Control unit for actuator

Abstract

A guide unit (10, 100, 110) for an actuator (12) with a sliding element (14) and a guide element (16), wherein the actuator (12) has a drive rod (22) extending out of a cylindrical base body (28), the sliding element (14) has a slider (46) which is detachably connected to the drive rod (22), and a guide rod (48) which is attached to the slider (46), the guide element (16) has a guide plate (64) which is attached to the cylinder base body (28), and a guide tube (66) which is attached to the guide plate (64), the guide rod (48) is inserted sliding through the guide tube (66), the slider (46) is connected to the drive rod (22) via a floating mechanism, the floating mechanism comprises a flat first retaining ring (58) and a second retaining ring (60) with an L-shaped cross-section, and a ring-shaped plate section of the second retaining ring (60) is arranged between a flange section (52) of the slider (46) and the drive rod (22), characterized in that the floating mechanism comprises a bolt (56) which is inserted into the drive rod (22), wherein the first retaining ring (58) is arranged between the flange section (52) of the slider (46) and the head of the bolt (56), and an outer diameter of the tubular part (59) of the second retaining ring (60) is smaller than an inner diameter of the flange section (52) of the slider (46), and a shaft section of the bolt (56) is inserted through the first retaining ring (58) and the second retaining ring (60).

Description

Technical field

[0001] The present invention relates to a guide unit for an actuator and in particular to a guide unit for a fluid pressure actuator. State of the art

[0002] Up to now, a means of transporting a workpiece or the like has been widely used to employ an actuator that drives a rod in an axial direction with the aid of a motor or fluid pressure, thereby moving a slider that transports or conveys the workpiece.

[0003] The present applicant has proposed an actuator in which a guide unit with a pair of guide rods is detachably provided on a drive unit and in which, by connecting a connecting plate, which is connected to the guide rods, to one end of a piston rod of the drive unit, the guide rods together with the piston rod perform a displacement (see JP 2011-106489 A).

[0004] US 6,305,668 B1 discloses an actuator with a guide plate, wherein a cylinder body is fixed to the guide plate and guide rods pass through the guide plate. The ends of the cylinder piston and the guide rods projecting from the guide plate are fixed to a support plate aligned parallel to the guide plate. During the extension movement of the cylinder piston, first bearings in the guide plate and second bearings in retaining clips of the guide rods guide the guide rods in the axial direction.

[0005] US 7,353,748 B2 discloses a linear actuator with a cylindrical base and a sliding table that moves back and forth in an axial direction along the cylindrical base. A floating mechanism that absorbs deflection or displacement between the sliding table and a piston rod is provided at a front end of the piston rod. The floating mechanism comprises a first sleeve and a second sleeve that accommodate the sliding table with clearance between them. Summary of the invention

[0006] The present invention was made with reference to the above-mentioned proposal and has the objective of proposing a guide unit for an actuator with a simple design in which it is possible to easily modify a bearing area of ​​guide rods, a distance (pitch) between the guide rods and an outer diameter of the guide rods depending on the size of a required load, an installation space and the respective application.

[0007] This problem is solved by the guide unit with the features of claim 1. Preferred embodiments of the invention are set forth in the dependent claims. The guide unit for an actuator, comprising a sliding element and a guide element, is characterized in that the actuator has a guide rod extending from a cylindrical base body, that the sliding element has a slider detachably connected to the guide rod, and guide rods fixed to the slider, that the guide element has a guide plate fixed to the cylindrical base body, and guide tubes fixed to the guide plate, and that the guide rods are slidably inserted through the guide tubes.

[0008] With the guide unit described above, the outer diameter of the guide rods, the distance between the guide rods, or the bearing area of ​​the guide rods can be easily modified as desired by changing the combination of the slider, the guide rods, the guide plate, and the guide tubes. Furthermore, the slider, the guide rods, the guide plate, and the guide tubes can each be designed with a simple structure.

[0009] In the guide unit described above, the guide plate is preferably formed by a rectangular plate element with mounting holes that extend through the plate element in one direction of its thickness and are located at its corners. This feature allows the guide plate to be designed with a particularly simple structure.

[0010] Furthermore, the guide plate can be formed by a rectangular plate element with mounting holes extending from one end face to the opposite end face. According to this feature, the guide plate can be designed with a simple structure, and it is also easy to mount the guide unit along a wall surface or similar fixture that serves as the mounting element.

