CN2114720U - Impact-proof separated piston power accumulator - Google Patents

Abstract

The utility model relates to an anti-shock isolated piston accumulator, which is suitable for hydraulic systems with variable working conditions, especially for hydraulic systems with short-period liquid supply. It has an accumulator body, a piston, a liquid storage chamber, and a pressure chamber. It is characterized in that a sealed and pressure-bearing ejector shell is fixed on the upper part of the pressure chamber, and a ejector rod and a return spring are installed in the upper part of the ejector rod. The magnetic body and the Hall magnetic sensor installed on the ejector shell. The sensor controls the unloading of the power source in time, which not only saves energy but also reduces the impact between the piston and the accumulator body, improves the working reliability of the accumulator, and prevents the hydraulic shock of the system caused by the inertia of the piston movement.

Description

The utility model relates to an anti-shock isolated piston accumulator, which is suitable for hydraulic systems with variable working conditions, especially for hydraulic systems with short-period liquid supply.

Various existing hydraulic systems with variable working conditions, such as hydraulic systems of various electro-hydraulic hammers, use isolated piston accumulators to accumulate high-pressure fluid supplied by power sources during non-working cycles to meet short-term high-pressure large-scale hydraulic systems. The need for flow liquid supply, that is, the need for high-frequency strikes by the hammer head. Since the operating frequency of the hydraulic system varies greatly, in order to ensure the normal operation of the system, the accumulator is required to be in the quasi-liquid supply state most of the time, that is, the accumulator is always full. When the isolated piston accumulator is full, the piston in the accumulator is at the upper limit position, and the power source should be unloaded and stop supplying liquid to it, so as to avoid danger caused by excessive overpressure. In the existing hydraulic system with piston accumulator, the unloading method of the power source mostly uses the pressure change (usually rising) as the unloading signal, and indirectly or directly controls the relief valve or the hydraulic system through the pressure relay and other signaling devices. The unloading valve unloads the hydraulic system. But the generation of the pressure rise signal must be the result after the piston in the accumulator is in the upper limit, that is, after the mechanical bumping to the top. Although the method of reserving the overpressure volume can reduce the impact of the roof, firstly, the effective volume of the accumulator will be lost; secondly, the set pressure value will be fluctuating due to the influence of temperature; thirdly, the response frequency of the pressure control element used is too low. It is difficult to adapt to the requirements of high-frequency pressure conversion conditions, so it is difficult to overcome the impact caused by the inertial motion of the piston under high-frequency actions. The contact switch is also used as the position sensor of the accumulator piston. Although it can be adjusted properly to meet the action requirements, it is difficult to avoid the impact caused by the misoperation of the piston due to the contact type, so that the contact switch is damaged. Frequent collisions will affect the structural strength of the accumulator, deform the piston and top cover of the accumulator, cause seal failure, and cause pressure shocks in the hydraulic system, resulting in adverse consequences.

The purpose of this utility model is to invent an accumulator that does not use the pressure change of the hydraulic system as the unloading signal of the hydraulic system so that the piston of the accumulator does not hit the top during work. When the accumulator piston moves to the predetermined position, it can send an unloading signal to unload the power source and stop the liquid supply, avoiding the mechanical impact caused by the untimely unloading of the accumulator piston and reducing the system hydraulic impact caused by it.

The utility model is shown in accompanying drawing 1, and it has accumulator body 1, piston 2, liquid storage chamber 3, pressure chamber 4, it is characterized in that: on the top of pressure chamber 4 is fixedly connected with ejector shell 5, ejector The casing 5 is sealed and pressure-bearing, and a push rod 6 and a return spring 7 are installed in the push rod casing 5 , a magnetic body 8 is installed on the top of the push rod 6 , and a Hall magnetic sensor 9 is installed on the push rod casing 5 .

Accompanying drawing 1 is the structural representation of the utility model.

Accompanying drawing 2 is the schematic diagram that the utility model is connected to hydraulic system. In the figure, there are: hydraulic power source 12, electromagnetic unloading valve 13, check valve 10, liquid tank 11.

