A high-frequency response, high-reliability, high-speed switching electromagnet device and control method

Abstract

The present invention discloses a high-frequency response, high-reliability, high-speed switching electromagnet device and a control method. A front pole shoe and a rear pole shoe are respectively arranged at the front and rear ends of the housing. The front pole shoe and the rear pole shoe are respectively fixedly connected to a front limit piece and a rear limit piece. An armature is movably arranged between the front limit piece and the rear limit piece in the front and rear directions. The main coil is arranged in a first chamber surrounded by the housing, the front pole shoe and the armature. The auxiliary coil is arranged in a second chamber surrounded by the housing, the rear pole shoe and the armature. The connecting rod unit is externally connected to the spool of the switching valve. The method includes applying voltages to the main and auxiliary coils by using a control system, making the armature continuously move back and forth by changing the magnetic flux and driving the push rod to move. The movement of the push rod controls the opening and closing state of the spool, thereby realizing the drive of the switching valve load. The present invention improves the flow control accuracy by increasing the frequency response of the driving electromagnet of the high-speed switching valve and reducing the minimum adjustable duty ratio, and at the same time can reduce the closing speed of the spool and improve the reliability of the high-speed switching valve.

Description

Technical Field

[0001] The invention belongs to a driving electromagnet device of a switching spool and its control method in the field of construction machinery, and particularly relates to a high-frequency response, high-reliability, high-speed switching electromagnet device and control method for driving the spool of a high-speed switching valve. Background Technique

[0002] In recent years, construction machinery has been developing towards the direction of intelligence. Due to its characteristics such as energy conservation and high efficiency, strong anti-oil pollution ability, and high sensing integration, digital hydraulic valves have gradually become the core components of the intelligent control of construction machinery, and digital hydraulic valves are also one of the important directions in the research and development of current hydraulic control components. Digital hydraulic valves can be divided into two types: fluid discrete type and signal discrete fluid continuous type. Among them, the fluid discrete type digital hydraulic valve can also be called a high-speed switching valve, and its core driving unit is a high-speed switching electromagnet. Therefore, the performance of the high-speed switching electromagnet also determines the performance of the fluid discrete type digital hydraulic valve.

[0003] In the application of construction machinery, the movement of the spool of the high-speed switching valve mostly uses a unidirectional high-speed switching electromagnet as the driving unit. The electromagnetic force generated by a single electromagnet coil is used to open the spool, and the restoring force generated by the spool return spring is used to close the spool. The flow control accuracy of the high-speed switching valve is mainly affected by the dynamic response speed when the spool opens and closes. The higher the dynamic response speed when the spool opens and closes, it means that the time required for opening and closing is smaller, then the minimum adjustable duty ratio of the PWM control signal of the high-speed switching valve is smaller, the frequency response is higher, and its flow control accuracy is also higher. Regarding the optimization problem of the dynamic characteristics of the high-speed switching valve, Zhong Qi of Zhejiang University studied the multi-voltage control strategy of the high-speed switching valve driven by a unidirectional high-speed switching electromagnet in the journal paper "Research on the Control Strategy of High-Speed Switching Valves", improved the dynamic characteristics of the high-speed switching valve, thereby reducing the minimum adjustable duty ratio of the control signal and improving the frequency response of the high-speed switching valve.

[0004] Although good results have been achieved in the research and application of high-speed switching valves, however, compared with electro-hydraulic proportional spool valves, high-speed switching valves still have problems such as obvious flow pulsation caused by discontinuous flow, low flow control accuracy, and large impact on the spool during high-speed opening and closing, resulting in reduced reliability, which limits the application range of high-speed switching valves in construction machinery and hinders the pace of the intelligent development of construction machinery. Summary of the Invention

[0005] To solve the problems existing in the existing high-speed on-off valves in the background art, the purpose of the present invention is to propose a high-frequency response, high-reliability high-speed on-off electromagnet device and control method for driving the spool of a high-speed on-off valve, which has the characteristics of fast opening and closing response speed of the armature, compact structure, and low closing speed, and can meet the requirements of high-frequency response, high-precision flow control, high integration and high reliability of the high-speed on-off valve. A novel electromagnet device and control method for the high-speed on-off valve spool can further improve the flow control accuracy, dynamic characteristics and reliability of the high-speed on-off valve, and expand the application range of the high-speed on-off valve in construction machinery. This is of great significance for accelerating the intelligent development process of construction machinery.