[0011] Furthermore, the guide plate can be formed by a plate element with an L-shaped cross-section, comprising a first plate section that is substantially perpendicular to the guide rods and a second plate section that is substantially parallel to the guide rods, and having mounting holes formed therein that pass through in one thickness direction of the second plate section. According to this feature, it is easy to manufacture the guide plate, and it is also easy to attach the guide unit to a wall surface or the like of a device that serves as an element to which the guide unit is attached.

[0012] Furthermore, the slider is connected to the guide rod via a floating mechanism. According to this feature, even if fastening errors occur between the piston rod, a cylinder base, the guide element, and the sliding element in directions perpendicular to the piston rod, these errors can be absorbed by the floating mechanism.

[0013] Furthermore, the guide tubes are preferably attached to the guide plate via a bolt, a threaded connection, or a retaining ring. This feature allows the guide plate and guide tubes to be freely attached to and detached from each other. If the combination of the guide plate and guide tubes is modified, one of these elements can be reused.

[0014] The slider is attached to the drive rod via a bolt. This feature makes attaching the slider and drive rod simple.

[0015] Furthermore, the guide rods can be attached to the slider via a bolt, a threaded connection, riveting, or welding. This feature simplifies the attachment of the guide rods and the slider.

[0016] By modifying the combination of the slider, guide rods, guide plate, and guide tubes in the guide unit for an actuator described above, it is possible to easily modify the outer diameter of the guide rods, the distance between the guide rods, or the bearing area of ​​the guide rods. Furthermore, simple shapes can be used for the slider, guide rods, guide plate, and guide tubes, simplifying their manufacture and reducing costs. Brief description of the drawings Fig. Figure 1 is a perspective view of a guide unit according to a first embodiment of the present invention; Fig. 2 is a front view of the in Fig. 1 shown command unit; Fig. 3 is a section along line III-III through the in Fig. 2 shown command unit; Fig. 4 is a section along line III-III in a specific working state of the in Fig. 2 shown command unit; Fig. Figure 5 is a perspective view of a guide unit according to a second embodiment of the present invention; and Fig. Figure 6 is a perspective view of a guide unit according to a third embodiment of the present invention. Description of embodiments

[0017] The following is a detailed description of preferred embodiments of a guide unit for an actuator according to the present invention, with reference to the accompanying drawings.

[0018] A guide unit 10 according to a first embodiment is described with reference to the Fig. 1, Fig. 2, Fig. 3 to Fig. 4 described.

[0019] The guide unit 10 is formed by connecting it to a fluid pressure actuator 12, for example a pneumatic cylinder. It comprises a sliding element 14 and a guide element 16.

[0020] The fluid pressure actuator 12 comprises a cylinder tube 18, a piston 20, and a piston rod (actuator rod) 22, etc. The piston 20 is slidably mounted within the cylinder tube 18. A cylindrical rod cover 24 is inserted into and fixed to one end of the thin-walled cylindrical cylinder tube 18, and a head cover 26 is inserted into and fixed to the other end of the cylinder tube 18, thereby forming a cylinder body 28. A first pressure chamber 30 is formed between one end of the piston 20 and the rod cover 24, and a second pressure chamber 32 is formed between the other end of the piston 20 and the head cover 26. Air is supplied to and discharged from the first pressure chamber 30 and the second pressure chamber 32 through a first port 34 and a second port 36, respectively. An external threaded section 38 is provided at one end of the rod cover 24 on a side opposite the cylinder tube 18.

[0021] The piston rod 22 is connected to one end of the piston 20 and extends through an inner part of the rod cover 24 into the environment. A threaded opening 40 with a base is formed in one end of the piston rod 22, which extends into the environment. A piston seal 42 is provided on an outer circumference of the piston 20. The piston seal 42 slides along an inner surface of the cylinder tube 18. A rod seal 44 is provided on an inner circumference of the rod cover 24. The rod seal 44 slides along the piston rod 22 and ensures the airtightness of the first pressure chamber 30 from the environment.

[0022] The sliding element 14 comprises a slider 46 and guide rods 48. The slider 46 consists of an elongated rectangular plate and has a circular first through-opening 50 in its center. The first through-opening 50 has a stepped shape, and an inwardly projecting flange section 52 is formed in it on one side near the piston rod 22. Near both ends in the longitudinal direction of the slider 46, second through-openings 54 are formed at substantially the same distance from the first through-opening 50. Internal threads are formed in the second through-openings 54.

[0023] The slider 46 is connected to the end of the piston rod 22, which projects outwards from the rod cover 24, by means of a first bolt 56, a flat first retaining ring 58, and a retaining ring 60 with an L-shaped cross-section. The second retaining ring 60 comprises a tubular part 59 that projects outwards from a surface of an annular plate section. The outer diameter of the tubular part 59 is smaller than the inner diameter of the flange section 52 of the slider 46, and the axial length of the tubular part 59 is essentially the same as the thickness of the flange section 52. A shank section of the first bolt 56 is inserted through the first retaining ring 58 and the second retaining ring 60.

