JP3593911B2 - Linear actuator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a linear actuator having a sensor mounting groove for mounting a sensor for detecting a moving position of a slide body reciprocating along a base by a driving device mounted along the base.
[0002]
[Prior art]
Conventionally, a drive unit mounted along the base reciprocates the slide body guided along the base longitudinal direction, as a sensor mounting groove for mounting a sensor for detecting the movement position of the slide body, For example, (1) those disclosed in Japanese Patent No. 2502856 and Japanese Patent Application Laid-Open No. 9-177717 are known. In these, a sensor mounting rail having a mounting groove is integrally formed on a side surface of the base. (2) In the device disclosed in JP-A-59-227351, a sensor mounting rail for mounting a sensor is mounted on a side wall surface of a base from a width direction (a direction perpendicular to a longitudinal direction). Also, (3) Japanese Patent Application Laid-Open No. 3-28508 discloses a rodless cylinder which is a linear actuator without a base, and has a length of a slide body integrally provided on a piston of the rodless cylinder. A sensor mounting rail provided with a mounting groove for a sensor that detects a moving position in the direction is mounted on the outer peripheral surface of the end cap at both ends in the longitudinal direction of the rodless cylinder from the width direction.
[0003]
[Problems to be solved by the invention]
In the conventional method (1), the sensor mounting rail and the base are integrally formed as a profile, and the sensor mounting rail of the profile is formed due to a difference in thickness between the sensor mounting rail and the base when the profile is formed. There was a problem that the part to be distorted. In addition, since the sensor mounting rail and the base are integrated, the outer shape of the profile increases, and thus the size of the profile increases. In addition, since the sensor mounting rail is formed integrally with the base, it is determined on both sides or one side in the base width direction from the beginning, and there is a problem that the position of the sensor mounting rail cannot be freely selected left and right.
[0004]
In (2), the sensor mounting rail and the base are configured separately. However, in order to mount the sensor mounting rail on the side wall surface of the base from the width direction, the sensor mounting rail is fixed on the side wall surface of the base. The screw hole of the screw must be machined from the width direction, and the screw hole for screwing the end plate to both ends in the longitudinal direction of the base must be machined from two directions. Since the length of the linear actuator is appropriately set, it is necessary to machine the screw holes at a pitch in the base longitudinal direction of the screw holes corresponding to each base length when machining the screw holes.
[0005]
In (3), the sensor mounting rail is different from that of the present invention in that the sensor mounting rail is not screwed on the side surface of the end cap from the width direction, and there are rodless cylinders having a plurality of lengths. Therefore, as in (2), there is a problem that machining from two directions and thread holes with a pitch corresponding to the length of each rodless cylinder are required. Further, when the apparatus is mounted on a mechanical device so that both ends are supported only by the end cap portion, the overall rigidity is lower than that using the base, and there is a possibility that the linear guide lacks smoothness.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to prevent distortion occurring in a profile when a sensor mounting rail and a base are extruded or drawn and to reduce the size of the profile. Another object of the present invention is to make it possible to select the mounting of the sensor mounting rail on the left and right in the width direction. It is another object of the present invention to reduce the processing direction of the base and simplify the processing by eliminating the processing corresponding to the screw hole pitch set for each length of each linear actuator.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the present invention, a linear actuator for reciprocating a slide guided on a base along a longitudinal direction of a base by a driving device mounted along the base, the moving position of the slide being In a linear actuator having a sensor mounting groove for mounting a sensor for detecting a sensor, a base for mounting a driving device, and a sensor mounting rail having a sensor mounting groove are each composed of a mold material, and the base is formed in a longitudinal direction of the base. The rail mounting engagement part is formed integrally, the sensor mounting rail matches the base length, the engaged part complementary to the rail mounting engagement part, the sensor mounting groove, and the screw-down hole for the fixing screw are formed. It is formed over the entire length in the longitudinal direction. The sensor mounting rail is sandwiched between the end plates fixed to the longitudinal ends of the base by engaging the engaged portions of the sensor from the longitudinal direction, and the screwed lower hole of the sensor mounting rail is viewed from the base longitudinal direction. The sensor mounting rail is fixed to an end plate by a fixing screw screwed into the base plate, and integrally assembled to a base.
[0010]
Further, rail mounting engagement portions are formed symmetrically on both sides in the width direction on the base .
