the timer cover of the hydraulic timer. An oil seal device for a hydraulic timer, wherein two annular walls are provided, and an oil seal rubber having a sealing lip that makes sliding contact with the wear ring member is attached between the first and second annular walls.