Confluence oil source valve of external control pilot pump of excavator

Abstract

The utility model discloses an excavator external control pilot pump confluence oil source valve. At present, an excavator pilot control system with a pilot pump in the market has the problem that the energy utilization rate of the pilot pump is low, and urgently needs to be solved. The purposes of improving the utilization rate of the pilot pump, improving the working efficiency and saving energy are achieved through the pressure reducing valve, the overflow valve and the flow collecting valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the excavator pilot control hydraulic system, more particularly to a kind of excavator external control pilot pump confluence oil source valve. BACKGROUND

[0002] The excavator pilot control system with pilot pump in current market has the problem of low energy utilization rate of pilot pump, and it is urgently needed to be solved.The purpose of the present application is to improve the utilization rate of pilot pump, improve work efficiency and save energy by pressure reducing valve, overflow valve and confluence valve. CONTENT OF THE PRESENT INVENTION

[0003] The purpose of the present application is to improve the utilization rate of pilot pump, improve work efficiency and save energy by pressure reducing valve, overflow valve and confluence valve.

[0004] 1、The excavator external control pilot pump confluence oil source valve includes pilot pump oil channel 1, pressure reducing valve inlet oil channel 2, pressure reducing valve 3, pressure reducing valve outlet oil channel 4, pressure reducing valve back oil channel 5, pilot oil overflow oil channel 6, overflow valve outlet oil channel 7, overflow valve 8, overflow valve spring 9, main pump oil channel 10, external control oil channel 11, confluence valve 12, confluence valve pilot pump oil channel 13, confluence valve spring 14.

[0005] Among them, pilot pump oil channel 1 is communicated with pressure reducing valve inlet oil channel 2, pilot oil overflow oil channel 6 and confluence valve pilot pump oil channel 13, pressure reducing valve 3 supplies oil for pressure reducing valve outlet oil channel 4, pressure reducing valve outlet oil channel 4 provides oil source for external pilot control system and is communicated with upper end of confluence valve 12, pressure reducing valve back oil channel 5 returns oil, pilot oil overflow oil channel 6 is communicated with right side and upper end of overflow valve 8, overflow valve outlet oil channel 7 is communicated with left side of overflow valve 8 and connects low pressure oil circuit, overflow valve spring 9 is arranged at lower end of overflow valve 8 to limit overflow pressure, main pump oil channel 10 is communicated with left side of confluence valve 12, external control oil channel 11 is respectively communicated with lower end of overflow valve 8 and confluence valve 12, confluence valve pilot pump oil channel 13 is communicated with right side of confluence valve 12, confluence valve spring 14 is arranged at upper end of confluence valve 12 and pressure reducing valve outlet oil channel 4 together determines opening pressure of confluence valve 12, in standby state, hydraulic oil from pilot pump oil channel 1 overflows through pilot oil overflow oil channel 6 and overflow valve 8, to ensure that confluence valve pilot pump oil channel 13 is not communicated with main pump oil channel 10, when external pilot control system works, pressure of main pump oil channel 10 begins to rise, when the sum of pressure of external control oil channel 11 and force of overflow valve spring 9 is greater than pressure of pilot oil overflow oil channel 6, spool of overflow valve 8 begins to move upward and gradually closes overflow of overflow valve 8, when pressure of external control oil channel 11 is greater than the sum of pressure of pressure reducing valve outlet oil channel 4 and force of confluence valve spring 14, spool of confluence valve 12 begins to move upward and gradually makes main pump oil channel 10 and confluence valve pilot pump oil channel 13 communicated, to realize confluence of pilot pump and main pump.

[0006] 2. The external control pilot pump combined flow oil source valve of the excavator comprises a pilot pump oil inlet channel 1, a pressure reducing valve oil inlet channel 2, a pressure reducing valve 3, a pressure reducing valve oil outlet channel 4, a pressure reducing valve oil return channel 5, a pilot oil overflow channel 6, an overflow valve oil outlet channel 7, an overflow valve 8, an overflow valve spring 9, a main pump oil channel 10, an external control oil channel 11, a combined flow valve 12, and a combined flow valve pilot pump oil inlet channel 13.

[0007] The pilot pump oil inlet channel 1 is communicated with the pressure reducing valve oil inlet channel 2, the pilot oil overflow channel 6, and the combined flow valve pilot pump oil inlet channel 13. The pressure reducing valve 3 supplies oil to the pressure reducing valve oil outlet channel 4. The pressure reducing valve oil outlet channel 4 provides an oil source for an external pilot control system. The pressure reducing valve oil return channel 5 returns oil. The pilot oil overflow channel 6 is communicated with the right side and the upper end of the overflow valve 8. The overflow valve oil outlet channel 7 is communicated with the left side of the overflow valve 8 and is connected to a low-pressure oil circuit. The overflow valve spring 9 is arranged at the lower end of the overflow valve 8 to limit the overflow pressure. The main pump oil channel 10 is communicated with the left side of the combined flow valve 12. The external control oil channel 11 is respectively communicated with the lower end of the overflow valve 8 and the combined flow valve 12. The combined flow valve pilot pump oil inlet channel 13 is communicated with the right side of the combined flow valve 12. The combined flow valve spring 14 is arranged at the upper end of the combined flow valve 12. In the standby state, the hydraulic oil from the pilot pump oil inlet channel 1 overflows through the pilot oil overflow channel 6 and the overflow valve 8, ensuring that the combined flow valve pilot pump oil inlet channel 13 is not communicated with the main pump oil channel 10. When the external pilot control system is working, the pressure of the main pump oil channel 10 begins to rise. When the sum of the pressure of the external control oil channel 11 and the force of the overflow valve spring 9 is greater than the pressure of the pilot oil overflow channel 6, the spool of the overflow valve 8 begins to move upward and gradually closes the overflow of the overflow valve 8. When the pressure of the external control oil channel 11 is greater than the force of the combined flow valve spring 14, the spool of the combined flow valve 12 begins to move upward and gradually makes the main pump oil channel 10 and the combined flow valve pilot pump oil inlet channel 13 communicated, realizing the combination of the pilot pump and the main pump.

[0008] 3. The external control pilot pump combined flow oil source valve of the excavator comprises a pilot pump oil inlet channel 1, a pressure reducing valve oil inlet channel 2, a pressure reducing valve 3, a pressure reducing valve oil outlet channel 4, a pressure reducing valve oil return channel 5, a pilot oil overflow channel 6, an overflow valve oil outlet channel 7, an overflow valve 8, an overflow valve spring 9, a main pump oil channel 10, an external control oil channel 11, a combined flow valve 12, and a combined flow valve pilot pump oil inlet channel 13.

