JP3710098B2 - Electric actuator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention conveys the workpiece by transmitting the rotational driving force of the motor unit provided in the frame to the slide table via a ball screw , and displacing the slide table along a guide rail fixed to the frame. The present invention relates to an electric actuator.
[0002]
[Prior art]
Conventionally, for example, an electric actuator has been used as a means for conveying a workpiece. This electric actuator basically includes an electric motor disposed in the frame of the actuator, and a driving force transmission means such as a ball screw that converts the rotational driving force of the electric motor into a linear motion and transmits it to other members. And a slide table that is displaced along the longitudinal direction of the frame via the driving force transmission means, and each component is formed of a single part and assembled to each component. ing.
[0003]
A coupling member is interposed between the electric motor and the ball screw to connect the motor shaft and the ball screw coaxially and transmit the rotational motion of the motor shaft to the ball screw. In addition, a support block or the like that pivotally supports the ball screw is provided at one end of the ball screw, and further, close to or integrated with the electric motor. An encoder that detects an angle or the like is provided.
[0004]
[Problems to be solved by the invention]
However, in the electric actuator according to the above-described prior art, an extra space other than the moving range of the slide table is required in the overall length in the longitudinal direction of the frame due to the provision of the coupling member and the like, and the overall length in the longitudinal direction of the frame There is an inconvenience that the moving range of the slide table cannot be set.
[0005]
Further, since various components in the electric actuator are each formed of a single part, there is a disadvantage that a lot of time is required for the assembly man-hour and the manufacturing cost increases.
[0006]
The present invention has been made to overcome the above-described disadvantages. The moving range of the slide table is increased so that the moving range and the frame length substantially coincide with each other, and the moving table is arranged on the frame. It is an object of the present invention to provide an electric actuator capable of reducing the assembly cost by unitizing the constituent elements to reduce the manufacturing cost.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention comprises a frame extending along the longitudinal direction;
A pair of linear guides fixed in parallel along the groove formed in the frame;
A slide table that is displaced along the longitudinal direction of the frame under the guiding action of the linear guide;
An end cover detachably mounted opposite to each other at both ends along the longitudinal direction of the frame;
A side cover that is detachably mounted opposite to both side surfaces orthogonal to the longitudinal direction of the frame;
A top cover provided on the upper surface portion along the longitudinal direction of the frame and detachably mounted via the end cover;
A motor unit is integrally provided at one end of the ball screw, and an encoder unit for detecting a rotation speed or a rotation angle of the motor unit is integrally provided at the other end of the ball screw. between the said screwed to the ball screw engagement blocks displaced in the axial direction of the ball screw is disposed, said motor unit, said ball screw, said encoder unit and said engagement block A drive unit that is integrally assembled ; and
A screw member for fixing the motor part to the frame;
The motor unit includes a casing, and a stator wound with a coil and fixed to the casing;
The encoder unit includes an encoder fixing block; a bearing member provided in the encoder fixing block and rotatably supporting the ball screw;
With
The frame is provided with a through-hole having a substantially rectangular cross section that penetrates along the longitudinal direction and is a wiring passage of the drive unit.
When assembling the drive unit to the frame, the motor unit and an encoder unit, by being positioned respectively on a pair of stepped portions formed at both end portions of the frame, pre-fixed linear guide in the frame de parallel accuracy of the ball screw of the drive unit is secured,
The slide table includes a pair of fixed blocks formed in parallel at a predetermined interval, and a holding block integrally coupled between the pair of fixed blocks. The driving block includes the driving unit. when assembled to the frame, the ball screw which can be inserted a gap is formed, characterized in Rukoto.
[0009]
[Action]
The electric actuator according to the present invention includes the drive unit in which the motor unit, the ball screw, the encoder unit, and the engagement block are integrally assembled, so that the drive unit can be easily assembled to the frame. When assembling the drive unit to the frame, by the motor unit and an encoder unit is positioned respectively on a pair of stepped portions formed at both end portions of the frame, pre-fixed linear guide in the frame And the parallel accuracy of the ball screw of the drive unit are ensured. As a result, the assembly work of these members can be performed efficiently in a short time. Further, according to the present invention, by providing a gap through which the ball screw can be inserted in the holding block constituting the slide table, the drive unit in which the motor unit, the ball screw, the encoder unit, and the engagement block are integrally assembled to the frame. When assembled, the engagement block can be easily assembled to the holding block of the slide table.
