JP5549315B2 - Connecting device and linear actuator - Google Patents

Description

  The present invention relates to a connecting device that connects a mover and a stator, and a linear actuator including the connecting device.

  In the linear actuator, a mode is known in which the mover and the stator are connected by a connecting device made of a leaf spring, and the mover is elastically supported in the thrust direction by the connecting device (see Patent Document 1). Moreover, also in the clutch, a mode is considered in which the movable element and the stator can be connected and disconnected by a connecting device including a leaf spring.

JP 2007-215400 A

  However, when the coupling device is composed mainly of leaf springs, the actuator drive frequency and external input (for example, input and disturbance from the device where the actuator is installed) are determined by the mass of the mover and the spring constant of the leaf spring. When the frequency or the resonance frequency determined by the mass of the leaf spring itself and the spring constant is matched (or N times), a resonance phenomenon occurs and the leaf spring itself is damaged or worn due to unexpected operation. There was a problem.

  In addition, if the coupling device is formed by laminating only a plurality of leaf springs, the friction between leaf springs, the friction at the fixed portion between the leaf spring and the mover, and the friction at the fixed portion between the leaf spring and the stator. As a result, fretting occurs, and the leaf springs themselves or the portions that contact each other in the fixed portion are struck against each other.

  On the other hand, in order to solve such problems, it is also possible to apply a lubricant such as oil or grease to the leaf spring, but depending on the type of lubricant, the secular change is large, and the lubricant is dust or the like. There is a problem that the impurities are adsorbed and the intended function is impaired.

  In addition, it is possible to change the resonance frequency by changing the mass of the leaf spring or changing the length of the arm part constituting a part of the leaf spring so that the resonance frequency is not reached during operation. However, there has been a problem that the elastic coefficient (spring constant) changes significantly, or a problem that the weight and size of the entire coupling device are greatly affected.

  The present invention has been made paying attention to such a problem, and its main purpose is to reduce the influence of resonance and to prevent or suppress the breakage and wear of the leaf spring and to exhibit the expected function. It is to provide a connecting device that can do this.

That is, the coupling device of the present invention includes a leaf spring that couples a stator and a movable element that operates with respect to the stator , and is applied to a linear actuator or a clutch. A first fixed contact portion that can come into contact with the stator-side fixing portion, and a mover-side fixing. The vibration buffer member that has a second fixed contact portion that can come into contact with the portion and that cushions vibrations can be configured as a whole plate spring including the stator side fixed portion and the mover side stator portion, or at least the stator side fixed portion and the movable portion. It is characterized by making it contact with a part of leaf | plate spring containing a child side stator part .

  Here, the coupling device of the present invention includes both a mode in which the leaf spring is a single layer and a mode in which a plurality of leaf springs are laminated. Further, in the present invention, “to connect the stator and the mover” means “to be able to connect the stator and the mover” as well as “to separate the stator and the mover” It is possible to connect. Furthermore, “contact” in the present invention is a concept including literally “contact and touch”, as well as “adhesion”, “welding”, “fusion”, and “crimping”.

  If it is such, the vibration damping member is brought into contact with the whole or a part of the leaf spring, thereby directly or indirectly mitigating vibration that may occur at the connecting portion between the movable element or the stator and the leaf spring. In addition, since the mass of the entire coupling device changes, it is necessary to change the mass of the leaf spring itself that can cause a significant change in the elastic coefficient (spring constant) and the dimensions of the arm portion that constitutes a part of the leaf spring. Therefore, the resonance frequency can be suitably changed, the resonance frequency can be prevented from being reached during operation, and damage and wear of the leaf spring itself due to resonance can be reduced.