[0009] Wherein, the pilot pump oil inlet 1 and the reducing valve oil inlet 2 pilot oil overflow oil inlet 6 and the confluence valve pilot pump oil inlet 13 are communicated, the reducing valve 3 is the reducing valve oil outlet 4 oil supply, the reducing valve oil outlet 4 is the external pilot control system and acts on the upper end of the confluence valve 12, the reducing valve oil return 5 is connected to the oil return, the pilot oil overflow oil inlet 6 and the overflow valve 8 right side and its upper end are communicated, the overflow valve oil outlet 7 and the overflow valve 8 left side are communicated and are connected to the low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the overflow valve 8 to limit the overflow pressure, the main pump oil inlet 10 and the confluence valve 12 left side are communicated, the external control oil inlet 11 is communicated with the overflow valve 8 and the confluence valve 12 lower end respectively, the confluence valve pilot pump oil inlet 13 and the confluence valve 12 right side are communicated, in standby state, the hydraulic oil from the pilot pump oil inlet 1 is overflowed through the pilot oil overflow oil inlet 6 and the overflow valve 8, the pressure of the reducing valve oil outlet 4 determines the opening pressure of the confluence valve 12, ensures that the confluence valve pilot pump oil inlet 13 and the main pump oil inlet 10 are not communicated, when the external pilot control system works, the pressure of the main pump oil inlet 10 begins to rise, when the sum of the pressure of the external control oil inlet 11 and the force of the overflow valve spring 9 is greater than the pressure of the pilot oil overflow oil inlet 6 and the overflow valve 8, the spool of the overflow valve 8 begins to move upward and gradually closes the overflow of the overflow valve 8, when the pressure of the external control oil inlet 11 is greater than the pressure of the reducing valve oil outlet 4, the spool of the confluence valve 12 begins to move upward and gradually makes the main pump oil inlet 10 and the confluence valve pilot pump oil inlet 13 communicated, realizes the confluence of the pilot pump and the main pump.

[0010] 4. The excavator external control pilot pump confluence oil source valve comprises a pilot pump oil inlet 1, a reducing valve oil inlet 2, a reducing valve 3, a reducing valve oil outlet 4, a reducing valve oil return 5, a pilot oil overflow oil inlet 6, an overflow valve oil outlet 7, an overflow valve 8, an overflow valve spring 9, a main pump oil inlet 10, an external control oil inlet 11, a confluence valve 12 and a confluence valve pilot pump oil inlet 13.

[0011] Wherein, the pilot pump oil inlet 1 is communicated with the pressure reducing valve inlet 2 and the combined valve pilot pump oil inlet 13, the pressure reducing valve 3 is supplied with oil by the pressure reducing valve outlet 4, the pressure reducing valve outlet 4 provides oil source for the external pilot control system and is communicated with the pilot oil overflow 6 and the upper end of the combined valve 12, the pressure reducing valve return 5 returns oil, the pilot oil overflow 6 is communicated with the right side of the overflow valve 8 and the upper end thereof, the overflow valve outlet 7 is communicated with the left side of the overflow valve 8 and is connected with the low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the overflow valve 8 to limit the overflow pressure, the main pump oil circuit 10 is communicated with the left side of the combined valve 12, the external control oil circuit 11 is communicated with the overflow valve 8 and the lower end of the combined valve 12 respectively, the combined valve pilot pump oil inlet 13 is communicated with the right side of the combined valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 passes through the pressure reducing valve 3, the pressure reducing valve outlet 4 and the pilot oil overflow 6, and then overflows through the overflow valve 8, at the same time, the pressure reducing valve outlet 4 outputs hydraulic oil to the upper end of the combined valve 12, so as to ensure that the combined valve pilot pump oil inlet 13 is not communicated with the main pump oil circuit 10, when the external pilot control system works, the pressure of the main pump oil circuit 10 begins to rise, when the sum of the pressure of the external control oil circuit 11 and the force of the overflow valve spring 9 is higher than the pressure of the pilot oil overflow 6, the spool of the overflow valve 8 begins to move upward and gradually closes the overflow of the overflow valve 8, when the pressure of the external control oil circuit 11 is higher than the pressure of the pressure reducing valve outlet 4, the spool of the combined valve 12 begins to move upward and gradually makes the main pump oil circuit 10 and the combined valve pilot pump oil inlet 13 communicated, so as to realize the combination of the pilot pump and the main pump.

[0012] 5. The combined valve of the excavator external control pilot pump comprises a pilot pump oil inlet 1, a pressure reducing valve inlet 2, a pressure reducing valve 3, a pressure reducing valve outlet 4, a pressure reducing valve return 5, a pilot oil overflow 6, an overflow valve outlet 7, an overflow valve spring 9, a main pump oil circuit 10, an external control oil circuit 11, a combined valve 12 and a combined valve pilot pump oil inlet 13.

[0013] Wherein, the confluence valve 12 has two functions of overflow and confluence, the pilot pump oil inlet 1 is communicated with the pressure reducing valve oil inlet 2 and the confluence valve pilot pump oil inlet 13, the pressure reducing valve 3 supplies oil for the pressure reducing valve oil outlet 4, the pressure reducing valve oil outlet 4 provides oil source for the external pilot control system and is communicated with the pilot oil overflow oil way 6 and the upper end of the confluence valve 12, the pressure reducing valve oil return 5 returns oil, the pilot oil overflow oil way 6 is communicated with the right overflow oil way of the confluence valve 12, the overflow valve oil outlet 7 is communicated with the left overflow oil way of the confluence valve 12 and connects the low pressure oil way, the overflow valve spring 9 is arranged at the lower end of the confluence valve 12 to limit the overflow pressure, the main pump oil way 10 is communicated with the left confluence oil way of the confluence valve 12, the external control oil way 11 is communicated with the lower end of the confluence valve 12, the confluence valve pilot pump oil inlet 13 is communicated with the right confluence oil way of the confluence valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 passes through the pressure reducing valve 3 and the pressure reducing valve oil outlet 4, the pilot oil overflow oil way 6 and the confluence valve 12 overflow and acts on the upper end of the confluence valve 12, ensuring that the confluence valve pilot pump oil inlet 13 is not communicated with the main pump oil way 10, when the external pilot control system works, the pressure of the main pump oil way 10 rises, when the sum of the pressure of the external control oil way 11 and the force of the overflow valve spring 9 is higher than the pressure of the upper end of the confluence valve 12, the confluence valve 12 spool is pushed to move upward to gradually close the passage of the pilot oil overflow oil way 6 and the overflow valve oil outlet 7 to prevent overflow, at the same time, the main pump oil way 10 and the confluence valve pilot pump oil inlet 13 are gradually communicated, realizing the confluence of the pilot pump and the main pump.

[0014] 6. The excavator external control pilot pump confluence oil source valve comprises a pilot pump oil inlet 1, a pressure reducing valve oil inlet 2, a pressure reducing valve 3, a pressure reducing valve oil outlet 4, a pressure reducing valve oil return 5, a pilot oil overflow oil way 6, an overflow valve oil outlet 7, an overflow valve spring 9, a main pump oil way 10, an external control oil way 11, a confluence valve 12 and a confluence valve pilot pump oil inlet 13.

