阅读说明：本技术 一种液压挖掘机安全装置 (Safety device of hydraulic excavator ) 是由 杨庆龙 莫有瑜 程金国 李春辉 韦家义 王昌耀 陈聪 于 2019-09-19 设计创作，主要内容包括：本发明公开了一种液压挖掘机安全装置,包括油箱、主油泵、主阀组件、动臂油缸和先导油泵、油缸先导阀,所述主阀组件的两个工作口分别与动臂油缸的两个油腔连接,所述主阀组件的压力油口、回油口分别与主油泵、油箱连接,所述油缸先导阀的压力油口、回油口分别与先导油泵、油箱连接,所述油缸先导阀的两个工作口分别与主阀组件的阀芯两端连接,还包括能够将动臂油缸的其中一个油腔与所述油缸先导阀的压力油口连通的安全油源阀组件。本发明的液压挖掘机安全装置,属于液压控制技术领域,结构简单,制作方便；在蓄能器没有压力和机器无法启动时,依然能使液压挖掘机的动臂下降,从而使铲斗放到地上,消除安全隐患。(The invention discloses a safety device of a hydraulic excavator, which comprises an oil tank, a main oil pump, a main valve component, a movable arm oil cylinder, a pilot oil pump and an oil cylinder pilot valve, wherein two working ports of the main valve component are respectively connected with two oil cavities of the movable arm oil cylinder, a pressure oil port and an oil return port of the main valve component are respectively connected with the main oil pump and the oil tank, a pressure oil port and an oil return port of the oil cylinder pilot valve are respectively connected with the pilot oil pump and the oil tank, two working ports of the oil cylinder pilot valve are respectively connected with two ends of a valve core of the main valve component, and the safety oil source valve component is capable of communicating one oil cavity of the movable arm oil cylinder with the pressure oil. The safety device of the hydraulic excavator belongs to the technical field of hydraulic control, and is simple in structure and convenient to manufacture; when the energy accumulator has no pressure and the machine can not be started, the movable arm of the hydraulic excavator still can be lowered, so that the bucket is placed on the ground, and potential safety hazards are eliminated.)

1. A safety device of a hydraulic excavator comprises an oil tank (7), a main oil pump (8), a main valve component (1), a movable arm oil cylinder (2), a pilot oil pump (9) and an oil cylinder pilot valve (5), two working ports of the main valve component (1) are respectively connected with two oil cavities of the movable arm oil cylinder (2), a pressure oil port and an oil return port of the main valve component (1) are respectively connected with a main oil pump (8) and an oil tank (7), a pressure oil port and an oil return port of the oil cylinder pilot valve (5) are respectively connected with a pilot oil pump (9) and an oil tank (7), two working ports of the oil cylinder pilot valve (5) are respectively connected with two ends of a valve core of the main valve component (1), the hydraulic control system is characterized by further comprising a safety oil source valve assembly (3) which can communicate one oil cavity of the movable arm oil cylinder (2) with a pressure oil port of the oil cylinder pilot valve (5).

2. The safety device of a hydraulic excavator according to claim 1, wherein the safety oil source valve assembly (3) comprises a cylinder oil supply pipeline, the oil inlet end of the cylinder oil supply pipeline is connected with one of the oil chambers of the boom cylinder (2), the oil outlet end of the cylinder oil supply pipeline is connected with the pressure oil port of the cylinder pilot valve (5), and a manual stop valve (301) is arranged on the cylinder oil supply pipeline.

3. a hydraulic excavator safety device as claimed in claim 2, wherein the cylinder feed line is provided with a pressure reducing valve (302) connected in series with the manual cut-off valve (301).

4. A hydraulic excavator safety device as claimed in claim 2 or 3 wherein an accumulator (4) is provided on the cylinder supply line.

5. The safety device of a hydraulic excavator according to claim 4, wherein the safety oil source valve assembly (3) further comprises a pilot pump oil supply branch, an oil inlet end of the pilot pump oil supply branch is connected with the pilot oil pump (9), an oil outlet end of the pilot pump oil supply branch is connected with an oil outlet end of the oil cylinder oil supply pipeline, and a check valve (304) is arranged on the pilot pump oil supply branch.

6. A hydraulic excavator safety device according to claim 5, wherein an overflow valve (303) connected to a tank (7) is provided in the pilot pump oil supply branch at the oil outlet of the check valve (304).

Technical Field

The invention relates to the technical field of hydraulic control, in particular to a safety device of a hydraulic excavator.

