Plunger rod device for vacuum induction furnace launder system

Abstract

The invention discloses a plunger rod device for a launder system of a vacuum induction furnace, which comprises a hydraulic driving assembly, a plunger actuator and a launder, the hydraulic driving assembly comprises a hydraulic cylinder, a coupler and a push rod, and the hydraulic cylinder is fixed on a mounting flange on the top surface of a tundish of the launder through a sealing seat; the interior of a tundish of the launder is in a vacuum state, and the hydraulic cylinder is located outside the tundish of the launder and is in vacuum isolation with the tundish of the launder through the sealing seat. An extension rod of the hydraulic cylinder faces downwards, and the tail end of the extension rod of the hydraulic cylinder is connected with a push rod through a coupler; the plunger actuator comprises a stop flange, a main body support, a rocker arm, a transmission plate, a plunger rod and two lever arm shafts. According to the plunger rod device for the vacuum induction furnace launder system, the problems that a traditional nozzle for the vacuum induction furnace launder system is not thorough in sealing, high in maintenance strength and short in service life are effectively solved.

Description

Technical Field

[0001] The invention relates to a plunger rod device for a launder system of a vacuum induction furnace. Background Art

[0002] The vacuum induction furnace is a complete set of vacuum smelting equipment that uses the principle of medium frequency induction heating in a vacuum environment to melt metals. It is also one of the important vacuum smelting equipment in the current metallurgical field for producing special alloy materials such as nickel-based high-temperature alloys, nuclear alloys, stainless steel, and ultra-high strength steel.

[0003] At present, with the vigorous development of the steel industry, vacuum induction furnaces are also changing with each passing day, especially in the field of special steel smelting, which has very demanding requirements on the mechanical properties of steel materials. These materials are often used in cutting-edge high-tech industries such as aerospace, satellite aerospace, etc. For this reason, we are concentrating on studying the performance and structure of vacuum melting furnaces from various angles such as ergonomics, energy consumption engineering, degree of automation, and green environmental protection. Here, the hot runner insertion device has attracted widespread attention in the field of special steel metallurgy at home and abroad for the production of high-quality electrodes to reduce slag and inclusions. At present, there are various disadvantages in the vacuum system of vacuum induction melting furnaces: it is easy to be polluted by gas during pouring, the product quality is low, the production cost is high, and there is a risk of metal entering the mold chamber. This is closely related to the use of long runners and built-in plunger systems or no plunger systems in the vacuum systems of vacuum induction furnaces. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a plunger rod device for a launder system of a vacuum induction furnace, which has a good switching blocking effect on the launder, a long service life, and a high degree of automation, and can effectively improve the quality of vacuum smelting products, improve the stability of the material of vacuum smelting products, reduce the labor intensity of workers, improve continuous production efficiency, and achieve energy conservation and emission reduction, green and high efficiency; it effectively solves the problems of low service life, high maintenance intensity, and low material quality of the traditional plunger mechanism used in the vacuum system of a vacuum induction furnace.

[0005] The technical solution to achieve the above object is: a plunger rod device for a launder system of a vacuum induction furnace, comprising a hydraulic drive assembly, a plunger actuator and a launder, wherein:

[0006] The hydraulic drive assembly includes a hydraulic cylinder, a coupling and a push rod. The hydraulic cylinder is fixed to a mounting flange on the top surface of the tundish of the flow channel through a sealing seat. The tundish of the flow channel is in a vacuum state. The hydraulic cylinder is located outside the tundish of the flow channel and is vacuum-isolated from the tundish of the flow channel through the sealing seat. The extension rod of the hydraulic cylinder is directed downward, and the end of the extension rod of the hydraulic cylinder is connected to a push rod through a coupling.

[0007] The plunger actuator includes a stop flange, a main body bracket, a rocker arm, a transmission plate, a plunger rod and two lever arm shafts. The main body bracket is fixed to the side wall of the flow channel through a mounting frame. A support column guide hole and two groups of lever arm shaft guide holes are vertically opened on the main body bracket. The stop flange is composed of a load-bearing flange and a support column connected to its bottom end. The support column can be inserted into the support column guide hole movably up and down. The stop flange is located directly below the push rod, and the push rod is coaxially arranged with the support column; the two lever arm shafts are one by one. Correspondingly inserted into the two groups of lever arm shaft guide holes, and each lever arm shaft moves up and down along the corresponding lever arm shaft guide hole; the middle part of the rocker arm is rotatably arranged at the bottom end of the main body bracket through a pin shaft, and the rocker arm performs rotational reciprocating motion around the pin shaft; one end of the rocker arm is connected to the bottom end of the support column, and the other end is respectively connected to the bottom ends of the two lever arm shafts; one end of the transmission plate is respectively connected to the top ends of the two lever arm shafts, and the other end is connected to the top end of the plunger rod, and the plunger rod is aligned with the casting nozzle of the flow channel.

