Electromagnetic actuator

Abstract

The invention relates to an electromagnetic actuator. The electromagnetic actuator comprises a coil, a guide sleeve, an armature and a magnetism isolating pad, the guide sleeve is fixedly installed on the radial inner side of the coil, the armature is installed on the radial inner side of the guide sleeve in an axial moving mode, the guide sleeve comprises an axial closed end, and a cavity is formed between the armature and the closed end. And the magnetic isolation pad is mounted on the axial outer side of the coil and the end part, opposite to the closed end, of the guide sleeve. The electromagnetic actuator further comprises a sleeve and an exhaust channel, the sleeve fixedly surrounds the radial outer side of the guide sleeve and the radial outer side of the magnetic isolation pad, the exhaust channel is formed between the sleeve and the guide sleeve and between the sleeve and the magnetic isolation pad, the guide sleeve comprises a connecting channel communicated with the cavity and the exhaust channel, and the exhaust channel is communicated to the end face, opposite to the closed end, of the magnetic isolation pad. The electromagnetic actuator provided by the invention has an improved structure.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic actuators, and in particular to an electromagnetic actuator with an improved structure. Background Art

[0002] In modern industry, electromagnetic actuators are widely used. Electromagnetic actuators use magnetic field forces generated by coils, for example, to drive actuators to control the movement of mechanical parts. Electromagnetic actuators are often used to drive valve devices to form solenoid valves. For example, in the suspension shock absorbers of motor vehicles, electromagnetic actuators are usually used to control the opening state of the valve devices. In addition, electromagnetic actuators can also be used to provide driving force for other mechanisms. For example, electromagnetic actuators can be used to control and adjust the valve lift of the engine.

[0003] A cavity is formed between the closed end of the guide sleeve of the electromagnetic actuator and the armature, and the air in the cavity will hinder the movement of the armature, so a channel needs to be provided to exhaust the air in the cavity when the armature moves. For example, CN 209892680 U discloses a solenoid valve for a shock absorber, wherein an exhaust structure is formed by an exhaust channel in the armature and a one-way valve, thereby achieving exhaust from the highest cavity downward. However, the inlet of the exhaust channel of the armature is located below the cavity. This design does not conform to the law of gas floating, and the exhaust effect is not ideal. At the same time, the one-way valve and the hollow channel inside the armature cause higher production costs. In addition, there may always be gas in the channel of the push rod. Due to the fluctuation of the oil pressure, the gas in the channel will continue to affect the pilot valve and thus affect the damping force. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide an improved electromagnetic actuator.

[0005] The above technical problems are solved by an electromagnetic actuator according to the present invention. The electromagnetic actuator includes a coil, a guide sleeve, an armature and a magnetic isolation pad. The guide sleeve is fixedly installed on the radial inner side of the coil, and the armature can be axially movably installed on the radial inner side of the guide sleeve. The guide sleeve includes an axially closed end, and a cavity is formed between the armature and the closed end. The magnetic isolation pad is installed on the axial outer side of the coil and the guide sleeve at the end opposite to the closed end. Among them, the electromagnetic actuator also includes a sleeve and an exhaust channel. The sleeve is fixedly surrounded on the radial outer side of the guide sleeve and the magnetic isolation pad. The exhaust channel is formed between the sleeve and the guide sleeve and between the sleeve and the magnetic isolation pad. The guide sleeve includes a connecting channel connecting the cavity and the exhaust channel, and the exhaust channel is connected to the end face of the magnetic isolation pad facing away from the closed end. By arranging the sleeve on the radial outer side of the guide sleeve and the magnetic isolation pad, the exhaust channel can be formed between the sleeve and the guide sleeve and the magnetic isolation, thereby simplifying the exhaust structure.

[0006] According to a preferred embodiment of the present invention, the magnetic isolation pad may include an injection molding part and a magnetic isolation ring, wherein the magnetic isolation ring axially abuts against the end face of the guide sleeve opposite to the closed end, and the injection molding part is filled between the magnetic isolation ring and the sleeve. The injection molding part fixes the magnetic isolation ring and the sleeve together, and the magnetic isolation ring is used to abut against the guide sleeve, thereby forming a sealed fit with the guide sleeve. Preferably, the magnetic isolation ring may be made of a non-magnetic metal material. The metal magnetic isolation ring may provide a higher structural strength.

