CN201407223Y

CN201407223Y - Improved priority unloading valve

Info

Publication number: CN201407223Y
Application number: CN2009201372538U
Authority: CN
Inventors: 严光贤
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-20
Filing date: 2009-03-20
Publication date: 2010-02-17
Anticipated expiration: 2019-03-20

Abstract

The utility model discloses an improved priority unloading valve, which comprises a priority valve, an overflow valve, a one-way valve, a low-pressure unloading control valve, an unloading valve pilotvalve and an unloading valve main valve, wherein the low-pressure unloading control valve is communicated with the unloading valve pilot valve and the unloading valve main valve respectively throughoil holes. The low-pressure unloading control valve is added to the utility model based on the original priority unloading valve, when the working hydraulic system is in inoperation state, the hydraulic oil output by a working pump and a diversion pump splits to return oil, thereby reducing the on-way pressure loss of the hydraulic oil as well as the thermal balance temperature of the hydraulic system, and improving the efficiency of the hydraulic system.

Description

The preferential unloading valve of modified model

Technical field

The utility model relates to a kind of hydraulic element, particularly relates to the preferential unloading valve of a kind of modified model.

Background technique

(patent No.: ZL00206564.9) disclose a kind of preferential unloading valve (as shown in Figure 1), it comprises pressure-gradient control valve 1 ', relief valve 2 ', one-way valve 3 ', unloading valve pilot valve 4 ' and unloading valve main valve 5 ' to Chinese patent.Thisly commonly use preferential unloading valve and only have high pressure unloading functions, when hydraulic system of working is not worked, as when loom is walked, the hydraulic oil interflow oil return of working pump and steering pump output, increased hydraulic oil oil return linear loss, can increase the working oil temperature of hydraulic system, influence the working efficiency of system.

The model utility content

The purpose of this utility model is to provide a kind of modified model preferential unloading valve.

For achieving the above object, technical solution of the present utility model is:

The utility model is the preferential unloading valve of a kind of modified model, it comprises pressure-gradient control valve, relief valve, one-way valve, unloading valve pilot valve and unloading valve main valve, pressure-gradient control valve is communicated with relief valve, one-way valve, unloading valve main valve respectively by oil circuit, and the unloading valve pilot valve is communicated with one-way valve and unloading valve main valve respectively; It also comprises a low pressure off-load control valve, and this low pressure off-load control valve is communicated with unloading valve pilot valve and unloading valve main valve respectively by oilhole.

Described low pressure off-load control valve mainly is made up of valve body, spool, spring and plug; Offer the low voltage control chamber of spring chamber and ccontaining spool on the described valve body, this spring chamber and low voltage control chamber are same cavity; Described plug is fixed on the accent of the spring chamber that is opened in valve body; Described spool is a cylindrical body, which is provided with annular groove and spool oilhole, and described annular groove is arranged on cylindrical waist; Described spool activity is nested with in the low voltage control chamber of valve body, on valve body, offer first, second, third oilhole that is connected with the unloading valve pilot valve, these three oilholes can be connected with spring chamber, annular groove and low voltage control chamber respectively, the 3rd oilhole can be connected with oil inlet and outlet EF mouth by the low voltage control chamber, and described spool oilhole, annular groove, second oilhole are connected with oil inlet and outlet EF mouth; Offer the 4th oilhole that is connected with the unloading valve main valve on valve body, spring chamber is connected with the unloading valve main valve by this article the 4th oilhole and is connected with the oil return inlet T mouth by the unloading valve main valve; Described spring is installed in the spring chamber, and its two ends lean respectively in the inner of plug and the outer end of spool.

After adopting such scheme, because the utility model is to have increased low pressure off-load control valve on the basis of existing preferential unloading valve, when the Control work hydraulic system is not worked, the hydraulic oil partial discharge of steering pump output (the remainder shunting when turning to work) or whole flow (turning to when not working) are directly by the unloading valve oil return, reduce hydraulic oil along stroke pressure loss and heat equilibrium of hydraulic system temperature, improved the efficient of hydraulic system.

Below in conjunction with the drawings and specific embodiments the utility model is further described.

Description of drawings

Fig. 1 is a schematic diagram of commonly using preferential unloading valve;

Fig. 2 is the schematic diagram of the preferential unloading valve of the utility model;

Fig. 3 is a plan view of the present utility model;

Fig. 4 is the sectional view of Fig. 3 along the A-A line;

Fig. 5 is the sectional view of Fig. 3 along the B-B line.

Embodiment

As Fig. 2, Fig. 3, Fig. 4, shown in Figure 5, the utility model is the preferential unloading valve of a kind of modified model, and it comprises pressure-gradient control valve 1, relief valve 2, one-way valve 3, unloading valve pilot valve 4, low pressure off-load control valve 5 and unloading valve main valve 6.

Described pressure-gradient control valve 1 is communicated with relief valve 2, one-way valve 3 and unloading valve main valve 6 respectively by oil circuit, and unloading valve pilot valve 4 and low pressure off-load control valve 5 are communicated with one-way valve 3 and unloading valve main valve 6 respectively.

As shown in Figure 4, described low pressure off-load control valve 5 mainly is made up of valve body 51, spool 52, spring 53 and plug 54.Offer the low voltage control chamber 512 of spring chamber 511 and ccontaining spool 52 on the described valve body 51, this spring chamber 511 and low voltage control chamber 512 are same cavity; Described plug 54 is fixed on the accent of the spring chamber 511 that is opened in valve body 51.

