TWI547658B - Wear ring for linear working apparatus - Google Patents

Description

Loss ring for linear motion devices

The present invention relates to a wear ring for use in a linear motion device having a displacement body that is displaced in the axial direction, and is attached to the above-described displacement body.

Conventionally, a fluid pressure cylinder having a piston that is linearly displaced by a pressure fluid has been used as a driving means for transporting and positioning a workpiece or for driving various industrial machines. People know.

The fluid pressure cylinder is disclosed, for example, in Japanese Laid-Open Patent Publication No. H5-187413, in which a piston is detachably inserted into a cylindrical cylinder tube, and a piston rod coupled to the piston is attached. The position is freely supported by a rod cover. Further, the piston and the piston rod are displaced in the axial direction by introducing a pressure fluid from the port provided in the cylinder tube and the piston rod cover into the cylinder tube. In such a fluid pressure cylinder, a packing and a wear ring are attached to the outer peripheral surface of the piston and are in sliding contact with the inner peripheral surface of the cylinder tube.

In the fluid pressure cylinder described above, generally, the piston is disposed coaxially with respect to the cylinder tube, and the gasket and the loss ring provided on the outer circumferential surface thereof are uniformly slidably coupled to the inner circumferential surface of the cylinder tube. However, for example, from the cylinder The end of the protruding piston tube, when the load is applied in a direction orthogonal to the axis thereof, or when the piston and the piston rod together are slightly inclined in the cylinder tube due to the weight of the piston rod or the like, the gasket and the loss The ring is in contact with the inner peripheral surface of the aforementioned cylinder tube. Therefore, the sliding resistance of the piston when it is displaced increases to become the displacement resistance of the piston, and there is a case where the loss ring causes partial wear.

A general object of the present invention is to provide a loss ring for a linear motion device which can smoothly linearly displace the aforementioned displacement body even when the displacement body is inclined with respect to the body. .

The present invention relates to a ring-shaped loss ring, which is provided in a linear motion device having a main body and a displacement body disposed in a manner of being displaceable along the inside of the main body, and is disposed in the displacement body through the groove portion. The outer peripheral surface is in contact with the inner wall surface of the main body, and the loss ring includes a main body portion formed in an annular shape and having an outer peripheral surface that is in contact with the inner wall surface in a planar shape; and a protruding portion The inner peripheral surface of the main body portion is formed to have a cross-sectional shape that protrudes toward the inner side of the radius, and abuts against the bottom wall of the groove portion; and the main body portion is when the displacement body is inclined with respect to the axis of the main body The outer peripheral surface is inclined to move in the groove portion while maintaining a state of abutting against the inner wall surface.

According to the present invention, the loss ring provided in the outer peripheral surface of the deformer through the groove portion includes an annular main body portion having an outer peripheral surface that is in contact with the inner wall surface in a planar shape, and a protruding portion having a cross-sectional shape. Provided on the inner peripheral surface of the body portion to protrude toward the inner side of the radius; the aforementioned protruding portion It is attached so as to abut against the bottom wall of the groove portion. Further, when the displacement body is inclined with respect to the axis of the main body, the loss ring is moved in the groove portion in order to maintain the state in which the outer circumferential surface abuts against the inner wall surface of the main body.

Therefore, in the linear motion device, even if the displacement body is inclined with respect to the axis of the main body for some reason, the loss ring is tilted through the protruding portion, whereby the contact area between the main body portion and the main body is not It will change and can be set to a constant contact area.

As a result, since the increase in the surface pressure applied to the loss ring can be suppressed even when the displacement body is inclined, the increase in the sliding resistance when the displacement body is displaced along the inside of the main body can be avoided, and the aforementioned The loss ring displaces the aforementioned displacement body smoothly and stably along the body.

The above objects and other objects, features and advantages will be apparent from the description of the preferred embodiments described herein.

In the first drawing, reference numeral 10 denotes a fluid pressure cylinder belonging to a linear motion device to which the loss ring according to the first embodiment of the present invention is applied.

As shown in FIGS. 1 and 2, the fluid pressure cylinder 10 includes a cylinder tube (main body) 12 formed in a bottomed cylindrical shape, and a piston rod cover attached to an open end of the cylinder tube 12. 14. A piston (displacement body) 16 that is located inside the cylinder tube 12 along the axial direction (arrows A and B), a piston rod 18 coupled to the piston 16, and an outer circumference of the piston 16 The loss ring of the face 20.

At the one end portion of the cylinder tube 12, a first port 22 for supplying/discharging pressure fluid is formed on the side surface thereof. The first port 22 is connected via the communication path 24 The cylinder chamber 26 formed inside the cylinder tube 12 is in communication with each other. Further, the cylinder chamber 26 is formed along the inside of the cylinder tube 12, and the piston 16 is disposed in the cylinder chamber 26 so as to be displaceable. The cylinder chamber 26 is composed of a first cylinder chamber 28 formed between the piston 16 and the closed end portion of the cylinder tube 12, and a second cylinder chamber 32 formed between the piston 16 and the piston rod cover 14. . In other words, the first cylinder chamber 28 communicates with the first port 22 via the communication passage 24.

