JP3759231B2 - Rodless cylinder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rodless cylinder that conveys a workpiece or the like by displacing a slider in accordance with a reciprocating motion of a piston.
[0002]
[Prior art]
Conventionally, for example, a rodless cylinder has been used as a means for transferring a workpiece. In this rodless cylinder, a piston is basically inserted into a cylindrical cylinder tube so as to be slidable in the axial direction of the cylinder, and a plurality of drives are provided on the outer periphery of the piston so as to face the inner wall of the cylinder tube. A magnet is provided. On the other hand, a slider is slidably provided outside the cylinder tube so as to surround the cylinder tube, and a driven magnet is disposed inside the slider so as to face the driving magnet. When a pressure fluid such as compressed air is introduced into the cylinder tube, the piston is displaced in the axial direction inside the cylinder tube. For this reason, the driven magnet is magnetically attracted to the driving magnet, and the slider slides outside the cylinder tube in accordance with the displacement of the piston.
[0003]
In this rodless cylinder, a guide member for guiding the slider may be provided in parallel with the cylinder tube.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional rodless cylinder, the outer periphery of the cylinder tube and the driven magnet are in contact with each other, so the sliding resistance is large, and the cylinder tube and the driven magnet are worn to generate dust and the like. There is a concern that when a rodless cylinder is used in a place where it does not like dust, such as for medical and food-related purposes or in a clean room, there is a problem that the dust flows out from the rodless cylinder. Yes. For this reason, the surface of the cylinder tube may be subjected to a surface treatment for reducing the sliding resistance, but this has been a cause of increasing the manufacturing cost of the rodless cylinder. Furthermore, if the assembly accuracy between the cylinder tube and the guide member is low, there is a concern that the above-mentioned sliding resistance will be higher and the generation of dust and the like may be increased, so it is necessary to assemble with high accuracy and the manufacturing cost further increases. There was a problem to do.
[0005]
The present invention has been made to solve the various problems described above, and the surface treatment of the cylinder tube is not required, the generation of dust and the like is prevented, and it is not necessary to assemble with high accuracy, thereby reducing the manufacturing cost. An object is to provide a possible rodless cylinder.
[0006]
[Means for Solving the Problems]
To achieve the above object, the present invention comprises a cylindrical cylinder tube,
A piston disposed inside the cylinder tube and slidable along a longitudinal direction of the cylinder tube;
A driving magnet disposed on the piston ;
Before SL is slidably supported by the guide member, wherein the cylinder tube has an insertion freely hole, a slider which is provided displaceably along the axial direction of the cylinder tube,
A driven magnet disposed opposite to the driving magnet across the cylinder tube in the hole of the slider;
Two or more guide members provided in parallel with the cylinder tube, for guiding the slider along the axial direction, and holding a slight gap formed between the driven magnet and the cylinder tube; ,
A ball bushing provided between the slider and the guide member and supporting the slider so as to be displaceable along the guide member;
It is characterized by providing.
[0007]
According to the present invention, by the introduction of pressure fluid into the cylinder tube piston slides inside the cylinder tube, said piston is arranged a drive magnet slides integrally, arranged on the slider has been the driven magnets and the driving magnets intends magnetically pull focus. The driven magnet displaces the outer periphery of the cylinder tube, and the slider is guided by the guide member and slides in the longitudinal direction of the cylinder tube. At this time, since the slider is guided along the axial direction by two or more guide members, the slider can be displaced while maintaining a gap between the driven magnet and the cylinder tube. The slider can be supported and displaced by a ball bush provided between the slider and the guide member.
[0008]
As a result, by providing the guide member, the slider can be stably displaced while maintaining a slight gap between the driven magnet and the cylinder tube, and a ball bush is provided to make the slider a guide member. Since there is no friction when displaced along, there is no generation of dust or the like.
[0009]
In this case, it is preferable that the slider includes a ball bush for supporting the guide member, because the slider can slide the guide member with little friction.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A rodless cylinder according to the present invention will be described in detail below with reference to the accompanying drawings by giving preferred embodiments.