[0015] Wherein, the confluence valve 12 has two functions of overflow and confluence, the pilot pump oil inlet 1 is communicated with the pressure reducing valve oil inlet 2 and the confluence valve pilot pump oil inlet 13, the pressure reducing valve 3 supplies oil for the pressure reducing valve oil outlet 4, the pressure reducing valve oil outlet 4 provides oil source for the external pilot control system, the pressure reducing valve oil return 5 returns oil, the pilot oil overflow oil inlet 6 is communicated with the right overflow oil inlet of the confluence valve 12 and the pilot pump oil inlet 1 and acts on the upper end of the confluence valve 12, the overflow valve oil outlet 7 is communicated with the left overflow oil inlet of the confluence valve 12 and connects the low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the confluence valve 12 to limit the overflow pressure, the main pump oil inlet 10 is communicated with the left confluence oil inlet of the confluence valve 12, the external control oil inlet 11 is communicated with the lower end of the confluence valve 12, the confluence valve pilot pump oil inlet 13 is communicated with the right confluence oil inlet of the confluence valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 provides oil source for the external pilot control system through the pressure reducing valve 3 and the pressure reducing valve oil outlet 4, passes through the pilot oil overflow oil inlet 6 and the confluence valve 12 overflow and acts on the upper end of the confluence valve 12, ensures that the confluence valve pilot pump oil inlet 13 is not communicated with the main pump oil inlet 10, when the external pilot control system works, the pressure of the main pump oil inlet 10 rises, when the sum of the pressure of the external control oil inlet 11 and the force of the overflow valve spring 9 is higher than the pressure of the upper end of the confluence valve 12, the confluence valve 12 spool is pushed to move upward to gradually close the passages of the pilot oil overflow oil inlet 6 and the overflow valve oil outlet 7 to prevent overflow, at the same time, the main pump oil inlet 10 and the confluence valve pilot pump oil inlet 13 are gradually communicated, realizing the confluence of the pilot pump and the main pump.

[0016] The external control pilot pump confluence oil source valve comprises a pilot pump oil inlet 1, a pressure reducing valve oil inlet 2, a pressure reducing valve 3, a pressure reducing valve oil outlet 4, a pressure reducing valve oil return 5, a pilot oil overflow oil inlet 6, an overflow valve oil outlet 7, an overflow valve spring 9, a main pump oil inlet 10, an external control oil inlet 11, a confluence valve 12 and a confluence valve pilot pump oil inlet 13.

[0017] Wherein, the flow valve 12 has two functions of overflow and flow, the pilot pump oil inlet 1 is communicated with the right overflow oil inlet of the flow valve 12, the pressure reducing valve oil inlet 2 and the flow valve pilot pump oil inlet 13, the pressure reducing valve 3 supplies oil for the pressure reducing valve oil outlet 4, the pressure reducing valve oil outlet 4 provides oil source for the external pilot control system and is communicated with the pilot oil overflow oil inlet 6, the pressure reducing valve oil return 5 returns oil, the pilot oil overflow oil inlet 6 acts on the upper end of the flow valve 12, the overflow valve oil outlet 7 is communicated with the left overflow oil inlet of the flow valve 12 and connects the low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the flow valve 12 to limit the overflow pressure, the main pump oil inlet 10 is communicated with the left flow oil inlet of the flow valve 12, the external control oil inlet 11 is communicated with the lower end of the flow valve 12, the flow valve pilot pump oil inlet 13 is communicated with the right flow oil inlet of the flow valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 provides oil source for the external pilot control system through the pressure reducing valve 3 and the pressure reducing valve oil outlet 4 and acts on the upper end of the flow valve 12 through the pilot oil overflow oil inlet 6, the oil in the pilot pump oil inlet 1 is overflowed through the flow valve 12, the flow valve pilot pump oil inlet 13 and the main pump oil inlet 10 are not communicated, when the external pilot control system works, the pressure of the main pump oil inlet 10 rises, when the sum of the pressure of the external control oil inlet 11 and the force of the overflow valve spring 9 is higher than the pressure of the upper end of the flow valve 12, the flow valve 12 starts to push the valve core to move upward to gradually close the overflow passage of the flow valve 12 to prevent overflow, at the same time, the main pump oil inlet 10 and the flow valve pilot pump oil inlet 13 are gradually communicated, the flow of the pilot pump and the main pump is realized. BRIEF DESCRIPTION OF DRAWINGS

[0018] The application will be further described in detail below in combination with the drawings and specific embodiments:

[0019] Figure 1 It is a schematic diagram of the principle structure of example one.

[0020] Figure 2 It is a schematic diagram of the principle structure of example two.

[0021] Figure 3 It is a schematic diagram of the principle structure of example three.

[0022] Figure 4 It is a schematic diagram of the principle structure of example four.

[0023] Figure 5 It is a schematic diagram of the principle structure of example five.

[0024] Figure 6 It is a schematic diagram of the principle structure of example six.

[0025] Figure 7 It is a schematic diagram of the principle structure of example seven. DETAILED DESCRIPTION

[0026] Example oneFigure 1

[0027] The external control pilot pump combined flow oil source valve of the excavator comprises a pilot pump oil inlet channel 1, a pressure reducing valve oil inlet channel 2, a pressure reducing valve 3, a pressure reducing valve oil outlet channel 4, a pressure reducing valve oil return channel 5, a pilot oil overflow channel 6, an overflow valve oil outlet channel 7, an overflow valve 8, an overflow valve spring 9, a main pump oil channel 10, an external control oil channel 11, a combined flow valve 12, a combined flow valve pilot pump oil inlet channel 13, and a combined flow valve spring 14.

[0028] The pilot pump oil inlet channel 1 is in communication with the pressure reducing valve oil inlet channel 2, the pilot oil overflow channel 6, and the combined flow valve pilot pump oil inlet channel 13. The pressure reducing valve 3 supplies oil to the pressure reducing valve oil outlet channel 4. The pressure reducing valve oil outlet channel 4 provides an oil source for an external pilot control system and is in communication with the upper end of the combined flow valve 12. The pressure reducing valve oil return channel 5 returns oil. The pilot oil overflow channel 6 is in communication with the right side and the upper end of the overflow valve 8. The overflow valve oil outlet channel 7 is in communication with the left side of the overflow valve 8 and is connected to a low-pressure oil circuit. The overflow valve spring 9 is arranged at the lower end of the overflow valve 8 to limit the overflow pressure. The main pump oil channel 10 is in communication with the left side of the combined flow valve 12. The external control oil channel 11 is in communication with the overflow valve 8 and the lower end of the combined flow valve 12, respectively. The combined flow valve pilot pump oil inlet channel 13 is in communication with the right side of the combined flow valve 12. The combined flow valve spring 14 is arranged at the upper end of the combined flow valve 12 together with the pressure reducing valve oil outlet channel 4 to determine the opening pressure of the combined flow valve 12. In the standby state, hydraulic oil from the pilot pump oil inlet channel 1 overflows through the pilot oil overflow channel 6 and the overflow valve 8, ensuring that the combined flow valve pilot pump oil inlet channel 13 is not in communication with the main pump oil channel 10. When the external pilot control system is working, the pressure of the main pump oil channel 10 begins to rise. When the sum of the pressure of the external control oil channel 11 and the force of the overflow valve spring 9 is greater than the pressure of the pilot oil overflow channel 6, the spool of the overflow valve 8 begins to move upward and gradually closes the overflow of the overflow valve 8. When the pressure of the external control oil channel 11 is greater than the sum of the pressure of the pressure reducing valve oil outlet channel 4 and the force of the combined flow valve spring 14, the spool of the combined flow valve 12 begins to move upward and gradually makes the main pump oil channel 10 and the combined flow valve pilot pump oil inlet channel 13 communicate, realizing the combination of the pilot pump and the main pump.