  In addition, the coupling device of the present invention has a configuration in which a vibration buffer member is sandwiched between adjacent leaf springs in an embodiment in which a plurality of leaf springs are laminated, thereby preventing fretting due to friction between leaf springs. Alternatively, the vibration damping member can also prevent or suppress the breakage and wear of the leaf springs caused by the leaf springs striking each other. Furthermore, a problem that can occur if the vibration buffer member is sandwiched between adjacent leaf springs to apply a lubricant such as oil or grease to the leaf springs, that is, the lubricant adsorbs impurities such as dust. Or the problem of being taken in in a connecting device can be solved.

  Particularly, in the coupling device of the present invention, the vibration buffer member is brought into contact with the fixed portions of the leaf springs corresponding to the mover and the stator. Therefore, the fixed portion (connecting portion) between the mover and the leaf spring, and the stator The vibration that can occur in the fixed portion (connecting portion) between the plate spring and the plate spring can be directly and effectively reduced, and the breakage and wear of the plate spring can be effectively prevented or suppressed.

  In addition, in the coupling device of the present invention, if the leaf spring and the vibration damping member are set to have the same shape, the leaf spring and the vibration damping member can be brought into contact with each other over the entire surface in the stacking direction. The vibration buffer function of the vibration buffer member can be obtained efficiently. Of course, even if the leaf spring and the vibration damping member are set to the same shape, it is possible to adopt a mode in which the vibration damping member is brought into contact with a part of the leaf spring.

  If the vibration damping member is made of porous PTFE (polytetrafluoroethylene) as the main material, a coupling device with excellent practicality and versatility is provided by using the characteristics of porous PTFE described below. can do.

  Typical characteristics of porous PTFE include low friction properties and cushioning properties (elastic effects), and these properties can suppress or prevent breakage and wear of the leaf spring. Moreover, since porous PTFE is excellent in chemical stability, thermal stability, flame retardancy, and light resistance, it is aged over a mode in which a lubricant such as oil or grease is applied to a leaf spring. Difficult to change and contributes to longer life of the coupling device. Further, porous PTFE exerts an excellent anchor effect by press-fitting an adhesive into the pores and solidifying it. Therefore, a vibration buffer member mainly made of porous PTFE is used as a leaf spring with an adhesive. By sticking, it is possible to solve a problem that may occur if a lubricant such as oil or grease is applied to the leaf spring, that is, a problem that the leaf spring causes a relative displacement during the operation of the mover. .

  Moreover, the linear actuator of this invention is provided with the needle | mover, the stator, and the connection apparatus which has the structure mentioned above. Therefore, it is possible to obtain the operational effects of the above-described coupling device, and the linear actuator is excellent in practicality. Furthermore, if the clutch provided with the needle | mover, the stator, and the connection apparatus which has the structure mentioned above is comprised, the effect by the connection apparatus mentioned above can be acquired, and it becomes a clutch excellent in practicality.

  ADVANTAGE OF THE INVENTION According to this invention, the influence by resonance can be reduced, the damage and abrasion of a leaf | plate spring can be prevented or suppressed, and the coupling device which can exhibit an expected function effectively can be provided.

The figure which shows typically sectional drawing of the linear actuator provided with the connection device which concerns on one Embodiment of this invention. The exploded view of the connection device concerning the embodiment. The front view of the leaf | plate spring which comprises the coupling device which concerns on the same embodiment. The front view of the vibration damping member which comprises the coupling device which concerns on the same embodiment.

  Hereinafter, a linear actuator 1 including a coupling device 5 according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the linear actuator 1 is an outer movable linear actuator 1 in which a mover 3 is disposed outside a stator 2. The stator 2 and the mover 3 are accommodated in a common housing 4. In the present embodiment, the housing 4 is configured by a hollow housing body 41 and a lid portion 42 that can be attached to the housing body 41.

  The stator 2 includes an inner core 21, a permanent magnet 22 disposed outside the inner core 21, a bobbin 23 that holds the permanent magnet 22 and can cover the inner core 21, and a coil wound around the outer periphery of the bobbin 23. 24 and a shaft 25 disposed in the center.