[0010]
【Example】
Next, a preferred embodiment of the electric actuator according to the present invention will be given and described in detail below with reference to the accompanying drawings.
[0011]
1 is a perspective view of an electric actuator according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a main part of the electric actuator shown in FIG. 1, and FIG. 3 is a partial cross-sectional side view of the electric actuator shown in FIG. 4 is a longitudinal sectional view taken along line IV-IV in FIG.
[0012]
As shown in FIG. 2, the electric actuator 10 basically includes a frame 12 that is elongated along the longitudinal direction, and grooves 14 a and 14 b that are defined on the upper surface of the frame 12. A pair of linear guides 16a and 16b fixed substantially in parallel to each other, a slide table 18 fixed to the linear guides 16a and 16b and displaced along the longitudinal direction of the frame 12, and defined at both ends of the frame 12. The drive unit 20 is positioned and fixed to the set of stepped portions 19 and 21 (see FIG. 2).
[0013]
A pair of end covers 22 and 24 are attached to both ends along the longitudinal direction of the frame 12 so as to face each other, and a pair of side covers 26a, 26b are mounted facing each other, and a top cover 28 is mounted on the upper surface of the frame 12 (see FIG. 1). The end covers 22 and 24, the side covers 26a and 26b, and the top cover 28 are detachably provided on the frame 12, respectively. Further, the frame 12 has first to fourth through holes 30a to 30d having a substantially rectangular cross section (see FIG. 4), and the first to fourth through holes 30a to 30d are formed in the drive unit 20. It is used as a wiring path of Grooves 32a and 32b having a substantially T-shaped cross section extending along the longitudinal direction and connected to other devices and the like are defined on the bottom surface of the frame 12.
[0014]
As shown in FIG. 2, the linear guides 16 a and 16 b are formed in substantially the same shape, and are positioned and fixed in the grooves 14 a and 14 b of the frame 12 through a plurality of fixing holes 34 that are separated by a predetermined distance. A pair of long guide rails 36a and 36b and a pair of guide blocks 38a and 38b slidably displaced along the longitudinal direction of the respective guide rails 36a and 36b. A rolling member (not shown) such as a ball is disposed in the annular passage at a sliding portion between the guide rails 36a and 36b and the guide blocks 38a and 38b, and the guide blocks 38a and 38b are moved along the guide rails 36a and 36b. Can be displaced smoothly.
[0015]
As shown in FIGS. 2 and 4, the slide table 18 is fixed to the pair of guide blocks 38 a and 38 b by screwing, and fixed blocks 40 a and 40 b formed substantially parallel with a predetermined distance therebetween, The holding block 42 is integrally coupled between the fixed blocks 40a and 40b and has a substantially arcuate cross section. A gap 46 having a width through which the ball screw 44 constituting the drive unit 20 can be inserted is defined on the upper surface of the holding block 42, and a substantially circular opening is defined continuously from the gap 46. (See FIGS. 2 and 4).
[0016]
As shown in FIGS. 2 and 3, the drive unit 20 includes a motor unit 48 and an encoder unit 50 provided coaxially at both ends of a ball screw 44 (driving force transmission means), and the motor unit 48 and the encoder. An engagement block 52 provided between the portion 50 and screwed to the ball screw 44 and displaced along the axial direction is integrally formed as a unit. The engaging block 52 is provided with a cylindrical portion 54, and the cylindrical portion 54 is attached to the opening portion of the holding block 42 through a mounting hole 56. In place of the ball screw 44 functioning as a feed screw, a timing belt or the like (not shown) may be used.
[0017]
As shown in FIG. 5, the motor portion 48 is fixed to the step portion 19 of the frame 12 via a screw 58, and a motor fixing block that is positioned at the center of the frame 12 by inserting a positioning pin (not shown). 60, and a casing 62 having a substantially rectangular cross section integrally connected to the motor fixing block 60. A stator 64 is provided on the outer peripheral portion of the casing 62, and a stator coil portion 66 in which a coil is wound around the inner wall surface of the stator 64 is provided. In the casing 62, an end portion of the ball screw 44 extending in the axial direction is supported by a bearing member 68, and a rotor 70 is held at a terminal portion of the ball screw 44 via a set screw 72. Yes.
