JP2013204697A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator capable of improving durability without changing a product size.SOLUTION: A pin plane 102 is formed in a stopper pin 101 on the side of an operation shaft 91 which is abutted in regulating movement of the operation shaft 91. A stopper plane 122 is formed in a stopper 121 on the side of a rotor 42. When the stopper pin 101 in contact with the stopper 121 regulates the axial movement of the operation shaft 91 due to the rotation of the rotor 42, the pin plane 102 of the stopper pin 101 and the stopper plane 122 of the stopper 121 are brought into surface-contact with each other. Thus, a contact surface can be enlarged remarkably, and a surface pressure between both planes can be reduced, thereby improving durability of the stopper pin 101 and the stopper 121.

Description

  The present invention relates to an actuator that converts rotational motion into linear motion.

  Conventionally, an electric linear actuator is known as an actuator that converts a rotational motion of a motor into a linear motion (for example, Patent Document 1).

  The electric linear actuator includes an electric motor, a ball screw including a screw shaft and a nut, a rod shaft extending in parallel to the ball screw, and a connecting member that connects the rod shaft and the nut. The rotary motion of the electric motor is converted into a linear motion by the ball screw.

  The connecting member is provided with a stopper portion, and the stopper portion abuts against the housing so that linear movement can be restricted.

  On the other hand, FIG. 3A is a diagram showing another actuator 801 and shows a stopper structure of the actuator 801 (for example, Patent Document 2).

  The actuator 801 includes a stepping motor 811, and a drive gear 813 of the stepping motor 811 fixed to the bracket 812 is configured to mesh with a rotation gear 814 supported by the bracket 812. The male threaded portion 815 of the output rod 816 is engaged with the male threaded portion 815 at the center of the rotating gear 814, and the output rod 816 moves in the axial direction according to the rotation of the stepping motor 811. It is configured.

  A cylindrical horizontal pin 821 extends laterally from the output rod 816, and a rectangular block-shaped protrusion 822 is provided on the upper surface of the rotating gear 814.

  As a result, as shown in FIG. 3B, the rotation is stopped when the horizontal pin 821 comes into contact with the side surface of the protrusion 822 from the rotation direction, and functions as a stopper. .

JP 2009-270709 A JP 2007-053857 A

  However, such a conventional actuator 801 has a structure in which the horizontal pin 821 of the output rod 816 is brought into contact with the side surface of the protrusion 822 having a rectangular block shape for the purpose of initializing the output rod 816 as an operation shaft. , Both the protrusion 822 and the horizontal pin 821 are required to be durable.

  At this time, if the horizontal pin 821 or the protrusion 822 is damaged, initialization cannot be performed, and the position control accuracy of the output rod 816 is deteriorated.

  Here, in order to improve the durability at the time of initialization, it is necessary to improve the strength of the contact portion between the horizontal pin 821 and the protruding portion 822 or to reduce the contact surface pressure. Cost increases can occur.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an actuator capable of improving durability without changing the product size.

  In order to solve the above-mentioned problem, in the actuator according to the first aspect of the present invention, the operating shaft in which the male screw portion that rotates the rotor and is screwed into the female screw portion of the rotor is formed on the peripheral surface in the axial direction. In the actuator that moves and stops the stopper pin provided on the operating shaft in contact with the stopper provided on the rotor to restrict the axial movement of the operating shaft, the stopper pin and the contact portion of the stopper are It consisted of a plane.

  That is, the contact portion between the stopper pin on the operating shaft and the stopper on the rotor side that abuts when restricting the movement of the operating shaft is a flat surface, compared with the case where the cylindrical stopper pin peripheral surface is in line contact. Thus, the contact area is enlarged.

  Thereby, both surface pressures are reduced and durability of the stopper pin and the stopper is improved.

  According to a second aspect of the present invention, the plane constituting the contact portion between the stopper pin and the stopper is set obliquely with respect to the rotor shaft.

  That is, the plane that constitutes the contact portion between the stopper pin and the stopper is set obliquely with respect to the rotor shaft, and compared with the case where the contact surface is formed parallel to the rotor shaft, Is enlarged.