[0024] A small-diameter projecting shaft section 62, which has an external thread on its outer circumference, is formed on each of the two guide rods 48. The respective guide rods 48 are attached to the slider 46 by screwing the projecting shaft sections 62 into the second through-openings 54 of the slider 46.

[0025] Several sliders 46, where the distances from the first through-opening 50 to the second through-openings 54 differ from one another, are prepared in advance, and several guide rods 48, whose outer diameters differ from one another, are prepared in advance. In addition, several sliders 46, which have different lengths in the longitudinal direction, can be prepared according to the distances from the first through-opening 50 to the second through-openings 54.

[0026] The guide element 16 comprises a guide plate 64 and a pair of guide tubes 66. The guide plate 64 is made of iron or aluminum and is formed by an elongated rectangular plate with a third through-opening 68 in its center for inserting the rod cover 24. Fourth through-openings 70 are also provided on its two sides for attaching the guide tubes 66. Internal threads are formed in the fourth through-openings 70. Additionally, fastening openings 72 are provided in the four corners of the guide plate 64 for attaching the guide plate 64 to a fastening element, such as a wall surface or other device.

[0027] The guide tubes 66 are essentially cylindrical and have five through-openings 74 for inserting the guide rods 48. At one end in the axial direction of each of the guide tubes 66, a small-diameter section 67 with an external thread is formed for screwing into the fourth through-openings 70 of the guide plate 64.

[0028] The rod cover 24 is inserted through the third through-opening 68 of the guide plate 64 and secured to the guide plate 64 by screwing a locking nut 78 onto the external threaded section 38 at the end of the rod cover 24. Two sliding bearings 80 are provided in each of the fifth through-openings 74 of the guide tubes 66. The guide rods 48 are inserted into the guide tubes 66 by means of the pair of sliding bearings 80.

[0029] Several guide plates 64, in which the distances from the third through-opening 68 to the fourth through-openings 70 and / or the inner radii of the fourth through-openings 70 differ from one another, are prepared in advance. Corresponding to the distances from the third through-opening 68 to the fourth through-openings 70, several guide plates 64 with different longitudinal lengths can also be prepared. In addition, several guide tubes 66, in which the inner diameters and / or the axial length of the fifth through-openings 74 differ from one another, are prepared in advance.

[0030] The guide unit 10 according to the present embodiment is essentially constructed as described above. Next, a method for assembling the guide unit 10 is described.

[0031] First, suitable elements are selected from the several sliders 46, guide rods 48, guide plates 64, and guide tubes 66 that have been prepared in advance, according to the required load. If the required load is large, it is necessary to reduce the load applied to the piston rod 22 and stabilize the operation of the actuator by increasing the outer diameter of the guide rods 48, the distance (pitch) between the pair of guide rods 48, or the bearing capacity of the guide rods 48.

[0032] If guide rods 48 with large outer diameters are selected, a guide plate 64 with fourth through-holes 70, whose inner diameters correspond to the outer diameters of the guide rod 48, and guide tubes 66 with fifth through-holes 74 having inner diameters corresponding to the outer diameters of the guide rods 48 are selected. If the distance between the pair of guide rods 48 is made large, a slider 46 in which the distance from the first through-hole 50 to the second through-holes 54 is large, and a corresponding guide plate 64 are selected. In particular, a guide plate 64 is selected in which the distance from the third through-hole 48 to the fourth through-holes 70 is large. If the bearing area of ​​the guide rod 48 is made large, guide tubes 66 with a large axial length are selected.

[0033] After the guide element 16 has been integrally assembled by screwing the small-diameter sections 67 of the selected guide tubes 66 into the fourth through-openings 70 of the selected guide plate 64, the rod cover 24 of the fluid pressure actuator 12 is inserted through the third through-openings 68 of the guide plate 64. Furthermore, the guide element 16 and the cylinder base 28 are integrally connected by screwing the locking nut 78 onto the external threaded section 38 at the end of the rod cover 24 and by tightening the locking nut 78 until it comes to rest against the guide plate 64.

