JP3795968B2 - Linear actuator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a linear actuator that reciprocates a slide table along an axial direction of a cylinder body by introducing a pressure fluid from a fluid inlet / outlet port.
[0002]
[Prior art]
Conventionally, for example, a linear actuator such as a fluid pressure cylinder has been used as means for conveying a workpiece or the like. The linear actuator conveys the workpiece placed on the slide table by reciprocating the slide table along the cylinder body in a straight line.
[0003]
A fluid pressure cylinder according to the prior art is shown in FIGS. 7A and 7B (see Japanese Utility Model Laid-Open No. 5-42716). The fluid pressure cylinder 1 has a cylinder body 2, and a guide rail 3 bulges along the longitudinal direction on the upper surface of the cylinder body 2.
[0004]
The fluid pressure cylinder 1 is provided with a table 4 that slides and displaces along the guide rail 3 under the action of displacement of a piston housed in a cylinder chamber. The table 4 includes a plurality of ball bearings (not shown). A ball circulation hole (not shown) is formed along the longitudinal direction of the table 4.
[0005]
A fluid pressure cylinder 5 according to another prior art is shown in FIG. 8 (see Japanese Utility Model Laid-Open No. 6-43302). The fluid pressure cylinder 5 is arranged along the axial direction of the cylinder body 6 under the guiding action of a cylinder body 6 provided with a cylinder chamber therein and a linear guide 7 fixed to the upper surface of the cylinder body 6. And a moving table 8. A first projecting portion 9 is formed to bulge upward at one end substantially orthogonal to the longitudinal direction of the cylinder body 6, and the first projecting portion 9 is sandwiched between one side surface of the table 8. The 2nd overhang | projection part 10 and the 3rd overhang | projection part 11 are bulged and formed toward the horizontal direction.
[0006]
In this case, the bolts 12 and 13 screwed into the second overhanging portion 10 and the third overhanging portion 11, respectively, come into contact with the first overhanging portion 9, so that the movement end position of the table 8 is restricted and the bolt The amount of movement of the table 8 is adjusted by adjusting the amount of screwing of 12 and 13.
[0007]
[Problems to be solved by the invention]
However, in the fluid pressure cylinders 1 and 5 according to the above-described prior art, the widths L ₁ and L _{2 of} the guide rail 3 and the linear guide 7 are relatively small compared to the width L of the cylinder bodies 2 and 6. For this reason, there is a disadvantage that the linear accuracy of the slide table deteriorates due to a load applied to the slide table from the horizontal direction.
[0008]
The present invention has been made to overcome the above disadvantages, and provides a linear actuator capable of maintaining the linear accuracy of the slide table even when a load is applied to the slide table from a substantially horizontal direction. The purpose is to provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a linear actuator for reciprocating a slide table along an axial direction of a cylinder body by introducing a pressure fluid from a fluid inlet / outlet port.
A cylinder body having a cylinder chamber formed therein;
A slide table that reciprocates along the axial direction of the cylinder body;
A cylinder mechanism for reciprocating the slide table under the displacement action of a piston slidably disposed along the cylinder chamber;
Attached to the cylinder body, and a plurality of passages for circulation under a rolling operation of the rolling elements have a flat guide block formed is a guide mechanism of the slide table is guided along the axial direction of the cylinder body ,
A bolt member for fixing the guide block to the cylinder body via a pair of mounting holes formed in the guide block and the cylinder body,
Holding means is interposed, positions and holds the guide block to the cylinder body between the cylinder body and the guide block,
Equipped with a,
The holding means includes a pair of pin members that are inserted into pin insertion holes formed in the cylinder body and the guide block, respectively, and the guide block is under the cooperative action of the pin member and the bolt member. Fixed to the cylinder body,
At both ends of the guide block, a pair of bulging portions projecting in the axial direction are formed, characterized in Rukoto.
[0010]
According to the present invention, the slide table reciprocates along the axial direction of the cylinder body under the action of the pressure fluid introduced from the fluid inlet / outlet port. When the slide table is displaced, even if a load is applied to the slide table from a substantially horizontal direction, the guide block is positioned and held on the cylinder body via a pin member that functions as a holding means. The guide block is fixed to the cylinder body via the bolt member, and the linear accuracy of the slide table can be kept good under the cooperative action of the pin member and the bolt member .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the linear actuator according to the present invention will be described in detail below with reference to the accompanying drawings.