[0029] Example Two Figure 2

[0030] The external control pilot pump combined flow oil source valve of the excavator comprises a pilot pump oil inlet channel 1, a pressure reducing valve oil inlet channel 2, a pressure reducing valve 3, a pressure reducing valve oil outlet channel 4, a pressure reducing valve oil return channel 5, a pilot oil overflow channel 6, an overflow valve oil outlet channel 7, an overflow valve 8, an overflow valve spring 9, a main pump oil channel 10, an external control oil channel 11, a combined flow valve 12, a combined flow valve pilot pump oil inlet channel 13, and a combined flow valve spring 14.

[0031] The pilot pump oil inlet channel 1 is communicated with the pilot oil overflow oil channel 6 and the confluence valve pilot pump oil inlet channel 13, the pressure reducing valve 3 is supplied with oil by the pressure reducing valve oil outlet channel 4, the pressure reducing valve oil outlet channel 4 provides an oil source for an external pilot control system, the pressure reducing valve oil return channel 5 returns oil, the pilot oil overflow oil channel 6 is communicated with the right side and the upper end of the overflow valve 8, the overflow valve oil outlet channel 7 is communicated with the left side of the overflow valve 8 and is connected to a low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the overflow valve 8 to limit the overflow pressure, the main pump oil channel 10 is communicated with the left side of the confluence valve 12, the external control oil channel 11 is respectively communicated with the lower end of the overflow valve 8 and the confluence valve 12, the confluence valve pilot pump oil inlet channel 13 is communicated with the right side of the confluence valve 12, and the confluence valve spring 14 is arranged at the upper end of the confluence valve 12. In the standby state, hydraulic oil from the pilot pump oil inlet channel 1 is overflowed through the pilot oil overflow oil channel 6 and the overflow valve 8, so that the confluence valve pilot pump oil inlet channel 13 is not communicated with the main pump oil channel 10. When the external pilot control system works, the pressure of the main pump oil channel 10 begins to rise. When the sum of the pressure of the external control oil channel 11 and the force of the overflow valve spring 9 is greater than the pressure of the pilot oil overflow oil channel 6, the spool of the overflow valve 8 begins to move upwards and gradually closes the overflow of the overflow valve 8. When the pressure of the external control oil channel 11 is greater than the force of the confluence valve spring 14, the spool of the confluence valve 12 begins to move upwards and gradually makes the main pump oil channel 10 and the confluence valve pilot pump oil inlet channel 13 communicated, so that the pilot pump and the main pump are confluenced.

[0032] Example three Figure 3

[0033] The excavator external control pilot pump confluence oil source valve comprises a pilot pump oil inlet channel 1, a pressure reducing valve oil inlet channel 2, a pressure reducing valve 3, a pressure reducing valve oil outlet channel 4, a pressure reducing valve oil return channel 5, a pilot oil overflow oil channel 6, an overflow valve oil outlet channel 7, an overflow valve 8, an overflow valve spring 9, a main pump oil channel 10, an external control oil channel 11, a confluence valve 12 and a confluence valve pilot pump oil inlet channel 13.

[0034] The pilot pump oil inlet channel 1 is communicated with the pilot oil overflow oil channel 6 and the combined valve pilot pump oil inlet channel 13, the pressure reducing valve 3 is supplied with oil by the pressure reducing valve oil outlet channel 4, the pressure reducing valve oil outlet channel 4 provides an oil source for an external pilot control system and acts on the upper end of the combined valve 12, the pressure reducing valve oil return channel 5 returns oil, the pilot oil overflow oil channel 6 is communicated with the right side and the upper end of the overflow valve 8, the overflow valve oil outlet channel 7 is communicated with the left side of the overflow valve 8 and is connected to a low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the overflow valve 8 to limit the overflow pressure, the main pump oil channel 10 is communicated with the left side of the combined valve 12, the external control oil channel 11 is respectively communicated with the lower end of the overflow valve 8 and the combined valve 12, and the combined valve pilot pump oil inlet channel 13 is communicated with the right side of the combined valve 12. In the standby state, the hydraulic oil from the pilot pump oil inlet channel 1 is overflowed through the pilot oil overflow oil channel 6 and the overflow valve 8, the pressure of the pressure reducing valve oil outlet channel 4 determines the opening pressure of the combined valve 12, and the combined valve pilot pump oil inlet channel 13 is ensured to be not communicated with the main pump oil channel 10. When the external pilot control system works, the pressure of the main pump oil channel 10 begins to rise, when the sum of the pressure of the external control oil channel 11 and the force of the overflow valve spring 9 is greater than the sum of the pressure of the pilot oil overflow oil channel 6 and the pressure of the overflow valve 8, the spool of the overflow valve 8 begins to move upwards and gradually closes the overflow of the overflow valve 8, when the pressure of the external control oil channel 11 is greater than the pressure of the pressure reducing valve oil outlet channel 4, the spool of the combined valve 12 begins to move upwards and gradually makes the main pump oil channel 10 and the combined valve pilot pump oil inlet channel 13 communicated, so that the combined valve 12 realizes the combination of the pilot pump and the main pump.

[0035] Embodiment four Figure 4

[0036] The excavator external control pilot pump combined oil source valve comprises a pilot pump oil inlet channel 1, a pressure reducing valve oil inlet channel 2, a pressure reducing valve 3, a pressure reducing valve oil outlet channel 4, a pressure reducing valve oil return channel 5, a pilot oil overflow oil channel 6, an overflow valve oil outlet channel 7, an overflow valve 8, an overflow valve spring 9, a main pump oil channel 10, an external control oil channel 11, a combined valve 12 and a combined valve pilot pump oil inlet channel 13.

[0037] Wherein, the pilot pump oil inlet 1 is communicated with the pressure reducing valve inlet 2 and the combined valve pilot pump oil inlet 13, the pressure reducing valve 3 is supplied with oil by the pressure reducing valve outlet 4, the pressure reducing valve outlet 4 provides oil source for the external pilot control system and is communicated with the pilot oil overflow 6 and the upper end of the combined valve 12, the pressure reducing valve return 5 returns oil, the pilot oil overflow 6 is communicated with the right side of the overflow valve 8 and the upper end thereof, the overflow valve outlet 7 is communicated with the left side of the overflow valve 8 and is connected with the low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the overflow valve 8 to limit the overflow pressure, the main pump oil inlet 10 is communicated with the left side of the combined valve 12, the external control oil inlet 11 is communicated with the overflow valve 8 and the lower end of the combined valve 12 respectively, the combined valve pilot pump oil inlet 13 is communicated with the right side of the combined valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 passes through the pressure reducing valve 3, the pressure reducing valve outlet 4 and the pilot oil overflow 6, overflows through the overflow valve 8, at the same time, the pressure reducing valve outlet 4 outputs hydraulic oil to the upper end of the combined valve 12, ensuring that the combined valve pilot pump oil inlet 13 is not communicated with the main pump oil inlet 10, when the external pilot control system works, the pressure of the main pump oil inlet 10 begins to rise, when the sum of the pressure of the external control oil inlet 11 and the force of the overflow valve spring 9 is higher than the pressure of the pilot oil overflow 6, the spool of the overflow valve 8 begins to move upward and gradually closes the overflow of the overflow valve 8, when the pressure of the external control oil inlet 11 is greater than the pressure of the pressure reducing valve outlet 4, the spool of the combined valve 12 begins to move upward and gradually makes the main pump oil inlet 10 and the combined valve pilot pump oil inlet 13 communicated, realizing the combination of the pilot pump and the main pump.