[0034] Next, the sliding element 14 is integrally connected by screwing the projecting shaft sections 62 of the selected guide rods 48 into the second through-holes 54 of the selected slider 46. The guide rods 48 are then inserted into the fifth through-holes 74 of the guide tubes 66, with the pair of sliding bearings 80 positioned between them. With the first bolt 56, the first retaining ring 58, and the second retaining ring 60 arranged (temporarily fixed) on the flange section 52 of the slider 46, the slider 46 is brought close to the end face of the piston rod 22 extending from the rod cover 24, and the first bolt 56 is screwed into the threaded opening 40 of the piston rod 22.In a state in which the annular plate section of the second retaining ring 60 is arranged between an end face of the flange section 52 and an end face of the piston rod 22, and the first retaining ring 58 is arranged between another end face of the flange section 52 and a rear face of the head of the first bolt 56, the first bolt 56 is screwed into the threaded opening 40 of the piston rod 22. Accordingly, the sliding element 14 and the piston rod 22 are integrally connected.

[0035] Since a certain gap exists between the inner circumference of the flange section 52 and the outer circumference of the tubular part 59 of the second retaining ring 60, and a floating structure is provided, even if fastening errors occur between the piston rod 22, the rod cover 24, the guide element 16, and the sliding element 14 in directions perpendicular to the axis of the piston rod 22, these errors can be absorbed by the floating structure. Using the fastening openings 72 of the guide plate 64, the guide unit 10, which has been mounted in the manner described above, is attached by bolts to a wall surface or the like of another device (not shown).

[0036] Next, the advantages and operating principles of the fluid pressure actuator 12 are described. The one in Fig. The state shown in 3, in which the piston rod 22 is retracted and received inside the cylinder base body 28, is described as a starting position.

[0037] In the starting position, the piston 20 slides towards the rod cover 24 when air is supplied to the second pressure chamber 32 through the second connection opening 36 and air is discharged from the first pressure chamber 30 via the first connection 34. Accordingly, the piston rod 22 and the sliding element 14, which is integrated with the piston rod 22, are extended in a direction in which the sliding element 14 moves away from the cylinder base body 28 (see figure). Fig. 4), and the transport or the like of a workpiece not shown at a position of the slider 46 is carried out.

[0038] Here, the pair of guide rods 48, which are parallel to each other and spaced a defined distance apart, are guided slidably within a bearing area of ​​a defined length in the guide element 16, which is attached to a wall surface or the like of another device. Therefore, even if a load is applied to the slider 46 in a direction transverse to the axis of the piston rod 22, an overload, such as a twisting or torsional load, or the like, is not transmitted to the piston rod 22.

[0039] Although in the present embodiment the guide tubes 66 are fixed to the guide plate 64 by screw threads, other means can also be provided, for example a bolt or a retaining ring, provided these means allow free attachment and removal of the guide plate 64 and the guide tubes 66 from each other. This is because, if it is assumed that the guide plate 64 and the guide tubes 66 can be freely attached to and detached from each other, it is possible to reuse one of these elements if the combination of the guide plate 64 and the guide tubes 66 is modified.

[0040] Although in the present embodiment the slider 46 is connected to the piston rod 22 via a floating mechanism formed by the first retaining ring 58 and the second retaining ring 60, etc., the connection of the slider 46 to the piston rod 22 can also use other fastening means, such as a bolt, a nut or the like.

[0041] Although in the present embodiment the guide rods 48 were attached to the slider 46 by screwing, the attachment of the guide rods 48 to the slider 46 can also be carried out by other means, for example bolting, riveting, welding or the like.

[0042] In the case that the guide rods 48 are fixed to the slider 46 by means of bolts and the slider 48 is fixed to the piston rod 22 by a bolt, recessed grooves extending in a longitudinal or lateral direction of the slider 46 can be formed in a plate surface of the slider 46 and the heads of the bolts can be received in these recessed grooves.

[0043] By modifying the combination of the slider 46, the guide rods 48, the guide plate 64, and the guide tubes 66 in the guide unit 10 according to the present invention, it is possible to easily modify the outer diameter of the guide rods 48, the distance between the guide rods 48, or the bearing area of ​​the guide rods 48 as desired. Furthermore, the slider 46, the guide rods 48, the guide plate 64, and the guide tubes 66 can each be designed with a simple structure. Since the slider 46 is connected to the piston rod 22 by the floating mechanism, even if fastening errors occur between the piston rod 22, the cylinder base 28, the guide element 16, and the sliding element 14 in directions perpendicular to the axis of the piston rod 22, these errors can be absorbed by the floating mechanism.

[0044] Next, a guide unit 100 according to a second embodiment is described with reference to Fig. 5 described. The guide unit 100 according to the present embodiment differs from the guide unit 10 according to the first embodiment only with regard to the guide plate. Those structural elements that are the same as in the guide unit 10 according to the first embodiment are designated with the same reference numerals, and a detailed description of these features is omitted here. The same applies to the other embodiment, which is described below.