Background

Before the hydraulic excavator stops, the bucket is generally contacted with the ground for safety, and then the hydraulic excavator stops and extinguishes. If the excavator bucket is not in contact with the ground and is stopped, the machine needs to be restarted to place the bucket into contact with the ground and then stopped. In order to avoid the need of restarting the machine after the bucket does not contact the ground, the conventional solution is to add an accumulator on the control oil path, so that high-pressure hydraulic oil still exists in the control oil path in a short time when an engine is just stalled, and under the condition that the bucket of the excavator does not contact the ground, the high-pressure oil in the control oil path can push a valve core of a main valve of the hydraulic excavator through an operating handle, so that a movable arm of the excavator descends under the action of gravity, and the bucket contacts the ground.

In the existing solution, when the machine is stopped for more than the pressure maintaining time of the energy accumulator, the control oil circuit has no pressure and the machine cannot be started, under the condition that the bucket does not contact the ground, only a special oil supply device can be used for supplying high-pressure hydraulic oil to the control oil circuit to enable the boom cylinder to descend, so that the bucket is placed on the ground.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art, and aims to provide a safety device of a hydraulic excavator, which has reliable performance and convenient operation.

In order to achieve the above object, the present invention provides a safety device for a hydraulic excavator, which includes an oil tank, a main oil pump, a main valve assembly, a boom cylinder, a pilot oil pump, a cylinder pilot valve, two working ports of the main valve assembly are respectively connected with two oil chambers of the boom cylinder, a pressure oil port and an oil return port of the main valve assembly are respectively connected with the main oil pump and the oil tank, a pressure oil port and an oil return port of the cylinder pilot valve are respectively connected with the pilot oil pump and the oil tank, two working ports of the cylinder pilot valve are respectively connected with two ends of a valve core of the main valve assembly, and the safety device further includes a safety oil source valve assembly capable of communicating one of the oil chambers of the boom cylinder with the pressure oil.

Further, the safety oil source valve assembly comprises an oil cylinder oil supply pipeline, an oil inlet end of the oil cylinder oil supply pipeline is connected with one of oil cavities of the movable arm oil cylinder, an oil outlet end of the oil cylinder oil supply pipeline is connected with a pressure oil port of the oil cylinder pilot valve, and a manual stop valve is arranged on the oil cylinder oil supply pipeline.

Furthermore, a pressure reducing valve connected with the manual stop valve in series is arranged on the oil supply pipeline of the oil cylinder.

Furthermore, an energy accumulator is arranged on the oil supply pipeline of the oil cylinder.

as a further improvement, the safety oil source valve assembly further comprises a pilot pump oil supply branch, wherein an oil inlet end of the pilot pump oil supply branch is connected with the pilot oil pump, an oil outlet end of the pilot pump oil supply branch is connected with an oil outlet end of the oil cylinder oil supply pipeline, and a check valve is arranged on the pilot pump oil supply branch.

Furthermore, an overflow valve connected with the oil tank is arranged on the oil supply branch of the pilot pump at the oil outlet of the one-way valve.

Advantageous effects

Compared with the prior art, the safety device of the hydraulic excavator has the following beneficial effects:

1) The safety device of the hydraulic excavator is simple in structure and convenient to manufacture; when the energy accumulator has no pressure and the machine cannot be started, the movable arm of the hydraulic excavator still can be lowered under the condition that the bucket does not contact the ground, so that the bucket is placed on the ground, and potential safety hazards are eliminated; the method has the characteristics of reliable performance, convenient operation and high cost performance;

2) In the safety device of the hydraulic excavator, after a manual stop valve in a safety oil source valve is communicated, the potential energy of a movable arm is converted into high-pressure hydraulic oil of a rodless cavity of a movable arm oil cylinder, and the high-pressure hydraulic oil is supplied to a pilot oil supply oil way; under the conditions that the machine is not started and the pilot oil supply oil way has no pressure, the pressure of the pilot oil supply oil way is recovered, and by operating the pilot valve of the oil cylinder, high-pressure oil in the pilot oil supply oil way pushes a valve core in a main valve assembly, so that a movable arm of the excavator descends under the action of gravity, and a bucket contacts the ground;

3) In the safety device of the hydraulic excavator, the manual stop valve in the safety oil source valve is manually turned to a stop state when the hydraulic excavator normally works, so that the interference of high-pressure oil in a rodless cavity of a movable arm oil cylinder on a pilot oil supply oil way when the hydraulic excavator normally works is effectively prevented.

