JPH0678762B2 - Magnet type cylinder device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnet type cylinder device, and more particularly, to a driving magnet and a yoke operated by compressed air or the like, and a cylinder tube interposed between the driving magnet and the yoke. TECHNICAL FIELD The present invention relates to a technique effectively applied to a magnet type rodless cylinder device or the like that is composed of a driven magnet and a yoke that are magnetically coupled with each other and are displaced together with them.

[Prior Art] In a magnet type cylinder device, a driving magnet and a driven magnet each having a yoke on both axial end surfaces are displaced inside and outside the cylinder tube along the axial direction of the cylinder tube. Some of them are freely arranged, and the driving magnet side and the driven magnet side are magnetically coupled to each other through a cylinder tube.
58-76804 issue).

In this magnet type cylinder device, the driving magnet side is displaced by the fluid pressure supplied to the inside of the cylinder tube, and the driven magnet side is displaced along with the driving magnet side by the magnetic attraction force of both magnets. It is considered as a structure.

[Problems to be Solved by the Invention] In this type of magnet type cylinder device, in order to ensure high performance, the setting of the operating point (permeance coefficient) of the magnet and the design of the magnetic circuit are the most important factors. is there.

The latter magnetic circuit design is an element that cannot be separated from the magnet operating point because it affects the magnet operating point.

Then, basically, the magnet operating points of the driving magnet and the driven magnet are set to be the same, and they are set in the vicinity of the maximum energy product. In the magnetic circuit in which the magnetic flux flows, the driving magnet side and the driven magnet side are The two important points are to make the magnetic resistance of and as uniform as possible.

By the way, in the above-mentioned magnet type cylinder device, the axial width of the driving magnet and the driven magnet, and the axial width of the driving magnet side yoke and the driving magnet side yoke are the same. Has been done.

When the magnetic circuit of such a magnet type cylinder device is rewritten into an electric equivalent circuit, a circuit diagram as shown in FIG. 5 is obtained.

In FIG. 4, Rg: magnetic resistance of air gap between driving magnet side and driven magnet side, Rm: magnetic resistance inside magnet, Ry: magnetic resistance inside yoke, E: magnet magnetomotive force, φ: effective Magnetic flux, φo: total magnetic flux (φ = φo−φs), Rs: magnetic resistance outside the driven magnet, and φs: leakage magnetic flux, respectively. In addition, i and o added to the end of each symbol distinguish between the driving body side and the driven body side.

According to the equivalent circuit shown in FIG. 5, the magnetomotive forces of the driving magnet and the driven magnet are different, and when the magnetomotive force of one of the magnets is set to the optimum value on the demagnetization curve of the magnet material, The problem is that the operating point of the other magnet deviates from the optimum value and the total magnetomotive force (Eo + Ei) of both magnets does not reach the optimum value.

Further, in the above-mentioned magnet type cylinder device, the widths in the axial direction of the driving magnet side yoke and the driven magnet side yoke are also the same, so that the driving magnet side and the driven magnet side are the same. It is a problem that the magnetic resistance of the yoke that is in contact with the air gap is different between the driving magnet side and the driven magnet side. That is, the magnetic resistance of the yoke on the driving magnet side increases due to the difference in the length in the circumferential direction, the magnetic circuit is narrowed down on the driving magnet side, and the increase in the absolute magnetic flux is hindered. To be done.

That is, assuming that the width of the driven magnet side yoke located outside the tube and the width of the driving magnet side yoke located inside the tube are the same, the circumferential length is the driven magnet side. Side yoke becomes longer and, conversely, the driving magnet side yoke becomes shorter, and as a result, the facing area of the driving magnet side yoke becomes narrower than the facing area of the driven magnet side yoke. . Therefore, the magnetic circuit from the outer yoke to the inner yoke is narrowed to increase the magnetic resistance, which causes the magnetic flux to leak from the driven magnet to the outside.

An object of the present invention is to provide a magnet type cylinder device capable of improving the holding force between the driving magnet side and the driven magnet side, the operational reliability of the device, the downsizing and weight saving of the device. To do.

[Means for Solving the Problems] A magnet type cylinder device of the present invention includes a cylinder tube,
Covers respectively coupled to the openings at both ends of the cylinder tube, a driving body provided in the inside of the cylinder tube so as to be slidable in the axial direction and having a driving magnet and a driving side yoke, and a shaft outside the cylinder tube. A driven body having a driven magnet and a driven side yoke slidably provided in a direction, the driven magnet is made to correspond to the driven magnet, and the driven side yoke is provided with the driven side. The yokes are opposed to each other, and the axial width of the driven side yoke is set smaller than the axial width of the driving side yoke,
The width of the driven magnet in the axial direction is set to be larger than the width of the driving magnet in the axial direction.

[Action]

According to the above-mentioned means, the driving side yoke and the driven side yoke are opposed to each other, and the width of the driven side yoke is set smaller than the width of the driving side yoke, and the driven yoke is correspondingly set. The width is set to be larger than the width of the drive yoke, so leakage of magnetic flux from the driven side yoke located outside the tube to the drive side yoke located inside the tube is reduced, improving the holding power. To be done.