[0038] Example five Figure 5

[0039] 5. The excavator external control pilot pump combination oil source valve comprises a pilot pump oil inlet 1, a pressure reducing valve inlet 2, a pressure reducing valve 3, a pressure reducing valve outlet 4, a pressure reducing valve return 5, a pilot oil overflow 6, an overflow valve outlet 7, an overflow valve spring 9, a main pump oil inlet 10, an external control oil inlet 11, a combined valve 12 and a combined valve pilot pump oil inlet 13.

[0040] Wherein, the confluence valve 12 has two functions of overflow and confluence, the pilot pump oil inlet 1 is communicated with the pressure reducing valve oil inlet 2 and the confluence valve pilot pump oil inlet 13, the pressure reducing valve 3 supplies oil for the pressure reducing valve oil outlet 4, the pressure reducing valve oil outlet 4 provides oil source for the external pilot control system and is communicated with the pilot oil overflow oil way 6 and the upper end of the confluence valve 12, the pressure reducing valve oil return 5 returns oil, the pilot oil overflow oil way 6 is communicated with the right side overflow oil way of the confluence valve 12, the overflow valve oil outlet 7 is communicated with the left side overflow oil way of the confluence valve 12 and connects the low pressure oil way, the overflow valve spring 9 is arranged at the lower end of the confluence valve 12 to limit the overflow pressure, the main pump oil way 10 is communicated with the left side confluence oil way of the confluence valve 12, the external control oil way 11 is communicated with the lower end of the confluence valve 12, the confluence valve pilot pump oil inlet 13 is communicated with the right side confluence oil way of the confluence valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 passes through the pressure reducing valve 3 and the pressure reducing valve oil outlet 4, the pilot oil overflow oil way 6 and the confluence valve 12 overflow and acts on the upper end of the confluence valve 12, ensuring that the confluence valve pilot pump oil inlet 13 is not communicated with the main pump oil way 10, when the external pilot control system works, the pressure of the main pump oil way 10 rises, when the sum of the pressure of the external control oil way 11 and the force of the overflow valve spring 9 is higher than the pressure of the upper end of the confluence valve 12, the confluence valve 12 spool is pushed to move upward to gradually close the passage of the pilot oil overflow oil way 6 and the overflow valve oil outlet 7 to prevent overflow, at the same time, the main pump oil way 10 and the confluence valve pilot pump oil inlet 13 are gradually communicated, realizing the confluence of the pilot pump and the main pump.

[0041] Example four Figure 6

[0042] 6. The excavator external control pilot pump confluence oil source valve comprises a pilot pump oil inlet 1, a pressure reducing valve oil inlet 2, a pressure reducing valve 3, a pressure reducing valve oil outlet 4, a pressure reducing valve oil return 5, a pilot oil overflow oil way 6, an overflow valve oil outlet 7, an overflow valve spring 9, a main pump oil way 10, an external control oil way 11, a confluence valve 12 and a confluence valve pilot pump oil inlet 13.

[0043] Wherein, the confluence valve 12 has two functions of overflow and confluence, the pilot pump oil inlet 1 is communicated with the pressure reducing valve oil inlet 2 and the confluence valve pilot pump oil inlet 13, the pressure reducing valve 3 supplies oil for the pressure reducing valve oil outlet 4, the pressure reducing valve oil outlet 4 provides oil source for the external pilot control system, the pressure reducing valve oil return 5 returns oil, the pilot oil overflow oil inlet 6 is communicated with the right overflow oil inlet of the confluence valve 12 and the pilot pump oil inlet 1 and acts on the upper end of the confluence valve 12, the overflow valve oil outlet 7 is communicated with the left overflow oil inlet of the confluence valve 12 and connects the low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the confluence valve 12 to limit the overflow pressure, the main pump oil inlet 10 is communicated with the left confluence oil inlet of the confluence valve 12, the external control oil inlet 11 is communicated with the lower end of the confluence valve 12, the confluence valve pilot pump oil inlet 13 is communicated with the right confluence oil inlet of the confluence valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 provides oil source for the external pilot control system through the pressure reducing valve 3 and the pressure reducing valve oil outlet 4, passes through the pilot oil overflow oil inlet 6 and the overflow of the confluence valve 12 and acts on the upper end of the confluence valve 12, ensures that the confluence valve pilot pump oil inlet 13 is not communicated with the main pump oil inlet 10, when the external pilot control system works, the pressure of the main pump oil inlet 10 rises, when the sum of the pressure of the external control oil inlet 11 and the force of the overflow valve spring 9 is higher than the pressure of the upper end of the confluence valve 12, the confluence valve 12 core is pushed to move upward to gradually close the channels of the pilot oil overflow oil inlet 6 and the overflow valve oil outlet 7 to prevent overflow, at the same time, the main pump oil inlet 10 and the confluence valve pilot pump oil inlet 13 are gradually communicated, realizing the confluence of the pilot pump and the main pump.

[0044] Example four Figure 7

[0045] 7. The excavator external control pilot pump confluence oil source valve comprises a pilot pump oil inlet 1, a pressure reducing valve oil inlet 2, a pressure reducing valve 3, a pressure reducing valve oil outlet 4, a pressure reducing valve oil return 5, a pilot oil overflow oil inlet 6, an overflow valve oil outlet 7, an overflow valve spring 9, a main pump oil inlet 10, an external control oil inlet 11, a confluence valve 12 and a confluence valve pilot pump oil inlet 13.

[0046] Wherein, the confluence valve 12 has two functions of overflow and confluence, the pilot pump oil inlet 1 is communicated with the right side overflow oil inlet of the confluence valve 12, the pressure reducing valve oil inlet 2 and the confluence valve pilot pump oil inlet 13, the pressure reducing valve 3 supplies oil for the pressure reducing valve oil outlet 4, the pressure reducing valve oil outlet 4 provides oil source for the external pilot control system and is communicated with the pilot oil overflow oil inlet 6, the pressure reducing valve oil return 5 returns oil, the pilot oil overflow oil inlet 6 acts on the upper end of the confluence valve 12, the overflow valve oil outlet 7 is communicated with the left side overflow oil inlet of the confluence valve 12 and connects the low pressure oil circuit, the overflow valve spring 9 is arranged at the lower end of the confluence valve 12 to limit the overflow pressure, the main pump oil inlet 10 is communicated with the left side confluence oil inlet of the confluence valve 12, the external control oil inlet 11 is communicated with the lower end of the confluence valve 12, the confluence valve pilot pump oil inlet 13 is communicated with the right side confluence oil inlet of the confluence valve 12, in the standby state, the hydraulic oil from the pilot pump oil inlet 1 provides oil source for the external pilot control system through the pressure reducing valve 3 and the pressure reducing valve oil outlet 4 and acts on the upper end of the confluence valve 12 through the pilot oil overflow oil inlet 6, the oil of the pilot pump oil inlet 1 is overflowed through the confluence valve 12, the confluence valve pilot pump oil inlet 13 and the main pump oil inlet 10 are ensured not to be communicated, when the external pilot control system works, the pressure of the main pump oil inlet 10 is increased, when the sum of the pressure of the external control oil inlet 11 and the force of the overflow valve spring 9 is higher than the pressure of the upper end of the confluence valve 12, the confluence valve 12 starts to push the valve core to move upward to gradually close the overflow channel of the confluence valve 12 to prevent overflow, at the same time, the main pump oil inlet 10 and the confluence valve pilot pump oil inlet 13 are gradually communicated, the confluence of the pilot pump and the main pump is realized.