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. The linear actuator 1 shown in FIGS. 1 to 4 includes a base 2, a rodless cylinder 3 as a driving device, a linear guide 4, and a slide body 5. The base 2 is made of, for example, an extruded member of an aluminum alloy, and has a U-shaped cross section as shown in FIG. 5 so that the rodless cylinder 3 is disposed on the inner wall surface 6a side. Has become. As shown in FIGS. 5 and 6, a T groove 9 for attaching an attachment holder 8 and a T groove 10 for attaching a guide rail 4a of two linear guides 4 on both sides in the width direction are provided on the upper wall surface 7a of the base 2. On both sides in the width direction of the wall surface 11a and the side wall surface 12a, T-grooves 13 for mounting the linear actuator 1 are respectively provided over the entire length in the longitudinal direction of the base 2. A nut 47 for fixing the linear actuator 1 to a mechanical device or the like is inserted into each T groove 13 before the end plates 25 and 26 are attached to both ends of the base 2.
[0012]
Further, a T-shaped rail mounting engaging portion 14 is integrally formed symmetrically in the longitudinal direction of the base 2 on both side surfaces 12a on both sides in the width direction, and as shown in FIG. Is formed to be shorter than the entire length of the base 2. The cut portions at both ends in the longitudinal direction are cut to such a length that a fixing screw 16 for mounting a sensor mounting rail 15 described later and an end surface 14a of the rail mounting engaging portion 14 do not interfere with each other. The base 2 is formed with a through-hole 2A having a convex cross-section and penetrating the bottom wall 11 over the entire length thereof. The upper wall 6 of the through-hole 2A has a predetermined length from both ends in the longitudinal direction of the base 2. A bolt insertion groove 19 which has been cut is formed. On the lower surface of the upper wall 6 of the through-hole 2A, a projection 20 is integrally formed over the entire length of the through-hole 2A. The end portion of the through hole 2A is an insertion hole 18 for inserting the cylinder nut 17 at the same time. Reference numeral 21 denotes an air passage 21 integrally formed over the entire length in the longitudinal direction.
[0013]
As shown in FIG. 7, the sensor mounting rail 15 is a shaped member formed by extruding an aluminum alloy, for example, similarly to the base 2, and has a length substantially similar to the entire length of the base 2. The sensor mounting rail 15 has a sensor mounting groove 22 and an engaged portion 23 formed over the entire length in the longitudinal direction. The engaged portion 23 is formed in a complementary shape capable of engaging with the rail attachment engaging portion 14, and a part thereof is a screw-down hole 24 for the fixing screw 16 extending over the entire length in the longitudinal direction. The sensor mounting groove 22 includes a sensor mounting portion 22a for mounting a sensor and a lead wire holding portion 22b capable of holding a lead wire.
[0014]
The sensor mounting rail 15 is such that the engaged portion 23 is engaged with both or one of the rail mounting engaging portions 14 on both sides in the width direction of the base 2 as necessary, and is fixed to the longitudinal end of the base 2. In a state sandwiched between the end plates 25 and 26, the base plate 2 is fixed to the end plates 25 and 26 by fixing screws 16 screwed into the pilot holes 24 from the longitudinal direction of the base 2, and is integrally assembled to the base 2. As described above, the base 2 and the sensor mounting rail 15 which are separately formed from the shape members are integrally assembled, so that the distortion at the time of extrusion molding caused by the difference in the thickness of the sensor mounting rail 15 and the base 2 is prevented. In addition, since the outer shell of the base 2 can be reduced by using the sensor mounting rail 15 separately, the size of the die used for the extrusion molding of the base 2 can be reduced, and the cost can be reduced. In addition, the mounting of the sensor mounting rail 15 to the base 2 can be selected in both or one of the width directions or without mounting as required. In addition, the sensor mounting rail 15 is integrally formed with the pilot hole 24 which is screwed in the longitudinal direction and the fixing screw 16 is screwed in the longitudinal direction of the base 2 and assembled to the base 2. Processing in the width direction of the base 2 can be reduced as compared with the case of mounting, and processing corresponding to the screw hole pitch for each length in the longitudinal direction of each linear actuator 1 is unnecessary, which is preferable.
[0015]
One end plate 25 fixed to the longitudinal end of the base 2 is provided with supply / discharge ports 27 and 28, the other end plate 26 is provided with an air passage 29, and the air passage 29 is provided with an end pipe 30. Is slidably inserted, and the supply / discharge port 28 communicates with the air passage 29 via the air passage 21 of the base 2. When the rodless cylinder 3 is provided on the base 2, two pressing screws 44 for pressing the end pipe 30 toward the rodless cylinder 3 are screwed on the end plate 26 on the left and right sides of the end pipe 30. Have been combined.
