CN115030259B - Multi-way valve for loader, loader hydraulic system and loader - Google Patents

Abstract

The present invention discloses a multi-way valve for a loader, a loader hydraulic system and a loader in the technical field of a loader. The multi-way valve is an open center multi-way valve equipped with an oil inlet P1, an oil inlet P2 and a converging valve; the oil inlet P1 receiving the hydraulic oil output by the working pump is connected to the overflow valve through a first one-way valve; the oil inlet P2 receiving the hydraulic oil output by the steering pump is connected to the overflow valve through a second one-way valve; the oil inlet P2 is connected to the oil inlet P1 through a converging valve, and at the same time, is connected to the oil circuit between the first valve stem and the second valve stem through the converging valve; the converging valve is used to divide or merge the hydraulic oil output by the working pump and the hydraulic oil output by the steering pump according to the set working state. The present invention realizes the coordinated control of the lifting and lowering of the boom and the compound action of bucket unloading and bucket collection, improves the working efficiency, and has the characteristics of simple structure and low manufacturing and maintenance costs.

Description

Multi-way valve for loader, loader hydraulic system and loader

Technical Field

The invention belongs to the technical field of loaders, and in particular relates to a multi-way valve for a loader, a loader hydraulic system and a loader.

Background technique

At present, most of the hydraulic systems in loaders adopt open center series multi-way. The lifting and lowering of the working device boom and the bucket unloading and bucket collection can only be performed separately. For example, the boom can only be lifted after the bucket collection action is completed. The boom and bucket cannot be lifted manually at the same time, which affects the working efficiency. In order to solve such problems, the load independent flow distribution (LUDV) control system is currently used in the loader industry to distribute the flow in proportion to each actuator to achieve compound action. However, for conventional loader systems, although dual pumps are used, the multi-way valve uses one inlet and there is only one operating handle. It is difficult to accurately control the reversing stroke by tilting the single handle 45°. The lifting and lowering of the boom and the bucket unloading and bucket collection compound actions are not coordinated. At the same time, the load independent flow distribution (LUDV) system has a high cost and most of the hydraulic components are imported, which is difficult to promote in the mid-end market.

Summary of the invention

In order to solve the deficiencies in the prior art, the present invention provides a multi-way valve for a loader, a loader hydraulic system and a loader, which realize the coordinated control of the lifting and lowering of the boom and the unloading and retracting of the bucket, thereby improving the working efficiency and having the characteristics of simple structure and low manufacturing and maintenance costs.

In order to achieve the above object, the technical solution adopted by the present invention is:

In a first aspect, a multi-way valve for a loader is provided, wherein the multi-way valve is an open center multi-way valve equipped with an oil inlet P1, an oil inlet P2 and a combining valve; the oil inlet P1 for receiving the hydraulic oil output by the working pump is connected to the overflow valve via a first one-way valve; the oil inlet P2 for receiving the hydraulic oil output by the steering pump is connected to the overflow valve via a second one-way valve; the oil inlet P2 is connected to the oil inlet P1 via a combining valve, and at the same time, is connected to the oil circuit between the first valve stem and the second valve stem via the combining valve; the combining valve is used to divert or combine the hydraulic oil output by the working pump and the hydraulic oil output by the steering pump according to a set working state.

Furthermore, the multi-way valve also includes a control oil port b3, and the control oil port b3 is connected to the converging valve.

Furthermore, the multi-way valve also includes A1 port and B1 port for connecting to the bucket cylinder, and A2 port and B2 port for connecting to the boom cylinder; A1 port and B1 port are respectively connected to the first valve stem, and A2 port and B2 port are respectively connected to the second valve stem.

In a second aspect, a loader hydraulic system is provided, comprising the multi-way valve for a loader as described in the first aspect, wherein the oil inlet P1 of the multi-way valve is connected to the outlet of a working pump; the oil inlet P2 of the multi-way valve is connected to the outlet of a steering pump through a priority valve; the A1 port and the B1 port of the multi-way valve are connected to a dump bucket cylinder; the A2 port and the B2 port of the multi-way valve are connected to a boom cylinder; the priority valve is connected to a steering cylinder through a steering gear; the outlet of the steering pump is connected to a pilot oil source valve, and the pilot oil source valve is connected to the multi-way valve through a pilot valve.