  Thereby, both surface pressure is further reduced, and the durability of the stopper pin and the stopper is further improved.

  Furthermore, in the actuator of claim 3, one of the stopper pin and the stopper is made of resin and the other is made of metal.

  That is, one of the stopper pin and the stopper is made of resin, and the other is made of metal.

  For this reason, the durability on the resin molding side is reduced, but the durability is improved by reducing the surface pressure by increasing the contact area described above.

  As described above, in the actuator according to the first aspect of the present invention, the contact portion between the stopper pin on the operating shaft side that contacts when the movement of the operating shaft is regulated and the stopper on the rotor side is configured as a plane. Thus, the contact area can be increased.

  Thereby, both surface pressure can be reduced and the durability of the stopper pin and the stopper can be improved.

  For this reason, compared with the case where a stopper pin and a stopper are enlarged and an intensity | strength is improved, durability can be improved, without causing the expansion of a product size or the increase in product cost. Thereby, even when the stopper pin and the stopper are brought into contact with each other for the purpose of initialization, the stopper pin or the stopper can be reliably prevented from being damaged, and the position control accuracy of the operating shaft can be ensured. it can.

  Further, in the actuator according to claim 2, as compared with the case where the plane is formed parallel to the rotor axis by setting the plane constituting the contact portion between the stopper pin and the stopper obliquely with respect to the rotor axis. The contact area at the time of contact can be enlarged.

  Thereby, both surface pressure can be further reduced and durability of the stopper pin and the stopper can be further improved.

  Furthermore, in the actuator according to a third aspect, one of the stopper pin and the stopper is made of resin, and the other is made of metal.

  For this reason, the durability on the resin molding side is reduced, but the durability can be improved by reducing the surface pressure by expanding the contact area described above.

  Thereby, durability can be aimed at, ensuring cost reduction by resin molding, weight reduction, and moldability ease.

It is explanatory drawing which shows 1st embodiment of this invention. It is explanatory drawing which shows 2nd embodiment of this invention. It is explanatory drawing which shows the conventional actuator.

  (First embodiment)

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an actuator 1 according to the present embodiment. The actuator 1 is provided in an automatic transmission of an automobile and is used for controlling hydraulic pressure in the automatic transmission.

  The casing 11 of the actuator 1 includes a proximal end case 12 constituting the proximal end side, and a distal end side case 13 provided on the distal end side of the proximal end case 12. The base end side case 12 is formed by press forming a metal, and is formed in a container shape opened toward the front end.

  The distal end side case 13 is formed of a synthetic resin, and is formed in the large diameter portion 21 on the proximal end side connected to the proximal end side case 12. A small-diameter portion 22 is formed on the distal end side of the large-diameter portion 21, and the distal-side case 13 is configured to penetrate from the distal end to the proximal end.

  A stepping motor 31 is accommodated in the casing 11, and a connector connecting portion 32 extends from a side portion of the base end side case 12. The connector connecting portion 32 is provided with an electrode terminal, and the electrode terminal is connected to the stepping motor 31.

  Thereby, an input signal from a plug connected to the connector connecting portion 32 is configured to be supplied to the stepping motor 31 via the electrode terminal, and the stepping motor 31 responds to the input signal. It is configured to operate.

  The stepping motor 31 includes a stator 41 fixed to the casing 11 and a hollow rotor 42 rotatably held in the stator 41.

  The stator 41 includes a plurality of stator coils 51,..., And the stator coil 51 is configured to be supplied with the input signal. Thereby, each status coil 51, ... is comprised so that it may be excited according to the said input signal.

  A proximal end cylindrical portion 61 extending toward the proximal end is formed at the proximal end of the rotor 42, and a distal end side cylindrical portion 62 extending toward the distal end side is formed at the distal end of the rotor 42. ing. In the rotor 42, the base end side cylindrical portion 61 is rotatably supported by a bearing concave portion 64 of the base end side case 12 via a rear bearing 63, and the tip end side cylindrical portion 62 supports the front bearing 65. And is rotatably supported in the large-diameter portion 21 of the distal end side case 13.