  The inner core 21 is made of a thin steel plate laminated in the thrust (reciprocating) direction A. The inner core 21 has a through hole 211 through which the shaft 25 can be inserted at the center, and a permanent magnet set part 222 on which the permanent magnet 22 can be set at a part of the outer edge facing the through hole 211. It is what you have.

  The permanent magnets 22 are respectively disposed on a pair of permanent magnet set portions 222 in the inner core 21. The paired permanent magnets 22 are arranged symmetrically with respect to the axis of the shaft 25.

  The bobbin 23 is divided into two in the thrust direction A, and can be covered by sandwiching the inner core 21 and the permanent magnet 22 from both axial ends of the shaft 25. Each bobbin 23 has an insertion hole 231 through which the shaft 25 can be inserted, and a pair of upper and lower coil winding recesses 232 in which the coil 24 can be wound.

  The shaft 25 has a substantially cylindrical shape that is attached to the insertion hole 231 in the bobbin 23 and the through hole 211 in the inner core 21. The axial direction of the shaft 25 is the same as the thrust direction A.

  The coils 24 are wound around the coil winding recesses 232 of the bobbin 23 and connected so that current flows in the same direction A on the upper and lower sides of the shaft 25. And the needle | mover 3 demonstrated below can be reciprocated by switching the direction through which an electric current flows. In the present embodiment, the pair of bobbins 23 are joined to each other, and the stator 2 formed by winding the coils 24 around the coil winding recesses 232 is set to have a substantially rectangular parallelepiped shape. Yes.

  The mover 3 includes an outer core 31 and a movable spacer 32. The outer core 31 is formed by laminating and bonding thin steel plates in the thrust direction A. The outer core 31 is disposed outside the inner core 21. A predetermined gap is formed between the inner surface of the outer core 31 and the outer surface of the inner core 21 facing each other. In FIG. 1, the entire outer core 31 and the entire inner core 21 are hatched (oblique lines).

  The movable spacer 32 is directly connected to the outer core 31 and is connected to the stator 2 via the connecting device 5. The outer core 31 and the movable spacer 32 are frame-shaped having a substantially rectangular shape when viewed from the front.

  The mover 3 having such a configuration is coupled to the stator 2 via a coupling device 5. The connecting device 5 supports the stator 21 and the movable element 3 connected coaxially and concentrically. As shown in FIG. 2, a plurality of laminated leaf springs 51 and adjacent leaf springs 51 are connected. And a vibration buffer member 52 sandwiched between the two. The leaf spring 51 and the vibration damping member 52 have the same or substantially the same shape, and the center portion of the leaf spring 51 (a shaft insertion hole 512a to be described later) and the center portion of the vibration damping member 52 (a shaft insertion hole 522a to be described later). In FIG. 2, for convenience of explanation, the leaf spring 51 is moved to the left side of the drawing, and the vibration damping member 52 is moved to the right side of the drawing.

  As shown in FIG. 3, the leaf spring 51 is formed between a frame portion 511 having a frame shape, a step portion 251 provided on the shaft 25, and the first spacer S1, or between the first spacer S1 and the second spacer S2. A stator side fixing portion 512 sandwiched between and fixed to the stator 2 side; a mover side fixing portion 513 sandwiched between the movable spacer 32 and the flange F and fixed to the mover 3 side; It is a thin plate-like one integrally having an arm portion 514 that connects the stator side fixing portion 512 and the mover side fixing portion 513.

  The frame portion 511 has a substantially rectangular shape having a pair of upper and lower short sides 511a and a pair of left and right long sides 511b, and has bolt insertion holes 511c penetrating in the thickness direction at the four corners. .

  The stator side fixing portion 512 is provided at the center of the leaf spring 51 and has a substantially annular shape having a shaft insertion hole 512a through which the shaft 25 can be inserted. The “stator side fixing portion 512” corresponds to “a fixed portion of the leaf spring with respect to the stator” in the present invention.