Furthermore, when the bucket cylinder is operated alone, first, the hydraulic oil output by the steering pump flows to the multi-way valve through the pilot oil source valve and the pilot valve, controlling the reversal of the first valve stem so that the first valve stem is in the left position or the right position; at the same time, the hydraulic oil output by the working pump flows into the oil inlet P1 of the multi-way valve, and the hydraulic oil output by the steering pump flows into the oil inlet P2 of the multi-way valve through the priority valve; the hydraulic oil flowing into the oil inlet P2 of the multi-way valve merges with the hydraulic oil flowing into the oil inlet P1 of the multi-way valve through the merging valve and then flows to the first valve stem; the hydraulic oil flows to the rod chamber or rodless chamber of the bucket cylinder through the left position or the right position of the first valve stem, which is used to control the bucket cylinder to retract or extend the bucket.

Furthermore, when the boom cylinder is retracted by operating alone, first, the hydraulic oil output by the steering pump flows to the multi-way valve through the pilot oil source valve and the pilot valve, controlling the reversal of the second valve stem so that the second valve stem is in the left position; at the same time, the hydraulic oil output by the working pump flows into the oil inlet P1 of the multi-way valve, and the hydraulic oil output by the steering pump flows into the oil inlet P2 of the multi-way valve through the priority valve; the hydraulic oil flowing into the oil inlet P2 of the multi-way valve merges with the hydraulic oil flowing into the oil inlet P1 of the multi-way valve through the merging valve and flows to the first valve stem; the merged hydraulic oil passes through the first valve stem and flows to the second valve stem, and flows to the rodless chamber of the boom cylinder through the left position of the second valve stem, and the boom cylinder is retracted.

Furthermore, when the boom cylinder is extended by operating alone, first, the hydraulic oil output by the steering pump flows to the multi-way valve through the pilot oil source valve and the pilot valve, controlling the reversing of the second valve stem and the combining valve, so that the second valve stem is in the right position and the combining valve is in the right position; at the same time, the hydraulic oil output by the working pump flows into the oil inlet P1 of the multi-way valve, passes through the first valve stem and flows to the oil channel between the first valve stem and the second valve stem; the hydraulic oil output by the steering pump flows into the oil inlet P2 of the multi-way valve through the priority valve; the hydraulic oil at the oil inlet P2 passes through the right position of the combining valve, merges with the hydraulic oil from the oil inlet P1 in the oil channel between the first valve stem and the first valve stem, passes through the second valve stem and flows to the rodless chamber of the boom cylinder, and the boom cylinder is extended.

Furthermore, when the boom cylinder and the bucket cylinder are operated to extend at the same time: first, the hydraulic oil output by the steering pump flows to the multi-way valve through the pilot oil source valve and the pilot valve, controlling the reversal of the second valve stem, the combining valve and the first valve stem, so that the second valve stem is in the right position, the combining valve is in the right position, and the first valve stem is in the right position; at the same time, the hydraulic oil output by the working pump flows into the oil inlet P1 of the multi-way valve, passes through the right position of the first valve stem and flows to the rodless chamber of the bucket cylinder, and the bucket cylinder extends; the hydraulic oil output by the steering pump flows into the oil inlet P2 of the multi-way valve through the priority valve, flows to the right position of the second valve stem through the combining valve, and then flows to the rodless chamber of the boom cylinder, and the boom cylinder extends.

Furthermore, when the boom cylinder is extended and the bucket cylinder is retracted at the same time: first, the hydraulic oil output by the steering pump flows to the multi-way valve through the pilot oil source valve and the pilot valve, controlling the reversal of the second valve stem, the combining valve and the first valve stem, so that the second valve stem is in the right position, the combining valve is in the right position, and the first valve stem is in the left position; at the same time, the hydraulic oil output by the working pump flows into the oil inlet P1 of the multi-way valve, passes through the left position of the first valve stem and flows to the rod chamber of the bucket cylinder, and the bucket cylinder retracts; the hydraulic oil output by the steering pump flows into the oil inlet P2 of the multi-way valve through the priority valve, flows to the right position of the second valve stem through the combining valve, and then flows to the rodless chamber of the boom cylinder, and the boom cylinder extends.