[0011]
1 and 2, reference numeral 10 indicates a rodless cylinder according to the present embodiment. The rodless cylinder 10 includes rectangular plate-like members 12a and 12b, and both ends of a cylindrical cylinder tube 14 and guide shafts 16a and 16b are fixed to the plate-like members 12a and 12b. The cylinder tube 14 and the guide shafts 16a and 16b are arranged in parallel. A damper 18 made of a material such as rubber is fixed to each plate-like member 12a, 12b so as to slightly protrude from the surface of the plate-like member 12a, 12b.
[0012]
A piston 20 is provided inside the cylinder tube 14 so as to be slidable in the axial direction of the cylinder tube 14. The piston 20 includes a rod-shaped core member 22 that is elongated along the axial direction at the center thereof, and a diameter-enlarged portion 24 is formed at the center of the core member 22. As shown in FIG. 3, a plurality of ring members 28 made of a material such as iron as a magnetic material are provided on the outer periphery of the enlarged diameter portion 24, and the ring members 28 are interposed between the ring members 28. Drive magnets 30 a to 30 c having substantially the same diameter as that of 28 are sandwiched, and each of the drive magnets 30 a to 30 c is isolated by the ring member 28. The driving magnets 30a to 30c are formed such that one surface is an N pole and the other surface is an S pole. Cylindrical members 32 a and 32 b are fixed to the outer periphery of the core member 22 with the ring member 28 interposed therebetween. Grooves 34a and 34b are defined on the outer circumferences of the cylindrical members 32a and 32b, and packings 36a and 36b are provided in the grooves 34a and 34b, and pressure introduced into the cylinder tube 14 by the packings 36a and 36b. Fluid leakage is blocked. Accordingly, the inside of the cylinder tube 14 is separated by the piston 20 into a chamber 40a on one end side and a chamber 40b on the other end side.
[0013]
As shown in FIG. 1, the one plate-like member 12a is provided with a first port 42 communicating with the chamber 40a. The first port 42 is connected to a compressed air supply source (not shown) via a solenoid valve (not shown). Communicate. A hole 44 is defined coaxially with the cylinder tube 14 inside the other plate-like member 12b, and a passage 46 defined along the longitudinal direction of the plate-like member 12b is formed in the hole 44. Communicate. The passage 46 further communicates with a passage 48 defined along the axial direction inside the one guide shaft 16a. A second port 50 is provided in the opening of the passage 48 on the side of one plate-like member 12a, and the second port 50 communicates with a compressed air supply source (not shown) via a solenoid valve (not shown). Reference numeral 52 is a plug member for closing the passage 46.
[0014]
The cylinder tube 14 and the guide shafts 16a and 16b are provided with a slider 56 slidable in the axial direction. Holes 58a and 58b through which the guide shafts 16a and 16b are inserted are defined in the slider 56, and there are a large number of gaps between the walls forming the holes 58a and 58b and the outer walls of the guide shafts 16a and 16b. A ball bush 62 composed of a ball 60 is provided, and the ball bush 62 is retained by a retaining ring 64. Therefore, the slider 56 is supported by the guide shafts 16a and 16b by the ball bushing 62 and can slide with little friction in the axial direction thereof.
[0015]
A hole 68 through which the cylinder tube 14 is inserted is defined in the slider 56, and a wall member forming the hole 68 has a ring member 70 formed of a material such as iron as shown in FIG. Are provided. Each ring member 70 sandwiches a plurality of driven magnets 72 a to 72 c, and thus the driven magnets 72 a to 72 c are separated from each other by the ring member 70. One of the surfaces of the driven magnets 72a to 72c is formed as an S pole and the other surface is an N pole so as to be opposite to the polarities of the driving magnets 30a to 30c. 72c and the driving magnets 30a-30c are configured to attract each other. The driven magnets 72 a to 72 c and the ring member 70 are integrally formed and are prevented from coming off by a retaining ring 76 via a support member 74.
[0016]
The driven magnets 72 a to 72 c and the inner wall surface of the ring member 70 are formed slightly spaced from the outer peripheral surface of the cylinder tube 14.
[0017]
The rodless cylinder 10 according to the present embodiment is basically configured as described above. Next, its operation, action, and effect will be described.