  The mover side fixing portion 513 is provided at each of the upper end portion and the lower end portion of the leaf spring 51, and has a substantially partial annular shape having an upper opening portion 513a or a lower opening portion 513b that opens upward or downward. The “mover-side fixing portion 513” corresponds to the “fixed portion of the leaf spring with respect to the mover” in the present invention.

  The arm portion 514 includes a first arm 514a extending from a plurality of predetermined locations (four locations in the illustrated example) of the stator side fixing portion 512 toward the long side portion 511b of the frame portion 511, and a frame portion extending from the tip of the first arm 514a. 511 includes a second arm 514b that extends substantially in parallel with the long side portion 511b and a third arm 514c that extends from the tip of the second arm 514b toward the mover-side fixing portion 513. In the present embodiment, a total of four arm portions 514 form an approximately eight shape together with the stator side fixing portion 512 and the mover side fixing portion 513.

  In the present embodiment, four plate springs 51 having such a shape are stacked, and a vibration buffer member 52 is interposed between the plate springs 51.

  The vibration buffer member 52 is made of porous PTFE (polytetrafluoroethylene) as a main material. In the present embodiment, as the vibration buffer member 52, as shown in FIG. 4, a thin plate having the same shape as or substantially the same shape as the leaf spring 51 is applied.

  That is, the vibration buffer member 52 includes a frame contact portion 521 that can contact the frame portion 511 of the leaf spring 51, a first fixed contact portion 522 that can contact the stator-side fixing portion 512 of the leaf spring 51, and the leaf spring 51. The second fixed contact portion 523 that can come into contact with the movable element side fixed portion 513 and the arm contact portion 524 that can come into contact with the arm portion 514 in the leaf spring 51 are integrally provided.

  The frame contact portion 521 has a substantially rectangular shape having a pair of upper and lower short sides 521a and a pair of left and right long sides 521b, and has bolt insertion holes 521c penetrating in the thickness direction at the four corners. is there.

  The first fixed contact portion 522 is provided in the central portion of the vibration damping member 52 and has a substantially annular shape having a shaft insertion hole 522a through which the shaft 25 can be inserted.

  The second fixed contact portion 523 is provided at each of the upper end portion and the lower end portion of the vibration damping member 52, and has a substantially partial annular shape having an upper opening portion 523a and a lower opening portion 523b that open upward or downward.

  The arm contact portion 524 includes, among the arm contact portions 524, a first arm contact portion 524a and a second arm corresponding to the first arm 514a, the second arm 514b, and the third arm 514c of the arm portion 514 in the leaf spring 51, respectively. The contact portion 524b and the third arm contact portion 524c are provided.

  In the present embodiment, the vibration buffer member 52 having such a shape is attached to the plate spring 51 using an adhesive, whereby a plurality of plate springs 51 and the vibration buffer member 52 sandwiched between the plate springs 51 and The connecting device 5 provided with is configured. In FIG. 1, the entire coupling device 5 is hatched (shaded).

  In the present embodiment, of the pair of upper and lower parallel pins P penetrating the outer core 31 and the movable spacer 32 constituting the mover 3 in the thrust direction A, one of the parallel pins P is positioned above the mover side fixing portion 513. The opening 513a is inserted into the upper opening 523a in the second fixed contact portion 523, and the other pin P is inserted into the lower opening 513b in the mover side fixing portion 513 and the lower opening 523b in the second fixed contact portion 523. It is inserted. Note that both end portions of these parallel pins P are fitted into a recess F1 provided in the flange F (see FIG. 1). Also, the bolt through holes 511c formed in the frame portion 511 and the bolts B inserted through the bolt through holes 521c formed in the frame contact portion 521 are also used in the bolt through holes (not shown) formed in the mover 3 and the flange F, respectively. It penetrates and is fastened to the nut N.