According to a third aspect, a loader is provided, wherein the loader is equipped with the loader hydraulic system according to the second aspect.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention adopts a conventional double-inlet open-center multi-way valve and adds a converging valve to realize the composite action of boom lifting, bucket retracting and unloading. When the composite action is performed, the hydraulic oil flowing out of the working pump and the steering pump no longer merges, but flows to the bucket cylinder and the boom cylinder respectively, so that the hydraulic oils of different actuators do not affect each other, thereby improving the coordination of the composite action and improving the working efficiency.

(2) The multi-way valve of the present invention can be completely domestically produced and has the characteristics of simple structure and low manufacturing and maintenance costs;

(3) The hydraulic system of the present invention is simpler, easier to understand, more convenient to maintain and has lower cost than the load independent flow distribution (LUDV) system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the principle of a multi-way valve for a loader provided by an embodiment of the present invention;

FIG2 is a schematic diagram of the principle of a loader hydraulic system provided by an embodiment of the present invention;

In the figure: 1. hydraulic oil tank; 2. working pump; 3. steering pump; 4. priority valve; 5. steering gear; 6. steering cylinder; 7. pilot oil source valve; 8. multi-way valve; 9. pilot valve; 10. ball valve; 11. boom cylinder; 12. bucket cylinder; 13. radiator; 14. return oil filter element; 81. first one-way valve; 82. second one-way valve; 83. converging valve; 84. spring; 85. overflow valve; 86. first valve stem; 87. second valve stem.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

Embodiment 1:

As shown in FIG. 1 and FIG. 2 , a multi-way valve for a loader is provided. The multi-way valve 8 merges and divides the hydraulic oil of the steering pump 3 and the working pump 2 through the merging valve 83 based on the working state of the hydraulic system.

The multi-way valve 8 is an open center multi-way valve with multiple working ports, which are respectively connected to the corresponding bucket cylinder 12 and boom cylinder 11. Two oil inlets are set to be connected to the working pump 2 and the priority valve 4, and multiple control oil ports are connected to the pilot valve 7.

The multi-way valve 8 includes a first one-way valve 81, a second one-way valve 82, a converging valve 83, a spring 84, a control oil port b3, a relief valve 85, a first valve stem 86, and a second valve stem 87. The oil inlet P1 of the multi-way valve 8 is connected to the outlet of the working pump 2, and the oil inlet P2 of the multi-way valve 8 is connected to the priority valve 4. The control oil port b3 is connected to the control oil port b2. The oil inlet P1 of the multi-way valve 8 is connected to the relief valve 85 through the first one-way valve 81, the oil inlet P2 is connected to the relief valve 85 through the second one-way valve 82, the oil inlet P2 is connected to the oil inlet P1 through the converging valve 83, and the oil inlet P2 is connected to the oil path between the first valve stem 86 and the second valve stem 87 through the converging valve 83.

The merging valve 83 includes oil ports h1, h2, h3, h4 and h5. When the spring 84 of the merging valve 83 is in the initial position, the oil port h1 of the merging valve 83 is connected to the oil inlet P2 of the multi-way valve 8, and the oil port h3 is connected to the oil inlet P1 of the multi-way valve 8; the oil port h4 is connected to the oil path between the first valve stem 86 and the second valve stem 87, and the oil port h5 is connected to the control oil port b3 of the multi-way valve 8. When the merging valve 83 is switched to the right position under the action of the control oil port b3, the oil port h2 is connected to the oil inlet P2 of the multi-way valve 8.

Embodiment 2:

Based on the multi-way valve for a loader described in Example 1, this embodiment provides a loader hydraulic system, in which the oil inlets of the working pump 2 and the steering pump 3 are connected to the hydraulic oil tank 1, the outlet of the steering pump 3 is connected to the P port of the priority valve 4, and the EF port of the priority valve 4 is connected to the oil inlet P2 of the multi-way valve 8; the outlet of the working pump 2 is connected to the oil inlet P1 of the multi-way valve 8.

The control oil port b3 of the multi-way valve 8 is connected to the port a2.