Drawings

Fig. 1 is a schematic diagram of a hydraulic excavator safety device according to the present invention.

In the figure: 1. a main valve assembly; 2. a boom cylinder; 3. a safety oil source valve assembly; 301. a manual stop valve; 302. a pressure reducing valve; 303. an overflow valve; 304. a one-way valve; 4. an accumulator; 5. an oil cylinder pilot valve; 6. a high-pressure pilot oil supply path; 7. an oil tank; 8. a main oil pump; 9. a pilot oil pump.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

The specific embodiments of the present invention are such that: as shown in fig. 1, a safety device of a hydraulic excavator includes an oil tank 7, a main oil pump 8, a main valve assembly 1, a boom oil cylinder 2, a pilot oil pump 9, and an oil cylinder pilot valve 5, where the oil cylinder pilot valve 5 is an electromagnetic valve, the main valve assembly 1 is a reversing valve, two working ports of the main valve assembly 1 are respectively connected with two oil chambers of the boom oil cylinder 2, a pressure oil port and an oil return port of the main valve assembly 1 are respectively connected with the main oil pump 8 and the oil tank 7, the pressure oil port and the oil return port of the oil cylinder pilot valve 5 are respectively connected with the pilot oil pump 9 and the oil tank 7, two working ports of the oil cylinder pilot valve 5 are respectively connected with two ends of a valve core of the main valve assembly 1, and the safety oil source valve assembly 3 capable of communicating one of the. After the excavator is flamed out, after the main oil pump 8 and the pilot oil pump 8 stop working, one of the oil cavities of the boom cylinder 2 can be communicated with the pressure oil port of the cylinder pilot valve 5 through the safety oil source valve assembly 3 to supply oil to the cylinder pilot valve 5, the cylinder pilot valve 5 can control the valve core of the main valve assembly 1 to shift, so that one of the oil cavities of the boom cylinder 2 is communicated with the oil tank 6 through the main valve assembly 1, the piston rod in the boom cylinder 2 automatically descends under the action of gravity, and the bucket of the hydraulic excavator can slowly contact the ground.

The safety device of the hydraulic excavator is simple in structure and convenient to manufacture. When the machine cannot be started and the bucket does not contact the ground, the movable arm of the hydraulic excavator still can be lowered, so that the bucket is placed on the ground, and potential safety hazards are eliminated; has the characteristics of reliable performance, convenient operation and high cost performance.

The manual stop valve 301 in the safety oil source valve of the invention is manually turned to a stop state when the hydraulic excavator normally works, thereby effectively preventing the interference of the high-pressure oil of the movable arm oil cylinder 2 to the oil supply way of the oil cylinder pilot valve 5 when the hydraulic excavator normally works.

In this embodiment, the safety oil source valve assembly 3 includes an oil supply pipeline, an oil inlet end of the oil supply pipeline is connected to one of the oil chambers of the boom oil cylinder 2, an oil outlet end of the oil supply pipeline is connected to the pressure oil port of the cylinder pilot valve 5, the rodless chamber is one of the oil chambers of the boom oil cylinder 2, the oil supply pipeline is connected to the rodless oil chamber of the boom oil cylinder 2, and the oil supply pipeline is provided with a manual stop valve 301. In the safety device of the hydraulic excavator, after a manual stop valve 301 in a safety oil source valve 3 is opened, a rodless cavity of a boom cylinder 2 is communicated with a pressure oil port of a cylinder pilot valve 5, the rodless cavity is converted into high-pressure hydraulic oil in the rodless cavity of the boom cylinder 2 through the gravitational potential energy of a boom, and the high-pressure hydraulic oil is provided for the pressure oil port of the cylinder pilot valve 5; when the main oil pump 8 and the pilot oil pump 8 are not started, the pressure of an oil supply path of the oil cylinder pilot valve 5 is recovered, and by operating the oil cylinder pilot valve 5, high-pressure oil in an oil cylinder oil supply pipeline pushes a valve core in the main valve assembly 1, so that a movable arm of the excavator descends under the action of gravity, and a bucket contacts the ground.

In the present embodiment, a pressure reducing valve 302 connected in series to the manual cut-off valve 301 is provided in the cylinder oil supply line. The pressure reducing valve 302 can control the oil supply pressure of the oil supply pipeline of the oil cylinder, and prevent the pressure of the hydraulic oil flowing from the slave arm oil cylinder 2 to the oil cylinder pilot valve 5 from being too high.