[0006] The technical solution of the present invention is as follows:

[0007] 1. A high-frequency response, high-reliability high-speed on-off electromagnet device:

[0008] It includes an electromagnet assembly with a cavity inside, a connecting rod unit and an armature. There are openings in the middle of the front and rear ends of the electromagnet assembly. The two ends of the connecting rod unit are respectively located at the openings at the front and rear ends of the electromagnet assembly. The electromagnet assembly is sleeved on the outer surface of the connecting rod unit so as to be movable back and forth. The armature is arranged in the inner cavity of the inner circle of the electromagnet assembly so as to be movable back and forth, and the armature is fixedly connected to the connecting rod unit;

[0009] The electromagnet assembly is externally connected to a control system. The front end of the connecting rod unit is connected to one end of an external on-off valve, and the other end of the on-off valve is connected to an external on-off valve load. The control system controls the change of the magnetic flux in the electromagnet assembly, thereby changing the position of the armature affected by the magnetic flux, and further changing the position of the connecting rod unit fixedly connected to the armature. By changing the position of the connecting rod unit, the opening and closing state of the spool in the on-off valve is controlled, and thus the driving of the on-off valve load is realized;

[0010] The front direction of the device is the direction close to the on-off valve in the device, and the rear direction of the device is the direction far from the on-off valve in the device.

[0011] The electromagnet assembly includes a front pole shoe, a ring-shaped permanent magnet, a housing, a ring-shaped main coil, a ring-shaped secondary coil, a rear pole shoe, a ring-shaped rear limit piece and a ring-shaped front limit piece; on the inner side walls at the front and rear ends of the housing, there are respectively provided a ring-shaped front pole shoe and a ring-shaped rear pole shoe, and the front pole shoe and the rear pole shoe are respectively sleeved on the front and rear ends of the connecting rod unit so as to be movable back and forth. The front limit piece and the rear limit piece are respectively sleeved on the front and rear ends of the connecting rod unit so as to be movable back and forth. The front limit piece is fixedly connected to the rear end of the inner circle of the front pole shoe, and the rear limit piece is fixedly connected to the front end of the inner circle of the rear pole shoe. An armature is arranged between the front limit piece and the rear limit piece so as to be movable back and forth;

[0012] The described housing is an annular cylinder with an annular flange provided in the middle inside. The annular flange in the housing is located between the main coil and the secondary coil. The front part of the housing, the front pole shoe, and the front part of the armature enclose an annular first chamber. The rear part of the housing, the rear pole shoe, and the rear part of the armature enclose an annular second chamber. The main coil and the secondary coil are respectively arranged inside the first chamber and the second chamber. A permanent magnet is arranged inside the first chamber between the main coil and the front pole shoe; both the main coil and the secondary coil are externally connected to a control system.

[0013] The described electromagnet assembly further includes a first magnetic isolation ring and a second magnetic isolation ring. An annular cavity is provided inside the annular flange in the housing. The first magnetic isolation ring is placed in the annular cavity and fixedly connected to the housing. An annular hole groove is provided in the middle of the outer circle of the armature. The second magnetic isolation ring is placed in the annular hole groove and fixedly connected to the armature.

[0014] The described link unit includes a push rod and a guide rod. The rear end of the push rod and the front end of the guide rod are coaxially fixedly connected through the inner circle of the armature. The front end of the push rod is externally connected to a switching valve; the front pole shoe and the front limit piece are both sleeved on the outer surface of the push rod so as to be movable back and forth, and the rear pole shoe and the rear limit piece are both sleeved on the outer surface of the guide rod so as to be movable back and forth.

[0015] The described switching valve includes a first valve body, a second valve body, a valve core, and a compression spring. The valve core is arranged between the first valve body and the second valve body so as to be movable back and forth. One end of the valve core and the second valve body are connected through the compression spring, and the other end of the valve core is connected to the front end of the push rod.

[0016] Both the front pole shoe and the rear pole shoe are made of a magnetic conductive material, and the magnetic conductive material adopts a new type of soft magnetic composite material.