[0007] According to another preferred embodiment of the present invention, the electromagnetic actuator may further include a housing and a sealing ring, the coil and the sleeve are mounted on the radial inner side of the housing, the injection molded portion extends radially over the coil and abuts the housing via the sleeve, and the sealing ring is mounted between the sleeve and the housing to seal the coil. The sleeve cooperates with the housing to form an annular space encapsulating the coil, and the sealing ring can prevent liquid from invading the annular space where the coil is located.

[0008] According to another preferred embodiment of the present invention, the magnetic isolating ring may not extend radially inwardly beyond the end surface of the guide sleeve facing away from the closed end, thereby preventing the magnetic isolating ring from hindering the axial movement of the armature.

[0009] According to another preferred embodiment of the present invention, a radial gap may exist between the injection molding portion and the outer side surface of the guide sleeve, thereby facilitating the assembly of the guide sleeve and the magnetic isolation pad.

[0010] According to another preferred embodiment of the present invention, the exhaust channel may include a first channel section formed between the sleeve and the guide sleeve and a second channel section formed between the sleeve and the magnetic isolation pad, and the first channel section is formed as an annular space surrounding the guide sleeve. Such an annular space can be formed on the radial outer side of the guide sleeve by turning, thereby simplifying the processing technology.

[0011] According to another preferred embodiment of the present invention, the sleeve can be fixedly connected with the guide sleeve at the axial end toward the closed end. In particular, the sleeve can be welded with the guide sleeve at the axial end toward the closed end, thereby ensuring the sealing effect of the first channel section.

[0012] According to another preferred embodiment of the present invention, the connecting channel can be connected to the end of the side wall of the cavity facing the closed end. This makes it easy for the rising air in the cavity to enter the exhaust channel through the connecting channel.

[0013] According to another preferred embodiment of the present invention, the electromagnetic actuator may further include an air inlet channel formed in the armature, thereby eliminating the need to form a channel on the push rod, thereby preventing gas fluctuations in the channel from affecting components abutted by the push rod, such as a pilot valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is further described below in conjunction with the accompanying drawings. The same reference numerals in the drawings represent elements with the same functions.

[0015] Figure 1 A schematic diagram showing an electromagnetic actuator according to an exemplary embodiment of the present invention; and

[0016] Figure 2 Show Figure 1 A partial enlarged view of the electromagnetic actuator shown. DETAILED DESCRIPTION

[0017] The following is a description of the specific implementation of the electromagnetic actuator according to the present invention in conjunction with the accompanying drawings. The following detailed description and drawings are used to exemplarily illustrate the principles of the present invention. The present invention is not limited to the preferred embodiments described, and the protection scope of the present invention is defined by the claims.

[0018] According to an embodiment of the present invention, an electromagnetic actuator is provided. The electromagnetic actuator can generate a driving force through an electromagnetic field, thereby controlling the movement of a mechanical component. For example, the electromagnetic actuator can be used in a suspension shock absorber or a valve mechanism of a motor vehicle. The embodiment of the present invention takes the electromagnetic valve in the suspension shock absorber as an example to illustrate the structure and function of the electromagnetic actuator. It should be understood that the electromagnetic actuator can also be applied to other devices.

[0019] Figure 1 and Figure 2 An exemplary embodiment of an electromagnetic actuator according to the present invention is shown. In this embodiment, the electromagnetic actuator is installed in a suspension shock absorber to form a solenoid valve for adjusting the damping force of the shock absorber. Figure 1 FIG. 2 shows a longitudinal cross-sectional view of the electromagnetic actuator through the central axis. Figure 1 As shown, the electromagnetic actuator includes a housing 1, a coil 2, a coil support 3, a guide sleeve 4, an armature 5, a push rod 6 and a magnetic isolation pad.

[0020] The housing 1 is formed in a substantially cylindrical shape. Other components of the electromagnetic actuator are mounted on the radial inner side of the housing 1. The hollow coil support 3 is coaxially fixed on the radial inner side of the housing 1. The coil 2 is coaxially wound on the radial outer side of the coil support 3.