[0018]
As shown in FIG. 6, the encoder unit 50 rotatably supports the vicinity of the end of the ball screw 44 through a bearing member 74 and is fixed to the stepped portion 21 of the frame 12 through a screw 76. The encoder fixing block 78 is connected to the encoder fixing block 78 via connecting members 80 and 82, and an encoder main body 84 that detects the rotational speed or rotational angle of the motor. In this case, the encoder body 84 is integrally connected to the encoder fixing block 78 and is held by the encoder fixing block 78.
[0019]
The drive unit 20 positions and fixes the motor unit 48 and the encoder unit 50 to the stepped portions 19 and 21 defined at both ends of the frame 12, respectively, thereby fixing the ball screw 44 and the guide rails 36a and 36b. The parallel accuracy can be ensured. Further, positioning holes (not shown) defined in the motor fixing block 60 and the encoder fixing block 78 and positioning holes 86 and 88 defined in the step portions 19 and 21 of the frame 12, respectively. By inserting a positioning pin (not shown) through (see FIG. 2), the motor fixing block 60 and the encoder fixing block 78 can be respectively positioned at the center of the frame.
[0020]
In the drive unit 20, the motor unit 48, the ball screw 44 and the encoder unit 50 are configured as a unit. For example, by using a pulse motor such as a stepping motor (not shown), the motor unit 48 and the ball screw 44. May be configured as a unit.
[0021]
Further, instead of the encoder main body 84, a configuration in which a sensor such as a limit switch is provided in the encoder fixing block 78 may be employed.
[0022]
The electric actuator 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described.
[0023]
First, the assembly process of the electric actuator 10 will be described.
[0024]
As shown in FIG. 2, the linear guides 16 a and 16 b are positioned and fixed in the grooves 14 a and 14 b of the frame 12. Subsequently, the fixing blocks 40a and 40b of the slide table 18 are screwed along the guide blocks 38a and 38b constituting the linear guides 16a and 16b. Next, the engagement block 52 of the drive unit 20 manufactured as a single component is fitted into the holding block 42 of the slide table 18 in advance. In this case, after the ball screw 44 is inserted through the gap 46 of the holding block 42, the ball screw 44 is moved along the axial direction so that the cylindrical portion 54 can be fitted into the opening of the holding block 42. it can.
[0025]
Subsequently, the motor unit 48 and the encoder unit 50 constituting the drive unit 20 are positioned and fixed to the frame 12. That is, after the motor fixing block 60 and the encoder fixing block 78 are positioned on the step portions 19 and 21 of the frame 12 to ensure parallel accuracy between the ball screw 44 and the guide rails 36a and 36b, the positioning pins (not shown) are used. The motor fixing block 60 and the encoder fixing block 78 can be positioned and fixed at the center of the frame 12.
[0026]
Thus, after the pair of linear guides 16a and 16b, the slide table 18 and the drive unit 20 are simply assembled from the upper surface direction of the frame 12, the end covers 22, 24, the side covers 26a and 26b and the top cover are attached to the frame 12. Wear 28. In addition, it is also possible to use it with the frame 12 exposed without attaching the various covers according to the user's application.
[0027]
The electric actuator 10 assembled in this manner energizes a power source (not shown) to drive the motor unit 48 and rotates the ball screw 44 that functions as a motor shaft. In this case, the rotation speed or rotation angle of the motor is detected by the encoder body 84 provided at the end of the ball screw 44, and the detection signal is introduced into a controller (not shown) through lead wires inserted into the through holes 30a to 30d. Is done.
[0028]
The rotational movement of the ball screw 44 is transmitted to the engagement block 52 screwed to the ball screw 44, and the slide table 18 holding the engagement block 52 is smoothly linear along the linear guides 16a and 16b. It is displaced to.
[0029]
As described above, in the electric actuator 10 according to the present embodiment, the motor unit 48 and the encoder unit 50 are provided coaxially and integrally at both ends of the ball screw 44, respectively, and the motor unit 48, the encoder unit 50, the ball The drive unit 20 is configured by integrating the components including the screw 44 and the engagement block 52. For this reason, compared with the prior art which performed the assembling work for each component, the electric actuator 10 according to this example can reduce the number of assembling steps and reduce the manufacturing cost.