[0017] II. A control method applied to the described device, including the following steps:

[0018] Step 1: Use the control system to apply a voltage to the main coil with a preset initial positive voltage u11 and monitor the current in the main coil in real time. After applying the initial positive voltage u11 for a preset first time period T1, increase the voltage applied to the main coil to an opening positive voltage u12. The suction force generated by the main coil on the armature pushes the armature to move forward. At the same time, the push rod fixedly connected to the armature pushes the valve core forward. When the armature continues to move forward until it contacts the front limit piece: the valve core is converted from the initial closed state to the open state;

[0019] Step 2: After the valve core is converted to the open state, reduce the voltage applied to the main coil to a stable positive voltage u13, and use the stable positive voltage u13 applied to the main coil to control the valve core to always be in the open state;

[0020] Step 3: After applying a stable positive voltage u13 for a preset second time period T2, change the voltage applied to the main coil to a reverse closed negative voltage u14, and at the same time apply a preset closed positive voltage u21 to the secondary coil. The compressed spring pushes the valve core and the push rod to move backward and drives the armature to move backward. When the current on the main coil monitored in the control circuit drops to 0, reduce the voltage applied to the main coil to 0;

[0021] Step 4: After the voltage on the main coil drops to 0 for a preset third time period T3, apply a voltage to the main coil with a preset ending positive voltage u16, and at the same time change the voltage applied to the secondary coil to a negative ending negative voltage u22. At the same time, the armature and the valve core continue to move backward and decelerate. When the armature moves to contact the rear limit piece: the valve core changes from the open state to the closed state; after the valve core changes to the closed state, reduce the voltages applied to both the main coil and the secondary coil to 0;

[0022] Step 5: Repeat Step 1 to Step 4, use the control system to control the voltage changes in the main coil and the secondary coil, thereby changing the magnetic flux in the device. The armature affected by the magnetic flux moves back and forth continuously and drives the push rod to move back and forth. The opening and closing state of the valve core is controlled by the forward and backward movement of the push rod, thereby realizing the drive of the switch valve load.

[0023] The working principle of the device of the present invention is as follows:

[0024] (1) The armature in the device generates a forward thrust on the valve core to open it, and the compression spring (return spring) generates a backward thrust on the valve core to close it. Generally, the movement of the valve core is always consistent with the movement of the armature. Therefore, only the movement principle of the armature will be described hereafter. The movement of the armature is determined by the control signal of the control system;

[0025] (2) When the main coil and the secondary coil are de-energized (i.e., no voltage is applied) under the control of the control system, neither of the two coils generates an electromagnetic force on the armature; at this time, the permanent magnet generates two magnetic flux circuits, as Figure 3 (a) shown, one is the main magnetic flux circuit Φ that only passes through the front pole shoe and the housing and does not pass through the armature 01 , and the other is the secondary magnetic flux circuit Φ that passes through the armature, the housing, and the front pole shoe 02 ; since the secondary magnetic flux circuit Φ 02 passes through the armature and the magnetic flux circuit is long, resulting in a large magnetic resistance and a relatively small actual magnetic flux. The magnetic flux of the secondary magnetic flux circuit Φ 02 only accounts for a very small part of the total magnetic flux generated by the permanent magnet. The forward electromagnetic force generated by the permanent magnet on the armature is small and is not sufficient to make the armature overcome the spring force of the return spring and move forward. Under the action of the return spring, the armature moves backward until it contacts the rear limit piece. At this time, the valve core of the high-speed switch valve corresponds to the closed state;

[0026] (3) When the main coil is energized under the control of the control system (it is required that the direction of the magnetic flux generated by the main coil is consistent with the main magnetic flux loop generated by the permanent magnet and opposite to the secondary magnetic flux loop), the main coil and the permanent magnet generate a superimposed magnetic flux, forming two new superimposed magnetic flux loops. As shown in Figure 3 (b), one is the magnetic flux loop Φ formed through the interior of the permanent magnet 12 , with a stronger magnetic flux, and the other is the loop Φ formed without passing through the interior of the permanent magnet 11 , with a weaker magnetic flux; both magnetic flux loops pass through the armature and the front pole shoe, generating a forward electromagnetic force on the armature. Moreover, the two magnetic flux loops Φ 11 and the magnetic flux loop Φ 12 have the same polarity, and the superposition of the magnetic flux loop Φ 11 and the magnetic flux loop Φ 12 enhances the forward electromagnetic force on the armature, causing the armature to move forward against the backward spring force generated by the return spring until it contacts the front limit piece, and the push rod pushes the valve core to open at high speed;

[0027] (4) When the secondary coil is energized under the control of the control system, the magnetic flux loop generated by the secondary coil passes through the rear pole shoe and the armature, generating a backward electromagnetic force on the armature. As shown in Figure 3 (c), the secondary coil generates a closed magnetic flux Φ passing through the armature, the housing, and the rear pole shoe 21 , generating a backward electromagnetic suction force on the armature. The armature moves backward rapidly under the combined action of the spring force of the return spring and the electromagnetic suction force generated by the energization of the secondary coil until the armature contacts the rear limit piece, achieving accelerated (high-speed) closing. At this time, the valve core is in the closed state again.