The oil inlet P1 of the multi-way valve 8 is in communication with the oil passage of the first check valve 81, the oil inlet P2 of the multi-way valve 8 is in communication with the oil passage of the second check valve 82, the first check valve 81 and the second check valve 82 are in communication with the relief valve 85, and the relief valve 85 is in communication with the oil passage of the T port of the multi-way valve 8. The oil inlet P2 of the multi-way valve 8 is in communication with the oil port h1 of the converging valve 83, the oil port h3 of the converging valve 83 is in communication with the oil inlet P1 of the multi-way valve 8, the oil port h4 of the converging valve 83 is in communication with the oil passage behind the first valve stem 86 and in front of the second valve stem 87, and the oil port h5 of the converging valve 83 is in communication with the control oil port b3 of the multi-way valve 8.

The A1 port and the B1 port of the multi-way valve 8 are connected to the bucket cylinder 12 ; the A2 port and the B2 port of the multi-way valve 8 are connected to the boom cylinder 11 .

The T port of the multi-way valve 8 is connected to the hydraulic oil tank 1 through the radiator 13 and the oil return filter element 14.

The P1 port of the pilot oil source valve 7 is connected to the outlet of the steering pump 3 , and the pilot oil source 7 is connected to the P port of the pilot valve 9 through the ball valve 10 .

The control oil port b1 of the pilot valve 9 is connected to the control oil port b1 of the multi-way valve 8 .

The control oil port a1 of the pilot valve 9 is connected to the control oil port a1 of the multi-way valve 8 .

The control oil port b2 of the pilot valve 9 is connected to the control oil port b2 of the multi-way valve 8 .

The control oil port a2 of the pilot valve 9 is connected to the control oil port b2 of the multi-way valve 8 .

The control oil port a2 of the multi-way valve 8 is connected to the control oil port b3;

The control oil port 2C of the pilot valve 9 is connected to the control oil port 2C of the multi-way valve 8 .

The T port of the pilot valve 9 is connected to the hydraulic oil tank 1.

The CF port of the priority valve 4 is connected to the P port of the steering gear 5.

The LS port of the priority valve 4 is connected to the LS port of the steering gear 5 .

The working oil ports of the steering gear 5 are connected to the steering cylinders 6 respectively.

The T port of the steering gear 5 is connected to the hydraulic oil tank 1.

The T port of the priority valve 4 is connected to the hydraulic oil tank 1 .

Working condition 1: When the bucket cylinder 12 only needs to be operated to be retracted (bucket unloading) or extended (bucket retracting): First, the hydraulic oil from the hydraulic oil tank 1 flows to the P1 port of the pilot oil source valve 7 through the steering pump 3, then flows to the ball valve 10, and then flows to the pilot valve 9. The hydraulic oil flows to the b1 port or a1 port of the multi-way valve 8 through the b1 port or a1 port of the pilot valve 9, controlling the reversal of the first valve stem 86, so that the first valve stem 86 is in the left position or the right position.

At the same time, the hydraulic oil from the hydraulic oil tank 1 flows to the oil inlet P1 of the multi-way valve 8 through the working pump 2, and the hydraulic oil from the hydraulic oil tank 1 flows to the P port of the priority valve 4 through the steering pump 3, and then flows to the oil inlet P2 of the multi-way valve 8 through the EF port of the priority valve 4. The hydraulic oil at the oil inlet P2 of the multi-way valve 8 flows to the h3 port of the merging valve 83 through the h1 port of the merging valve 83, and then merges with the hydraulic oil from the oil inlet P1 of the multi-way valve 8 and flows to the first valve stem 86. The hydraulic oil flows to the rod chamber or rodless chamber of the bucket cylinder 12 through the left or right position of the first valve stem 86, and the bucket cylinder 12 is retracted (bucket unloading) or extended (bucket retracting).

Working condition 2: When only the boom cylinder 11 needs to be operated to be retracted (the boom is lowered): First, the hydraulic oil from the hydraulic oil tank 1 flows to the P1 port of the pilot oil source valve 7 through the steering pump 3, then flows to the ball valve 10, and then flows to the pilot valve 9. The hydraulic oil flows to the b2 port of the multi-way valve 8 through the b2 port of the pilot valve 9, controlling the reversal of the second valve stem 87, so that the second valve stem 87 is in the left position.

