JP2607696Y2 - Oil pump relief valve for engine lubrication - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relief valve used in an oil pump for engine lubrication.

[0002]

2. Description of the Related Art Conventionally, relief valves used in oil pumps for engine lubrication include those shown in FIGS. That is, it belongs to a normally closed sequence valve, and has a sleeve 2 fitted in a substantially cylindrical valve body 1.
A valve piston 7 and a spring receiver 8 in which a pressure receiving portion 4 and a sliding portion 5 are connected by a connecting rod 6 are fitted in a valve hole 3 formed in the valve body 1. 2, an inlet port 9 connected to an oil supply passage (not shown) of an oil pump for engine lubrication and an outlet port 10 formed opposite to the inlet port 9 are configured to open and close, and the valve piston Valve spring 1 between 7 and spring receiver 8
1 and the head 4 of the pressure receiving portion 4 of the valve piston 7
The hydraulic path 12 is formed so as to apply an inlet pressure to a. Reference numeral 13 denotes a split pin for stopping the spring receiver 8, and reference numeral 14 denotes a plug.

[0003] When the relief valve is not operated, the valve shown in FIG.
As shown in the figure, the valve piston 7 is pressed to the left by the valve spring 11, and the head 4a of the pressure receiving portion 4 of the valve piston 7 is seated on the valve seat 2a formed on the sleeve 2. The inlet port 9 and the outlet port 10 are closed by the sliding portion 5 of the first embodiment. When the relief valve is activated, that is, when the hydraulic pressure in the hydraulic passage 12 reaches or exceeds the set inlet pressure, the valve piston 7 is moved by the hydraulic pressure applied to the head 4a of the pressure receiving portion 4 as shown in FIG. It moves largely to the right against 8 and passes widely through the inlet port 9 and the outlet port 10. As a result, the oil upstream of the inlet port 9 is quickly released from the outlet port 10 and is reduced to the set inlet pressure.

[0004]

As described above, since the sliding amount of the valve piston 7 is increased, lubrication of the outer periphery of the sliding portion 5 of the valve piston 7 is deteriorated. ,
So-called galling occurred, and the operation failure of the valve piston 7 occurred. In view of the above, the present invention has been devised to provide a relief valve of an oil pump for engine lubrication that operates smoothly even when the sliding amount of a valve piston is large.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the relief valve of the engine lubrication oil pump according to the present invention has an inlet port connected to an oil feed passage of the engine lubrication oil pump in a valve hole of the valve body. And a valve piston that opens and closes an outlet port and a valve spring that presses the valve piston to apply an inlet pressure to a pressure receiving portion of the valve piston. A plurality of oil grooves are formed on at least an outer periphery of the moving portion facing the inlet port when the valve piston is not operated.

[0006]

In the relief valve of the oil pump for engine lubrication of the present invention having the above-mentioned structure, the valve piston is pressed by the valve spring when not operating, and the head of the pressure receiving portion of the valve piston comes into contact with the valve seat formed on the sleeve. At this time, the inlet port and the outlet port are closed by the sliding portion of the valve piston, but at this time, since a part of the oil groove faces the inlet port and the outlet port, the oil on the inlet port side is Flows toward the outlet port side (leaks) while filling a part of the oil groove facing the port. In this state, when the relief valve is operated, that is, when the oil pressure in the hydraulic passage reaches the set inlet pressure or more, the valve piston moves against the valve spring due to the oil pressure applied to the head of the pressure receiving portion. The oil upstream of the inlet port is quickly released from the outlet port through the inlet port and the outlet port, but the oil held in the oil groove formed on the outer periphery of the sliding portion when the valve piston moves moves through the valve. The inner surface of the hole is wetted and the galling does not occur. When the oil pressure in the oil passage falls below the set inlet pressure and the valve piston returns by the valve spring, the oil groove, particularly the oil groove on the opposite side to the connecting rod, is applied to the oil on the inner surface of the valve hole. Incorporate

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIGS. 1 to 4 in which the same reference numerals as those in FIGS. 5 and 6 indicate the same parts and members.
A plurality of oil grooves 24 are formed on the outer periphery of a sliding portion 23 connected to the pressure receiving portion 21 by a connecting rod 22. The oil groove 24 is formed at least on the outer periphery of the sliding portion 23 of the piston facing the inlet port 9 when the valve piston 20 is not operated. In the embodiment, as shown in FIGS. One is formed on the connecting rod 22 side of the sliding portion 23, and seven are provided at an appropriate interval slightly apart therefrom, and a total of eight are formed. Covers half of the cross section of port 9 (and thus outlet port 10). The shape of the oil groove 24 is an arc-shaped thin groove having a shallow cross section as shown in FIG.
Millimeter, depth is 0.4-0.7 mm, and pitch is about 3-4 mm. After all, the oil groove 2
For the shape, width, depth, pitch, number, etc. of 4, the shape, numerical value, and number are selected so that there is little leakage before valve opening, which will be described later, and lubricating oil that does not cause galling on the sliding portion 23 is selected. However, it is ultimately determined by experiments or the like.