Claims

1. A flow combining oil source valve for an excavator externally piloted pilot pump, characterized by: The external control pilot pump combined flow oil source valve comprises a pilot pump oil inlet channel (1), a pressure reducing valve oil inlet channel (2), a pressure reducing valve (3), a pressure reducing valve oil outlet channel (4), a pressure reducing valve oil return channel (5), a pilot oil overflow channel (6), an overflow valve oil outlet channel (7), an overflow valve (8), an overflow valve spring (9), a main pump oil channel (10), an external control oil channel (11), a combined flow valve (12), a combined flow valve pilot pump oil inlet channel (13), and a combined flow valve spring (14). The pilot pump oil inlet channel (1) is in communication with the pressure reducing valve oil inlet channel (2), the pilot oil overflow channel (6), and the combined flow valve pilot pump oil inlet channel (13). The pressure reducing valve (3) supplies oil to the pressure reducing valve oil outlet channel (4). The pressure reducing valve oil outlet channel (4) provides an oil source for an external pilot control system and is in communication with the upper end of the combined flow valve (12). The pressure reducing valve oil return channel (5) returns oil. The pilot oil overflow channel (6) is in communication with the right side and the upper end of the overflow valve (8). The overflow valve oil outlet channel (7) is in communication with the left side of the overflow valve (8) and is connected to a low-pressure oil circuit. The overflow valve spring (9) is arranged at the lower end of the overflow valve (8) to limit the overflow pressure. The main pump oil channel (10) is in communication with the left side of the combined flow valve (12). The external control oil channel (11) is in communication with the overflow valve (8) and the lower end of the combined flow valve (12), respectively. The combined flow valve pilot pump oil inlet channel (13) is in communication with the right side of the combined flow valve (12). The combined flow valve spring (14) is arranged at the upper end of the combined flow valve (12) together with the pressure reducing valve oil outlet channel (4) to determine the opening pressure of the combined flow valve (12). In the standby state, hydraulic oil from the pilot pump oil inlet channel (1) overflows through the pilot oil overflow channel (6) and the overflow valve (8), ensuring that the combined flow valve pilot pump oil inlet channel (13) is not in communication with the main pump oil channel (10). When the external pilot control system is working, the pressure of the main pump oil channel (10) begins to rise. When the sum of the pressure of the external control oil channel (11) and the force of the overflow valve spring (9) is greater than the pressure of the pilot oil overflow channel (6), the spool of the overflow valve (8) begins to move upwards and gradually closes the overflow of the overflow valve (8). When the pressure of the external control oil channel (11) is greater than the sum of the pressure of the pressure reducing valve oil outlet channel (4) and the force of the combined flow valve spring (14), the spool of the combined flow valve (12) begins to move upwards and gradually makes the main pump oil channel (10) and the combined flow valve pilot pump oil inlet channel (13) communicate, realizing the combination of the pilot pump and the main pump.

2. A flow combining oil source valve for an excavator externally piloted pilot pump, characterized by: The external control pilot pump combined flow oil source valve comprises a pilot pump oil inlet channel (1), a pressure reducing valve oil inlet channel (2), a pressure reducing valve (3), a pressure reducing valve oil outlet channel (4), a pressure reducing valve oil return channel (5), a pilot oil overflow channel (6), an overflow valve oil outlet channel (7), an overflow valve (8), an overflow valve spring (9), a main pump oil channel (10), an external control oil channel (11), a combined flow valve (12), a combined flow valve pilot pump oil inlet channel (13), and a combined flow valve spring (14). The pilot pump oil inlet channel (1) is in communication with the pressure reducing valve oil inlet channel (2), the pilot oil overflow channel (6), and the combined flow valve pilot pump oil inlet channel (13). The pressure reducing valve (3) supplies oil to the pressure reducing valve oil outlet channel (4). The pressure reducing valve oil outlet channel (4) provides an oil source for an external pilot control system. The pressure reducing valve oil return channel (5) returns oil. The pilot oil overflow channel (6) is in communication with the right side and the upper end of the overflow valve (8). The overflow valve oil outlet channel (7) is in communication with the left side of the overflow valve (8) and is connected to a low-pressure oil circuit. The overflow valve spring (9) is arranged at the lower end of the overflow valve (8) to limit the overflow pressure. The main pump oil channel (10) is in communication with the left side of the combined flow valve (12). The external control oil channel (11) is in communication with the lower end of the overflow valve (8) and the combined flow valve (12), respectively. The combined flow valve pilot pump oil inlet channel (13) is in communication with the right side of the combined flow valve (12). The combined flow valve spring (14) is arranged at the upper end of the combined flow valve (12). In the standby state, hydraulic oil from the pilot pump oil inlet channel (1) overflows through the pilot oil overflow channel (6) and the overflow valve (8), ensuring that the combined flow valve pilot pump oil inlet channel (13) is not in communication with the main pump oil channel (10). When the external pilot control system is working, the pressure of the main pump oil channel (10) begins to rise. When the sum of the pressure of the external control oil channel (11) and the force of the overflow valve spring (9) is greater than the pressure of the pilot oil overflow channel (6), the spool of the overflow valve (8) begins to move upwards and gradually closes the overflow of the overflow valve (8). When the pressure of the external control oil channel (11) is greater than the force of the combined flow valve spring (14), the spool of the combined flow valve (12) begins to move upwards and gradually makes the main pump oil channel (10) and the combined flow valve pilot pump oil inlet channel (13) communicate, realizing the combination of the pilot pump and the main pump.

