JPH0685904U - Position detector for fluid pressure cylinder - Google Patents

Abstract

(57) [Abstract] [Purpose] When the sensor case is installed in the mounting groove, the sensor case is automatically positioned and fixed in the center of the mounting groove. [Structure] A mounting groove 12 in which a sensor case 14 is mounted is formed in a cylinder body 11. The mounting groove 12 is formed by a semicircular bottom surface 18, side surfaces 19 extending straight from the bottom surface 18 in parallel with each other, and an inclined surface 20 formed on the rib 16. Sensor case 14
The cross-sectional shape of No. 2 corresponds to the cross-sectional shape of the mounting groove 12 and is set to a slightly smaller size. The fixing member 2 is attached to the cutout portion 25 formed at the end of the sensor case 14.
8 is arranged, and the sensor case 14 is fixed to the cylinder body 11 by a screw member 27 screwed to the sensor case 14 and the fixing member 28.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a position detecting device for a fluid pressure cylinder that detects the position of a moving member such as a piston in a fluid working device such as a fluid pressure cylinder.

[0002]

[Prior art]

 In order to detect the position of the piston that is reciprocally mounted in the fluid pressure cylinder and is actuated by the fluid, a position detector equipped with a sensor is installed in the mounting groove formed in the cylinder body of the fluid pressure cylinder. It is used.

As a conventional position detecting device, there is one disclosed in Japanese Utility Model Laid-Open No. 2-87104, FIG. 7 (A) shows this position detecting device, and FIG. 7 (B) shows this position detecting device. Shows the state where is attached to the cylinder body of the fluid pressure cylinder.

As shown in the figure, the sensor case 1 has a quadrilateral cross section, is molded of resin, and has a magnetic detection element (not shown) incorporated therein. In order to mount the sensor case 1 on the cylinder body 2, a mounting groove 3 having a quadrangular cross section with a width dimension D is formed in the cylinder 2, and the mounting groove 3 is formed between the ribs 4 in the width dimension. It is opened to the outside through a slit 5 formed as d.

The sensor case 1 is formed to have a width smaller than the width dimension d and is housed in the mounting groove 3. A clamp plate accommodating hole 6 is formed at the front end of the sensor case 1 by providing an upper piece 1a and a lower piece 1b, and the notch 7 is passed through the accommodating hole 6 to form the clamp plate 8 therein. Is to be inserted.

A screw member 9 whose tip contacts the lower piece 1 b is screwed to the clamp plate 8, and the sensor case 1 is attached to the mounting groove 3 by fastening the tip of the clamp plate 8 to the rib 4. It is designed to be fixed inside.

By the way, in recent years, it has been demanded to use a miniaturized fluid pressure cylinder in various automatic production apparatuses including a semiconductor manufacturing process. However, as shown in FIG. With the fluid pressure cylinder equipped with the position detection device, there was a limit to miniaturization. This is because when the cylinder body is downsized, the sensor case 1 itself must be downsized. For example, the upper piece 1a and the lower piece 1b are provided at the tip of the sensor case 1 having a width and a vertical dimension of about 3 to 4 mm. However, there is a problem in that it is difficult to form, or even if it is formed, the strength is not sufficient.

Moreover, both sides of the bottom surface of the mounting groove 3 become dead spaces, and in the type in which the mounting groove 3 is formed at the corner of the cylinder body, the interference between the portion and the hollow hole in the cylinder is prevented. It is difficult to downsize the cylinder to avoid it.

An improvement of the position detecting device shown in FIG. 7 is shown in FIG. 8, and the position detecting device shown in this figure is described in Japanese Utility Model Laid-Open No. 3-46005. Note that, in FIG. 8, members common to the members shown in FIG. 7 are denoted by the same reference numerals.

In this position detecting device, a housing hole 6a in the width direction is formed at the end of the sensor case 1, and a clamp plate 8 having a cross-sectional shape similar to the cross-sectional shape of the housing hole 6a is made to penetrate therethrough. The tip of the screw member 9 screwed to the clamp plate 8 is brought into contact with the bottom surface of the mounting groove 3.