  Such a connecting device 5 supports the mover 3 in the thrust direction A while being elastically deformed as a whole when the mover 3 reciprocates. In particular, the arm portion 514 in the leaf spring 51 and the arm contact portion 524 in the vibration buffer member 52 are not directly fixed to the stator 2 and the movable element 3, so that the movable element 3 that is easily elastically deformed and reciprocates is appropriately used. Can be elastically supported. In particular, among the arm portions 514 of the leaf spring 51, the second arm 514 b which is a portion relatively separated from the stator side fixing portion 512 and the mover side fixing portion 513, and the arm contact portion 524 of the vibration buffer member 52. Among them, the second arm contact portion 524b is relatively easily elastically deformed as compared with other portions, and can appropriately elastically support the movable element 3 that reciprocates.

  Furthermore, since the coupling device 5 according to the present embodiment has the vibration buffer member 52 in contact with the entire plate spring 51, the vibration acting on the plate spring 51 can be reduced and the mass of the entire coupling device 5 can be reduced. By changing the resonance frequency, the breakage and wear of the leaf spring 51 due to vibration resonance can be reduced.

  In particular, since the coupling device 5 according to the present embodiment sandwiches the vibration damping member 52 between the laminated leaf springs 51, the occurrence of fretting due to friction between the leaf springs 51 can be prevented or suppressed. It is possible to prevent or suppress the breakage and wear of the leaf spring 51 due to the leaf springs 51 striking each other.

  Further, since the vibration damping member 52 is sandwiched between the adjacent leaf springs 51 and the vibration damping member 52 is adhered to the leaf spring 51 with an adhesive, a lubricant such as oil or grease is applied to the leaf spring 51. If there is a problem that may occur, that is, the problem of adsorbing impurities such as dust or taking them into the connecting device 5 can be solved.

  Further, in the coupling device 5 according to the present embodiment, the leaf spring 51 includes a stator side fixing portion 512 that is a portion that is fixed to the stator 2 and a mover side fixing portion 513 that is a portion that is fixed to the mover 3. Further, since the vibration damping member 52 (specifically, the first fixed contact portion 522 and the second fixed contact portion 523) is in contact with each other, the connecting portion between the stator 2 and the leaf spring 51, and the mover 3 It is possible to directly and effectively relieve vibrations that may occur at the connecting portion with the leaf spring 51, and to effectively prevent or suppress damage and wear of the leaf spring 51.

  In addition, since the coupling device 5 according to the present embodiment sets the leaf spring 51 and the vibration damping member 52 in the same shape, the leaf spring 51 and the vibration damping member 52 are mutually or entirely in the stacking direction. It is possible to make contact almost entirely, and the vibration damping function of the vibration damping member 52 can be obtained efficiently.

  In addition, since the vibration damping member 52 is made of porous PTFE as a main material, the coupling device 5 excellent in practicality and versatility can be provided using the characteristics of the porous PTFE.

  Specifically, by utilizing the low friction property and cushioning property (elastic effect) of the porous PTFE, it is possible to greatly reduce the wear and the striking force between the leaf springs 51, and such a porous PTFE By adhering the vibration damping member 52 as the main raw material to the leaf spring 51, an adhesive layer that can function as a relaxation agent can be formed between the leaf springs 51, and the plate springs 51 have different behaviors (flapping, etc.). Can be suppressed.

  Further, when the coupling device 5 is fixed to the stator 3 or the mover 2, even if the elastic effect (cushioning property) of the porous PTFE is reduced due to the fixing pressure, the low friction property of the porous PTFE is reduced. Thus, the effect of reducing friction can be obtained.

  Furthermore, due to the chemical stability, thermal stability, flame retardancy, light resistance, etc. of porous PTFE, compared with the mode in which oil or grease is applied to the leaf spring 51, the environmental resistance and aging resistance are improved. It becomes an excellent connecting device. Further, by press-fitting and solidifying the adhesive into the pores of the porous PTFE, it is possible to perform mechanical adhesion due to the anchor effect, prevent the displacement of the leaf spring 51 seen in oil or grease, A reduction in the capability of the coupling device 5 due to the displacement of the spring 51 can be avoided.