  The rotor 42 is formed in a cylindrical shape, and a plurality of permanent magnets 71 are fixed to the outer peripheral surface of the rotor 42. The permanent magnets 71 are arranged so as to face the stator coils 51, and the rotor 42 is controlled to rotate according to the excitation state of the stator coils 51,. It is configured to be.

  On the inner side surface of the rotor 42, convex ridges partially protruding inward are formed in a ring shape, and a reduced diameter portion is formed. An internal thread portion is formed on the inner side surface of the ridge (not shown).

  An operation shaft 91 is inserted into the rotor 42, and the operation shaft 91 includes a proximal-side component 92 that is inserted deeper than the ridge of the rotor 42, and a distal end than the ridge. It is comprised by the front end side structure part 93 extended to the side. A male screw portion 94 is formed on the outer peripheral surface of the base end side configuration portion 92, and the male screw portion 94 is configured to be screwed with the female screw portion formed on the convex strip of the rotor 42. ing.

  A stopper pin 101 that constitutes a stopper is press-fitted and fixed to the base end side peripheral surface of the distal end side configuration portion 93 of the operating shaft 91. The stopper pin 101 is formed of a cylindrical metal part, and a tip portion thereof is cut along the axis of the stopper pin 101 to be processed into a stepped shape. Thereby, a flat pin plane 102 is formed at the tip of the stopper pin 101.

  The pin plane 102 is cut and formed to a depth half that of the diameter of the stopper pin 101 so that the area thereof is maximized, and is formed on the central axis of the stopper pin 101. The stopper pin 101 is disposed so that the pin plane 102 is parallel to the operating shaft 91, that is, the rotor shaft 111 from which the operating shaft 91 extends, and is fixed to the operating shaft 91 in this state. ing.

  On the other hand, a stopper 121, which is a block-shaped protrusion, is integrally formed on the inner side surface of the distal end side cylindrical portion 62 of the rotor 42 with a resin forming the rotor 42, and the stopper 121 is formed on the side surface. A flat stopper plane 122 is formed.

  Accordingly, the stopper pin 101 is configured to abut against the stopper 121 formed on the rotor 42 from the side surface thereof, that is, from the stopper plane 122 side. The stopper flat surface 122 is in surface contact, and the movement of the operating shaft 91 that moves in the axial direction along with the rotation of the rotor 42 can be restricted.

  The distal end side configuration portion 93 of the operating shaft 91 is rotatably supported by the small diameter portion 22 of the distal end side case 13, and the distal end portion extends outward from the distal end side case 13. It is configured.

  The proximal end portion of the metal guide shaft 131 is fixed to the side portion of the distal end side case 13 from which the operating shaft 91 extends. The guide shaft 131 extends in parallel with the operation shaft 91, and its tip end portion extends in the protruding direction of the operation shaft 91.

  A guide member 141 is provided between the guide shaft 131 and the operating shaft 91. The guide member 141 is formed of a metal block, and is movable along the guide shaft 131 while being fixed to the operating shaft 91.

  Accordingly, the operating shaft 91 is configured to be engaged with the guide shaft 131 via the guide member 141, thereby preventing inadvertent rotation, and the stator of the stepping motor 31. When the rotor 42 is rotated in response to the input signal applied to 41, the operating shaft 91 screwed into the female screw portion of the rotor 42 is moved in the axial direction, and the casing of the operating shaft 91 is moved. The amount of protrusion from 11 can be varied.

  In the present embodiment having the above-described configuration, a pin plane 102 is formed on the stopper pin 101 on the side of the operating shaft 91 that contacts when the movement of the operating shaft 91 is restricted, and a stopper 121 is formed on the stopper 121 on the rotor 42 side. A flat surface 122 is formed, and when the stopper pin 101 abuts on the stopper 121 and restricts the movement of the operating shaft 91 in the axial direction accompanying the rotation of the rotor 42, the stopper pin 101 The pin plane 102 and the stopper plane 122 of the stopper 121 are in surface contact.

  For this reason, compared with the case where the circumferential surface of the cylindrical stopper pin is in line contact with the side surface of the stopper, the contact area can be greatly increased, and thereby the surface pressure of both can be reduced. The durability of the stopper 121 can be improved.