3. A flow combining oil source valve for an excavator externally piloted pilot pump, characterized by: The external control pilot pump combined flow oil source valve comprises a pilot pump oil inlet channel (1), a pressure reducing valve oil inlet channel (2), a pressure reducing valve (3), a pressure reducing valve oil outlet channel (4), a pressure reducing valve oil return channel (5), a pilot oil overflow channel (6), an overflow valve oil outlet channel (7), an overflow valve (8), an overflow valve spring (9), a main pump oil channel (10), an external control oil channel (11), a combined flow valve (12), a combined flow valve pilot pump oil inlet channel (13), the pilot pump oil inlet channel (1) is communicated with the pressure reducing valve oil inlet channel (2), the pilot oil overflow channel (6) and the combined flow valve pilot pump oil inlet channel (13), the pressure reducing valve (3) supplies oil to the pressure reducing valve oil outlet channel (4), the pressure reducing valve oil outlet channel (4) provides an oil source for an external pilot control system and acts on the upper end of the combined flow valve (12), the pressure reducing valve oil return channel (5) returns oil, the pilot oil overflow channel (6) is communicated with the right side and the upper end of the overflow valve (8), the overflow valve oil outlet channel (7) is communicated with the left side of the overflow valve (8) and is connected to a low pressure oil circuit, the overflow valve spring (9) is arranged at the lower end of the overflow valve (8) to limit the overflow pressure, the main pump oil channel (10) is communicated with the left side of the combined flow valve (12), the external control oil channel (11) is respectively communicated with the overflow valve (8) and the lower end of the combined flow valve (12), the combined flow valve pilot pump oil inlet channel (13) is communicated with the right side of the combined flow valve (12), in the standby state, hydraulic oil from the pilot pump oil inlet channel (1) overflows through the pilot oil overflow channel (6) and the overflow valve (8), the pressure of the pressure reducing valve oil outlet channel (4) determines the opening pressure of the combined flow valve (12), and the combined flow valve pilot pump oil inlet channel (13) is ensured to be not communicated with the main pump oil channel (10). When the external pilot control system works, the pressure of the main pump oil channel (10) starts to rise, when the sum of the pressure of the external control oil channel (11) and the force of the overflow valve spring (9) is greater than the pressure of the pilot oil overflow channel (6) and the overflow valve (8) starts to move upward and gradually closes the overflow of the overflow valve (8), when the pressure of the external control oil channel (11) is greater than the pressure of the pressure reducing valve oil outlet channel (4), the valve core of the combined flow valve (12) starts to move upward and gradually makes the main pump oil channel (10) and the combined flow valve pilot pump oil inlet channel (13) communicated, and the combination of the pilot pump and the main pump is realized.

4. A flow combining oil source valve for an excavator externally piloted pilot pump, characterized by: The external control pilot pump combined flow oil source valve of the excavator comprises a pilot pump oil inlet channel (1), a pressure reducing valve oil inlet channel (2), a pressure reducing valve (3), a pressure reducing valve oil outlet channel (4), a pressure reducing valve oil return channel (5), a pilot oil overflow channel (6), an overflow valve oil outlet channel (7), an overflow valve (8), an overflow valve spring (9), a main pump oil channel (10), an external control oil channel (11), a combined flow valve (12), and a combined flow valve pilot pump oil inlet channel (13). The pilot pump oil inlet channel (1) is communicated with the pressure reducing valve oil inlet channel (2) and the combined flow valve pilot pump oil inlet channel (13). The pressure reducing valve (3) supplies oil to the pressure reducing valve oil outlet channel (4). The pressure reducing valve oil outlet channel (4) provides an oil source for an external pilot control system and is communicated with the pilot oil overflow channel (6) and the upper end of the combined flow valve (12). The pressure reducing valve oil return channel (5) returns oil. The pilot oil overflow channel (6) is communicated with the right side and the upper end of the overflow valve (8). The overflow valve oil outlet channel (7) is communicated with the left side of the overflow valve (8) and is connected to a low-pressure oil circuit. The overflow valve spring (9) is arranged at the lower end of the overflow valve (8) to limit the overflow pressure. The main pump oil channel (10) is communicated with the left side of the combined flow valve (12). The external control oil channel (11) is respectively communicated with the overflow valve (8) and the lower end of the combined flow valve (12). The combined flow valve pilot pump oil inlet channel (13) is communicated with the right side of the combined flow valve (12). In the standby state, hydraulic oil from the pilot pump oil inlet channel (1) passes through the pressure reducing valve (3), the pressure reducing valve oil outlet channel (4), and the pilot oil overflow channel (6) to overflow through the overflow valve (8), and at the same time, the pressure reducing valve oil outlet channel (4) outputs hydraulic oil to the upper end of the combined flow valve (12), so that the combined flow valve pilot pump oil inlet channel (13) is not communicated with the main pump oil channel (10). When the external pilot control system works, the pressure of the main pump oil channel (10) begins to rise. When the sum of the pressure of the external control oil channel (11) and the force of the overflow valve spring (9) is higher than the pressure of the pilot oil overflow channel (6), the spool of the overflow valve (8) begins to move upwards and gradually closes the overflow of the overflow valve (8). When the pressure of the external control oil channel (11) is greater than the pressure of the pressure reducing valve oil outlet channel (4), the spool of the combined flow valve (12) begins to move upwards and gradually makes the main pump oil channel (10) and the combined flow valve pilot pump oil inlet channel (13) communicated, so that the pilot pump and the main pump are combined.

5. A flow combining oil source valve for an excavator externally piloted pilot pump, characterized by: The external control pilot pump combined flow oil source valve of the excavator comprises a pilot pump oil inlet channel (1), a pressure reducing valve oil inlet channel (2), a pressure reducing valve (3), a pressure reducing valve oil outlet channel (4), a pressure reducing valve oil return channel (5), a pilot oil overflow channel (6), an overflow valve oil outlet channel (7), an overflow valve spring (9), a main pump oil channel (10), an external control oil channel (11), a combined flow valve (12), and a combined flow valve pilot pump oil inlet channel (13), The combined valve (12) has two functions of overflow and combination. The pilot pump oil inlet (1) is communicated with the pressure reducing valve oil inlet (2) and the combined valve pilot pump oil inlet (13). The pressure reducing valve (3) supplies oil for the pressure reducing valve oil outlet (4). The pressure reducing valve oil outlet (4) provides an oil source for the external pilot control system and is communicated with the pilot oil overflow oil inlet (6) and the upper end of the combined valve (12). The pressure reducing valve oil return (5) returns oil. The pilot oil overflow oil inlet (6) is communicated with the right overflow oil inlet of the combined valve (12). The overflow valve oil outlet (7) is communicated with the left overflow oil inlet of the combined valve (12) and is connected with the low pressure oil circuit. The overflow valve spring (9) is arranged at the lower end of the combined valve (12) to limit the overflow pressure. The main pump oil inlet (10) is communicated with the left combined oil inlet of the combined valve (12). The external control oil inlet (11) is communicated with the lower end of the combined valve (12). The combined valve pilot pump oil inlet (13) is communicated with the right combined oil inlet of the combined valve (12). In the standby state, the hydraulic oil from the pilot pump oil inlet (1) is overflowed through the pressure reducing valve (3) and the pressure reducing valve oil outlet (4) through the pilot oil overflow oil inlet (6) and the combined valve (12) and acts on the upper end of the combined valve (12), so that the combined valve pilot pump oil inlet (13) is not communicated with the main pump oil inlet (10). When the external pilot control system works, the pressure of the main pump oil inlet (10) rises. When the sum of the pressure of the external control oil inlet (11) and the force of the overflow valve spring (9) is higher than the pressure of the upper end of the combined valve (12), the combined valve (12) is pushed to move upward to gradually close the passages of the pilot oil overflow oil inlet (6) and the overflow valve oil outlet (7) to prevent overflow, and at the same time, the main pump oil inlet (10) and the combined valve pilot pump oil inlet (13) are gradually communicated, so that the combination of the pilot pump and the main pump is realized.