At the same time, the hydraulic oil from the hydraulic oil tank 1 flows to the oil inlet P1 of the multi-way valve 8 through the working pump 2, and at the same time, the hydraulic oil from the hydraulic oil tank 1 flows to the P port of the priority valve 4 through the steering pump 3, and then flows to the oil inlet P2 of the multi-way valve 8 through the EF port of the priority valve 4. The hydraulic oil flowing to the oil inlet P2 of the multi-way valve 8 passes through the h1 port of the merging valve 83 to the h3 port of the merging valve 83, and then merges with the hydraulic oil from the oil inlet P1 of the multi-way valve 8 and flows to the first valve stem 86. The merged hydraulic oil passes through the first valve stem 86 and flows to the second valve stem 87, and flows to the rodless chamber of the boom cylinder 11 through the left position of the second valve stem 87, and the boom cylinder 11 is retracted and the boom is lowered.

Working condition three: when only the boom cylinder 11 needs to be operated to extend (boom lifting), the hydraulic oil from the hydraulic oil tank 1 first flows to the P1 port of the pilot oil source valve 7 through the steering pump 3, then flows to the ball valve 10, and then flows to the pilot valve 9. The pilot valve 9 is operated to make the hydraulic oil flow to the control oil ports b3 and a2 of the multi-way valve 8 through the a2 port of the pilot valve 9. The pilot oil flowing to the a2 port of the multi-way valve 8 causes the second valve stem 87 to switch to the right position, and the pilot oil flowing to the control oil port b3 of the confluence valve 83 causes the confluence valve 83 to switch to the right position.

At the same time, the hydraulic oil from the hydraulic oil tank 1 flows to the oil inlet P1 of the multi-way valve 8 through the working pump 2, and flows to the oil passage between the first valve stem 86 and the second valve stem 87 after passing through the first valve stem 86. The hydraulic oil from the hydraulic oil tank 1 flows to the P port of the priority valve 4 through the steering pump 3, and then flows to the oil inlet P2 of the multi-way valve 8 through the EF port of the priority valve 4. The hydraulic oil from the oil inlet P2 of the multi-way valve 8 passes through the right position of the converging valve 83, so that the hydraulic oil flows to the h4 port of the converging valve 83 through the h2 port of the converging valve 83, and then merges with the hydraulic oil from the working pump 2 in the oil passage between the first valve stem 86 and the first valve stem 87, and flows to the rodless chamber of the boom cylinder 11 after passing through the second valve stem 87, so that the boom cylinder 11 extends and the boom is lifted.

Working condition four: when the boom cylinder 11 is extended (boom lifting) and the bucket cylinder 12 is extended (bucket retracting) at the same time: first, the hydraulic oil from the hydraulic oil tank 1 flows to the P1 port of the pilot oil source valve 7 through the steering pump 3 and then flows to the ball valve 10, and then flows to the pilot valve 9, and flows to the a2 port of the pilot valve 9 to the a2 port of the multi-way valve 8 and the control oil port b3, so that the second valve stem 87 moves to the left and is in the right position, and the converging valve 83 moves to the left and is in the right position; at the same time, it flows to the a1 port of the pilot valve 9 to the a1 port of the multi-way valve 8, and the first valve stem 86 moves to the left and is in the right position.

The hydraulic oil from the hydraulic oil tank 1 flows to the oil inlet P1 of the multi-way valve 8 through the working pump 2, flows to the rodless chamber of the bucket cylinder 12 after passing through the right position of the first valve stem 86, and the bucket cylinder 12 extends and the bucket retracts. The hydraulic oil from the hydraulic oil tank 1 flows to the P port of the priority valve 4 through the EF port of the priority valve 4, flows to the oil inlet P2 of the multi-way valve 8, flows to the confluence valve 83, flows to the right position of the second valve stem 87 through the h2 port and h4 port of the confluence valve 83, and flows to the rodless chamber of the boom cylinder 11, and the boom cylinder 11 extends and the boom is lifted.