[0008] The above-mentioned plunger rod device for the launder system of a vacuum induction furnace, wherein the two lever arm shafts are arranged parallel to each other, and the bottom ends of the two lever arm shafts are connected to counterweight blocks.

[0009] The above-mentioned plunger rod device for a launder system of a vacuum induction furnace, wherein the bottom end of the plunger rod is provided with a ceramic tip.

[0010] The above-mentioned plunger rod device for the launder system of a vacuum induction furnace, wherein a U-shaped groove is opened at one end of the transmission plate, the top end of the plunger rod is arranged in the U-shaped groove, and can be adjusted forward and backward along the U-shaped groove, and the plunger rod and the casting nozzle of the launder are kept in a coaxial state.

[0011] In the above-mentioned plunger rod device for a launder system of a vacuum induction furnace, a sealing ring is provided between the contact surface of the hydraulic cylinder and the sealing seat.

[0012] In the above-mentioned plunger rod device for a launder system of a vacuum induction furnace, the bearing flange of the stop flange is made of graphite bronze material.

[0013] The above-mentioned plunger rod device for the flow channel system of a vacuum induction furnace, wherein, during pouring, the hydraulic cylinder drives the push rod downward through the coupling to knock the bearing flange of the stop flange, and the support column of the stop flange moves downward. During the downward movement of the support column, the two lever arm shafts are driven to move upward through the rocker arm, and then the plunger rod is driven to move upward through the transmission plate, away from the pouring nozzle of the flow channel; when the pouring stops, the hydraulic cylinder drives the push rod to retract through the coupling, stops the pressure applied to the stop flange, and the plunger actuator returns to its initial state, and the plunger rod moves downward under the action of gravity to block the pouring nozzle of the flow channel.

[0014] The above-mentioned plunger rod device for a launder system of a vacuum induction furnace, wherein the hydraulic drive assembly further comprises a first electromagnetic reversing valve, and the first electromagnetic reversing valve is provided with a first hydraulic interface and a second hydraulic interface;

[0015] The hydraulic cylinder comprises an upper cylinder chamber, a piston and a lower cylinder chamber, the upper cylinder chamber is provided with an upper hydraulic interface, and the lower cylinder chamber is provided with a lower hydraulic interface;

[0016] The upper hydraulic interface of the upper cylinder chamber is connected to the first hydraulic interface of the first electromagnetic reversing valve through the upper reciprocating air path; the lower hydraulic interface of the lower cylinder chamber is connected to the second hydraulic interface of the first electromagnetic reversing valve through the lower reciprocating air path;

[0017] The first electromagnetic reversing valve communicates with a hydraulic controller, and the hydraulic controller controls the movement direction of the hydraulic cylinder by controlling the first electromagnetic reversing valve.

[0018] The above-mentioned plunger rod device for a vacuum induction furnace flow channel system, wherein, also includes a bladder accumulator, the outlet of the bladder accumulator is connected to the upper reciprocating air path and the lower reciprocating air path of the hydraulic cylinder respectively through a second electromagnetic reversing valve, and the outlet of the bladder accumulator is flow-controlled by a throttle valve, the bladder accumulator is switch-controlled by a manual plate ball valve, the second electromagnetic reversing valve communicates with the hydraulic controller, and the hydraulic controller controls whether to use the bladder accumulator to work by controlling the second electromagnetic reversing valve.

[0019] The above-mentioned plunger rod device for the flow channel system of a vacuum induction furnace, wherein, it also includes a third solenoid reversing valve, the upper cylinder chamber is provided with an upper proximity switch, and the lower cylinder chamber is provided with a lower proximity switch; the third solenoid reversing valve is connected to the upper reciprocating air circuit and the lower reciprocating air circuit respectively, and the third solenoid reversing valve is provided with a first control signal end corresponding to the upper reciprocating air circuit interface and a second control signal end corresponding to the lower reciprocating air circuit interface, the upper proximity switch, the lower proximity switch, the first control signal end and the second control signal end all communicate with the hydraulic controller through signal terminals, and the hydraulic controller switches the entire hydraulic drive assembly by controlling the third solenoid reversing valve.

