Patent Publication Number: US-2022226917-A1

Title: Electro-hydraulic combined device

Description:
TECHNICAL FIELD 
     The present disclosure relates to the technical field of electro machining equipment, in particular to an electro-hydraulic combined device. 
     BACKGROUND ART 
     Electro machining is a kind of non-traditional machining technology, including spark-erosion machining and electric arc machining, which is widely used in industries such as mold and aerospace components manufacturing. The electro machining can be applied to machine workpieces made of hard material and complex-shapes which are difficult to be processed with traditional cutting methods. The electro machining is usually used to machine electrical conductive material and can machine complex cavities or contours on difficult-to-cut materials, such as titanium alloy, tool steel, carbon steel, and cemented carbide. Generally, the electric arc machining in the electro machining has high machining efficiency, and there is a restriction that a surface machined by the electric arc machining is rough. The machining quality of the spark-erosion machining is higher, whereas has a low efficiency. Since the arc discharge produces erosion craters, it is necessary to subsequently implement a finish machining process such as mechanical milling, to improve the surface quality in the actual application. Under this background, the electro machining and the mechanical machining are combined. That is, there is a demand for a composite machining machine tool that realizes electro machining firstly and then the cutting upon the equipment. In the machine tool, electro machining can be realized by using an electrode shank for electro machining in cooperation with a pulse power supply and a high-speed inner flushing-fluid system, and the precision machining of parts can be realized by using a mechanical milling shank. 
     In the electro machining, the electrode shank for electro machining mainly plays following four roles of mounting a tool electrode, transmitting a rotation of a spindle of a machine tool to the tool electrode, loading power to the tool electrode, and applying high-speed inner flushing fluid to a flushing hole of the tool electrode. That is, the electrode shank for electro machining has four functions of mounting electrode, rotation, electric conduction, and flushing. Therefore, the electrode shank for electro machining is an important component of this type of composite machining machine tool. The existing electrode shank for electro machining, especially an electrode shank for electric arc machining, often requires the spindle of the machine tool to have a function of central flushing; and/or is provided with a power supply through the spindle of the machine tool; and/or has a power supply directly mounted on the shank for electric arc machining. However, not spindles of all machine tools have the function of central flushing. The mounting of the power supply through the spindle of the machine tool also needs an additional and special insulation structure, which increases the complexity of the structure of the spindle of the machine tool. Parts for power and parts for fluid supply need to be manually mounted or removed in a tool changing process even though the power is only loaded onto the shank for electric machining, which further affects the automation degree of the equipment. 
     The electro machining processes that need inner flushing fluid and electrode rotation, such as the electric arc machining and the spark-erosion machining, all need the electrode shank for electro machining and all have the above technical problems. 
     SUMMARY 
     Some embodiments aim to provide an electro-hydraulic combined device, so as to solve the above technical problems in the existing art and improve the usability of electro machining, the applicability to a spindle of a machine tool, and the automation degree of machining. 
     In order to achieve the above-mentioned purpose, some embodiments provide the following solution. 
     The present disclosure provides an electro-hydraulic combined device, including an insulator, an electro-hydraulic joint supply base, a terminal of electro-hydraulic joint supply pipes, and the electro-hydraulic joint supply pipes, where the insulator is fixedly connected with a spindle shell or a spindle base of a spindle of a machine tool; a top end of the electro-hydraulic joint supply base is fixedly connected with the insulator; a connection port of a working fluid suppling pipe and a binding post are arranged on the electro-hydraulic joint supply base; a bottom end of the electro-hydraulic joint supply base is provided with a terminal connection port; the connection port of the working fluid supplying pipe and the terminal connection port are communicated with a first fluid channel in the electro-hydraulic joint supply base; when the terminal connection port is snap-engaged with a top end of the terminal of the electro-hydraulic joint supply pipes, the first fluid channel in the electro-hydraulic joint supply base is jointed with a second fluid channel in the terminal; the second fluid channel in the terminal is further communicated with a flushing fluid container on an electrode shank for electro machining through the electro-hydraulic joint supply pipes; the binding post, the electro-hydraulic joint supply base, the terminal, the electro-hydraulic joint supply pipes, and the electrode shank for electro machining are conductive and electrically conducted; the electrode shank for electro machining and the spindle are insulated from each other. 
     Preferably, the connection port of the working fluid supplying pipe is configured to communicate with a working fluid container, and working fluid in the working fluid container is pumped through the connection port of the working fluid supplying pipe and into the electro-hydraulic joint supply base by a pressure pump. 