[Embodiment 1] FIG. 1 is a sectional view showing a magnet type cylinder device according to an embodiment of the present invention with a part thereof omitted.

The magnet type cylinder device of this embodiment is a double-acting rodless cylinder device using an axially magnetized magnet, and as shown in FIG. 1, a cylinder tube 1 made of a non-magnetic material and both ends of this cylinder tube 1. Covers 2 and 3 are respectively connected to the opening side.

The cylinder tube 1 has a ring-shaped cross section in the radial direction, and the covers 2 and 3 have a perfect circular cross section in the radial direction.

The cylinder tube 1 and the covers 2 and 3 are connected to each other by a caulking structure 4, and the caulking structure 4 is combined to thin the cylinder tube 1.

A drive body 5 is slidably accommodated inside the cylinder tube 1 along the axial direction, and the inside of the cylinder tube 1 is partitioned into two cylinder chambers 1a and 1b, respectively.

The cylinder chambers 1a and 1b are connected to the supply and discharge ports 2a and 3a respectively opened in the covers 2 and 3, respectively, and the fluid pressure of compressed air or the like supplied from the supply and discharge ports 2a and 3a to the cylinder chambers 1a and 1b. The drive body 5 is slidable inside the cylinder tube 1 along the axial direction.

The driving body 5 includes a pair of wear rings 5a and a plurality of drive magnets 5b interposed between the pair of wear rings 5a.
And a yoke 5c arranged on both end surfaces of the drive magnet 5b in the axial direction, and a bumper 6 arranged on the outer end surface side of the wear ring 5a, respectively. Are each ring-shaped.

The fastening rod 7 is penetrated through the through holes on the axis of the wear ring 5a, the driving magnet 5b, the yoke 5c, and the bumper 6,
Nuts 8 are respectively fastened to the threaded portions of both ends of the fastening rod 7 to form the driving body 5.

A driven body 9 having a ring-shaped cross section in a radial direction is fitted on the outer peripheral surface side of the cylinder tube 1 so as to be slidable along the axial direction of the cylinder tube 1.

The driven body 9 includes a pair of wear rings 9a and a plurality of driven magnets interposed between the pair of wear rings 9a.
9b, a yoke 9c arranged on both end surfaces in the axial direction of the driven magnet 9b, and a tube 9d fitted on the outer peripheral surfaces of the driven magnet side 9b and the yoke 9c. Each member has a ring-shaped cross section in the radial direction.

Then, both ends of the tube 9d are respectively fitted into the fitting recesses 9e of the wear ring 9a to form the driven body 9, and the driven body 9 is magnetically coupled to the driving body 5 via the cylinder tube 1. Since the driven body 9 is driven by the driven body 5,
It is a structure that is accompanied by the displacement of and is displaced at the same time.

Here, the axial widths W ₁ and W ₂ of the driving magnet 5b and the corresponding driven magnet 9b in this embodiment are different from each other.

That is, the width W ₁ of the driving magnet 5b in the axial direction is smaller than the width W _{2 of the} driven magnet 9b in the axial direction, and the width W ₁ of the driving magnet 5b and the width W of the driven magnet 9b. Due to the difference from ₂ , the magnet operating points of the driving magnet 5b and the driven magnet 9b are set to the optimum values on the demagnetization curves of the respective magnet materials.

Similarly, the axial widths W ₃ and W ₄ of the yoke 5c on the driving magnet 5b side and the corresponding yoke 9c on the driven magnet 9b side are also different from each other.

That is, the axial width W ₃ of the yoke 5c is made larger than the axial width W ₄ of the yoke 9c, and due to the difference between the width W ₃ of the yoke 5c and the width W _{4 of the} yoke 9c, The magnetic resistance with the yoke 9c is made uniform. Also,
By making the magnetic resistance uniform, leakage of magnetic flux from the yoke 9c to the outside is reduced.

Next, the operation of this embodiment will be described.

In the state shown in FIG. 1, when a fluid pressure such as compressed air is supplied from the supply / discharge port 2a to the cylinder chamber 1a, the fluid pressure acts on the left end surface of the driving body 5, so that the driving body 5 is shown in FIG. Is displaced to the right of.

Further, the driven body 9 is accompanied by the displacement of the driven body 5 by the holding force between the driving magnet 5b and the driven magnet 9c, and
It is displaced to the right of the figure.

Next, when fluid pressure is supplied from the supply / discharge port 3a to the cylinder chamber 1b, the fluid pressure acts on the right end surface of the driving body 5, so that the driving body 5 displaced to the right side in FIG. Is displaced to the left side of.

Further, the driven body 9 is accompanied by the displacement of the driven body 5 by the holding force between the driving magnet 5b and the driven magnet 9c, and
It is displaced to the left side of the figure.

The magnet type cylinder device of this embodiment is operated in this manner.

In this case, according to the magnet type cylinder device of the present embodiment,
The axial width W ₁ of the driving magnet 5b is smaller than the axial width W _{2 of the} driven magnet 9c, and the width W ₁ of the driving magnet 5b and the width W ₂ of the driven magnet 9b are Due to the difference, the magnet operating points of the driving magnet 5b and the driven magnet 9b are set to the optimum values on the demagnetization curves of the respective magnet materials, so that the driving magnet 5b side and the driven magnet 9b are The holding power with the side can be improved.