6. An excavator externally piloted, in-line, oil source valve for a pilot pump, characterized by: The combined valve (12) has two functions of overflow and combination. The pilot pump oil inlet (1) is communicated with the pressure reducing valve oil inlet (2) and the combined valve pilot pump oil inlet (13). The pressure reducing valve (3) supplies oil for the pressure reducing valve oil outlet (4). The pressure reducing valve oil outlet (4) provides an oil source for the external pilot control system and is communicated with the pilot oil overflow oil inlet (6) and the upper end of the combined valve (12). The pressure reducing valve oil return (5) returns oil. The pilot oil overflow oil inlet (6) is communicated with the right overflow oil inlet of the combined valve (12). The overflow valve oil outlet (7) is communicated with the left overflow oil inlet of the combined valve (12) and is connected with the low pressure oil circuit. The overflow valve spring (9) is arranged at the lower end of the combined valve (12) to limit the overflow pressure. The main pump oil inlet (10) is communicated with the left combined oil inlet of the combined valve (12). The external control oil inlet (11) is communicated with the lower end of the combined valve (12). The combined valve pilot pump oil inlet (13) is communicated with the right combined oil inlet of the combined valve (12). In the standby state, the hydraulic oil from the pilot pump oil inlet (1) is overflowed through the pressure reducing valve (3) and the pressure reducing valve oil outlet (4) through the pilot oil overflow oil inlet (6) and the combined valve (12) and acts on the upper end of the combined valve (12), so that the combined valve pilot pump oil inlet (13) is not communicated with the main pump oil inlet (10). When the external pilot control system works, the pressure of the main pump oil inlet (10) rises. When the sum of the pressure of the external control oil inlet (11) and the force of the overflow valve spring (9) is higher than the pressure of the upper end of the combined valve (12), the combined valve (12) is pushed to move upward to gradually close the passages of the pilot oil overflow oil inlet (6) and the overflow valve oil outlet (7) to prevent overflow, and at the same time, the main pump oil inlet (10) and the combined valve pilot pump oil inlet (13) are gradually communicated, so that the combination of the pilot pump and the main pump is realized. The combined valve (12) has two functions of overflow and combination. The pilot pump oil inlet (1) is communicated with the oil inlet (2) of the pressure reducing valve and the combined valve pilot pump oil inlet (13). The pressure reducing valve (3) supplies oil for the oil outlet (4) of the pressure reducing valve. The oil outlet (4) of the pressure reducing valve provides oil source for the external pilot control system. The oil return (5) of the pressure reducing valve is connected to the oil return. The pilot oil overflow oil inlet (6) is communicated with the right overflow oil inlet of the combined valve (12) and the pilot pump oil inlet (1) and acts on the upper end of the combined valve (12). The overflow valve oil outlet (7) is communicated with the left overflow oil inlet of the combined valve (12) and is connected to the low pressure oil circuit. The overflow valve spring (9) is arranged at the lower end of the combined valve (12) to limit the overflow pressure. The main pump oil inlet (10) is communicated with the left combination oil inlet of the combined valve (12). The external control oil inlet (11) is communicated with the lower end of the combined valve (12). The combined valve pilot pump oil inlet (13) is communicated with the right combination oil inlet of the combined valve (12). In the standby state, the hydraulic oil from the pilot pump oil inlet (1) provides oil source for the external pilot control system through the pressure reducing valve (3) and the oil outlet (4) of the pressure reducing valve. The overflow is realized through the pilot oil overflow oil inlet (6) and the combined valve (12) and acts on the upper end of the combined valve (12), so as to ensure that the combined valve pilot pump oil inlet (13) is not communicated with the main pump oil inlet (10). When the external pilot control system works, the pressure of the main pump oil inlet (10) rises. When the sum of the pressure of the external control oil inlet (11) and the force of the overflow valve spring (9) is higher than the pressure at the upper end of the combined valve (12), the combined valve (12) is pushed to move upward to gradually close the passage of the pilot oil overflow oil inlet (6) and the overflow valve oil outlet (7) to prevent overflow. At the same time, the main pump oil inlet (10) and the combined valve pilot pump oil inlet (13) are gradually communicated, so as to realize the combination of the pilot pump and the main pump.

7. An excavator externally piloted, combined flow, pump delivery valve characterized by: The external control pilot pump combined flow oil source valve comprises a pilot pump oil inlet channel (1), a pressure reducing valve oil inlet channel (2), a pressure reducing valve (3), a pressure reducing valve oil outlet channel (4), a pressure reducing valve oil return channel (5), a pilot oil overflow oil channel (6), an overflow valve oil outlet channel (7), an overflow valve spring (9), a main pump oil channel (10), an external control oil channel (11), a combined flow valve (12), and a combined flow valve pilot pump oil inlet channel (13). The combined flow valve (12) has overflow and combined flow functions. The pilot pump oil inlet channel (1) is communicated with the right side overflow oil channel of the combined flow valve (12), the pressure reducing valve oil inlet channel (2), and the combined flow valve pilot pump oil inlet channel (13). The pressure reducing valve (3) supplies oil to the pressure reducing valve oil outlet channel (4). The pressure reducing valve oil outlet channel (4) provides an oil source for an external pilot control system and is communicated with the pilot oil overflow oil channel (6). The pressure reducing valve oil return channel (5) returns oil. The pilot oil overflow oil channel (6) acts on the upper end of the combined flow valve (12). The overflow valve oil outlet channel (7) is communicated with the left side overflow oil channel of the combined flow valve (12) and is connected to a low pressure oil circuit. The overflow valve spring (9) is arranged at the lower end of the combined flow valve (12) to limit the overflow pressure. The main pump oil channel (10) is communicated with the left side combined flow oil channel of the combined flow valve (12). The external control oil channel (11) is communicated with the lower end of the combined flow valve (12). The combined flow valve pilot pump oil inlet channel (13) is communicated with the right side combined flow oil channel of the combined flow valve (12). In the standby state, hydraulic oil from the pilot pump oil inlet channel (1) provides an oil source for the external pilot control system through the pressure reducing valve (3) and the pressure reducing valve oil outlet channel (4) and acts on the upper end of the combined flow valve (12) through the pilot oil overflow oil channel (6), so that the oil in the pilot pump oil inlet channel (1) overflows through the combined flow valve (12) and ensures that the combined flow valve pilot pump oil inlet channel (13) is not communicated with the main pump oil channel (10). When the external pilot control system works, the pressure of the main pump oil channel (10) rises. When the sum of the pressure of the external control oil channel (11) and the force of the overflow valve spring (9) is higher than the pressure at the upper end of the combined flow valve (12), the combined flow valve (12) starts to push the valve core to move upward and gradually closes the overflow channel of the combined flow valve (12) to prevent overflow, and at the same time, the main pump oil channel (10) and the combined flow valve pilot pump oil inlet channel (13) are gradually communicated, so that the pilot pump and the main pump are combined.

Images