     Preferably, the binding post is configured to be electrically connected with a power supplier. 
     Preferably, a joint of the terminal connection port and the terminal is sealed when the terminal connection port is snap-engaged with the top end of the terminal. 
     Preferably, a sealing ring is arranged between the terminal connection port and the terminal to prevent the working fluid from leaking, and the sealing ring is configured to not affect direct contact for electric conduction between the terminal connection port and the terminal. 
     Preferably, the connection port of the working fluid supplying pipe, the first fluid channel in the electro-hydraulic joint supply base, the terminal connection port, the second fluid channel in the terminal, the electro-hydraulic joint supply pipes, and a third fluid channel in the electrode shank for electro machining jointly form a working fluid channel. 
     Preferably, the connection port of the working fluid supplying pipe, the electro-hydraulic joint supply base, the terminal connection port, the terminal, the electro-hydraulic joint supply pipes, the electrode shank for electro machining, and an electrode jointly form an electric conduction channel. 
     Preferably, the electrode shank for electro machining and a connection port of a spindle shank are insulated from each other by disposing an insulation layer therebetween. 
     Compared with the existing art, the following technical effects are achieved by some embodiments. 
     The electro-hydraulic combined device of some embodiments improves the usability of electro machining and applicability to the spindle of the machine tool, and increases the rigidity and the automation degree of the clamping of electrodes for electro machining, which realizes the high integration of the inner flushing working fluid and an electricity connection. The electro-hydraulic combined device of the present disclosure has a compact structure. The electro-hydraulic joint supply base thereof is used to enable a combination of electrical and hydraulic connection ports. Furthermore, the inner and outer structures of the electro-hydraulic combined device have high rigidity, which can greatly improve the rigidity and the machining accuracy of an electrode system for electro machining By means of the flushing fluid container, the functions of mounting the electrode, rotation, electric conduction, and flushing can be realized at the same time. When the electro-hydraulic combined device is used for electro machining, the spindle of the machine tool does not need to have the function of central flushing, and have no additional power loading structure for the electrode. So, fluid supply modules and power supply modules do not need to be removed during replacement of the electrode/cutting shank, so that the tool changing time for the electrode is greatly saved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to more clearly illustrate technical solutions in the embodiments of the present application or in the prior art, a brief introduction to the accompanying drawings required for the embodiment will be provided below. Obviously, the accompanying drawings in the following description are only some of the embodiments of the present disclosure. Those of ordinary skill in the art would also be able to derive other drawings from these drawings without making creative efforts. 
         FIG. 1  is a first schematic structural diagram of an electro-hydraulic combined device according to the present disclosure; 
         FIG. 2  is a second schematic structural diagram of an electro-hydraulic combined device according to the present disclosure; and 
         FIG. 3  is a sectional view of a detail part A in  FIG. 2 . 
     
    
    
     In the figures:  1  spindle shell;  2  insulator;  3  electro-hydraulic joint supply base;  4  connection port of a working fluid supplying pipe;  5  binding post;  6 : terminal connection port;  7  sealing ring;  8  terminal of electro-hydraulic joint supply pipes;  9  connection port of a spindle shank;  10  universal spacing groove;  11  hollow rotating shaft;  12  rotating mechanism;  13  electrode spacing groove;  14  electrode connection port;  15  flushing fluid container; and  16  electro-hydraulic joint supply pipe. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention. 
     Some embodiments aim to provide an electro-hydraulic combined device, so as to solve the above technical problems in the existing art and improve the usability of electro machining and the applicability to a spindle of a machine tool. 
     In order to make the objectives, features, and advantages mentioned above of the present disclosure more apparent and easily understood, the present disclosure will be further described in detail below with reference to the drawings and particular implementations. 
     As shown in  FIG. 1  to  FIG. 3 , the electro-hydraulic combined device of the present embodiment includes an insulator  2 , an electro-hydraulic joint supply base  3 , a terminal of electro-hydraulic joint supply pipes  8 , a flushing fluid container  15 , and two electro-hydraulic joint supply pipes  16 . 