[0028] The control method is the voltage command timing of the control system for the main coil and the secondary coil and the mutual cooperation relationship between the main coil and the secondary coil. By reasonably configuring the control voltage magnitude and timing of the main coil and the secondary coil, the response speed of the electromagnet armature can be improved, thereby improving the opening and closing response speed of the high-speed switching valve, reducing the minimum adjustable duty ratio of the high-speed switching valve, and improving the flow control accuracy; the closing speed of the valve core can be reduced to reduce the closing impact of the valve core and improve the reliability of the high-speed switching valve.

[0029] The beneficial effects of the present invention are as follows:

[0030] 1. Compared with the traditional unidirectional switch electromagnet, an electromagnet device for driving the high-speed switch valve core asymmetrically and bidirectionally is proposed. By introducing a secondary coil to generate a backward electromagnetic force on the armature, the restoring force of the armature is assisted to improve the dynamic performance of the high-speed switching valve; usually, the device can optimize the structure and reasonably configure the opening and closing time of the high-speed switch valve core. Therefore, through the structural optimization of the asymmetric device, the effect of reducing the opening and closing time of the high-speed switch valve core simultaneously can be achieved;

[0031] 2. In the present invention, the secondary coil plays a role in assisting the armature to return, providing a large design space. Through reasonable design, while improving the device performance, the structure can be kept compact, meeting the requirements of high performance and high integration of the high-speed switching valve. In addition, the failure of the secondary coil does not affect the normal operation of the electromagnet device of the high-speed switching valve (only reducing the frequency response and the minimum adjustable duty cycle to a certain extent). Therefore, its reliability is the same as that of the unidirectional switch electromagnet. For the traditional symmetric bidirectional electromagnet, the electromagnet coils at both ends are respectively in the push and pull states, independently responsible for the opening and closing movements of the valve core, resulting in low efficiency. The double coil group reduces the overall reliability. The symmetry requires the same size of the coils at both ends, leading to a small design space and being not conducive to keeping the structure compact.

[0032] 3. The corresponding control method of the device of the present invention can further improve the opening and closing response speed of the asymmetric bidirectional electromagnet, increase the frequency response of the driving electromagnet of the high-speed switching valve, reduce the minimum adjustable duty cycle, thereby improving the flow control accuracy. At the same time, it can reduce the closing speed of the valve core and improve the reliability of the high-speed switching valve. Brief Description of the Drawings

[0033] Figure 1 is a schematic structural diagram of the device of the present invention;

[0034] Figure 2 is a schematic structural diagram of the permanent magnet;

[0035] Figure 3 is a schematic diagram of the internal magnetic flux circuit of the high-speed switching electromagnet device when the main coil and the secondary coil are powered off and powered on: Figure 3 (a) is the magnetic flux circuit when the main coil and the secondary coil are powered off simultaneously; Figure 3 (b) is the magnetic flux circuit when the main coil is applied with positive voltage and the secondary coil is powered off; Figure 3 (c) is the magnetic flux circuit when the main coil is powered off and the secondary coil is applied with positive voltage;

[0036] Figure 4 is a timing diagram of the control method and the movement of the valve core of the high-speed switching valve.

[0037] In the figure: 1. Push rod; 2. Front pole shoe; 3. Permanent magnet; 4. Housing; 5. Main coil; 6. First magnetic isolation ring; 7. Secondary coil; 8. Rear pole shoe; 9. Guide rod; 10. Rear limit piece; 11. Second magnetic isolation ring; 12. Armature; 13. Front limit piece. Detailed Embodiments

[0038] The present invention will be further described below with reference to the drawings and embodiments.

[0039] As Figure 1As shown, the device includes an electromagnet assembly with a cavity inside, a connecting rod unit, and an armature 12. There are openings in the middle of the front and rear ends of the electromagnet assembly. The two ends of the connecting rod unit are respectively located at the openings at the front and rear ends of the electromagnet assembly. The electromagnet assembly is sleeved on the outer surface of the connecting rod unit so as to be movable back and forth. The armature 12 is arranged in the internal cavity of the inner circle of the electromagnet assembly so as to be movable back and forth, and the armature 12 is fixedly connected to the connecting rod unit;

[0040] The electromagnet assembly is externally connected to a control system. The front end of the connecting rod unit is connected to one end of a high-speed switching valve. The connecting rod unit is used to drive the spool of the high-speed switching valve. The other end of the switching valve is connected to an external switching valve load. The control system controls the change of the magnetic flux in the electromagnet assembly, thereby changing the position of the armature 12 affected by the magnetic flux, and further changing the position of the connecting rod unit fixedly connected to the armature 12. By changing the position of the connecting rod unit, the opening and closing state of the spool in the switching valve is controlled, and thus the driving of the switching valve load is realized.