[0018]
A solenoid valve (not shown) is operated, compressed air is introduced into the first port 42, and the second port 50 is opened to atmospheric pressure. Compressed air is introduced into the chamber 40a of the cylinder tube 14 from the first port 42, and the piston 20 slides in the direction of arrow A by the pressure of the compressed air. Therefore, the driving magnets 30a to 30c are displaced to magnetically attract the driven magnets 72a to 72c, and the slider 56 slides on the guide shafts 16a and 16b in the direction of arrow A. At this time, since there is a slight gap between the driven magnets 72a to 72c and the outer peripheral surface of the cylinder tube 14, there is no sliding resistance and wear, and there is no fear of generation of dust or the like. Further, since the guide shafts 16a and 16b are supported by the ball bushing 62, the sliding resistance is small and no dust is generated.
[0019]
When the piston 20 is further displaced in the direction of arrow A, the end portion of the slider 56 comes into contact with the damper 18 and the slider 56 is positioned. For this reason, the driving magnets 30a to 30c are attracted to the driven magnets 72a to 72c, and the piston 20 is prevented from being further displaced in the direction of the arrow A from this position.
[0020]
Next, when a solenoid valve (not shown) is operated, the first port 42 is opened to the atmosphere and the compressed air is introduced into the second port 50, the compressed air is introduced into the chamber 40b, and the piston 20 slides in the direction of arrow B. To do. Therefore, similarly to the above, the driven magnets 72a to 72c are attracted to the driving magnets 30a to 30c, and the slider 56 is displaced in the arrow B direction.
[0021]
In this rodless cylinder 10, if there is an error in the assembly of the guide shafts 16 a and 16 b and the ball bush 62, part of the inner peripheral surface of the driven magnets 72 a to 72 c may approach the outer peripheral surface of the cylinder tube 14. is there. In this case, the driven magnets 72a to 72c do not need to contact the outer peripheral surface of the cylinder tube 14, and therefore, within the range of the gap between the outer peripheral surface of the cylinder tube 14 and the inner peripheral surfaces of the driven magnets 72a to 72c. If so, an assembly error between the guide shafts 16a and 16b and the ball bushing 62 is allowed.
[0022]
In the rodless cylinder 10 according to the present embodiment, as shown in FIG. 3, the polarities of the drive magnets 30a to 30c are all arranged in the same direction, and the driven magnets 72a to 72c are the drive magnets 30a to 30c. As shown in FIG. 4, the polarity of the driving magnet 30b is opposite to that of the driving magnets 30a and 30c, and the driven magnet 72b is also corresponding to the driving magnet 30b. You may arrange | position opposite to the to-be-driven magnets 72a and 72c.
[0023]
【The invention's effect】
According to the rodless cylinder according to the present invention, the following effects and advantages can be obtained.
[0024]
Since the cylinder tube and the driven magnet are slightly separated from each other, there is no fear that dust or the like is generated due to wear, and the rodless cylinder can be used for medical, food-related, clean rooms, and the like.
[0025]
Further, since the guide shaft is supported by the ball bush, the sliding resistance is reduced, and further, the surface treatment of the cylinder tube is not required, and it is not necessary to assemble with high accuracy, so that the manufacturing cost can be reduced. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a rodless cylinder according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II-II showing the rodless cylinder of FIG.
FIG. 3 is a partially enlarged sectional view of the rodless cylinder of FIG. 1;
FIG. 4 is a partially enlarged cross-sectional view of a rodless cylinder according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Rodless cylinder 12a, 12b ... Plate-shaped member 14 ... Cylinder tube 16a, 16b ... Guide shaft 20 ... Piston 30a-30c ... Driving magnet 56 ... Slider 62 ... Ball bushing 72a-72c ... Driven magnet

Claims (1)

A cylindrical cylinder tube;
A piston disposed inside the cylinder tube and slidable along a longitudinal direction of the cylinder tube;
A driving magnet disposed on the piston ;
Before Symbol is slidably supported by the guide member, wherein the cylinder tube has an insertion freely hole, a slider which is provided displaceably along the axial direction of the cylinder tube,
A driven magnet disposed opposite to the driving magnet across the cylinder tube in the hole of the slider;
Two or more guide members provided in parallel with the cylinder tube, for guiding the slider along the axial direction, and holding a slight gap formed between the driven magnet and the cylinder tube; ,
A ball bushing provided between the slider and the guide member and supporting the slider so as to be displaceable along the guide member;
A rodless cylinder comprising:

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