     The insulator  2  is fixedly connected with a spindle shell  1  of a spindle of the machine tool. It should be noted that the insulator  2 , such as a spindle seat, is a non-rotatable part on the spindle. A top end of the electro-hydraulic joint supply base  3  is fixedly connected with the insulator  2 . A connection port of a working fluid supplying pipe  4  and a binding post  5  are arranged on the electro-hydraulic joint supply base  3 . The connection port of the working fluid supplying pipe  4  communicates with a working fluid container. A pressure pump is arranged on a pipeline between the connection port of the working fluid supplying pipe  4  and the working fluid container. And, working fluid in the working fluid container is pumped through the connection port of the working fluid supplying pipe  4  and into the electro-hydraulic joint supply base  3  by the pressure pump. The binding post  5  is used to be electrically connected with a power supply. 
     A bottom end of the electro-hydraulic joint supply base  3  is provided with a terminal connection port  6 . The connection port of the working fluid supplying pipe  4  and the terminal connection port  6  communicate with a fluid channel in the electro-hydraulic joint supply base  3 . When the terminal connection port  6  is snap-engaged or coupled with a top end of the terminal of the electro-hydraulic joint supply pipes  8 , the fluid channel in the electro-hydraulic joint supply base  3  communicates with a fluid channel in the terminal  8 . A joint of the terminal connection port  6  and the terminal  8  is sealed. A sealing ring  7  is arranged between the terminal connection port  6  and the terminal  8 . An area of the sealing ring  7  is less than an area of a contact surface between the terminal connection port  6  and the terminal  8 . 
     The fluid channel of the terminal  8  further communicates with a flushing fluid container  15  on an electrode shank for electro machining through the two electro-hydraulic joint supply pipes  16 . The electrode shank for electro machining includes the flushing fluid container  15 , rotating mechanisms  12 , a hollow rotating shaft  11 , and an electrode connection port  14 . The hollow rotating shaft  11  is fixedly connected with the spindle through a connection port of the spindle shank  9 , and is capable of being driven by the spindle to rotate. An electrode is fixedly connected with a bottom end of the hollow rotating shaft  11  through the electrode connection port  14 . A fluid guide hole communicating with the flushing fluid container  15  is formed in a side wall of the hollow rotating shaft  11 . The fluid guide hole communicates with a fluid channel inside the hollow rotating shaft  11 . The fluid channel inside the hollow rotating shaft  11  communicates with the electrode through a working fluid channel in the electrode connection port  14  via a shaft end opening. The electrode connection port  14  is of a hollow structure. And the working fluid channel and an electrode fixing surface are arranged in the middle. And, the electrode is fixed at the bottom end of the hollow rotating shaft  11  through the electrode connection port  14 . An upper end and a lower end of the flushing fluid container container  15  are each provided with one rotating mechanism  12 . The hollow rotating shaft  11  is rotatably fitted with the flushing fluid container container  15  through the two rotating mechanisms  12 . The rotating mechanisms  12  seal the upper end and the lower end of the flushing fluid container  15 . The rotating mechanisms  12  are sealed itself. The flushing fluid container  15  is connected with outer rings of the rotating mechanisms  12 . The hollow rotating shaft  11  is connected with inner rings of the rotating mechanisms  12 . The two rotating mechanisms  12  respectively seal the upper end and the lower end of the flushing fluid container  15 . 
     The binding post  5 , the electro-hydraulic joint supply base  3 , the terminal  8 , the electro-hydraulic joint supply pipes  16 , the flushing fluid container  15 , the rotating mechanisms  12 , and the hollow rotating shaft  11  are all conductive and electrically conducted. The electrode shank and the connection port of the spindle shank  9  are insulated from each other by means of providing an insulation layer (or the insulation may be realized by other solutions as long as it is capable of ensuring that the machining electrode shank and the spindle are insulated from each other) between the electrode shank and the connection port of the spindle shank  9 . A universal spacing groove  10  is formed on an outer side wall of the connection port of the spindle shank  9 , and an electrode spacing groove  13  is formed on an outer side wall of the flushing fluid container  15 . 