  In addition, the coupling device 5 according to the present embodiment has an effect that impurities are not taken in or pinched between the leaf springs 51 due to the low electric resistance of the porous PTFE, coupled with not using oil or grease. be able to.

  Further, the waterproof and moisture-permeable property and water repellency of the porous PTFE can provide a moisture-proof effect around the leaf springs 51, and it is difficult for the space between the leaf springs 51 to become high humidity, so that the oxidation resistance of the leaf springs 51 is improved. This is particularly useful in a mode in which the connecting device is disposed in a sealed space like the linear actuator 1 of the present embodiment.

  As described in detail above, the coupling device 5 according to the present embodiment can prevent the function from being reduced or stopped due to the breakage or wear of the leaf spring 51.

  In addition, this invention is not limited to embodiment mentioned above. For example, the vibration damping member may be any member that can contact at least a part of the leaf spring, and a member that is not the same shape as the leaf spring may be applied as the vibration damping member. Or even if it is a case where a leaf | plate spring and a vibration buffer member are set to the same shape, you may employ | adopt the aspect which makes a vibration buffer member contact only a part of leaf | plate spring intentionally.

  Furthermore, in the above-described embodiment, as an aspect in which the vibration damping member is brought into contact with the leaf spring, an aspect in which the vibration damping member is bonded using an adhesive is illustrated, but instead of this, “welding”, “fusion”, or “crimping” It is good also as an aspect which carries out. Further, the vibration buffer member may be pressed against the leaf spring.

  Further, the coupling device may include a single leaf spring, and a vibration buffer member may be in contact with a part or all of the leaf spring.

  Further, the vibration buffer member may be formed using Gore-Tex (registered trademark) as a main material, or formed using rubber or silicon as a main material.

  In addition, the shape of the leaf spring and the vibration damping member may be changed as appropriate, such as setting the outer shape of the leaf spring to be circular.

  In the above-described embodiment, the mode in which the coupling device is applied to the outer movable linear actuator is illustrated. However, the present invention is not limited to this and may be applied to the inner movable linear actuator. The linear actuator may be, for example, a voice coil type, a moving magnet type, or a linear solenoid type.

  Further, the connecting device according to the present invention having the above-described configuration is arranged at a connecting portion between the mover and the stator, and the connecting device is biased in a direction to move the mover closer to the stator or away from the stator, For example, based on whether or not the energization state of the exciting coil is cut off, the state can be changed between a state where the mover is in contact (connected) with the stator and a state where the mover is disconnected from the stator. It is also possible to configure a clutch.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Linear actuator 2 ... Stator 3 ... Movable element 5 ... Connecting device 51 ... Leaf spring 52 ... Vibration damping member

Claims (5)

A plate spring that connects a stator and a movable element that operates with respect to the stator, and is applied to a linear actuator or a clutch,
The leaf spring has a stator side fixing portion fixed to the stator side, and a mover side fixing portion fixed to the mover side,
A vibration buffer member having a first fixed contact portion that can come into contact with the stator side fixed portion and a second fixed contact portion that can come into contact with the mover side fixed portion and cushions vibrations is fixed to the stator side And a part of the leaf spring including at least the stator side fixing portion and the mover side stator portion. apparatus. The coupling device according to claim 1, wherein a plurality of the leaf springs are stacked, and the vibration damping member is sandwiched between adjacent leaf springs. The coupling device according to claim 1 or 2, wherein the vibration damping member is formed of porous PTFE as a main material. The coupling device according to claim 1, wherein the vibration buffer member has the same or substantially the same shape as the leaf spring . A linear actuator comprising a mover, a stator, and the coupling device according to claim 1.

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