[0030]
When the drive unit 20 is unitized, mass production becomes possible, and when a failure occurs for some reason, it can be easily separated from the frame 12 to easily form a new drive unit 20. Can be replaced.
[0031]
Further, in the electric actuator 10 according to the present embodiment, the motor shaft and the ball screw 44 are formed coaxially without using a coupling member, so that the slide table 18 has a length occupied by the coupling member. The moving range is increased, and as a result, the slide table 18 can be moved over substantially the entire length of the frame 12.
[0032]
【The invention's effect】
According to the electric actuator of the present invention, the following effects can be obtained.
[0033]
That is, the motor unit, the ball screw, the encoder unit, and the engagement block are configured as a drive unit integrally assembled, and the motor unit and the encoder unit are respectively provided in a set of stepped portions formed at both ends of the frame. the will lock to the frame of the drive unit and positioned to reduce the assembly man-hours in manufacturing the electric actuator, Ru can be reduced in the manufacturing cost.
[0034]
Further, since the motor unit and the encoder unit are integrated with one end and the other end of the ball screw without using a coupling member as in the prior art, the space for arranging the coupling member is reduced. Thus, the range in which the slide table moves can be increased, and the slide table can be moved over substantially the entire length of the frame .
[Brief description of the drawings]
FIG. 1 is a perspective view of an electric actuator according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a main part of the electric actuator shown in FIG.
FIG. 3 is a partial sectional side view of the electric actuator shown in FIG. 1;
4 is a longitudinal sectional view taken along line IV-IV shown in FIG.
FIG. 5 is a partial cross-sectional view of a motor unit constituting the drive unit.
FIG. 6 is a partial cross-sectional view of an encoder unit constituting the drive unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Electric actuator 12 ... Frame 14a, 14b ... Groove part 16a, 16b ... Linear guide 18 ... Slide table 19, 21 ... Step part 20 ... Drive unit 36a, 36b ... Guide rail 38a, 38b ... Guide block 40a, 40b ... Fixed block 42 ... Holding block 48 ... Motor part 50 ... Encoder part 52 ... Engagement block 54 ... Cylindrical part 60 ... Motor fixing block 78 ... Encoder fixing block 84 ... Encoder body

Claims (1)

A frame extending along the longitudinal direction;
A pair of linear guides fixed in parallel along the groove formed in the frame;
A slide table that is displaced along the longitudinal direction of the frame under the guiding action of the linear guide;
An end cover detachably mounted opposite to each other at both ends along the longitudinal direction of the frame;
A side cover that is detachably mounted opposite to both side surfaces orthogonal to the longitudinal direction of the frame;
A top cover provided on the upper surface portion along the longitudinal direction of the frame and detachably mounted via the end cover;
A motor unit is integrally provided at one end of the ball screw, and an encoder unit for detecting a rotation speed or a rotation angle of the motor unit is integrally provided at the other end of the ball screw. between the said screwed to the ball screw engagement blocks displaced in the axial direction of the ball screw is disposed, said motor unit, said ball screw, said encoder unit and said engagement block A drive unit that is integrally assembled ; and
A screw member for fixing the motor part to the frame;
The motor unit includes a casing, and a stator wound with a coil and fixed to the casing;
The encoder unit includes an encoder fixing block; a bearing member provided in the encoder fixing block and rotatably supporting the ball screw;
With
The frame is provided with a through-hole having a substantially rectangular cross section that penetrates along the longitudinal direction and is a wiring passage of the drive unit.
When assembling the drive unit to the frame, the motor unit and an encoder unit, by being positioned respectively on a pair of stepped portions formed at both end portions of the frame, pre-fixed linear guide in the frame de parallel accuracy of the ball screw of the drive unit is secured,
The slide table includes a pair of fixed blocks formed in parallel at a predetermined interval, and a holding block integrally coupled between the pair of fixed blocks. The driving block includes the driving unit. when assembling the said frame, the electric actuator, wherein Rukoto said ball screw which can be inserted a gap is formed.

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