[0012]
In FIG. 1, reference numeral 20 indicates a linear actuator according to an embodiment of the present invention. The linear actuator 20 is a cylinder body 22 and a slide table that reciprocates linearly along the longitudinal direction of the cylinder body 22. 24 and a guide mechanism 28 (see FIG. 2) interposed between the cylinder body 22 and the slide table 24 and held by the cylinder body 22 via a pair of pin members (holding means) 26a and 26b. And have.
[0013]
As shown in FIG. 2 and FIG. 3, a laterally long concave portion 30 whose one end is curved is formed in the upper surface portion of the cylinder main body 22, and one portion for inserting pin members 26 a and 26 b into the concave portion 30. A pair of pin insertion holes 32a and 32b are formed at a predetermined interval. Further, a pair of mounting holes 34a and 34b for mounting the guide mechanism 28 to the cylinder body 22 are formed penetratingly at portions close to the pin insertion holes 32a and 32b.
[0014]
Two sensor mounting long grooves 36a and 36b are formed in one side surface portion of the cylinder body 22 along the longitudinal direction, and a stopper block 38, which will be described later, is in contact with the other side surface portion of the slide table 24. A displacement adjustment member (displacement adjustment means) 40 that regulates the displacement is screwed. A sensor (not shown) is engaged with a predetermined portion in the sensor mounting long grooves 36a and 36b.
[0015]
As shown in FIG. 4, the displacement amount adjusting member 40 includes a block body 42, a screw member 46 that is screwed into the hole of the block body 42, and is fixed to the block body 42 via a nut 44. The amount of displacement of the slide table 24 can be adjusted by increasing or decreasing the amount of screwing of the screw member 46 with respect to the block body 42. The damper member 47 is attached to one end of the screw member 46.
[0016]
Further, a set of through holes 43a and 43b (see FIG. 5) arranged in parallel in the axial direction is formed inside the cylinder body 22, and the through holes 43a and 43b are substantially A cylinder mechanism including a piston 48 formed in the same shape and having a seal ring 45 and a magnetic body 47 mounted on the outer peripheral surface and a piston rod 50 connected to the piston 48 is provided (see FIG. 6).
[0017]
One end of each of the through holes 43a and 43b is hermetically closed by an end cap 54 that is mounted via a retaining ring 52, and the other end of the through holes 43a and 43b is held via the retaining ring 52. The ring body 56, the rod packing 58 and the collar 60 are airtightly closed. An O-ring 62 is fitted on the outer peripheral surface of the collar 60 via an annular groove.
[0018]
In this case, the first cylinder chamber 64a and the second cylinder chamber 64b are juxtaposed by the end cap 54 and the collar 60 that respectively close the pair of through holes 43a and 43b. The chamber 64b is formed so as to communicate with each other via the communication passages 66a and 66b. A pair of fluid inlet / outlet ports 68a and 68b are formed on one side surface of the cylinder body 22, and the fluid inlet / outlet ports 68a and 68b are formed to communicate with the second cylinder chamber 64b, respectively. A floating bush 70 is connected to the tip of the piston rod 50 via a screw member.
[0019]
As shown in FIG. 1, the slide table 24 is composed of a table body 74 and an end plate 76 which are fastened by screws in a substantially L-shaped cross section via a pair of bolts 72a and 72b. The floating bush 70 is held through a semicircular hole formed in the plate 76. The end plate 76 is provided with a buffer member (not shown), and the buffer member has an impact generated when the end plate 76 contacts the end surface of the cylinder body 22 at the end position of one displacement region of the slide table 24. Operates the function to alleviate The table main body 74 is formed with four workpiece holding holes 78a to 78d.
[0020]
As shown in FIG. 2, the table main body 74 is formed with a pair of guide portions 80 that bulge integrally along the longitudinal direction, and the inner wall surfaces of the guide portions 80 facing each other along the longitudinal direction. Thus, ball rolling grooves 82a and 82b are formed. A stopper block 38 is screwed to one side surface of the table body 74, and the stopper block 38 is displaced integrally with the slide table 24, and a buffer member (not shown) abuts against the stopper block 38. The amount of displacement is regulated.