In this case, unlike the case of FIG. 7, the screw member 9 has a structure in which stress due to tightening does not act on the lower piece 1a of the sensor case 1, so that the clamp plate 8 and the sensor case 1 are If there is backlash, the sensor case 1 will be backlashed even when the sensor case 1 is fixed. Further, in this case, it is difficult to fasten the upper piece 1a by using a tapping screw as the screw member 9 in order to prevent the looseness. This is because, in this case, as in the case shown in FIG. 7, since the upper piece 1a and the lower piece 1b are provided at the tip of the sensor case 1, the thickness of the upper piece 1a becomes thin and the screw member 9 This is because if a screw hole is formed in the upper piece 1a by using a so-called tapping screw when tightening, the crack may occur in the upper piece 1a.

FIG. 9 is a view showing the position detecting device disclosed in Japanese Utility Model Laid-Open No. 3-69703. In this case, a protrusion that abuts the rib 4 of the mounting groove 3 on the resin sensor case 1 itself. The portion 1c is formed so that the nut 8a is embedded inside the sensor case 1. In this position detecting device, when the screw member 9 is screwed and fastened to the nut 8a and fastened, the fastening force is transmitted to the rib 4 via the sensor case 1 itself. Is added, the protrusion 1c of the sensor case 1 may be broken.

In each of the above-mentioned conventional techniques, it is not easy to accurately position the sensor case 1 at the center position in the mounting groove 3. This is because the width dimension of the sensor case 1 must be set smaller than the width dimension of the mounting groove 3 in order to facilitate the insertion of the sensor case 1 into the mounting groove 3. When the sensor case 1 is inserted into the sensor case 1, there is looseness between the sensor case 1 and the mounting groove 3, and when the sensor case 1 is fastened using the screw member 9, the sensor case 1 is positioned at a predetermined position. Not easy to do.

Therefore, the work of fastening the sensor case 1 to the central position in the mounting groove 3 requires carefulness, and the workability of the mounting work of the sensor case is not good.

Japanese Utility Model Laid-Open No. 3-93607 discloses a position detecting device in which the cross-sectional shape of the sensor case 1 is circular. FIG. 10 shows this position detecting device.

As shown in the drawing, a mounting groove 3 having a circular cross section is formed in the fluid pressure cylinder 1, and the cross-sectional shape of the sensor case 1 is set to a circular cross section having a diameter slightly smaller than that of the mounting groove 3. There is. In order to fasten the sensor case 1, the screw member 9 is coupled to the screw hole 1d formed in the sensor case 1.

In this case, when inserting the sensor case 1 into the mounting groove 3, it is difficult to set the attitude of the sensor case 1 in the direction shown by the arrow in FIG. There is a problem that it is difficult to set the posture of the sensor element incorporated in the case 1 to a desired state with respect to the piston in the cylinder body.

[0018]

[Problems to be solved by the device]

 The purpose of the present invention is to provide a centering function that allows the sensor case itself to be positioned at a predetermined position in the mounting groove when the sensor case is fastened with a screw member after the sensor case is inserted into the mounting groove. It is to provide a position detecting device having the same.

Another object of the present invention is to provide a position detecting device applicable to a small fluid pressure cylinder.

Still another object of the present invention is to use a tapping screw as a screw member to fasten the sensor case in the mounting groove even if the sensor case is made small to correspond to a small fluid pressure cylinder. An object of the present invention is to provide a position detecting device that can attach a screw member while forming a screw hole in itself.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0022]

[Means for Solving the Problems]

 The following is a brief description of the outline of the typical invention disclosed in the present application.

That is, the mounting groove into which the sensor case is mounted is formed by a semicircular bottom surface, both side surfaces extending straight from the bottom surface so as to be substantially parallel to each other, and an inclined surface provided on the rib. . The inclined surfaces face each other with an upward inclination toward the slit. The sensor case has a cross-sectional shape corresponding to the cross-sectional shape of the mounting groove and has a slightly smaller size, and is fixed to the mounting groove by a screw member. When the screw member is tightened, the inclined surface of the sensor case is brought into pressure contact with the inclined surface of the mounting groove, whereby the sensor case is positioned at the center of the mounting groove. An end portion of the sensor case is cut out, and a fixing member is arranged at that portion, and a screw member is screwed to the sensor case and the fixing member.