[0021] The guide sleeve 4 is formed into a substantially cylindrical shape and is coaxially fixed to the radial inner side of the coil 2 and the coil support 3. The guide sleeve 4 includes two ends opposite to each other in the axial direction, one end of which is a closed end 4a and the other end is an open end 4b. The open end 4b is axially directed toward a component to be driven by the electromagnetic actuator, such as a pilot valve ( Figure 1 lower center component).

[0022] The armature 5 is formed as a substantially cylindrical component and is axially movable mounted on the radial inner side of the guide sleeve 4. The outer side of the armature 5 is in contact with the inner side of the guide sleeve 4, so that it can slide along the inner side of the guide sleeve 4 during axial movement. At the same time, a cavity is formed between the armature 5 and the closed end 4a of the guide sleeve 4. An elastic member 11 (e.g., a coil spring) is arranged in the cavity, and the elastic member 11 abuts axially between the closed end 4a and the armature 5 in a pre-compressed state.

[0023] The push rod 6 passes through the radial inner side of the armature 5 (particularly arranged coaxially) and is fixed to the armature 5. The end of the push rod 6 facing away from the closed end 4a protrudes axially from the armature 5 so as to abut against the component to be driven by the electromagnetic actuator. The armature 5 is made of ferromagnetic material. When the coil 2 is energized, the electromagnetic field generated can exert a magnetic field force acting in the axial direction on the armature 5, so that the armature 5 together with the push rod 6 overcomes the elastic force of the elastic member 11 and moves axially relative to the guide sleeve 4. Therefore, the movement and axial position of the armature 5 can be controlled by controlling the current in the coil 2.

[0024] The magnetic isolation pad is installed on the axial outer side of the end of the coil 2 (coil support 3) opposite to the closed end 4a of the guide sleeve 4 and the axial outer side of the open end 4b of the guide sleeve 4. The magnetic isolation pad is made of non-magnetic material to block the magnetic field generated by the coil 2 in the axial direction.

[0025] The electromagnetic actuator also includes a sleeve 7. The sleeve 7 is a generally cylindrical component made of a non-magnetic material, which can be formed by stretching a non-magnetic metal material, for example. The sleeve 7 surrounds the radial outer side of the guide sleeve 4 and the magnetic isolation pad and is fixed to both of them. A portion of the sleeve 7 is located radially inside the coil 2 and the coil support 3 and overlaps with the coil support 3 in the axial direction, while the other portion protrudes outside the coil support 3 in the axial direction away from the closed end 4a. The magnetic isolation pad is accommodated in the portion of the sleeve 7 protruding outside the coil support 3.

[0026] An exhaust channel Co is formed between the sleeve 7 and the guide sleeve 4 and between the sleeve 7 and the magnetic isolation pad, and the exhaust channel Co is connected to the end surface of the magnetic isolation pad that faces away from the closed end 4a. At the same time, a connecting channel 4c connecting the cavity and the exhaust channel Co is formed in the guide sleeve 4. The air in the cavity can thus be discharged through the connecting channel 4c and the exhaust channel Co.

[0027] A discharge hole 1a may be formed on the side wall of the housing 1. The discharge hole 1a is located axially outside the end of the sleeve 7 that faces away from the closed end 4a. The air discharged from the exhaust passage Co between the magnetic isolation pad and the sleeve 7 can be discharged from the housing 1 through the discharge hole 1a.

[0028] In addition, the electromagnetic actuator may further include an air intake channel Ci, which is formed in the armature 5. The air intake channel Ci may, for example, axially penetrate the armature 5. Thus, it is not necessary to form a channel on the push rod 6, thereby preventing gas fluctuations in the channel from affecting the components abutted by the push rod 6, such as the pilot valve.

[0029] Figure 2 Shows Figure 1 A partial enlarged view of the cross section shown. Figure 2 As shown, the connecting passage 4c can preferably be communicated to the end of the side wall of the cavity towards the closed end 4a. In addition, the connecting passage 4c can preferably extend horizontally in the radial direction. This makes it easy for the air rising in the cavity to enter the exhaust passage through the connecting passage 4c.