In this embodiment, an energy accumulator 4 is disposed on the oil supply line of the oil cylinder, the energy accumulator 4 is disposed at the oil outlet end of the oil supply line of the oil cylinder, and can provide high-pressure oil to the pilot valve 5 of the oil cylinder to control the main valve assembly 1, and a valve between the rodless oil cavity of the boom oil cylinder 2 and the oil return port of the main valve assembly 1 is opened to allow the hydraulic oil in the rodless oil cavity of the boom oil cylinder 2 to flow back to the oil tank 7.

In this embodiment, the safety oil source valve assembly 3 further includes a pilot pump oil supply branch, an oil inlet end of the pilot pump oil supply branch is connected to the pilot oil pump 9, an oil outlet end of the pilot pump oil supply branch is connected to an oil inlet end of the oil cylinder pilot valve oil supply, and a check valve 304 is disposed on the pilot pump oil supply branch. The pilot pump oil supply branch can be connected with the pilot pump 9 and the cylinder pilot valve 5, and the one-way valve 304 can prevent high-pressure oil in the cylinder oil supply pipeline from flowing back to the pilot pump 9, so that equipment damage is avoided, and the pressure of the high-pressure oil flowing to the cylinder pilot valve 5 is ensured to meet requirements.

In this embodiment, an overflow valve 303 connected to the oil tank 7 is disposed at an oil outlet of the check valve 304 on the pilot pump oil supply branch, so as to prevent excessive hydraulic pressure in the pilot pump oil supply branch and the cylinder oil supply pipeline, and protect the hydraulic equipment from being safe and practical.

In this embodiment, as shown in fig. 1, each component in the safety oil source valve assembly 3 constitutes a modular structure, that is, the modular safety oil source valve assembly 3 is provided with a p4 interface, a p1 interface, a p3 interface and a t1 interface, wherein two ends of the oil cylinder oil supply pipeline are respectively connected to the p4 interface and the p1 interface, two ends of the pilot pump oil supply branch are respectively connected to the p4 interface and the p3 interface, an oil outlet end of the overflow valve 303 is connected to the p1 interface, the energy accumulator 4 is provided at an oil outlet end of the oil cylinder oil supply pipeline, and the pilot pump oil supply branch can supply oil to the energy accumulator 4 to realize energy accumulation. The safe oil source valve component 3 is installed in a modularized mode and is convenient to connect, and the cost is saved by integrating a pipeline for connecting the pilot pump 9 and the oil cylinder pilot valve 5.

The main valve assembly 1 is provided with two working oil ports A, B, a pressure oil port P and an oil return port T, and an oil port A/B of the main valve assembly 1 is respectively communicated with a rod-containing/rodless cavity of the movable arm oil cylinder 2 to form a high-pressure oil loop for providing high-pressure hydraulic oil for the movable arm oil cylinder 2; and a high-pressure pilot oil supply path 6 connected with a p1 interface on the safety oil source valve component 3 is arranged on a pipeline connecting the oil port B of the main valve component 1 and the rodless cavity of the boom cylinder 2.

The spool oil port a/b of the main valve assembly 1 communicates with the hydraulic oil port a1/b1 of the cylinder pilot valve 5 to form a pilot control oil path to the main valve assembly 1, and controls the lift of the boom cylinder 2. The p4 interface of the safety oil source valve assembly 3 is communicated with the p2 of the cylinder pilot valve 5 to form a pilot oil supply path for supplying high-pressure hydraulic oil to the cylinder pilot valve 5. The rodless chamber of the boom cylinder 2 communicates with the p1 port of the relief oil source valve 3 to form a high-pressure pilot oil supply passage 6 that supplies oil to the relief oil source valve 3. The oil tank 7 is communicated with a pressure oil port P of the main valve assembly 1 through the main oil pump 8 to form a high-pressure oil supply path for supplying high-pressure hydraulic oil to the main valve assembly 1, the oil tank 7 is communicated with a port P3 of the safety oil source valve 3 through the pilot pump 9 to form a pilot oil supply path for supplying high-pressure hydraulic oil to the safety oil source valve 3, and the pilot oil supply path is in butt joint with a pilot pump oil supply branch in the safety oil source valve assembly 3. Correspondingly, the oil tank 7 is communicated with an oil return port T of the main valve assembly, a T1 port of the safety oil source valve 3 and a T2 port of the cylinder pilot valve 5 to form an oil return path to the oil tank 7.

The above is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that several variations and modifications can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the utility of the patent.