[0024]

[Action]

 When the screw member is screwed, the inclined surface of the mounting groove comes into pressure contact with the inclined surface of the mounting groove, and the sensor case is positioned toward the center of the mounting groove by the action of this inclined surface. Therefore, when mounting the sensor case in the mounting groove, the sensor case can be fixed in a predetermined posture or position by simply fixing the sensor case with a screw member. The distance or positional relationship between the magnet provided on the piston and the sensor element incorporated in the sensor case can be set to a desired state.

Since the bottom surface of the mounting groove is semi-circular, when the mounting groove is formed at the corner of the cylinder body, the mounting groove itself can be brought close to the hollow hole in the cylinder body. It can be miniaturized. Since the thickness of the sensor case can be increased while the size is reduced, a sufficient internal volume for accommodating the sensor element can be ensured.

Since the screw member is screwed to the fixing member and the fastening portion arranged in the cutout portion, the length of the female screw to be screwed can be sufficiently secured, and the resin sensor case can be used. Even if the screw member is attached, the sensor case is not damaged and the tapping screw can be used.

[0027]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (Embodiment 1) FIGS. 1 (A) and 1 (B) are a front view and a side view showing a position detecting device of a fluid pressure cylinder according to an embodiment of the present invention, and FIG. 2 is a front end portion of a sensor case. 3A is a front view of FIG. 2, and FIG. 3B is a partially cutaway side view.

As shown in FIG. 1, the fluid pressure cylinder 10 has a cylinder main body 11 which is a substantially rectangular parallelepiped as a whole, and the cylinder main body 11 is formed by, for example, extrusion molding. At the time of this molding, the mounting groove 12 for mounting the sensor case is formed in the cylinder body 11. In the illustrated case, three mounting grooves 12 are formed, and each mounting groove 12 extends along the longitudinal direction of the cylinder body 11.

A hollow hole is formed in the cylinder body 11 for accommodating a piston (not shown) so as to be capable of reciprocating in the axial direction. A piston rod 13 having this piston at its tip projects from one end of the cylinder body 11. ing.

The sensor case 14 is in the form of a rod having a lateral cross-sectional shape with a slightly smaller size that substantially corresponds to the cross-sectional shape of the mounting groove 12, and its tip is shown in FIGS. 2 and 3. In the center of the sensor case 14, a contact type sensor element such as a reed switch or a non-contact type sensor element such as an IC switch is incorporated, and is attached to a piston (not shown) at the tip of the piston rod 13. An on / off signal is generated by the magnetic force of the attached magnet. This signal is sent to the control unit (not shown) by the cable 15 shown in FIG.

Three mounting grooves 12 are formed in the illustrated cylinder body 11, and sensor cases 14 are mounted in two of them. An enlarged view of each mounting groove 12 is as shown in FIG.

As shown in the figure, two ribs 16 are formed on the cylinder body 11 so as to be positioned on the outer side of the mounting groove 12, and these ribs 16 project in the width direction from each other and slits between them. 17 are formed. The mounting groove 12 is communicated with the outside through the slit 17. When the width of the mounting groove 12 is D and the width of the slit 17 is d, the width d is set smaller than the width D.

The mounting groove 12 has a semicircular bottom surface 18, left and right side surfaces 19 that extend straight from the end of the bottom surface 18 toward the outer surface of the cylinder body 11, and slopes formed on the respective ribs 16. And the surface 20. The two inclined surfaces 20 incline upward toward the slit 17 and face each other.

The sensor case 14 has a sectional shape corresponding to the sectional shape of the mounting groove 12. That is, it has a semi-circular bottom surface 21, straight left and right side surfaces 22, and an inclined surface 23 that corresponds to the inclined surface 20 of the rib 16, and a protrusion 24 corresponding to the slit 17 is provided on the upper surface. Has been formed.

As shown in FIG. 3 (B), a notch 25 is formed in the bottom-side portion of the semicircle at the tip of the sensor case 14, so that the fastening portion 26 is provided on the inclined surface 23 side. It is provided.