[0020] The plunger rod device for the launder system of a vacuum induction furnace of the present invention drives the push rod of the hydraulic assembly to be coaxially fixed with the stop flange in the plunger actuator, the hydraulic cylinder is located outside the tundish, and a sealing seat is used for vacuum sealing; the plunger actuator is fixed to the side of the launder body through a bearing, and the plunger actuator transmits movement and changes the direction of movement through the bottom rocker arm. Finally, when the plunger rod descends, it blocks the pouring nozzle of the launder to achieve the effect of closing. The plunger actuator is ensured to move vertically up and down through the guide hole. The principle is to switch the plunger rod on and off at the launder nozzle through the hydraulic cylinder, control the metal solution to enter the ingot casting chamber, and achieve the predetermined process effect. At the same time, for the design of the launder length, a shorter launder structure is used while maintaining the slag blocking function to achieve a lower pouring superheat and prevent the occurrence of frozen steel. This design can effectively improve the quality of vacuum melting products, improve the stability of the material of vacuum melting products, reduce the labor intensity of workers, improve continuous production efficiency, and achieve energy conservation and emission reduction, green and high efficiency; it effectively solves the problems of low service life, high maintenance intensity and low material quality of the plunger mechanism traditionally used in the vacuum system of vacuum induction furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a plunger rod device for a launder system of a vacuum induction furnace according to the present invention;

[0022] Figure 2 This is the electrical schematic diagram of the hydraulic cylinder. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the specific implementation methods thereof are described in detail below in conjunction with the accompanying drawings:

[0024] See also Figure 1 and Figure 2 The best embodiment of the present invention is a plunger rod device for a launder system of a vacuum induction furnace, comprising a hydraulic drive assembly A, a plunger actuator B and a launder C.

[0025] The hydraulic drive assembly A comprises a hydraulic cylinder 1, a coupling 4 and a push rod 5. The hydraulic cylinder 1 is fixed to a mounting flange 3 on the top surface of the tundish of the flow channel C through a sealing seat 2. A sealing ring is provided between the contact surfaces of the hydraulic cylinder 1 and the sealing seat 2.

[0026] The middle package of flow trough C is in a vacuum state. The hydraulic cylinder 1 is located outside the middle package of flow trough C and is vacuum-isolated from the middle package of flow trough C through the sealing seat 2. The extension rod of the hydraulic cylinder 1 is directed downward, and the end of the extension rod of the hydraulic cylinder 1 is connected to the push rod 5 through the coupling 4.

[0027] The plunger actuator B includes a stop flange 6, a main frame 7, a rocker arm 8, a transmission plate 12, a plunger rod 13 and two arm shafts 11. The main frame 7 is fixed to the side wall of the flow channel C through a mounting frame 10. The main frame 7 is vertically provided with a support column guide hole and two sets of arm shaft guide holes. The entire plunger actuator C can be adjusted left and right in horizontal position through the bearings and bolts on the mounting frame 10, and the final positioning and fixing is achieved through the locking screws on the mounting frame 10.

[0028] The stop flange 6 is composed of a load-bearing flange 61 and a support column 62 connected to its bottom end. The load-bearing flange 61 at the top is made of graphite bronze material, which has the characteristics of high load-bearing capacity to improve the service life of this mechanism; the support column 62 can be inserted into the support column guide hole movably up and down, and the stop flange 6 is located directly below the push rod 5, and the push rod 5 and the support column 62 are coaxially arranged to improve the mechanical properties; the push rod 5 is equivalent to extending the extension rod of the hydraulic cylinder 1. When the extension rod of the hydraulic cylinder 1 is extended, the movement can be transmitted to the stop flange 6 through the push rod 5, and the support column 62 can only make vertical reciprocating motion up and down along the support column guide hole.

[0029] The two arm shafts 11 are inserted into the two groups of arm shaft guide holes in a one-to-one correspondence, and each arm shaft 11 reciprocates up and down along the corresponding arm shaft guide hole. The two arm shafts 11 are arranged parallel to each other, and the bottom ends of the two arm shafts 11 are connected with a counterweight block 9, which has two functions. The first function is to ensure that the two arm shafts 11 can move synchronously, and the second function is to adjust the counterweight to counteract the buoyancy of the liquid metal in the flow channel C to ensure the sealing effect of the plunger rod 13 on the casting nozzle 14.

