JPS6139111Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a metering pump that mechanically delivers a small amount of pressure oil.

It is known that supplying lubricating oil to these parts is effective in preventing wear of the intake valves and valve seats of diesel engines with a supercharger and with a supercharger and aftercooler.

A metering pump is used in this case.

This metering pump is designed as shown in FIGS. 1 to 5, and a rotary spool 2 fitted to a valve body 1 rotates a worm wheel 4 that meshes with a worm 3 provided on the rotary spool 2. Therefore, at a certain rotation angle, the inflow hole 5 provided in the spool 2 communicates with the suction hole 6 provided in the valve body 1,
Oil discharged from the engine's lubricating pump connected to the suction hole 6 is caused to flow into the pressure accumulation chamber 7 from the inflow hole 5. A piston 8 is fitted into the pressure storage chamber 7, and the piston 8 is moved back by the inflow of the pressure oil, and the pressure oil is stored (metered) in the pressure storage chamber 7. As the rotation of the spool 2 progresses from this state, the communication between the inflow hole 5 and the suction hole 6 is cut off, and then the outflow hole 10 provided in the rotating spool 2 communicates with the pressure accumulation chamber 7 and the discharge hole provided in the valve body 1. The piston 8 communicates with the hole 11 , and the pressure oil in the pressure storage chamber 7 is discharged from the discharge hole 11 by the piston 8 . A back pressure chamber 9 facing the back surface of the piston 8 is connected to the suction hole 6.

By repeating this operation in sequence, a small amount of pressurized oil is intermittently supplied from the discharge hole 11 to worn parts such as intake valves and valve seats of the engine connected to the discharge hole 11.

In the above metering pump, a cam 12 is in contact with one end surface of the rotary spool 2, and by rotating this cam 12 with a lever 13, the rotary spool 2 is moved in the axial direction. The opening degree of the inflow hole 5 and the outflow hole 10 with respect to the suction hole 6 and the discharge hole 11 is adjusted to adjust the discharge amount.

In the conventional metering pump mentioned above, when the oil temperature rises and the differential pressure between the inlet pressure and the back pressure increases, the discharge amount increases significantly even if the rotation of the rotary spool 2 is constant, making it difficult to maintain the predetermined oil supply amount. There was a defect that it could not be maintained.

The main reason why the discharge amount increases as the differential pressure increases is that oil escapes to the discharge hole 11 from the clearance between the valve body 1 and the rotating spool 2.

The present invention was developed with the above in mind. By discharging only the oil from the pressure accumulation chamber from the discharge hole, the specified oil supply is always maintained even when the oil temperature rises or the differential pressure increases. It is an object of the present invention to provide a metering pump that can hold the amount of water.

That is, narrow grooves 14 and 15 are provided in the circumferential direction on both sides of the outflow hole 11 of the rotary spool 2 in the conventional metering pump, and the valve body 1 has locations corresponding to both of the narrow grooves 14 and 15. A drain hole 16 communicating with the outside is provided in the drain hole 16 .

Since the present invention is as described above, even if oil flows out from the inlet 5 of the rotary spool 2 and the back pressure chamber 7 to the discharge hole 11 through the gap between the valve body 1 and the rotary spool 2, In the middle of this narrow groove 14,1
5 and is directly discharged from the drain hole 16 to the outside.

Therefore, only the oil from the pressure accumulation chamber 7 is discharged from the discharge hole 11 of the valve body 1, and a predetermined oil supply amount can always be maintained even if the oil temperature rises or the differential pressure increases.

[Brief explanation of the drawing]

Figures 1 to 5 show a conventional metering pump. Figure 1 is a front view, Figure 2 is a partially cutaway side view, and Figure 3 is a cross-sectional view taken along the - line in Figure 1. 4 is a cross-sectional view taken along the - line in FIG. 2, FIG. 5 is a cross-sectional view taken along the - line in FIG. 1, and FIG. 6 is a cross-sectional view showing an embodiment of the present invention. be. 1 is a valve body, 2 is a rotating spool, 5 is an inflow hole, 6
1 is a suction hole, 7 is a pressure accumulation chamber, 8 is a piston, 9 is a back pressure chamber, 10 is an outflow hole, 11 is a discharge hole, 14 and 15 are narrow grooves, and 16 is a drain hole.

Claims (1)

[Scope of utility model registration request] By rotating the rotary spool 2 within the valve body 1, which has a pressure accumulation chamber 7 at its axial center and has an inflow hole 5 and an outflow hole 10 communicating with the pressure accumulation chamber 7 shifted in the axial direction. The suction hole 6 provided in the valve body 1 communicates with the inflow hole 5, and the discharge hole 11 provided in the valve body 1 communicates with the outlet hole 10 alternately, and the back surface of the piston 8 fitted in the pressure accumulation chamber 7 is , a metering pump that communicates with a suction hole 6 and faces a back pressure chamber 9, narrow grooves 14 and 15 are provided in the circumferential direction on both sides of the rotary spool 2 across the outflow hole 11, and the valve body 1
There is a drain hole 1 communicating with both the narrow grooves 12 and 13.
A metering pump characterized by having 6.