A screw member 27 is screwed to the fastening portion 26, and a fixing member 28 is screwed to the screw member 27. The fixing member 28 is set to have a width dimension equal to or smaller than the width between both side surfaces 22 of the sensor case 14 and not to protrude from the tip surface of the sensor case 14. Further, the fixing member 28 is provided with a small-diameter projection portion 29 at the lower portion in order to lengthen the screw connection portion with the screw member 27.

As shown in FIG. 3B, a slit 31 for engaging a tool 30 such as a screwdriver is formed on the upper end of the screw member 27. In the case shown in the figure, the screw member 27 uses a self-tapping screw with an outer diameter of 2 mm. In consideration of versatility, the inner diameter of the screw member 27 is about 2.8 mm so that it can be used with a 2.5 mm flat-blade screwdriver. A counterbore 32 is formed in the sensor case 14.

To mount the sensor case 14 having the above-described structure in the mounting groove 12 of the cylinder body 11, the sensor case 14 is slid into the mounting groove 12. At this time, since the shape of the cross section of the sensor case 14 is set to be slightly smaller than the cross section of the mounting groove 12, the sensor case 14 can be slid easily.

After that, when the screw member 27 is rotated using a tool 30 such as a screwdriver, the tip of the screw member 27 abuts the bottom surface of the mounting groove 12, and the inclined surface of the sensor case 14, that is, the pressing surface 23 of the rib 16. Press contact with the inclined surface 20. At this time, due to the pressure contact between both inclined surfaces 20 of the rib 16 and the inclined surface 23 of the sensor case 14, a positioning force toward the center portion in the width direction is applied to the sensor case 14, and the sensor case is automatically moved. The sleeve 14 is mounted in the mounting groove 12 in a predetermined posture. Therefore, the distance between the sensor element and the magnet in the state where the sensor case 14 is attached can be made constant according to the set value, and the position adjustment work becomes unnecessary.

Since the bottom surface of the mounting groove 12 is semicircular, the dead space of the mounting groove 12 is eliminated as compared with the case where the sectional shape of the mounting groove 12 is substantially quadrangular. Moreover, since the mold for extruding the cylinder body 11 has no corners, the life of the mold is extended. Since the sensor case 14 is formed with the both side surfaces 19 extending straight from the semicircular bottom surface 18, the cross-sectional area of the sensor case 14 can be increased while the cylinder body 11 is downsized. A sufficient space can be secured for the sensor element.

Embodiment 2 FIG. 4A is a sectional view of a cylinder body 11 according to another embodiment of the present invention, and FIG. 4B is any one of those shown in FIG. FIG. 4 is a cross-sectional view showing a sensor case 14 attached to a mounting groove 12.

In this case, in the above-described embodiment, the mounting groove 12 is formed by aligning the center of the mounting groove 12 with the radial center line of the hollow hole, while the center of the mounting groove 12 is formed. The mounting groove 12 is displaced from the radial center line of the hollow hole, and the mounting groove 12 is arranged near the corner of the cylinder body 11. In FIG. 4, reference numeral 33 indicates a hollow hole formed in the cylinder body 11.

In the position detecting device shown in FIG. 4, a predetermined thickness can be provided between the semicircular bottom surface 18 of the mounting groove 12 and the hollow hole 33, and as shown by the chain double-dashed line, As compared with the case where the mounting groove 12 is a quadrangle, the mounting groove 12 can be brought closer to the hollow hole 33, so that the cylinder body 11 can be downsized. The shapes of the mounting groove 12 and the sensor case 14 are the same as those in the above embodiment.

(Embodiment 3) FIGS. 5A and 5B are views showing a position detecting device for a fluid pressure cylinder according to still another embodiment of the present invention. In this case, the shape of the mounting groove 12 formed in the cylinder body 11 is similar to that of the above-described embodiment, but the notch portion 25 in the above-described embodiment is formed at the tip of the sensor case 14. Absent. Therefore, the screw member 27 is threadedly connected to the sensor case 14 in the radial direction, and the tip of the screw member 27 is brought into contact with the bottom surface 18 of the mounting groove 12.

In this case, the length of the female screw to which the screw member 27 is screwed can be sufficiently secured in the sensor case 14, and when the screw member 27 is tightened, damage or breakage of the sensor case 14 is prevented. To be done. Moreover, a centering function of automatically adjusting the attitude of the sensor case 14 can be obtained as in the above-described embodiment.