From the above, it can be seen that when the boom cylinder 11 is extended (boom lifting) and the bucket cylinder 12 is extended (bucket retracting) at the same time, the outlet hydraulic oil of the working pump 2 flows to the rodless chamber of the bucket cylinder 12 through the first valve stem 86, and the hydraulic oil at the outlet of the steering pump 3 flows to the rodless chamber of the boom cylinder 11 after passing through the priority valve 4, the combining valve 83 of the multi-way valve 8, and the second valve stem 87. The hydraulic oil flowing to the rodless chamber of the bucket cylinder 12 comes from the working pump 2, and the hydraulic oil flowing to the rodless chamber of the boom cylinder 11 comes from the steering pump 3, which do not affect each other, thereby improving the maneuverability and coordination of the compound movement.

Working condition five: when the boom cylinder 11 is extended (boom lifting) and the bucket cylinder 12 is retracted (bucket unloading) at the same time: first, the hydraulic oil from the hydraulic oil tank 1 flows to the P1 port of the pilot oil source valve 7 through the steering pump 3 and then flows to the ball valve 10, and then flows to the pilot valve 9, and flows to the a2 port of the pilot valve 9 to the a2 port of the multi-way valve 8 and the control oil port b3, so that the second valve stem 87 moves to the left and is in the right position, and the converging valve 83 moves to the left and is in the right position; at the same time, it flows to the b1 port of the multi-way valve 8 through the b1 port of the pilot valve 9, and the first valve stem 86 moves to the right and is in the left position.

The hydraulic oil from the hydraulic oil tank 1 flows to the oil inlet P1 of the multi-way valve 8 through the working pump 2, flows to the rod chamber of the bucket cylinder 12 after passing through the left position of the first valve stem 86, and the bucket cylinder 12 retracts to unload the bucket. The hydraulic oil from the hydraulic oil tank 1 flows to the P port of the priority valve 4 through the steering pump 3, flows to the oil inlet P2 of the multi-way valve 8 through the EF port of the priority valve 4, flows to the confluence valve 83, flows to the right position of the second valve stem 87 through the h2 port and h4 port of the confluence valve 83, and then flows to the rodless chamber of the boom cylinder 11, and the boom cylinder 11 extends to lift the boom.

It can be seen that when the boom cylinder 11 is extended (boom lifting) and the bucket cylinder 12 is extended (bucket unloading) at the same time, the outlet hydraulic oil of the working pump 2 flows to the rod chamber of the bucket cylinder 12 through the first valve stem 86, and the hydraulic oil at the outlet of the steering pump 3 flows to the rodless chamber of the boom cylinder 11 after passing through the priority valve 4, the confluence valve 83 of the multi-way valve 8, and the second valve stem 87 in the right position. The hydraulic oil flowing to the rod chamber of the bucket cylinder 12 comes from the working pump 2, and the hydraulic oil flowing to the rodless chamber of the boom cylinder 11 comes from the steering pump 3, which do not affect each other, thereby improving the controllability and coordination of the compound movement.

The invention uses the internal oil passage of the multi-way valve to combine and divide the hydraulic oil from the working pump and the priority valve and then supplies it to the boom cylinder and the bucket cylinder. The boom lifting, boom lowering, bucket retracting and bucket unloading are controlled by moving the reversing rod of the multi-way valve. The combining valve in the multi-way valve controls the combining and dividing of the hydraulic oil from the priority valve and the hydraulic oil from the working pump. When the boom is lowered, the bucket is retracted, or the bucket is unloaded, the hydraulic oil from the priority valve passes through the combining valve and the hydraulic oil from the working pump before the first valve stem of the multi-way valve, and then flows to the boom cylinder and the bucket cylinder through the first valve stem or the second valve stem; when the boom is lifted, the hydraulic oil from the priority valve passes through the combining valve and the hydraulic oil from the working pump after passing through the first valve stem, and then merges behind the first valve stem and in front of the second valve stem, and then flows to the boom cylinder through the second valve stem; when the boom is lifted and the bucket is manually operated or the bucket is unloaded at the same time, the hydraulic oil from the working pump flows to the bucket cylinder through the first valve stem, and the hydraulic oil from the priority valve flows to the boom cylinder through the second valve stem after passing through the combining valve, thereby realizing the combined action of boom lifting and bucket retracting or bucket unloading.