     In the present embodiment, the electro-hydraulic joint supply base  3  is connected and fixed to the spindle seat or a non-rotatable part on an end surface of the spindle or a side surface through an insulation bottom plate and is kept stationary during electro machining. The electro-hydraulic joint supply base  3  is of a hollow structure and is made of a conductive material. The connection port of the working fluid supplying pipe  4  is formed in a side surface or a top surface of the electro-hydraulic joint supply base  3 . A working fluid supplying pipe is connected with the connection port of the working fluid supplying pipe  4 . During machining, the working fluid enters a fluid channel in the electro-hydraulic joint supply base  3  through the connection port of the working fluid supplying pipe  4 . The electro-hydraulic joint supply base  3  is additionally provided with the power binding post  5 . A power line for electro machining is connected with the binding post  5 . During machining, an output current of a pulse power supply flows through the entire electro-hydraulic joint supply base  3  via the binding post  5 . The lower part of the electro-hydraulic joint supply base  3  is provided with the terminal connection port  6  of an electrode clamping shank. The terminal connection port  6  is of a hollow structure, so as to allow the terminal  8  to be plugged. During mounting of an electrode shank, the terminal  8  is plugged into the terminal connection port  6  to form a channel for the working fluid and to conduct current. After the terminal is plugged into the terminal connection port  6 , under the action of a tool changing mechanism or a manually applied thrust, an outer side surface of the terminal  8  and an inner surface of the terminal connection port  6  are in full contact with each other, and thus a pressure therebetween may be generated, so as to ensure sealing and full-contact electric conduction. 
     An electric conduction channel in the electro-hydraulic combined device of the present embodiment is provided, and the electricity flows through the binding post  5 , the electro-hydraulic joint supply base  3 , the terminal connection port  6 , the terminal  8 , the electro-hydraulic joint supply pipes  16 , the flushing fluid container  15 , the rotating mechanisms  12 , the hollow rotating shaft  11 , the electrode connection port  14 , and the electrode in sequence. The working fluid channel is provided, and the working fluid flows through the pressure pump, the working fluid supplying pipe, the connection port of the working fluid supplying pipe  4 , the fluid channel in the electro-hydraulic joint supply base  3 , the terminal connection port  6 , the terminal  8 , the electro-hydraulic joint supply pipes  16 , the flushing fluid container  15 , the fluid guide hole in the side wall of the hollow rotating shaft  11 , the fluid channel in the hollow rotating shaft  11 , the electrode connection port  14 , and the electrode in sequence. The arrows in  FIG. 3  represent a flowing direction of the working fluid in the electro-hydraulic joint supply base  3 . It should be noted that the flushing fluid container  15  is overall sealed, and the middle part of the hollow rotating shaft  11  is immersed in the working fluid in the flushing fluid container  15 . So, even if the hollow rotating shaft  11  ceaselessly rotates, the working fluid in the flushing fluid container  15  will also continuously enters the fluid channel in the hollow rotating shaft  11  through the fluid guide hole. 
     A top end of the terminal of electro-hydraulic joint supply pipes  8  has a certain taper, which plays an introduction role and facilitates directly enabling fast connection with the terminal connection port  6 , Furthermore, after the connection, the electro-hydraulic joint supply pipes  16  provide an auxiliary support, thus improving the rigidity and accuracy of the system. Because a limit fork on a tool magazine base clamping unit as well as a limit fork on a tool changing mechanical arm are coupled with the electrode spacing groove  13  on the outer wall of the flushing fluid container  15 , an angle between the hollow rotating shaft  11  and the flushing fluid container  15  below the electrode shank is fixed before and after the tool changing. In this way, it is possible to avoid a failure of plugging the tool into an electrode connection port due to the relative rotation between the hollow rotating shaft  11  and the flushing fluid container  15  before and after clamping. 
     The electro-hydraulic combined device of the present embodiment may further enhance the flushing effect and make machining more stable in addition to providing a connection method for the power supply. The electrode shank and the electro-hydraulic joint supply base  3  in the electrode-hydraulic joint supply device of the present embodiment have compact sizes and will not affect the cutting function of the existing machine tool. The shank may be very short, which has little impact on an axial stroke (z-directional stroke) of the machine tool. Thus, the machining range of the machine tool is greatly ensured. Above all, the present embodiment is favorable for realizing an automatic tool changing function, and the electro machining including electric arc machining and the spark-erosion machining is highly integrated with the traditional cutting on one machine tool. 
     In the description of the present disclosure, it should be noted that orientations or positional relationships indicated by the terms “top”, “bottom” and the like are based on orientations or positional relationships as shown in the drawings, and are only for the purpose of facilitating and simplifying the description of the present disclosure instead of indicating or implying that devices or elements indicated must have particular orientations, and be constructed and operated in the particular orientations, so that these terms should not be construed as limiting the present disclosure. 
     In this specification, specific embodiments aim to illustrate the principle and implementation of the present disclosure. The explanation of the above embodiments is only used to help understand the method and its core idea of the present disclosure. According to the idea of the present disclosure, there will be some changes in the specific implementation and application scope for those skilled in the art. To sum up, the contents of this specification should not be construed as limiting the present disclosure.