CN2222273Y

CN2222273Y - No negative pressure type hydraulic safety valve

Info

Publication number: CN2222273Y
Application number: CN 93244779
Authority: CN
Inventors: 王建国
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-10-14
Filing date: 1993-10-14
Publication date: 1996-03-13
Anticipated expiration: 2003-10-14

Abstract

The utility model relates to a non-negative pressure safety valve of a hydraulic control valve (a five-path valve) which is used in the hydraulic system of a combined harvester. In the utility model, a space which is encircled by a valve body and a guiding plunger piston is communicated with a low pressure region, which makes the lower end of a conical valve incapable of forming negative pressure in the process of working, and the conical valve is under the action of the tension of a spring and the pressure of oil, which makes the working pressure of the hydraulic system maintained at a desired range.

Description

No negative pressure type deadweight safety valve

The utility model is a kind of being installed in hydraulic system DLT530A No. five valves, can make system pressure keep within the required range safety valve.

Be used for the safety valve on DLT530A No. five valves that Tianjin Machinery Plant on the combine-harvester produces at present, there is a slotted hole lower end of its valve body, and the middle part of slotted hole has side opening to communicate with valve body high pressure oil outward.A cone valve that can move up and down is arranged in the slotted hole, and there is a spring upper end of cone valve, and cone valve when the pressure of high pressure oil surpasses the pressure of spring, moves the upper end closed of slotted hole on the cone valve under the effect of spring.High pressure oil flows into low pressure area from the slotted hole upper end, reaches the effect of steady pressure.In order to prevent the cone valve deflection, the lower end of cone valve is provided with plunger, and plunger matches with slotted hole, and the lower end of slotted hole is surrounded an enclosed space.When cone valve moves up, produce negative pressure in the enclosed space.Cone valve not only will overcome the tension force of spring, but also will overcome the negative pressure of enclosed space, but the negative pressure of enclosed space is not constant.It is relevant with many factors such as the machining accuracy of part, installation methods, so often cause the hydraulic system pressure shakiness, influences proper functioning.According to investigations, the method that does not also address this problem at present.

The purpose of this utility model is that a kind of improved no negative pressure relief valve will be provided.It can make the slotted hole lower end not have negative pressure, makes cone valve only be subjected to the tension force of spring and the pressure of oil, makes safety valve working properly.

The utility model is achieved in that at perforate of the bottom of plunger or slotted hole or groove, with enclosed space and exterior.When moving on the cone valve, do not have negative pressure, thereby make safety valve working properly.The utility model compared with prior art, therefore it can make original enclosed space and exterior, can not produce negative pressure, can make hydraulic system pressure stable.Concrete structure of the present utility model is provided by following enforcement and accompanying drawing thereof.

Fig. 1 is the sectional view of no negative pressure relief valve.

This device has on a valve body 10, built-in spring 1, cone valve 2, the slotted hole 9 and has side opening 7, in zone of high pressure 3 and low pressure area 6 hydraulic oil is arranged all.Be provided with pilot spool 8 in the lower end of cone valve 2, it and slotted hole closely cooperate, and its effect is a radial deflection when preventing that cone valve 2 from moving up and down.Pilot spool 8, the bottom of it and slotted hole 9 surrounds a space 5, have aperture 4 in the lower end of slotted hole 9, (do not have this hole before improving, space 5 is that an enclosed space can produce negative pressure when cone valve 2 moves up, influence the motion of cone valve 2), in the ordinary course of things, cone valve 2 under the effect of spring force with the upper end closure of slotted hole 9, when the pressure of oil in the zone of high pressure 3 rises to the certain pressure value, cone valve 2 is moved up, and high pressure oil flows into low pressure area 6 from the upper end of slotted hole 9.Because the lower end of slotted hole 9 does not have enclosed space, does not have negative pressure.So 2 of cone valves are subjected to the pressure of elastic force and oil, stable working can maintain the pressure in the hydraulic system in the required scope.Except that opening the aperture 4 in the lower end of slotted hole 9, also can on the bottom of valve body 10 or lower sides, offer aperture 4, perhaps on pilot spool 8, offer hole or groove, make the lower end of slotted hole 9 not have enclosed space, no negative pressure.

Claims

1, a kind of being used in the hydraulic system, make system pressure maintain the no negative pressure relief valve of required pressure range, comprise a valve body 10, built-in spring 1, cone valve 2, the lower end of cone valve 2 is a pilot spool 8, and slotted hole 9 is arranged at valve body 10 bottoms, and pilot spool 8 closely cooperates with slotted hole 9, have side opening 7 on the slotted hole 9, it is characterized in that slotted hole 9 bottoms have hole 4, hole 4 communicates with the space 5 that valve body 10 and pilot spool 8 surround, and communicates with zone of high pressure 3.

2, safety valve according to claim 1 is characterized in that having on the pilot spool 8 hole or groove.

3, newspaper is characterized in that according to the described safety valve of claim 1 hole 4 is opened on the bottom or lower sides of valve body 10.