Embodiment 4 FIGS. 6A to 6C are views showing a position detecting device for a fluid pressure cylinder according to still another embodiment of the present invention. In this case as well, the cross-sectional shape of the mounting groove 12 is the same as that of each of the above-described embodiments, but unlike the embodiment shown in FIGS. 1 to 4, the tip of the sensor case 14 has a slit side. A cutout portion 25 is formed in the portion. Therefore, the fastening portion 26 is provided on the bottom surface side portion of the sensor case 14.

A fixing member 28a is arranged at the position of the cutout portion 25. The fixing member 28a has a hexagonal outer peripheral shape as shown in the drawing, and the outer surface is the side surface 19 of the mounting groove 12. It is designed to engage. Further, as shown, an inclined surface 23a is formed on this end surface.

A recess 34 is formed in the fastening portion 26 of the sensor case 14 to engage the tip of the screw member 27 that is screwed to the fixing member 28 a.

Therefore, in this embodiment, when the screw member 27 is tightened, the inclined surface 23 a presses the inclined surface 20 of the rib 16 while the outer peripheral surface of the fixing member 28 is engaged with the side surface 19. The center of the sensor case 14 is positioned at the center of the mounting groove 12. As a result, the posture or position of the sensor element in the sensor case 14 is set to a predetermined state. The shape of the outer peripheral surface of the fixing member 28a may be any shape, such as a quadrangle other than the hexagonal shape, as long as the outer surface is engaged with the side surface 19 to prevent the fixing member 28a from rotating. .

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

[0051]

[Effect of device]

 The effects obtained by the representative one of the inventions disclosed in the present application will be briefly described as follows.

(1). Since the mounting groove for accommodating the sensor case has the inclined surface formed by the rib, when the sensor case is fastened with the screw member, the sensor case is automatically operated by the action of the inclined surface. The sensor case is positioned and fixed at the center of the mounting groove, so that the sensor case can be easily mounted.

(2). Since the sensor case can have a thickness in the depth direction, it is possible to secure a sufficient volume for accommodating the sensor element.

(3). The bottom surface of the mounting groove is semi-circular, and the bottom surface of the sensor case is also semi-circular correspondingly, so the dead space of the mounting groove can be eliminated and the mounting groove can be eliminated. Can be brought close to the hollow hole in the cylinder body.

(4) Since the mounting groove can be brought close to the inside of the hollow hole, the shape of the cylinder body including the mounting groove can be downsized.

(5). Since the screw member for fixing the sensor case in the mounting groove is screwed into the long screw hole formed in the sensor case, the screw member can be used without increasing the thickness of the entire sensor case. The strength of the joint can be increased, and breakage or damage of the screw hole can be prevented.

[Brief description of drawings]

FIG. 1 is a front view (A) and a side view (B) showing a position detecting device for a fluid pressure cylinder according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a tip portion of the sensor case shown in FIG.

FIG. 3 is an enlarged sectional view (A) showing a main part of FIG. 1 (A) and a sectional view (B) taken along line 3B-3B in FIG.

FIG. 4 is a sectional view (A) showing a position detecting device for a fluid pressure cylinder according to another embodiment of the present invention and a sectional view (B) showing a main part thereof.

FIG. 5 is an enlarged sectional view (A) showing a position detecting device for a fluid pressure cylinder according to still another embodiment of the present invention and a side view (B) of the sensor case shown in FIG.

FIG. 6 is an enlarged sectional view (A) and FIG. (A) showing a position detecting device for a fluid pressure cylinder according to still another embodiment of the present invention.
FIG. 4 is a side view (B) showing the sensor case shown in FIG. 2 and a plan view (C) of FIG.

FIG. 7 is a perspective view (A) showing a conventional position detecting device and a sectional view (B) taken along line 7B-7B in the same figure.

FIG. 8 is a sectional view (A) showing another conventional position detecting device and a sectional view (B) taken along line 8B-8B in the same figure.

FIG. 9 is a sectional view showing still another conventional example of the position detecting device for a fluid pressure cylinder.