[0021]
As shown in FIG. 3, the guide mechanism 28 for guiding the slide table 24 includes a flat guide block 84 that is wide in a direction substantially orthogonal to the axis, and both end portions along the longitudinal direction of the guide block 84. A set of ball return members 86, a cover member 88, and a scraper 90 to be mounted are provided, and a set of pin members 26a and 26b for positioning and holding the guide block 84 on the cylinder body 22. The cover member 88 is formed with a semicircular ball return groove 94 for circulating a ball bearing 92 that rolls under the cooperative action of the ball return member 86.
[0022]
Ball rolling grooves 96a and 96b are formed on both side surfaces of the guide block 84 along the longitudinal direction, and a set penetrating along the longitudinal direction is formed in a portion adjacent to the ball rolling grooves 96a and 96b. Are formed at predetermined intervals. A continuous ball circulation path is formed by the ball rolling grooves 82a and 82b of the guide portion 80, the ball rolling grooves 96a and 96b of the guide block 84, the ball circulation hole 98, and the ball return groove 94 of the cover member 88, As the ball bearing 92 rolls along the ball circulation path, the slide table 24 can be smoothly reciprocated.
[0023]
In addition, angular bulges 100a and 100b are integrally formed at both ends along the longitudinal direction of the guide block 84, and the bulges 100a and 100b are formed so as to be spaced apart from each other by a predetermined distance. The pitch P of the mounting holes 102a and 102b in the set can be increased.
[0024]
Furthermore, pin insertion holes 104a and 104b for inserting a pair of pin members 26a and 26b are formed on the bottom surface of the guide block 84 at a predetermined interval, and are formed in the pin insertion holes 104a and 104b. A pair of mounting holes 102a and 102b each having a thread groove formed therein are formed through the adjacent portions. As will be described later, a guide mechanism 28 including a guide block 84 is attached to the upper surface portion of the cylinder body 22 via a bolt member 106 that is screwed into the thread grooves of the attachment holes 102a and 102b.
[0025]
The linear actuator 20 according to the present embodiment is basically configured as described above. Next, its operation and effects will be described.
[0026]
Pressure fluid is introduced into one fluid inlet / outlet port 68b from a fluid pressure supply source (not shown). In this case, the other fluid inlet / outlet port 68a is opened to the atmosphere under the operation of a switching valve (not shown).
[0027]
The pressure fluid is sequentially supplied to the second cylinder chamber 64b and the first cylinder chamber 64a communicating with the fluid and out port 68b, to press the piston 48 in the direction of arrow X ₁ (see FIG. 6). Incidentally, the floating bush 70 which engages the piston rod 50 under the pressing action of the piston 48 is displaced in the direction of arrow X _1, the under for rolling operation of ball bearings 92 end plates 76 integrally with the slide table 24 is Displace.
[0028]
In the process of the slide table 24 is displaced toward the direction of arrow X _1, leading to the displacement terminal end position by abutting the damper member 47 mounted on the stopper block 38 screw member 46 which is displaced with the said slide table 24 . In this case, the displacement amount of the slide table 24 can be increased or decreased by loosening the nut 44 and adjusting the screwing amount of the screw member 46 with respect to the block body 42.
[0029]
When displacing the slide table 24 in the opposite direction, the pressure fluid is supplied to the fluid inlet / outlet port 68a. The supplied pressure fluid to the second cylinder chamber 64b, sequentially introduced into the first cylinder chamber 64a, which presses the piston 48 in the arrow X ₂ direction. Under the pressing action of the piston 48, the illustrated end plate 76 and the slide table 24 through a floating bush 70 which engages the piston rod 50 is integrally displaced in the direction of arrow X _2, provided on the end plate 76 The buffer member that is not in contact with the end surface of the slide table 24 returns to the initial position shown in FIG.
[0030]
Next, the assembly process of the guide mechanism 28 to the cylinder body 22 will be described.