[0030] The middle part of the rocker arm 8 is rotatably arranged at the bottom end of the main bracket 7 through a pin shaft, and the rocker arm 8 performs rotational reciprocating motion around the pin shaft; one end of the rocker arm 8 is connected to the bottom end of the support column 62, and the other end is respectively connected to the bottom ends of the two lever arm shafts 11; through this rocker arm 8, the vertical movement direction of the stop flange 6 can be reversely transmitted to the lever arm shaft 11, when the stop flange 6 moves downward, the lever arm shaft 11 moves upward; conversely, when the stop flange 6 moves upward, the lever arm shaft 11 moves downward.

[0031] One end of the transmission plate 12 is connected to the top ends of the two lever arm shafts 11 respectively, and the other end is connected to the top end of the plunger rod 13, and the plunger rod 13 is aligned with the casting nozzle 14 of the flow channel.

[0032] The transmission plate 12 and the arm shaft 11 can move up and down synchronously. A U-shaped groove is opened at the other end of the transmission plate 12. The U-shaped groove is used to install the plunger rod 13. The installation position of the plunger rod 13 can be adjusted forward and backward along the U-shaped groove. The ultimate goal is to align the plunger rod 13 with the casting nozzle of the flow channel and maintain a coaxial state. By using the plunger rod 13 to seal the casting nozzle 14, the purpose of preventing molten metal from entering the mold chamber is achieved.

[0033] The bottom end of the plunger rod 13 is provided with a ceramic tip for sealing the pouring nozzle 14 .

[0034] The plunger rod device for the flow channel system of a vacuum induction furnace of the present invention, when pouring, the hydraulic cylinder 1 drives the push rod 5 to move downward through the coupling 4, knocks the bearing flange 61 of the stop flange 6, and the support column 62 of the stop flange 6 moves downward. During the downward movement of the support column 62, the two lever arm shafts 11 are driven to move upward at the same time through the rocker arm 8, and then the plunger rod 13 is driven to move upward through the transmission plate 12, away from the pouring nozzle 14 of the flow channel C, so that the metal liquid in the flow channel C can enter the casting mold room for the next step; when the pouring is stopped, the hydraulic cylinder 1 drives the push rod 5 to retract through the coupling 4, stops the pressure applied to the stop flange 6, the plunger actuator returns to the initial state, and the plunger rod 13 moves downward under the action of gravity to block the pouring nozzle 14 of the flow channel C, preventing the metal liquid from entering the casting mold room.

[0035] The plunger rod device for the launder system of a vacuum induction furnace of the present invention can realize left-right adjustment of the entire plunger actuator C in horizontal position through the bearings and bolts on the mounting frame 10. At the same time, the plunger rod 13 can also be adjusted forward and backward through the U-shaped groove on the transmission plate 12 to increase the sealing performance of the pouring nozzle 14 of the launder C. The length of the launder C is designed to be as short as possible, and two major purposes are achieved at the same time, which is to consider both the effective removal of large-sized slag and the realization of a lower pouring superheat (which will reduce the solubility of nitrogen and reduce the inclusions of nitrides.) and to prevent the occurrence of frozen steel. In this embodiment,

[0036] Unless the entire system is acted upon by the hydraulic cylinder, the plunger rod 13 is always in contact with the pouring nozzle 14 of the launder C. If the plunger rod 13 is stuck in the open position, the tundish of the launder can still be pushed back into the tundish chamber for maintenance without hitting the push rod 5 of the hydraulic drive assembly.

[0037] The plunger rod device for the flow channel system of a vacuum induction furnace of the present invention, the hydraulic drive component may also include a first solenoid reversing valve 1, the first solenoid reversing valve 15 is provided with a first hydraulic interface and a second hydraulic interface; the hydraulic cylinder 1 includes an upper cylinder chamber 31, a piston 32 and a lower cylinder chamber 33, the upper cylinder chamber 31 is provided with an upper hydraulic interface, and the lower cylinder chamber 33 is provided with a lower hydraulic interface; the upper hydraulic interface of the upper cylinder chamber 31 is connected to the first hydraulic interface of the first solenoid reversing valve 15 through an upper reciprocating air circuit 16; the lower hydraulic interface of the lower cylinder chamber 33 is connected to the second hydraulic interface of the first solenoid reversing valve 15 through a lower reciprocating air circuit 17; the first solenoid reversing valve 15 communicates with the hydraulic controller, and the hydraulic controller controls the movement direction of the hydraulic cylinder 1 by controlling the first solenoid reversing valve 15.