[0041] The switching valve load includes equipment such as a power stage spool valve, an excavator, a hydraulic cylinder, a pump truck, and a robotic arm.

[0042] The front direction of the device is the direction close to the spool of the switching valve in the device, and the rear direction of the device is the direction away from the spool in the device.

[0043] The electromagnet assembly includes a front pole shoe 2, a ring-shaped permanent magnet 3, a housing 4, a ring-shaped main coil 5, a ring-shaped secondary coil 7, a rear pole shoe 8, a ring-shaped rear limit piece 10, and a ring-shaped front limit piece 13; on the inner side walls of the front and rear ends of the housing 4, there are respectively arranged a front pole shoe 2 with a ring-shaped cross-section and a rear pole shoe 8 with a ring-shaped cross-section, and the front pole shoe 2 and the rear pole shoe 8 are respectively sleeved on the front and rear ends of the connecting rod unit so as to be movable back and forth. The front limit piece 13 and the rear limit piece 10 are respectively sleeved on the front and rear ends of the connecting rod unit so as to be movable back and forth. The front limit piece 13 is fixedly connected to the rear end of the inner circle of the front pole shoe 2, and the rear limit piece 10 is fixedly connected to the front end of the inner circle of the rear pole shoe 8. An armature 12 is arranged between the front limit piece 13 and the rear limit piece 10 so as to be movable back and forth. Both the front limit piece 13 and the rear limit piece 10 are made of magnetic isolation materials, which are used to limit the displacement of the armature 12 and at the same time prevent the front and rear ends of the armature 12 from being attracted to the front pole shoe 2 or the rear pole shoe 8 respectively. The armature 12 can move linearly between the front limit piece 13 and the rear limit piece 10. The armature 12 is hollowed out to achieve a lightweight design, so as to reduce the mass and improve the dynamic characteristics;

[0044] The housing 4 is an annular cylinder with an annular flange provided in the middle inside. The annular flange in the housing 4 is located between the main coil 5 and the secondary coil 7. The front part of the housing 4, the front pole shoe 2 and the front part of the armature 12 enclose an annular first chamber, and the rear part of the housing 4, the rear pole shoe 8 and the rear part of the armature 12 enclose an annular second chamber. The main coil 5 and the secondary coil 7 are respectively arranged inside the first chamber and the second chamber to realize the axial fixation of the main coil 5 and the secondary coil 7. A permanent magnet 3 is arranged inside the first chamber between the main coil 5 and the front pole shoe 2. Figure 2 It is a schematic structural diagram of the permanent magnet 3. The permanent magnet 3 is used to provide an initial forward electromagnetic force to the armature, and when the permanent magnet 3 and the main coil 5 act together, it accelerates the closing speed of the spool; both the main coil 5 and the secondary coil 7 are externally connected to a control system.

[0045] The electromagnet assembly further includes a first magnetic isolation ring 6 and a second magnetic isolation ring 11. An annular cavity is provided inside the annular flange of the housing 4. The first magnetic isolation ring 6 is placed in the annular cavity and fixedly connected to the housing 4. An annular hole groove is provided in the middle of the outer circle of the armature 12. The second magnetic isolation ring 11 is placed in the annular hole groove and fixedly connected to the armature 12. The first magnetic isolation ring 6 is used to prevent the magnetic fluxes generated by the main coil 5 and the secondary coil 7 on the housing 4 from interfering with each other, and the second magnetic isolation ring 11 is used to prevent the magnetic fluxes generated by the main coil 5 and the secondary coil 7 on the armature 12 from interfering with each other.

[0046] The connecting rod unit includes a non-magnetic push rod 1 and a non-magnetic guide rod 9. The rear end of the push rod 1 and the front end of the guide rod 9 are coaxially fixedly connected through the inner circle of the armature 12. The front end of the push rod 1 is externally connected to the spool of the switching valve; the front pole shoe 2 and the front limit piece 13 are both sleeved on the outer surface of the push rod 1 so as to be movable back and forth, and the rear pole shoe 8 and the rear limit piece 10 are both sleeved on the outer surface of the guide rod 9 so as to be movable back and forth. The connecting rod unit composed of the push rod 1 and the guide rod 9 is used to support and guide the armature 12.