  Therefore, compared with the case where the stopper pin 101 or the stopper 121 is enlarged and the strength is improved, the durability can be improved without increasing the product size of the actuator 1 or increasing the product cost. .

  Further, even when the stopper pin 101 and the stopper 121 are brought into contact with each other for the purpose of initializing the home position, the stopper pin 101 or the stopper 121 can be reliably prevented from being damaged. The position control accuracy can be ensured.

  The stopper pin 101 is made of metal, and the stopper 121 is made of resin.

  For this reason, the durability of the stopper 121 on the resin molding side is reduced, but the durability can be improved by reducing the surface pressure by increasing the contact area.

  Thereby, durability can be aimed at, ensuring cost reduction by resin molding, weight reduction, and moldability ease.

  At this time, in the present embodiment, the stopper 42 formed integrally with the rotor 42 is made of resin by molding the rotor 42 formed of relatively large parts. For this reason, compared with the case where the said comparatively large said rotor 42 is formed with a metal, cost reduction can be achieved. Further, the rotor 42 whose rotation is controlled can be reduced in weight by resin molding, and the rotor 42 having a complicated shape can be easily formed.

  In this embodiment, the stopper pin 101 is made of metal, and the rotor 42 and the stopper 121 integrally formed with the rotor 42 are made of resin. It is not limited to.

For example, the stopper pin 101 may be formed of resin and the stopper 121 may be formed of metal, or both the stopper pin 101 and the stopper 121 may be formed of metal or resin.

  (Second embodiment)

  FIG. 2 is a diagram showing the second embodiment, where the same or equivalent parts as those in the first embodiment are denoted by the same reference numerals and the explanation is omitted, and only different parts are explained. To do.

  That is, the pin plane 102 and the stopper plane 122 constituting the contact portion between the stopper pin 101 and the stopper 121 are set obliquely with respect to the rotor shaft 111.

  More specifically, the pin plane 102 of the stopper 121 press-fitted and fixed to the operating shaft 91 is within the lead angle of the lead screw formed on the operating shaft 91 with respect to the axial direction of the operating shaft 91. The stopper plane 122 of the stopper 121 provided on the rotor 42 side is also inclined at the same angle.

  Preferably, when the rotor 42 is rotated and the operating shaft 91 is moved to the proximal end side, the pin plane 102 abuts on the stopper plane 122 at an angle close to perpendicular.

  In the present embodiment according to the above configuration, the pin plane 102 of the stopper pin 101 and the stopper plane 122 of the stopper 121 are set obliquely with respect to the rotor shaft 111 so that the planes 102 and 122 are Compared with the case where the rotor shaft 111 is formed in parallel, the contact area at the time of contact can be further increased.

  Thereby, the surface pressure of both 102 and 122 can be further reduced, and the durability of the stopper pin 101 and the stopper 121 can be further improved as compared with the first embodiment.

  Then, the stopper plane 122 of the stopper pin 101 is fixed at an angle within the lead angle of the lead screw with respect to the operating shaft 91, and the stopper plane 122 on the rotor 42 side is also inclined at the same angle. Thus, the flat surfaces 102 and 122 parallel to the operating shaft 91 can be formed, the contact area can be increased, and the contact surface pressure can be further reduced in the same necessary space as the conventional stopper pin. .

DESCRIPTION OF SYMBOLS 1 Actuator 42 Rotor 91 Actuation shaft 94 Male thread part 101 Stopper pin 102 Pin plane 111 Rotor shaft 121 Stopper 122 Stopper plane

Claims (3)

The rotor has a male threaded portion that engages with the female threaded portion of the rotor and moves the working shaft formed on the peripheral surface in the axial direction, and a stopper pin provided on the working shaft is provided on the rotor. In the actuator that contacts the stopper and restricts the movement of the operating shaft in the axial direction,
An actuator characterized in that the stopper pin and the abutting portion of the stopper are configured in a plane.   The actuator according to claim 1, wherein a plane constituting a contact portion between the stopper pin and the stopper is set obliquely with respect to a rotor shaft.   3. The actuator according to claim 1, wherein one of the stopper pin and the stopper is made of resin and the other is made of metal.

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