[0038] The plunger rod device for the flow channel system of a vacuum induction furnace of the present invention may, as an optimization, further include a bladder accumulator 18, the outlet of the bladder accumulator 18 being respectively connected to the upper reciprocating air path 16 and the lower reciprocating air path 27 of the hydraulic cylinder 1 through a second solenoid reversing valve 19, and the outlet of the bladder accumulator 18 being flow-controlled through a throttle valve 20, the bladder accumulator 18 being switch-controlled through a manual plate ball valve 22, the second solenoid reversing valve 19 communicating with the hydraulic controller, and the hydraulic controller controlling whether to use the bladder accumulator 18 to work by controlling the second solenoid reversing valve 19.

[0039] The plunger rod device for the launder system of a vacuum induction furnace of the present invention may further include, as an optimization, a third electromagnetic reversing valve 21, an upper cylinder chamber 31 is provided with an upper proximity switch, and a lower cylinder chamber 33 is provided with a lower proximity switch; the third electromagnetic reversing valve 21 is connected to the upper reciprocating gas circuit 16 and the lower reciprocating gas circuit 17 respectively, and the third electromagnetic reversing valve 21 is provided with a first control signal end corresponding to the upper reciprocating gas circuit interface and a second control signal end corresponding to the lower reciprocating gas circuit interface, and the upper proximity switch, the lower proximity switch, the first control signal end and the second control signal end are all communicated with the hydraulic controller through the signal terminal, and the hydraulic controller switches the entire hydraulic drive assembly by controlling the third electromagnetic reversing valve 21. When the upper proximity switch / lower proximity switch detects that the piston is in place, the upper proximity switch / lower proximity switch feeds back a signal to the hydraulic controller, and the hydraulic controller controls the third electromagnetic reversing valve 21 to close, and the hydraulic drive assembly stops retracting / pressing down.

[0040] The plunger rod device for the launder system of a vacuum induction furnace of the present invention not only improves the quality of production materials, but also improves the service life and stability of the mechanism. It makes the filtering and discharge of the casting nozzle 14 of the launder C more controllable, and the superheat of the metal liquid in the launder C is higher to achieve lower production costs and higher material quality.

[0041] The plunger rod device for the launder system of a vacuum induction furnace of the present invention adopts a hydraulic cylinder 1 to control the lifting and lowering of the plunger rod 13, so the degree of automation is high, the labor intensity of workers is low, the requirements on human factors are low, and the ergonomics is humanized and simplified, and the operation is intuitive and easy. At the same time, the entire hydraulic cylinder is located in a conventional environment, which ensures the reliability of the equipment, makes the equipment more operable, and the maintenance of the equipment is convenient and simple, and the operating cost is low.

[0042] In summary, the plunger rod device for the launder system of a vacuum induction furnace of the present invention improves the performance and automation of the vacuum induction furnace, improves the quality of vacuum smelting products, improves the stability of the material of vacuum smelting products, reduces the labor intensity of workers, expands the continuous production efficiency, and achieves energy conservation and emission reduction, green and high efficiency. It effectively solves the problems of incomplete nozzle sealing, high maintenance intensity and short service life of the traditional launder system of a vacuum induction furnace.

[0043] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A plunger rod device for a launder system of a vacuum induction furnace, characterized in that: It includes a hydraulic drive assembly, a plunger actuator and a flow channel, wherein: The hydraulic drive assembly includes a hydraulic cylinder, a coupling and a push rod. The hydraulic cylinder is fixed to a mounting flange on the top surface of the tundish of the flow channel through a sealing seat. The tundish of the flow channel is in a vacuum state. The hydraulic cylinder is located outside the tundish of the flow channel and is vacuum-isolated from the tundish of the flow channel through the sealing seat. The extension rod of the hydraulic cylinder is directed downward, and the end of the extension rod of the hydraulic cylinder is connected to a push rod through a coupling. The plunger actuator includes a stop flange, a main body bracket, a rocker arm, a transmission plate, a plunger rod and two lever arm shafts. The main body bracket is fixed to the side wall of the flow channel through a mounting frame. A support column guide hole and two groups of lever arm shaft guide holes are vertically opened on the main body bracket. The stop flange is composed of a load-bearing flange and a support column connected to its bottom end. The support column can be inserted into the support column guide hole movably up and down. The stop flange is located directly below the push rod, and the push rod is coaxially arranged with the support column; the two lever arm shafts are one by one. Correspondingly inserted into the two groups of lever arm shaft guide holes, and each lever arm shaft moves up and down along the corresponding lever arm shaft guide hole; the middle part of the rocker arm is rotatably arranged at the bottom end of the main body bracket through a pin shaft, and the rocker arm performs rotational reciprocating motion around the pin shaft; one end of the rocker arm is connected to the bottom end of the support column, and the other end is respectively connected to the bottom ends of the two lever arm shafts; one end of the transmission plate is respectively connected to the top ends of the two lever arm shafts, and the other end is connected to the top end of the plunger rod, and the plunger rod is aligned with the casting nozzle of the flow channel.