[0047] The switching valve includes a first valve body, a second valve body, a spool and a compression spring. The spool is arranged between the first valve body and the second valve body so as to be movable back and forth. One end of the spool and the second valve body are connected through the compression spring, and the other end of the spool is connected to the front end of the push rod 1. The second valve body is located in front of the first valve body, and the fixed connection part between the second valve body and the first valve body is an integral structure. When the first valve body and the second valve body are connected through the spool, the spool is in the open state, and when the spool is located at the rearmost end of the switching valve so that the first valve body and the second valve body are not connected, the spool is in the closed state.

[0048] Both the front pole shoe 2 and the rear pole shoe 8 are made of a magnetic conductive material, and the magnetic conductive material adopts a new type of soft magnetic composite material.

[0049] In the initial state, that is, when no voltage is applied to the main coil 5 and the secondary coil 7, the voltage u10 in the main coil 5 and the voltage u20 in the secondary coil 7 are both 0. Neither the main coil 5 nor the secondary coil 7 generates electromagnetic attraction on the armature 12. Under the action of the compression spring, the armature 12 is located at the rear end of the device and contacts the rear limit piece 10, and does not contact the front limit piece 13. At this time, the electromagnetic force generated by the permanent magnet 3 is not sufficient to overcome the elastic force of the compression spring to push the armature 12 to move forward. At this time, the push rod 1 fixedly connected to the armature 12 controls the valve core of the switch valve to be in a closed state.

[0050] A control method applied to a high-frequency response, high-reliability, high-speed switching electromagnet device includes the following steps:

[0051] Step 1: As Figure 4 shown, use the control system to apply a voltage to the main coil 5 with a preset initial positive voltage u11 and monitor the current in the main coil 5 in real time. After applying the initial positive voltage u11 for a preset first time period T1, increase the voltage applied to the main coil 5 to the opening positive voltage u12. The electromagnetic force generated by the main coil 5 increases, and the suction force generated by the main coil 5 on the armature 12 pushes the armature 12 to move forward rapidly (i.e., in the direction close to the front pole shoe 2). At the same time, the push rod 1 fixedly connected to the armature 12 pushes the valve core forward (i.e., the push rod 1 gives the valve core a forward thrust). When the armature 12 continues to move forward until it contacts the front limit piece 13: the valve core quickly switches from the initial closed state to the open state; when the armature 12 does not contact the front limit piece 13, the opening and closing state of the valve core does not change;

[0052] Apply a low-amplitude initial positive voltage u11 to the main coil 5 in advance and ensure that the electromagnetic force generated by the main coil 5 and the permanent magnet 3 at this time is not sufficient to overcome the elastic force of the compression spring, so that the valve core remains in the closed state. Applying the initial positive voltage u11 is to make the main coil 5 have a certain initial current to increase the initial force during the device opening process, accelerate the device opening speed, and improve the dynamic response performance. At this time, the secondary coil 7 is not powered on, and u20 = 0;

[0053] Step 2: After the valve core is switched to the open state, reduce the voltage applied to the main coil 5 to the stable positive voltage u13, and use the stable positive voltage u13 applied to the main coil 5 to control the valve core to always be in the open state. Reducing the voltage applied to the main coil 5 is to reduce the initial current in the main coil 5, so as to reduce the forward initial electromagnetic resistance generated by the initial current of the main coil 5 during the rapid closing process of the armature 12, and reduce the energy consumption of the valve core in the open state, reduce the heat generation of the main coil 5. At this time, the secondary coil 7 is not powered on, and the given voltage is u20 = 0;

[0054] Step 3: After applying a stable positive voltage u13 for a preset second time period T2, change the voltage applied to the main coil 5 to a preset reverse closed negative voltage u14 to quickly eliminate the suction force generated by the coil 5 on the armature 12, increase the speed of the armature 12's return. At the same time, apply a preset closed positive voltage u21 to the secondary coil 7 and detect the current in the secondary coil 7 in real time. The compressed spring pushes the valve core and the push rod 1 to move backward and drives the armature 12 to move backward. The suction force generated by the main coil 7 on the armature 12 assists the armature 12 to move backward. When the current monitored in the control circuit drops to 0 on the main coil 5, reduce the voltage applied to the main coil 5 to 0 (i.e., the given voltage u15 = 0). At this time, when the armature 12 has not contacted the rear limit piece 10 and the voltage applied to the secondary coil 7 is still the closed positive voltage u21, applying a reverse voltage to the main coil 5 is to accelerate the decrease in the current in the main coil 5, reduce the forward electromagnetic resistance of the armature 12, energize the secondary coil 7 to generate a backward electromagnetic force on the armature 12, assist the compressed spring to pull back the armature 12, improve its backward return force and return speed, and accelerate the closing speed of the valve core;