Embodiment three:

Based on the multi-way valve for a loader described in Example 1 and the loader hydraulic system described in Example 2, this embodiment provides a loader, and the loader is equipped with the loader hydraulic system described in Example 2.

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (5)

1. A loader hydraulic system, characterized by comprising a multi-way valve (8) for a loader, the multi-way valve being an open center multi-way valve provided with an oil inlet P1, an oil inlet P2 and a confluence valve (83);

an oil inlet P1 for receiving hydraulic oil output by the working pump (2) is connected with an overflow valve (85) through a first one-way valve (81);

an oil inlet P2 for receiving hydraulic oil output by the steering pump (3) is connected with an overflow valve (85) through a second one-way valve (82);

the oil inlet P2 is connected with the oil inlet P1 through a converging valve (83), and is communicated with an oil way between the first valve rod (86) and the second valve rod (87) through the converging valve (83); the confluence point of the oil inlet P2 and the oil inlet P1 is positioned in front of the valves of the first valve rod (86) and the second valve rod (87);

the converging valve (83) is used for dividing or converging hydraulic oil output by the working pump (2) and hydraulic oil output by the steering pump (3) according to a set working state;

the multi-way valve further comprises a control oil port b3, and the control oil port b3 of the multi-way valve is connected with the control end of the converging valve (83);

the multi-way valve further comprises control oil ports a1, b1, a2 and b2, wherein the control oil ports a1 and b1 of the multi-way valve are respectively connected with two control ends of a first valve rod (86); the control oil ports a2 and b2 of the multi-way valve are respectively connected with two control ends of a second valve rod (87);

the multi-way valve also comprises an A1 port and a B1 port which are used for connecting a tipping bucket oil cylinder (12), and an A2 port and a B2 port which are used for connecting a movable arm oil cylinder (11); the port A1 and the port B1 are respectively connected with a first valve rod (86), and the port A2 and the port B2 are respectively connected with a second valve rod (87);

an oil inlet P1 of the multi-way valve (8) is connected with an outlet of the working pump (2);

an oil inlet P2 of the multi-way valve (8) is connected with an outlet of the steering pump (3) through a priority valve (4);

the port A1 and the port B1 of the multi-way valve (8) are connected with a tipping bucket oil cylinder (12);

the port A2 and the port B2 of the multi-way valve (8) are connected with a movable arm oil cylinder (11);

the priority valve (4) is connected with a steering cylinder (6) through a steering gear (5);

an outlet of the steering pump (3) is connected with a pilot oil source valve (7), and the pilot oil source valve (7) is connected with a multi-way valve (8) through a pilot valve (9);

the control oil ports b3 and a2 of the multipath valve are respectively connected with the control oil port a2 of the pilot valve (9); control oil ports a1, b1 and b2 of the multipath valve are respectively connected with control oil ports a1, b1 and b2 of a pilot valve (9);

when the boom cylinder (11) is operated to extend and the tipping bucket cylinder (12) is operated to extend simultaneously, the boom cylinder is operated to extend: firstly, hydraulic oil output by a steering pump (3) flows to a multi-way valve (8) through a pilot oil source valve (7) and a pilot valve (9), and a second valve rod (87), a converging valve (83) and a first valve rod (86) are controlled to change directions, so that the second valve rod (87) is positioned at the right position, the converging valve (83) is positioned at the right position, and the first valve rod (86) is positioned at the right position;

meanwhile, hydraulic oil output by the working pump (2) flows into an oil inlet P1 of the multi-way valve (8), flows to a rodless cavity of the tipping bucket oil cylinder (12) after passing through the right position of the first valve rod (86), and the tipping bucket oil cylinder (12) stretches out; hydraulic oil output by the steering pump (3) flows into an oil inlet P2 of the multi-way valve (8) through the priority valve (4), flows to the right position of the second valve rod (87) through the converging valve (83), flows to a rodless cavity of the movable arm oil cylinder (11), and the movable arm oil cylinder (11) stretches out;