Further, the axial width W ₃ of the yoke 5c is made larger than the axial width W ₄ of the yoke 9c, and the width of the yoke 5c is increased.
Due to the difference between W ₃ and the width W ₄ of the yoke 9c, the magnetic reluctance between the yoke 5c and the yoke 9c is made uniform, and the uniform magnetic reluctance prevents the leakage of the magnetic flux from the yoke 9c to the outside. Since the reduction is achieved, the holding force between the driving magnet 5b side and the driven magnet 9b side can be improved.

Further, in the present embodiment, since the cylinder tube 1 and the covers 2 and 3 are respectively joined by the caulking structure 4 to reduce the thickness of the cylinder tube 1, the cylinder tube 1 is driven by the reduction in thickness. The holding force between the driving magnet 5b side and the driven magnet 9b side can also be improved by shortening the air gap between the magnet 5b side and the driven magnet 9b side.

[Embodiment 2] FIG. 2 is a partial cross-sectional view schematically showing a magnet type cylinder device according to another embodiment of the present invention.

In the magnet type cylinder device of the second embodiment, the collar portion is
9f is integrally formed on the inner peripheral surface of the yoke 9c along the circumferential direction.

Also in the magnet type cylinder device of the second embodiment, similarly to the first embodiment, the driving magnet 5b and the driven magnet 9b are driven.
Since the axial widths W ₁ and W ₂ of the magnets are different from each other and the axial widths W ₃ and W _{4 of the} yoke 5c and the yoke 9c are different from each other, the driving magnet 5b side and the driven magnet 9b side are The holding power of the is improved.

[Embodiment 3] FIG. 3 is a schematic partial cross-sectional view showing a magnet type cylinder device according to still another embodiment of the present invention.

In the magnet type cylinder device of the third embodiment, unlike the first and second embodiments described above, the width W ₅ in the axial direction of the entire driving magnet 5b and the yoke 5c and the driven magnet 9b and the entire yoke 9c is W ₆ is different.

That is, the overall axial width W _{5 of} the drive magnet 5b and the yoke 5c is made larger than the overall axial width W _{6 of the} driven magnet 9b and the yoke 9c.

Also in the magnet type cylinder device of the third embodiment, similar to the first and second embodiments, the driving magnet 5b and the driven magnet 9 are driven.
The axial widths W ₁ and W _{2 of} b are different from each other, and the yoke 5c
Since the axial widths W ₃ and W ₄ of the yoke 9c are different from each other, the holding force between the driving magnet 5b side and the driven magnet 9b side is improved.

[Effects of the Invention] According to the structure of the magnet type cylinder device according to the first aspect of the present invention, the following effects can be obtained.

According to the structure of the magnet type cylinder device of the first aspect of the present invention, the following effects can be obtained.

That is, the width of the driven side yoke is set smaller than the width of the driving side yoke, and correspondingly, the width of the driven magnet is set larger than the width of the driving magnet. Since the magnetic reluctance of the yoke with the driving magnet side can be made uniform with each other, and the leakage of the magnetic flux from the driven magnet to the outside can be reduced by making the magnetic resistance even with each other, the magnetic field between both magnet sides can be reduced. The holding power can be improved.

Therefore, it is possible to improve the operational reliability of the device. Further, it is possible to reduce the size and weight of the device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a magnet type cylinder device according to an embodiment of the present invention with a part thereof omitted, and FIG. 2 is a magnet type cylinder device according to another embodiment of the present invention. FIG. 3 is a partial cross-sectional view schematically showing a magnet type cylinder device which is still another embodiment of the present invention, and FIG. 4 is a magnetic view of a conventional magnet type cylinder device. It is a circuit diagram which shows a circuit by an electrical equivalent circuit. 1 ... Cylinder tube, 1a, 1b ... Cylinder chamber, 2,3 ... Cover, 2a, 3a ... Supply / exhaust port, 4 ... Caulking structure, 5 ... Drive body, 5a ... Wear ring, 5b ... Drive Magnet, 5c …… yoke, 6 …… bumper 7 …… fastening rod, 8 …… nut, 9 …… driven body, 9a …… wear ring, 9b …… driven magnet, 9c …… yoke, 9d ...... tubes, 9e ...... fitting concave portions, 9f ...... flange portion, W ₁ to _W-6 ...... width.

Claims (1)

[Claims] 1. A driving body having a cylinder tube, a cover coupled to openings at both ends of the cylinder tube, and a driving magnet and a driving-side yoke slidably provided in the cylinder tube in an axial direction. And a driven body that is provided slidably in the axial direction outside the cylinder tube and has a driven magnet and a driven-side yoke. The driven magnet corresponds to the driven magnet. The driven side yoke is opposed to the driving side yoke, the axial width of the driven side yoke is set smaller than the axial width of the driving side yoke, and the axial width of the driven magnet is set. Is set to be larger than the axial width of the drive magnet.