[0055] Step 4: After the voltage on the main coil 5 drops to 0 and after a preset third time period T3, apply a voltage to the main coil 5 with a preset end positive voltage u16. At the same time, change the voltage applied to the secondary coil 7 to a preset negative end negative voltage u22. At this time, the armature 12 and the valve core continue to move backward and decelerate. When the armature 12 moves to contact the rear limit piece 10: the valve core changes from the open state to the closed state; when the armature 12 does not contact the rear limit piece 10, the opening and closing state of the valve core does not change;

[0056] After the valve core changes to the closed state, reduce the voltages applied to both the main coil 5 and the secondary coil 7 to 0; apply a positive voltage to the main coil 5 to provide a forward electromagnetic force for the armature 12, and apply a reverse voltage to the secondary coil 7 to accelerate the current in the secondary coil 7 to drop to zero, so as to reduce the instantaneous backward electromagnetic force of the armature 12. The main coil 5 and the secondary coil 7 cooperate to realize the decelerated closing of the on-off valve and reduce the closing impact;

[0057] Step 5: Repeat Step 1 to Step 4, use the control system to control the voltage changes in the main coil 5 and the secondary coil 7, thereby changing the magnetic flux in the device. The armature 12 affected by the magnetic flux moves back and forth continuously and drives the push rod 1 to move back and forth. The opening and closing state of the valve core is controlled by the back and forth movement of the push rod 1, and further the on-off of the first valve body (oil inlet) P and the second valve body (oil outlet) T of the on-off valve is controlled, and further the driving of the on-off valve load is realized.

Claims

1. A high-frequency response, high-reliability, high-speed switching electromagnet device, characterized in that: It includes an electromagnet assembly with a cavity inside, a connecting rod unit, and an armature (12). There are openings in the middle of the front and rear ends of the electromagnet assembly. The two ends of the connecting rod unit are respectively located at the openings at the front and rear ends of the electromagnet assembly. The electromagnet assembly is sleeved on the outer surface of the connecting rod unit so as to be movable back and forth. The armature (12) is arranged in the internal cavity of the inner ring of the electromagnet assembly so as to be movable back and forth, and the armature (12) is fixedly connected to the connecting rod unit; The electromagnet assembly is externally connected to a control system. The front end of the connecting rod unit is connected to one end of an external switching valve, and the other end of the switching valve is connected to an external switching valve load. The control system changes the position of the armature (12) affected by the magnetic flux by controlling the change of the magnetic flux in the electromagnet assembly, and then changes the position of the connecting rod unit fixedly connected to the armature (12). The opening and closing state of the valve core in the switching valve is controlled by the position change of the connecting rod unit, so as to realize the driving of the switching valve load; The front direction of the device is the direction close to the switching valve in the device, and the rear direction of the device is the direction far from the switching valve in the device; The electromagnet assembly includes a front pole shoe (2), a ring-shaped permanent magnet (3), a housing (4), a ring-shaped main coil (5), a ring-shaped secondary coil (7), a rear pole shoe (8), a ring-shaped rear limit piece (10), and a ring-shaped front limit piece (13); Ring-shaped front pole shoes (2) and ring-shaped rear pole shoes (8) are respectively provided on the inner side walls of the front and rear ends of the housing (4), and the front pole shoes (2) and the rear pole shoes (8) are respectively sleeved on the front and rear ends of the connecting rod unit so as to be movable back and forth. The front limit piece (13) and the rear limit piece (10) are respectively sleeved on the front and rear ends of the connecting rod unit so as to be movable back and forth. The front limit piece (13) is fixedly connected to the rear end of the inner ring of the front pole shoe (2), and the rear limit piece (10) is fixedly connected to the front end of the inner ring of the rear pole shoe (8). An armature (12) is arranged between the front limit piece (13) and the rear limit piece (10) so as to be movable back and forth; The housing (4) is an annular cylinder with a ring-shaped flange in the middle inside. The ring-shaped flange in the housing (4) is located between the main coil (5) and the secondary coil (7). The front part of the housing (4), the front pole shoe (2), and the front part of the armature (12) enclose an annular first chamber. The rear part of the housing (4), the rear pole shoe (8), and the rear part of the armature (12) enclose an annular second chamber. The main coil (5) and the secondary coil (7) are respectively arranged inside the first chamber and the second chamber. A permanent magnet (3) is arranged inside the first chamber between the main coil (5) and the front pole shoe (2); Both the main coil (5) and the secondary coil (7) are externally connected to the control system.