[0045] The guide plate 102 is an elongated rectangular plate, which, except for its central longitudinal section where the rod cover 24 is attached, has thick walls. Near both ends in the longitudinal direction, mounting holes 104 are also provided, extending from a side end face on one longitudinal side of the guide plate 102 to a side end face on the other longitudinal side of the guide plate 102. The guide unit 100 is mounted along a wall surface or the like of another device using the pair of mounting holes 104.

[0046] In the guide unit 100 according to the present embodiment, the guide plate 102 can be manufactured with a simple design, in addition to achieving the same advantages and effects as in the guide unit 10 according to the first embodiment. Furthermore, it is easy to attach the guide unit 100 to a wall surface or the like of another device.

[0047] Next, a guide unit 110 according to a third embodiment is described with reference to Fig. 6 described. The guide unit 110 according to the present embodiment differs from the guide unit 10 according to the first embodiment only with regard to the guide plate.

[0048] The guide plate 112 consists of a plate element with an L-shaped cross-section and comprises a first plate section 114, which is arranged substantially perpendicular to the guide rods 48, and a second plate section 116, which is bent substantially perpendicular to the first plate section 114 and runs substantially parallel to the guide rods 48. Mounting holes 118, which extend in one thickness direction, are formed near the four corners of the second plate section 116. The guide unit 110 is attached to a wall surface or the like of another device by means of the four mounting holes 118.

[0049] In the guide unit 110 according to the present embodiment, in addition to achieving the same advantages and effects as in the guide unit 10 according to the first embodiment, the manufacture of the guide plate 112 is simple. Furthermore, it is simple to attach the guide unit 110 to a wall surface or the like of another device.

[0050] The guide unit for an actuator according to the present invention is not limited to the embodiments discussed above. It is understood that various alternatives or additional structures can be provided without departing from the scope of the invention as defined in the appended claims. For example, instead of the fluid pressure actuator, an actuator can be used in which a rod is driven back and forth by a motor.

Claims

[1] A guide unit (10, 100, 110) for an actuator (12) comprising a sliding element (14) and a guide element (16), wherein the actuator (12) has a drive rod (22) extending out of a cylindrical base body (28), the sliding element (14) has a slider (46) which is detachably connected to the drive rod (22), and a guide rod (48) which is attached to the slider (46), the guide element (16) has a guide plate (64) which is attached to the cylinder base body (28), and a guide tube (66) which is attached to the guide plate (64), the guide rod (48) is inserted sliding through the guide tube (66), the slider (46) is connected to the drive rod (22) via a floating mechanism, the floating mechanism comprises a flat first retaining ring (58) and a second retaining ring (60) with an L-shaped cross-section, and a ring-shaped plate section of the second retaining ring (60) is arranged between a flange section (52) of the slider (46) and the drive rod (22), characterized by , that the floating mechanism comprises a bolt (56) which is inserted into the drive rod (22), wherein the first retaining ring (58) is arranged between the flange section (52) of the slider (46) and the head of the bolt (56), and an outer diameter of the tubular part (59) of the second retaining ring (60) is smaller than an inner diameter of the flange section (52) of the slider (46), and a shaft section of the bolt (56) is inserted through the first retaining ring (58) and the second retaining ring (60). [2] The guide unit (10) for an actuator (12) according to claim 1, wherein the guide plate (64) is formed by a rectangular plate element, wherein fastening openings (72) which pass through in a thickness direction are formed in its corners. [3] The guide unit (100) for an actuator (12) according to claim 1, wherein the guide plate (102) is formed by a rectangular plate element, wherein fastening openings (104) are formed therein, which pass from one side end surface to another, opposite side end surface. [4] The guide unit (110) for an actuator (12) according to claim 1, wherein the guide plate (112) is formed by a plate element with an L-shaped cross-section, comprising a first plate section (114) arranged substantially perpendicular to the guide rod (48), and a second plate section (116) arranged substantially parallel to the guide rod (48), and having fastening openings (118) formed therein, which pass through in a thickness direction of the second plate section (116). [5] The guide unit (10, 100, 110) for an actuator (12) according to one of claims 1 to 4, wherein the guide tube (66) is attached to the guide plate (64) via a bolt, a threaded connection or a retaining ring. [6] The guide unit (10, 100, 110) for an actuator (12) according to any one of claims 1 to 4, wherein the guide rod (48) is attached to the slider (46) by means of a bolt, a threaded connection, riveting or welding.

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