[0008] In the relief valve of the present invention having the above-described structure, as in the conventional relief valve shown in FIG.
0 is pressed to the left by the valve spring 11, and the head 21 a of the pressure receiving portion 21 of the valve piston 20 is seated on the valve seat 2 a formed on the sleeve 2. The inlet port 9 and the outlet port 10 are closed. At this time, a part of the oil groove 24
Since it faces the outlet port 10, the oil on the inlet port 9 side flows toward the outlet port 10 while filling a part of the oil groove 24 facing the inlet port 9 (in short, the oil leaks but is very small). In this state, when the relief valve is operated, that is, when the oil pressure in the hydraulic passage 12 reaches the set inlet pressure or more, as shown in FIG.
Due to the hydraulic pressure applied to the head 21a of the first port, it moves to the right against the valve spring 8 and widely communicates with the inlet port 9 and the outlet port 10, whereby the oil upstream of the inlet port 9 is quickly discharged from the outlet port 10. When the valve piston 20 moves, the oil held in the oil groove 24 formed on the outer periphery of the sliding portion 23 wets the inner surface of the valve hole 3 and does not cause the galling when the valve piston 20 moves. When the oil pressure in the hydraulic passage 12 drops below the set inlet pressure and the valve piston 20 returns to the position shown in FIG. 1 again by the valve spring 11, the oil groove 24, in particular, the oil on the side opposite to the connecting rod 22 is turned off. The groove 24 takes in the oil applied to the inner surface of the valve hole 3.

[0009]

The relief valve of the oil pump for engine lubrication of the present invention has a valve piston for opening and closing an inlet port and an outlet port connected to an oil supply passage of the oil pump for engine lubrication in a valve hole of a valve body. In a relief valve of an oil pump for engine lubrication, in which a valve spring to be pressed is fitted and an inlet pressure is applied to a pressure receiving portion of the valve piston, at least a non-operation of the sliding portion of the valve piston at a sliding portion of the valve piston. A plurality of oil grooves are formed on the outer periphery facing the inlet port at the time, so that the oil retained in the oil grooves formed on the outer periphery of the sliding portion during the movement of the valve piston can be removed by the valve. There is an effect that the operation of the valve piston can always be kept smooth without wetting the inner surface of the hole and causing the galling.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a relief valve of an oil pump for engine lubrication of the present invention when the relief valve is not operated.

FIG. 2 is a longitudinal sectional view of the relief valve according to the present invention during operation.

FIG. 3 is a front view of the valve piston of the relief valve of the present invention.

FIG. 4 is a partially enlarged view of an oil groove formed in a valve piston of the relief valve of the present invention.

FIG. 5 is a vertical cross-sectional view of a conventional oil pump for engine lubrication when a relief valve is not operated.

FIG. 6 is a longitudinal sectional view of a conventional relief valve during operation 1; valve body 2; sleeve 3; valve hole 4; pressure receiving portion (of a conventional valve piston) 5; sliding portion (as above) 6; 7) Conventional valve piston 8; Spring receiver 9; Inlet port 10; Outlet port 11; Valve spring 12; Hydraulic path 13; Split pin 14; Plug 20; Valve piston 21 of the present invention; 22; connecting rod (same as above) 23; sliding portion (same as above) 24; oil groove.

Claims (1)

(57) [Scope of request for utility model registration] 1. A valve piston for opening and closing an inlet port and an outlet port connected to an oil supply passage of an engine lubrication oil pump and a valve spring for pressing the valve piston are fitted in a valve hole of the valve body. In the relief valve of the oil pump for engine lubrication, wherein the inlet pressure is applied to the pressure receiving portion, a plurality of sliding portions of the valve piston are provided at least on the outer periphery facing the inlet port when the valve piston is not operated. A relief valve for an oil pump for engine lubrication, wherein individual oil grooves are formed.