[0030] The exhaust channel Co can be divided into a first channel section Co1 formed between the sleeve 7 and the guide sleeve 4 and a second channel section Co2 formed between the sleeve 7 and the magnetic isolation pad. Figure 1 As shown, the first channel section Co1 can preferably be formed as an annular space surrounding the radially outer side of the guide sleeve 4. This annular space can be provided by turning the guide sleeve 4. Specifically, by turning the outer side surface of the guide sleeve 4, the outer side surface of the guide sleeve 4 can have a larger outer diameter at one end close to the closed end 4a. The sleeve 7 is fixed together with the part with a larger outer diameter of the outer side surface of the guide sleeve 4, and an annular space is formed between the sleeve 7 and the part with a smaller outer diameter of the outer side surface of the guide sleeve 4. This can reduce the processing difficulty of the channel. The sleeve 7 can be fixedly connected to the guide sleeve 4 at the axial end toward the closed end 4a, particularly welded together. The axial end of the sleeve 7 thus forms a sealing fit with the guide sleeve 4.

[0031] The radius of the portion of the sleeve 7 axially protruding from the coil support 3 is larger than the radius of the portion axially overlapping with the coil support 3, so that the portion of the sleeve 7 axially protruding from the coil support 3 extends over the coil support 3 and contacts the inner wall of the housing 1. Thus, the sleeve 7 forms a space on the axial outer side of the coil support 3 to accommodate the magnetic isolation pad.

[0032] The annular magnetic isolation gasket is coaxially fixed in the portion of the sleeve 7 protruding from the coil support 3. The magnetic isolation gasket is formed of a non-magnetic material and overlaps with the coil support 3 and the guide sleeve 4 in the radial direction to block the magnetic field. Preferably, the magnetic isolation gasket may include a magnetic isolation ring 8 and an injection molding portion 9. The magnetic isolation ring 8 is formed as an annular plate-like structure extending in a plane perpendicular to the central axis. The magnetic isolation ring 8 axially abuts against the end face of the open end 4b of the guide sleeve 4, and may preferably form a sealed fit by pressure. The magnetic isolation ring 8 may preferably be made of a non-magnetic metal material to provide greater structural strength. The magnetic isolation ring 8 may not extend radially inward beyond the end face of the open end 4b of the guide sleeve 4, thereby preventing obstruction of the axial movement of the armature 5.

[0033] The injection molding part 9 is formed by an annular injection molding material filled between the magnetic isolation ring 8 and the sleeve 7. The injection molding part 9 is located on the radial inner side of the sleeve 7 and basically overlaps and extends with the coil support 3 in the radial direction. The sleeve 7 separates the injection molding part 9 from the coil support 3 and the housing 1. The second channel section Co2 of the exhaust channel Co is formed between the sleeve 7 and the injection molding part 9 and is connected to the first channel section Co1. The injection molding part 9 can be made of materials such as plastic. The injection molding part 9 is formed in the injection molding process and the magnetic isolation ring 8 and the sleeve 7 are fixedly connected together. During assembly, the sleeve 7 and the magnetic isolation pad fixed together can be installed on the guide sleeve 4 first, and then the guide sleeve 4 and the sleeve 7 are fixedly connected together. To this end, there can be a radial gap between the injection molding part 9 and the outer side surface of the guide sleeve 4, so as to facilitate the assembly of the guide sleeve 4 and the injection molding part 9. This radial gap can be sealed by the magnetic isolation ring 8.

[0034] The electromagnetic actuator may further include a sealing ring 10. The injection molded portion 9 extends radially over the coil 2 and abuts against the inner wall of the housing 1 via the sleeve 7. The sealing ring 10 is installed between the sleeve 7 and the housing 1 to seal the coil 2. The sealing ring 10 may be a ring made of elastic material such as rubber.

[0035] In the electromagnetic actuator according to the present invention, the exhaust channel is formed between the sleeve and the guide sleeve and between the sleeve and the magnetic isolation pad, which simplifies the exhaust structure, thereby reducing the processing difficulty and production cost. The magnetic isolation pad is composed of an injection molding part and a magnetic isolation ring, which simplifies the structure and installation process of the magnetic isolation pad. This electromagnetic actuator does not need to form a channel on the push rod, thereby avoiding the gas fluctuation in the channel affecting the parts abutted by the push rod.