when the boom cylinder (11) is simultaneously operated to extend and the tipping bucket cylinder (12) is operated to retract, the tipping bucket cylinder (12) is operated to retract: firstly, hydraulic oil output by a steering pump (3) flows to a multi-way valve (8) through a pilot oil source valve (7) and a pilot valve (9), and a second valve rod (87), a converging valve (83) and a first valve rod (86) are controlled to change directions, so that the second valve rod (87) is positioned at the right position, the converging valve (83) is positioned at the right position and the first valve rod (86) is positioned at the left position;

meanwhile, hydraulic oil output by the working pump (2) flows into an oil inlet P1 of the multi-way valve (8), flows to a rod cavity of the tipping bucket oil cylinder (12) after passing through the left position of the first valve rod (86), and the tipping bucket oil cylinder (12) is retracted; the hydraulic oil output by the steering pump (3) flows into an oil inlet P2 of the multi-way valve (8) through the priority valve (4), flows to the right position of the second valve rod (87) through the converging valve (83), flows to the rodless cavity of the movable arm oil cylinder (11), and extends out of the movable arm oil cylinder.

2. The hydraulic system of the loader according to claim 1, wherein when the skip cylinder (12) is independently operated, firstly, hydraulic oil output by the steering pump (3) flows to the multi-way valve (8) through the pilot oil source valve (7) and the pilot valve (9), and the first valve rod (86) is controlled to be reversed, so that the first valve rod (86) is in a left position or a right position;

meanwhile, hydraulic oil output by the working pump (2) flows into an oil inlet P1 of the multi-way valve (8), and hydraulic oil output by the steering pump (3) flows into an oil inlet P2 of the multi-way valve (8) through the priority valve (4); the hydraulic oil flowing into the oil inlet P2 of the multi-way valve (8) is converged with the hydraulic oil flowing into the oil inlet P1 of the multi-way valve (8) through a converging valve (83) and then flows to a first valve rod (86); hydraulic oil flows to a rod cavity or a rodless cavity of the skip cylinder (12) through the left position or the right position of the first valve rod (86) and is used for controlling the skip cylinder (12) to retract or extend out of the bucket.

3. The hydraulic system of the loader according to claim 1, wherein when the boom cylinder (11) is independently operated to retract, first, hydraulic oil output from the steering pump (3) flows to the multi-way valve (8) through the pilot oil source valve (7) and the pilot valve (9), and the second valve rod (87) is controlled to be reversed, so that the second valve rod (87) is in the left position;

meanwhile, hydraulic oil output by the working pump (2) flows into an oil inlet P1 of the multi-way valve (8), and hydraulic oil output by the steering pump (3) flows into an oil inlet P2 of the multi-way valve (8) through the priority valve (4); the hydraulic oil flowing into the oil inlet P2 of the multi-way valve (8) is converged with the hydraulic oil flowing into the oil inlet P1 of the multi-way valve (8) through a converging valve (83) and then flows to a first valve rod (86); the hydraulic oil after confluence flows to the second valve rod (87) after passing through the first valve rod (86), flows to the rodless cavity of the movable arm oil cylinder (11) through the left bit stream of the second valve rod (87), and the movable arm oil cylinder (11) is retracted.

4. The hydraulic system of the loader according to claim 1, wherein when the boom cylinder (11) is independently operated to extend, first, hydraulic oil output from the steering pump (3) flows to the multi-way valve (8) through the pilot oil source valve (7) and the pilot valve (9), and the second valve rod (87) and the confluence valve (83) are controlled to be reversed, so that the second valve rod (87) is positioned at the right position and the confluence valve (83) is positioned at the right position;

meanwhile, hydraulic oil output by the working pump (2) flows into an oil inlet P1 of the multi-way valve (8), passes through the first valve rod (86) and then flows into an oil duct between the first valve rod (86) and the second valve rod (87); hydraulic oil output by the steering pump (3) flows into an oil inlet P2 of the multi-way valve (8) through the priority valve (4); after passing through the right position of the confluence valve (83), the hydraulic oil of the oil inlet P2 is converged with the hydraulic oil from the oil inlet P1 through an oil passage between the first valve rod (86) and the second valve rod (87), flows to a rodless cavity of the movable arm oil cylinder (11) after passing through the second valve rod (87), and the movable arm oil cylinder (11) stretches out.

5. A loader, characterized in that the loader is provided with a loader hydraulic system according to any one of claims 1-4.