The working principle of the utility model is as follows: when the hydraulic power source 12 is working, the high-pressure fluid enters the liquid storage chamber 3 of the accumulator to make the piston 2 move upward. Since a magnetic body 8 is installed on the top of the ejector rod 6, when the ejector rod 6 drives the magnetic body 8 to approach the Hall magnetic sensor 9 mounted on the ejector housing 5, the Hall magnetic sensor 9 outputs a signal. Since the Hall magnetic sensor 9 is connected to the circuit of the electromagnetic unloading valve 13 installed at the outlet of the power source 12, the electromagnetic unloading valve 13 operates under the action of this signal, so that the outlet of the power source 12 is directly communicated with the liquid tank 11 , greatly reducing its output power to achieve the purpose of saving energy. The function of the one-way valve 10 is to prevent the high-pressure liquid in the liquid storage chamber 3 from being released by the electromagnetic unloading valve 13 . When the hydraulic system needs liquid supply or the leakage increases, the liquid capacity of the liquid storage chamber 3 decreases, the piston 2 descends, and the ejector rod 6 also descends under the action of the return spring 7, and the magnetic body 8 and the Hall magnetic sensor 9 When the distance increases, after the sensing distance is exceeded, the output signal of the Hall magnetic sensor 9 disappears, the electromagnetic unloading valve 13 is closed, the power source 12 is reloaded, and the high-pressure fluid enters the liquid storage chamber 3 of the accumulator through the one-way valve 10 middle. The control of the electromagnetic unloading valve 13 by the Hall magnetic sensor 9 can ensure that the piston 2 in the accumulator is basically maintained at a predetermined upper limit position so that the liquid storage chamber 3 is in a state of full liquid.

In the utility model, the Hall magnetic sensor is used to detect the situation that the piston reaches the upper limit position and the unloading action of the electromagnetic unloading valve is controlled by the Hall magnetic sensor. In addition to basically keeping the piston in the accumulator floating at the upper limit position and the liquid storage chamber is always in a state of full liquid, it can also unload the power source when the liquid storage chamber is full to reduce energy loss. Due to the use of the Hall magnetic sensor for non-contact control, there is no impact between the piston and the accumulator body, which does not affect the structural strength of the accumulator, and neither causes the piston to damage the cooperation with the accumulator body due to impact deformation. Accuracy, and the preset pressure value will not be adjusted frequently due to temperature changes, and after the Hall magnetic sensor gives the unloading signal, the piston still has a certain movable space, which reduces the hydraulic shock caused by inertia.

The structure of the present utility model is as shown in accompanying drawing 1, can open a hole at the upper end of accumulator body 1, and push rod housing 5 is affixed thereon. Since the pressure chamber 4 on the top of the accumulator body 1 is connected with high-pressure gas, the fixed connection method should be pressure-resistant and sealed. It can be fixed by welding, or flanged or threaded, and sealed by adding a sealing ring. Hall magnetic sensitive sensor 9 can be contained in the outside of mandrel shell 5, isolates with the high-pressure cavity in it. However, at this time, the corresponding parts of the mandrel shell 5 and the Hall magnetic sensor 9 should be made of non-ferromagnetic materials, such as stainless steel, copper, aluminum and their alloys or other non-metallic materials. It is also possible that the entire ejector rod housing 5 is made of non-ferromagnetic material. In the present invention, the Hall magnetic sensitive sensor 9 can also be installed inside the mandrel housing 5, but at this time the sealing problem of the output lead of the Hall magnetic sensitive sensor 9 should be solved. Standard pressure-resistant sealed joints can be used for connection, or simply seal the lead wires with, for example, epoxy resin. In the utility model, the existing standard products of the magnetic body 8 and the Hall magnetic sensor 9 can be purchased as a set. The magnetic body 8 can also be made by itself according to the needs to adapt to the structural size of the push rod 6 . The distance between the upper end of the ejector rod 6 and the upper end of the inner cavity of the ejector rod housing 5 should be greater than the length of the ejector rod 6 extending into the pressure chamber 4 .

Claims (1)

1, a kind of isolated piston accumulator of protecting against shock, it has accumulation of energy body 1, piston 2, liquid-storing cavity 3, pressure chamber 4, it is characterized in that: be connected with push rod housing 5 on pressure chamber 4 tops, push rod housing 5 seal and pressure bearings are equipped with push rod 6 in push rod housing 5, Returnning spring 7, on push rod 6 tops magnetic 8 is housed, hall magnetic sensor 9 is housed on push rod housing 5.

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