[0036] Although possible embodiments are described by way of example in the above description, it should be understood that there are still a large number of variations of embodiments through the combination of all known and other technical features and embodiments that are easily conceivable to the skilled person. It should also be understood that the exemplary embodiment is only an example and that such an embodiment in no way limits the scope of protection, application and configuration of the present invention. The above description is more to provide the skilled person with a technical guide for converting at least one exemplary embodiment, wherein various changes can be made, especially changes in the functions and structures of the components, as long as they do not depart from the scope of protection of the claims.

[0037] Reference numerals list

[0038] 1 Housing

[0039] 1a Discharge hole

[0040] 2 Coils

[0041] 3 Coil support

[0042] 4 Guide sleeve

[0043] 4a Closed end

[0044] 4b Open end

[0045] 4c Connection Channel

[0046] 5 Armature

[0047] 6 Putter

[0048] 7 Sleeve

[0049] 8 Magnetic isolation ring

[0050] 9 Injection Molding Department

[0051] 10 Sealing ring

[0052] 11 Elastic parts

[0053] Ci Intake channel

[0054] Co exhaust duct

[0055] Co1 First channel section

[0056] Co2 Second channel section

Claims

1. An electromagnetic actuator, comprising a coil (2), a guide sleeve (4), an armature (5) and a magnetic isolation pad, wherein the guide sleeve (4) is fixedly mounted on the radial inner side of the coil (2), the armature (5) is axially movably mounted on the radial inner side of the guide sleeve (4), the guide sleeve (4) comprises an axially closed end (4a), a cavity is formed between the armature (5) and the closed end (4a), and the magnetic isolation pad is mounted on the axial outer side of the ends of the coil (2) and the guide sleeve (4) opposite to the closed end (4a), It is characterized in that The electromagnetic actuator also includes a sleeve (7) and an exhaust channel (Co), wherein the sleeve (7) is fixedly surrounded on the radial outer side of the guide sleeve (4) and the magnetic isolation pad, and the exhaust channel (Co) is formed between the sleeve (7) and the guide sleeve (4) and between the sleeve (7) and the magnetic isolation pad. The guide sleeve (4) includes a connecting channel (4c) connecting the cavity and the exhaust channel (Co), and the exhaust channel (Co) is connected to the end face of the magnetic isolation pad facing away from the closed end (4a).

2. The electromagnetic actuator according to claim 1, characterized in that: The magnetic isolation pad comprises an injection molding portion (9) and a magnetic isolation ring (8), wherein the magnetic isolation ring (8) abuts against the end surface of the guide sleeve (4) opposite to the closed end (4a) along the axial direction, and the injection molding portion (9) is filled between the magnetic isolation ring (8) and the sleeve (7).

3. The electromagnetic actuator according to claim 2, characterized in that: The magnetic isolation ring (8) is made of a non-magnetic metal material.

4. The electromagnetic actuator according to claim 2, characterized in that: The electromagnetic actuator further comprises a housing (1) and a sealing ring (10); the coil (2) and the sleeve (7) are mounted on the radial inner side of the housing (1); the injection molded portion (9) radially extends over the coil (2) and abuts against the housing (1) via the sleeve (7); and the sealing ring (10) is mounted between the sleeve (7) and the housing (1) to seal the coil (2).

5. The electromagnetic actuator according to claim 2, characterized in that: The magnetic isolation ring (8) does not extend radially inwardly beyond the end surface of the guide sleeve (4) facing away from the closed end (4a).

6. The electromagnetic actuator according to claim 2, characterized in that: There is a radial gap between the injection molded portion (9) and the outer side surface of the guide sleeve (4).

7. The electromagnetic actuator according to claim 1, characterized in that: The exhaust channel (Co) comprises a first channel section (Co1) formed between the sleeve (7) and the guide sleeve (4) and a second channel section (Co2) formed between the sleeve (7) and the magnetic isolation pad, wherein the first channel section (Co1) is formed as an annular space surrounding the guide sleeve (4).

8. The electromagnetic actuator according to claim 7, characterized in that: The sleeve (7) is fixedly connected to the guide sleeve (4) at the axial end portion facing the closed end (4a).

9. The electromagnetic actuator according to claim 1, characterized in that: The connecting channel (4c) communicates with the end of the side wall of the cavity facing the closed end (4a).

10. The electromagnetic actuator according to any one of claims 1 to 9, characterized in that: The electromagnetic actuator further comprises an air inlet passage (Ci), which is formed in the armature (5).

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