FIG. 10 is a sectional view showing still another conventional example of a position detecting device for a fluid pressure cylinder.

[Explanation of symbols]

 1 Sensor Case 1a Upper Piece 1b Lower Piece 1c Projection 2 Cylinder Body 3 Mounting Groove 4 Rib 5 Slit 6 Clamp Plate Receiving Hole 6a Receiving Hole 7 Notch 8 Clamp Plate 8a Nut 9 Screw Member 10 Fluid Pressure Cylinder 11 Cylinder Body 12 Mounting groove 13 Piston rod 14 Sensor case 15 Cable 16 Rib 17 Slit 18 Bottom surface 19 Side surface 20 Inclined surface 21 Bottom surface 22 Side surface 23 Inclined surface 23a Inclined surface 24 Projection portion 25 Notch portion 26 Fastening portion 27 Screw member 28 Fixing member 28a Fixing member 29 Protruding part 30 Tool 31 Slitting 32 Counterbore hole 33 Hollow hole 34 Recess

Claims (3)

[Scope of utility model registration request] 1. A position of a fluid pressure cylinder in which a mounting groove extending along a longitudinal direction is formed in a cylinder body of the fluid pressure cylinder, and a sensor case having a sensor element incorporated therein is mounted in the mounting groove. In the detection device, the cylinder main body is provided with ribs that project in the width direction of the mounting groove and form slits for communicating the mounting groove to the outside, and a semicircular bottom surface and an outer surface of the cylinder main body from the bottom surface. The mounting groove is formed by the both side surfaces that extend straight toward and the both inclined surfaces that are continuous with these both side surfaces and that are inclined upward toward the slit and that are formed on the rib, and that the mounting groove is crossed. The surface is formed in a shape corresponding to the mounting groove, and a notch is formed in the semicircular side portion of the tip portion to form a tightening surface having an inclined surface corresponding to the inclined surface of the rib. A portion is provided at the tip of the sensor case, and a screw member that is screwed to a fixing member arranged in the cutout portion and is in contact with the bottom surface is attached through the fastening portion. A position detecting device for a fluid pressure cylinder, characterized in that the sensor case is positioned and fixed at the center of the mounting groove by tightening a fastening portion of the sensor case with an inclined surface. 2. A position of a fluid pressure cylinder in which a mounting groove extending along a longitudinal direction is formed in a cylinder body of the fluid pressure cylinder, and a sensor case having a sensor element incorporated therein is mounted in the mounting groove. In the detection device, the cylinder main body is provided with ribs that project in the width direction of the mounting groove and form slits for communicating the mounting groove to the outside, and a semicircular bottom surface and an outer surface of the cylinder main body from the bottom surface. The mounting groove is formed by both side surfaces that extend straight toward and the two inclined surfaces that are continuous with these side surfaces and that are inclined upward toward the slit and that are formed in the rib, By forming a surface shape into a shape corresponding to the mounting groove, attaching a screw member abutting the bottom surface to the sensor case, and fastening the screw member Position detecting device of a fluid pressure cylinder, wherein the sensor case is to be fixed is positioned in the center of the mounting groove. 3. A position of a fluid pressure cylinder in which a mounting groove extending in a longitudinal direction is formed in a cylinder body of the fluid pressure cylinder, and a sensor case having a sensor element incorporated therein is mounted in the mounting groove. In the detection device, the cylinder main body is provided with ribs that protrude in the width direction of the mounting groove and form slits for communicating the mounting groove to the outside between the semi-circular bottom surface and the outer surface of the cylinder main body from the bottom surface. The mounting groove is formed by both side surfaces that extend straight toward and the two inclined surfaces that are continuous with these side surfaces and that are inclined upward toward the slit and that are formed in the rib, The surface is formed in a shape corresponding to the mounting groove, and a cutout portion is formed in a portion of the tip portion of the sensor case on the slit portion side of the tip portion. A screw member that abuts the case portion is screwed to a fixing member that is arranged in the cutout portion, and an inclined surface that abuts the inclined surface of the rib is formed on the fixing member, and the inclined surface of the fixing member is A position detecting device for a fluid pressure cylinder, wherein the sensor case is positioned and fixed at the center of the mounting groove by pressing against the inclined surface of the rib.