2. A plunger rod device for a launder system of a vacuum induction furnace according to claim 1, characterized in that: The two lever arm shafts are arranged parallel to each other, and the bottom ends of the two lever arm shafts are connected with counterweight blocks.

3. The plunger rod device for a launder system of a vacuum induction furnace according to claim 1, characterized in that: The bottom end of the plunger rod has a ceramic tip.

4. The plunger rod device for a launder system of a vacuum induction furnace according to claim 1, characterized in that: A U-shaped groove is formed at one end of the transmission plate, the top end of the plunger rod is arranged in the U-shaped groove and can be adjusted forward and backward along the U-shaped groove, and the plunger rod and the casting nozzle of the flow channel are kept in a coaxial state.

5. The plunger rod device for a launder system of a vacuum induction furnace according to claim 1, characterized in that: A sealing ring is arranged between the contact surface of the hydraulic cylinder and the sealing seat.

6. The plunger rod device for a launder system of a vacuum induction furnace according to claim 1, characterized in that: The bearing flange of the stop flange is made of graphite bronze material.

7. The plunger rod device for a launder system of a vacuum induction furnace according to claim 1, characterized in that: During pouring, the hydraulic cylinder drives the push rod downward through the coupling to knock the load-bearing flange of the stop flange, and the support column of the stop flange moves downward. During the downward movement of the support column, the two lever arm shafts are driven upward through the rocker arm, and then the plunger rod is driven upward through the transmission plate and away from the pouring nozzle of the flow channel; when the pouring stops, the hydraulic cylinder drives the push rod to retract through the coupling, stops the pressure applied to the stop flange, and the plunger actuator returns to its initial state. The plunger rod moves downward under the action of gravity to block the pouring nozzle of the flow channel.

8. The plunger rod device for a launder system of a vacuum induction furnace according to claim 1, characterized in that: The hydraulic drive assembly further includes a first electromagnetic reversing valve, on which a first hydraulic interface and a second hydraulic interface are provided; The hydraulic cylinder comprises an upper cylinder chamber, a piston and a lower cylinder chamber, the upper cylinder chamber is provided with an upper hydraulic interface, and the lower cylinder chamber is provided with a lower hydraulic interface; The upper hydraulic interface of the upper cylinder chamber is connected to the first hydraulic interface of the first electromagnetic reversing valve through the upper reciprocating air path; the lower hydraulic interface of the lower cylinder chamber is connected to the second hydraulic interface of the first electromagnetic reversing valve through the lower reciprocating air path; The first electromagnetic reversing valve communicates with a hydraulic controller, and the hydraulic controller controls the movement direction of the hydraulic cylinder by controlling the first electromagnetic reversing valve.

9. The plunger rod device for a launder system of a vacuum induction furnace according to claim 8, characterized in that: It also includes a bladder accumulator, the outlet of which is connected to the upper reciprocating air path and the lower reciprocating air path of the hydraulic cylinder respectively through a second electromagnetic reversing valve, and the outlet of the bladder accumulator is flow-controlled by a throttle valve, the bladder accumulator is switch-controlled by a manual plate ball valve, the second electromagnetic reversing valve communicates with the hydraulic controller, and the hydraulic controller controls whether to use the bladder accumulator to work by controlling the second electromagnetic reversing valve.

10. A plunger rod device for a launder system of a vacuum induction furnace according to claim 8 or 9, characterized in that: It also includes a third electromagnetic reversing valve, the upper cylinder chamber is provided with an upper proximity switch, and the lower cylinder chamber is provided with a lower proximity switch; the third electromagnetic reversing valve is connected to the upper reciprocating air circuit and the lower reciprocating air circuit respectively, and the third electromagnetic reversing valve is provided with a first control signal end corresponding to the upper reciprocating air circuit interface and a second control signal end corresponding to the lower reciprocating air circuit interface, the upper proximity switch, the lower proximity switch, the first control signal end and the second control signal end all communicate with the hydraulic controller through signal terminals, and the hydraulic controller switches the entire hydraulic drive component by controlling the third electromagnetic reversing valve.

Images