[0031]
A set of pin insertion holes 104a and 104b drilled in the bottom surface of the guide block 84 at a predetermined interval, and a set of pin insertion holes 32a and 32b drilled in the upper surface of the cylinder body 22. The pin members 26 a and 26 b are inserted into the guide body 28, and the guide mechanism 28 including the guide block 84 is positioned and fixed in the recess 30 of the cylinder body 22. Further, the bolt members 106 are respectively inserted into a set of mounting holes 34 a and 34 b formed so as to penetrate the cylinder body 22, and screw portions engraved at one end of the bolt member 106 are inserted into the guide block 84. The guide mechanism 28 is screwed to the cylinder body 22 by being screwed into the thread grooves of the mounting holes 102a and 102b.
[0032]
Thus, the guide block 84 constituting the guide mechanism 28 includes the bolt member 106 screwed into the mounting holes 102a and 102b formed with a large separation interval (pitch P), the pin insertion hole 104a, It is fixed to the cylinder body 22 under the cooperative action of the pin members 26a and 26b inserted into the 104b.
[0033]
In the linear actuator 20 according to the present embodiment, as shown in FIG. 5, the ratio of the width L ₃ of the guide mechanism 28 to the width L of the cylinder body 22 is increased, so that the guide rail 3 and the linear guide 7 according to the prior art are increased. Compared to, it is formed wider. In addition to the bolt member 106 for attaching the guide mechanism 28 to the cylinder body 22, pin members 26 a and 26 b are interposed between the guide block 84 and the cylinder body 22.
[0034]
Therefore, even if loads F ₁ and F ₂ (see FIG. 5) are applied to the slide table 24 from a substantially horizontal direction, the slide table 24 is stably supported, so that the linear accuracy of the slide table 24 is maintained. Smooth reciprocation. As a result, the workpiece can be stably conveyed via the slide table 24.
[0035]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0036]
That is, when the slide table is displaced, even when a load is applied to the slide table from a substantially horizontal direction, the guide mechanism is held by the cylinder body via the holding means. The linear accuracy can be kept good. As a result, the workpiece can be stably conveyed via the slide table.
[Brief description of the drawings]
FIG. 1 is a perspective view of a linear actuator according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the linear actuator shown in FIG.
3 is an exploded perspective view of a guide mechanism constituting the linear actuator shown in FIG. 1. FIG.
4 is a plan view of the linear actuator shown in FIG. 1. FIG.
5 is a longitudinal sectional view taken along line VV in FIG. 4. FIG.
6 is a cross-sectional view taken along line VI-VI in FIG.
7A is a plan view of a linear actuator according to the prior art, and FIG. 7B is a side view of FIG. 7A.
FIG. 8 is a perspective view of a linear actuator according to another prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 20 ... Linear actuator 22 ... Cylinder main body 24 ... Slide table 26a, 26b ... Pin member 28 ... Guide mechanism 32a, 32b, 104a, 104b ... Pin insertion hole 34a, 34b, 102a, 102b ... Mounting hole 40 ... Displacement Quantity adjusting members 64a, 64b ... Cylinder chamber 48 ... Piston 50 ... Piston rods 68a, 68b ... Fluid inlet / outlet port 76 ... End plate 80 ... Guide part 84 ... Guide blocks 100a, 100b ... Swelling part

Claims (2)

A linear actuator that reciprocates the slide table along the axial direction of the cylinder body by introducing a pressure fluid from the fluid inlet / outlet port,
A cylinder body having a cylinder chamber formed therein;
A slide table that reciprocates along the axial direction of the cylinder body;
A cylinder mechanism for reciprocating the slide table under the displacement action of a piston slidably disposed along the cylinder chamber;
Attached to the cylinder body, and a plurality of passages for circulation under a rolling operation of the rolling elements have a flat guide block formed is a guide mechanism of the slide table is guided along the axial direction of the cylinder body ,
A bolt member for fixing the guide block to the cylinder body via a pair of mounting holes formed in the guide block and the cylinder body,
Holding means is interposed, positions and holds the guide block to the cylinder body between the cylinder body and the guide block,
Equipped with a,
The holding means includes a pair of pin members that are inserted into pin insertion holes formed in the cylinder body and the guide block, respectively, and the guide block is under the cooperative action of the pin member and the bolt member. Fixed to the cylinder body,
It said guide at both ends of the block, linear actuator, characterized in Rukoto pair of bulging portions projecting in the axial direction are formed. In the linear actuator according to claim 1 Symbol placement, linear actuator, characterized in that the displacement amount adjusting means for adjusting the displacement of the slide table is provided.

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