2. The high-frequency response, high-reliability, high-speed switching electromagnet device according to claim 1, characterized in that: The electromagnet assembly further includes a first magnetic isolation ring (6) and a second magnetic isolation ring (11). There is an annular cavity inside the ring-shaped flange in the housing (4). The first magnetic isolation ring (6) is placed in the annular cavity and fixedly connected to the housing (4). There is an annular groove in the middle of the outer circle of the armature (12). The second magnetic isolation ring (11) is placed in the annular groove and fixedly connected to the armature (12).

3. The high-frequency response, high-reliability, high-speed switching electromagnet device according to claim 1, characterized in that: The described connecting rod unit includes a push rod (1) and a guide rod (9). The rear end of the push rod (1) and the front end of the guide rod (9) are coaxially and fixedly connected through the inner ring of an armature (12). The front end of the push rod (1) is externally connected to a switching valve. The front pole shoe (2) and the front limit piece (13) are both sleeved on the outer surface of the push rod (1) so as to be movable back and forth. The rear pole shoe (8) and the rear limit piece (10) are both sleeved on the outer surface of the guide rod (9) so as to be movable back and forth.

4. The high-frequency response, high-reliability, high-speed switching electromagnet device according to claim 1, characterized in that: The described switching valve includes a first valve body, a second valve body, a valve core and a compression spring. The valve core is arranged between the first valve body and the second valve body so as to be movable back and forth. One end of the valve core is connected to the second valve body through the compression spring. The other end of the valve core is connected to the front end of the push rod (1).

5. A high-frequency response, high-reliability, high-speed switching electromagnet device according to claim 1, characterized in that: The described front pole shoe (2) and rear pole shoe (8) are both made of a magnetically conductive material, and the magnetically conductive material adopts a soft magnetic composite material.

6. A control method applied to the device according to any one of claims 1-5, characterized in that, It includes the following steps: Step 1: Use the control system to apply a voltage to the main coil (5) with a preset initial positive voltage u11 and monitor the current in the main coil (5) in real time. After applying the initial positive voltage u11 for a preset first time period T1, increase the voltage applied to the main coil (5) to an opening positive voltage u12. The suction force generated by the main coil (5) on the armature (12) pushes the armature (12) to move forward. At the same time, the push rod (1) fixedly connected to the armature (12) pushes the valve core forward. When the armature (12) continuously moves forward until it contacts the front limit piece (13): the valve core is converted from the initial closed state to the open state; Step 2: After the valve core is converted to the open state, reduce the voltage applied to the main coil (5) to a stable positive voltage u13, and use the stable positive voltage u13 applied to the main coil (5) to control the valve core to always be in the open state; Step 3: After applying the stable positive voltage u13 for a preset second time period T2, change the voltage applied to the main coil (5) to a reverse closing negative voltage u14, and at the same time apply a preset closing positive voltage u21 to the secondary coil (7). The compression spring pushes the valve core and the push rod (1) to move backward and drives the armature (12) to move backward. When the current on the main coil (5) monitored in the control circuit drops to 0, reduce the voltage applied to the main coil (5) to 0; Step 4: After the voltage on the main coil (5) drops to 0 for a preset third time period T3, apply a voltage to the main coil (5) with a preset end positive voltage u16, and at the same time change the voltage applied to the secondary coil (7) to a negative end negative voltage u22. At the same time, the armature (12) and the valve core continue to move backward and decelerate. When the armature (12) moves to contact the rear limit piece (10): the valve core is converted from the open state to the closed state; after the valve core is converted to the closed state, reduce the voltages applied to both the main coil (5) and the secondary coil (7) to 0; Step 5: Repeat Steps 1 to 4. Use the control system to control the voltage changes in the main coil (5) and the secondary coil (7), thereby changing the magnetic flux in the device. The armature (12) affected by the magnetic flux moves back and forth continuously, and the push rod (1) moves back and forth. The opening and closing state of the valve core is controlled by the back-and-forth movement of the push rod (1), thereby realizing the drive of the switch valve load.

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