Described spool 52 is a cylindrical body, which is provided with annular groove 521 and spool oilhole 522, and described annular groove 521 is arranged on cylindrical waist; Described spool 52 activities are nested with in the low voltage control chamber 512 of valve body 51, on valve body 51, offer first oilhole 513, second oilhole 514, the 3rd oilhole 515 that are connected with unloading valve pilot valve 4, these three oilholes can be connected with spring chamber 511, annular groove 521 and low voltage control chamber 512 respectively, the 3rd oilhole 515 is connected with low voltage control valve pocket 512 and oil inlet and outlet EF mouth, and spool oilhole 522, annular groove 521, second oilhole 514 are connected with oil inlet and outlet EF mouth; Offer the 4th oilhole 516 that is connected with unloading valve main valve 6 on valve body 51, spring chamber 511 is connected with unloading valve main valve 6 by this article the 4th oilhole 516, unloading valve main valve control port 517 and is connected with the oil return inlet T mouth by the oilhole 66 on the spool 62 of unloading valve main valve 6, throttle orifice 61; Described spring 53 is installed in the spring chamber 511, and its two ends lean the outer end at the inner of plug 54 and spool 52 respectively.

Working principle of the present utility model:

After the loader power engine starts, when work system is not worked, the hydraulic oil of working pump output is by the multiple directional control valve oil return, the hydraulic fluid pressure of EF mouth is lower, low pressure off-load this moment control valve 5 is opened, the hydraulic oil of the lower pressure that enters from the EF mouth is by second oilhole 514, annular groove 521, oilhole 522, spring chamber 511, oilhole 516, unloading valve main valve control port 517, control chamber 63, oilhole 66, throttle orifice 61 is from the oil return of oil return inlet T mouth, because the throttling action of throttle orifice 61, spool 62 1 ends of unloading valve main valve 6 are that the hydraulic oil of control chamber 63 possesses certain hydraulic coupling, the other end oil back chamber 64 is communicated with the oil return inlet T mouth by oilhole 65, spool 62 overcomes spring force and moves to right under the effect of two end pressure differences, unloading valve main valve 6 is opened, the hydraulic oil that enters through the C chamber is no longer by one-way valve 3 and oil inlet and outlet EF mouth hydraulic oil interflow, but pass through unloading valve main valve 6 from the oil return of oil return inlet T mouth, one-way valve 3 closures.Second oilhole 514 is a throttling passage with the oil canal of annular groove 521.When the input pressure of oil inlet and outlet EF mouth raises, because throttling action, flow by oilhole 514 and annular groove 521 increases, two end pressure differences of spool 52 raise, spool 52 moves to left under the effect of pressure at two ends difference, oilhole 514 increases with the through-flow throttling action of annular groove 521, spool 52 2 end pressure differences further raise, spool 52 amounts of moving to left increase, when the pressure of EF mouth reaches certain value, the pillar of spool 52 has been sealed the port of second hydraulic fluid port 514, has cut off the oil canal of oil inlet and outlet EF mouth and annular groove 521.That is the hydraulic oil of oil inlet and outlet EF mouth can not enter unloading valve main valve 6, spool 62 travelling backwards under the effect of spring force of unloading valve main valve 6 is until unloading valve main valve 6 closures.The hydraulic oil that enters from the C chamber is exported from oil inlet and outlet EF mouth by one-way valve 3.When the oily EF mouth hydraulic fluid pressure of turnover is elevated to certain value, unloading valve pilot valve 4 is opened, the pilot valve 4 of the pressure oil of oil inlet and outlet EF mouth after opening, oilhole 41 first oilholes 513 spring chambers 511, the 4th oilhole 516, unloading valve main valve control port 517, control chamber 63, oilhole 66, throttle orifice 61 is from the oil return of oil return inlet T mouth, because the throttling action of throttle orifice 61, spool 62 2 ends of unloading valve main valve 6 produce pressure difference, spool 62 overcomes spring force and moves to right under the pressure difference effect of two ends, unloading valve main valve 6 is opened, and the hydraulic oil that enters from the C chamber passes through unloading valve main valve 6 from the oil return of oil return inlet T mouth, one-way valve 3 closures.

Emphasis of the present utility model just is: on the basis of original preferential unloading valve, increased low pressure off-load control valve.

Claims

1, the preferential unloading valve of a kind of modified model, it comprises pressure-gradient control valve, relief valve, one-way valve, unloading valve pilot valve and unloading valve main valve, pressure-gradient control valve is communicated with relief valve, one-way valve, unloading valve main valve respectively by oil circuit, and the unloading valve pilot valve is communicated with one-way valve and unloading valve main valve respectively; It is characterized in that: it also comprises a low pressure off-load control valve, and this low pressure off-load control valve is communicated with unloading valve pilot valve and unloading valve main valve respectively by oilhole.

2, the preferential unloading valve of modified model according to claim 1 is characterized in that: described low pressure off-load control valve mainly is made up of valve body, spool, spring and plug; Offer the low voltage control chamber of spring chamber and ccontaining spool on the described valve body, this spring chamber and low voltage control chamber are same cavity; Described plug is fixed on the accent of the spring chamber that is opened in valve body; Described spool is a cylindrical body, which is provided with annular groove and spool oilhole, and described annular groove is arranged on cylindrical waist; Described spool activity is nested with in the low voltage control chamber of valve body, on valve body, offer first, second, third oilhole that is connected with the unloading valve pilot valve, these three oilholes can be connected with spring chamber, annular groove and low voltage control chamber respectively, the 3rd oilhole can be connected with oil inlet and outlet EF mouth by the low voltage control chamber, and described spool oilhole, annular groove, second oilhole are connected with oil inlet and outlet EF mouth; Offer the 4th oilhole that is connected with the unloading valve main valve on valve body, spring chamber is connected with the unloading valve main valve by this article the 4th oilhole and is connected with the oil return inlet T mouth by the unloading valve main valve; Described spring is installed in the spring chamber, and its two ends lean respectively in the inner of plug and the outer end of spool.