[0016]
The rodless cylinder 3 is disposed on the inner side surface 6 of the base 2 to which the end plates 25 and 26 are fixed as shown in FIGS. The rodless cylinder 3 is a known one disclosed in, for example, JP-A-10-299714. A slit 33 is provided in the cylinder tube 32 provided with the cylinder hole 31 over the entire length in the longitudinal direction, and both ends of the cylinder tube 32 are fixed with end caps 34 that fit into and close the cylinder hole 31. Both ends of the inner and outer seal bands 35 and 36 for closing the inside and outside of the slit 33 are fixed to the end cap 34. The end caps 34 at both ends are provided with air passages 37 in the cylinder longitudinal direction. A piston 38 slidable in the longitudinal direction is fitted into the cylinder hole 31, a part of the piston 38 projects outward from the slit 33, and a mount 39 is integrally formed. It is fitted and constitutes an external moving body.
[0017]
1 and 2, the rodless cylinder 3 is attached to the base 2 by the air passage 37 of the left end cap 34, the supply / discharge port 27 of the left end plate 25, and the air passage 37 of the right end cap 34. The mounting bolt 41 is disposed so as to communicate with the end pipe 30 in the right end plate 26 and inserted into the end caps 34 at both ends from a direction perpendicular to the base 2 through the insertion groove 19 into the cylinder in the insertion hole 18. The nut 17 is screwed and fixed. The end pipe 30 is pressed against the end cap 34 on the end plate 26 side of the rodless cylinder 3 disposed on the base 2 by tightening the pressing screw 44 from the longitudinal direction of the base 2, and the air passages 37 of the end caps 34 at both ends are pressed. Are connected to the supply / discharge port 27 and the end pipe 30 respectively. A slide body 5 is integrally attached to an external moving body of the rodless cylinder 3. A guide rail 4a of the linear guide 4 is fixed to the T groove 10 of the base 2, and a guide 4b of the linear guide 4 slidably guided on the guide rail 4a is provided below the slide body 5. . A sensor magnet 42 is provided on the lower surface of the slide body 5. Attachment holders 8 each having a shock absorber 43 are fixed at opposite ends of the T groove 9 of the base 2 in the longitudinal direction. In the present invention, the molded product is formed by extruding the sensor mounting rail 15, but is not limited to the molded product.
[0018]
In the linear actuator 1 configured as described above, the slide body 5 reciprocates in the longitudinal direction together with the piston 38 by the supply and discharge of the compressed air (pressure fluid) from the supply and discharge ports 27 and 28, and the sensor mounting rail 15 The position of the slide body is detected by detecting the sensor magnet 43 by the sensor attached at the position of.
[0019]
【The invention's effect】
As described above, in the present invention, since the sensor mounting rail and the base are each formed of a shape member, distortion of the sensor mounting rail and the base is reduced. Further, by separating the sensor mounting rail from the base, the outer shape of the base can be reduced, so that the shape of the shape member can be reduced and the cost can be reduced. In addition, left and right mounting in the width direction of the sensor mounting rail can be selected. In addition, since the sensor mounting rail is screwed in from the longitudinal direction of the base with a fixing screw and fixed, the conventional processing in the base width direction can be omitted, and the processing corresponding to the longitudinal pitch of the screw holes for each base. This is preferable because it is not necessary.
[Brief description of the drawings]
FIG. 1 is a front view of a linear actuator.
FIG. 2 is a II view of FIG.
FIG. 3 is a sectional view taken along line III-III of FIG. 1;
FIG. 4 is an IV view of FIG. 1;
FIG. 5 is a side view of a base.
FIG. 6 is a VI view of FIG. 5;
FIG. 7 is a side view of a sensor mounting rail.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Linear actuator 2 Base 3 Drive device 5 Slide body 14 Rail attachment engagement part 15 Sensor attachment rail 16 Fixing screw 22 Sensor attachment groove 23 Engagement part 24 Threaded pilot holes 25, 26 End plate

Claims (2)

A linear actuator for reciprocating a slide body guided along the base length by a driving device mounted along the base, the sensor including a sensor mounting groove for mounting a sensor for detecting a movement position of the slide body. In the linear actuator, a base for mounting the driving device and a sensor mounting rail having a sensor mounting groove are each formed of a mold material, and a rail mounting engaging portion is integrally formed on the base in a longitudinal direction of the base. The sensor mounting rail coincides with the base length, and an engaged portion complementary to the rail mounting engaging portion, a sensor mounting groove, and a screw-down hole for a fixing screw are formed over the entire length in the longitudinal direction, The engaged portion of the sensor mounting rail is engaged with the rail mounting engaging portion from the longitudinal direction. In a state where the sensor mounting rail is sandwiched between end plates fixed to both longitudinal ends of the base, the sensor mounting rail is fixed to the sensor mounting rail by fixing screws screwed into the screw-in lower holes of the sensor mounting rail from the base longitudinal direction. A linear actuator that is fixed to the base and integrated with the base. 2. The linear actuator according to claim 1, wherein rail mounting engagement portions are formed symmetrically on both sides in the width direction of the base.

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