The piston rod cover 14 is provided with a threaded portion on the outer peripheral surface of one end portion thereof, and is integrally coupled to the open end portion of the cylinder tube 12 by screwing. At this time, the seal member 34 attached to the open end of the cylinder tube 12 abuts against the end surface of the piston rod cover 14, so that the airtightness in the cylinder chamber 26 is favorably maintained.

Further, a second port 36 for supplying/discharging pressure fluid is formed on a side surface of the piston rod cover 14, and the second port 36 is connected to a piston rod penetrating a central portion of the piston rod cover 14 via a communication passage 38. The holes 40 are connected. The piston rod hole 40 penetrates in the axial direction of the piston rod cover 14 (arrows A and B directions), and the piston rod 18 is detachably inserted into the inside thereof.

The piston rod hole 40 is transmitted through the annular groove bushing 42 at a substantially central portion along the axial direction, and is disposed on the other end side of the piston rod cover 14 adjacent to the bushing 42 (arrow B direction). A rod packing 44 is attached through the annular groove. The bushing 42 is formed of, for example, a metal material in a ring shape having a substantially rectangular cross section, and its inner peripheral surface abuts against the outer peripheral surface of the piston rod 18. Further, when the piston rod 18 is displaced in the axial direction (arrows A and B directions), the piston rod 18 is detachably supported by the outer peripheral surface thereof.

The piston 16 is formed, for example, of a metal material and penetrates the center thereof. The piston hole 46 of the portion is inserted through one end side (arrow A direction) of the piston rod 18, and is coupled by screwing.

Further, on the outer peripheral surface of the piston 16, first to third annular grooves 48, 50, and 52 are formed at predetermined intervals along the axial direction of the piston 16 (arrows A and B directions). The first annular groove 48 is provided on the side closest to the piston rod cover 14 (arrow B direction), and is provided with a piston packing 54 in the vicinity of the first annular groove 48. The annular groove 50 is provided with a magnet 56, and the loss ring 20 is attached to the third annular groove (groove portion) 52 which is farthest from the piston rod cover 14. Further, any of the first to third annular grooves 48, 50, and 52 is formed in a substantially rectangular cross section.

In other words, the first and second cylinder chambers 28 and 32 of the cylinder tube 12 can be satisfactorily held by the piston washer 54, and the magnet can be detected by a position detecting means (not shown) provided in the cylinder tube 12. 56, whereby the position of the piston 16 along the axial direction (arrows A, B direction) can be detected.

As shown in FIGS. 1 to 4, the loss ring 20 is formed of, for example, a resin material, and includes an annular body portion 58 that abuts against the inner wall surface 12a of the cylinder tube 12.

The main body portion 58 has a notch portion 60 in which a part thereof is cut along the axial direction (arrows A and B directions), and is formed in the radial direction by being freely enlarged in diameter by the notch portion 60, and is formed in the axial direction. The elongated section is generally rectangular.

The outer peripheral surface 58a of the main body portion 58 is formed in a cross-sectional planar shape substantially parallel to the axis of the main body portion 58. On the other hand, the inner peripheral surface 58b of the main body portion 58 is formed to be gentle toward the inner side of the radius and at a predetermined radius. The protruding portion has an arcuate cross section, and a chamfered portion 64 that is inclined in an oblique direction is formed at a boundary portion between the inner peripheral surface 58b and the both side walls 62a and 62b. The chamfered portion 64 is formed on the side walls 62a and 62b, for example, at an angle of 45°. In other words, the loss ring 20 is held in a state in which the inner circumferential surface 58b formed in a circular arc shape is in line contact with the bottom wall surface of the third annular groove 52.

Further, in a state in which the loss ring 20 is mounted on the piston 16, the outer circumferential surface 58a is in surface contact and abuts against the inner wall surface 12a of the cylinder tube 12. On the other hand, the inner circumferential surface 58b abuts against the cylinder tube 12 The bottom wall surface of the third annular groove 52.

The piston rod 18 is formed with a thin shaft portion 66 to which the piston 16 is coupled on one end side (arrow A direction), and has a larger diameter than the thin shaft portion 66 on the other end side (arrow B direction). Thick shaft portion 68. Further, the thick shaft portion 68 is inserted into the piston rod hole 40 of the piston rod cover 14 and is movably supported in the axial direction (arrows A and B directions) through the bushing 42. Further, the piston rod washer 44 abuts against the outer peripheral surface 58a of the thick shaft portion 68 to prevent pressure fluid from leaking between the piston rod hole 40 and the piston rod 18.

The fluid pressure cylinder 10 according to the linear motion device of the wear ring 20 according to the first embodiment of the present invention is basically configured as described above, and the operation and effects will be described below.

The pressure fluid (for example, compressed air) is supplied to the first port 22 by a pressure fluid supply source (not shown), and the pressure fluid supplied to the first port 22 is introduced into the first cylinder chamber 28 via the communication passage 24. . Thereby, the piston 16 provided inside the cylinder tube 12 is pressed toward the piston rod cover 14 side (arrow B direction) from the initial position shown in Fig. 1, and the piston 16 is directed toward Displaces toward the piston rod cover 14 side. Further, the pressure fluid in the second cylinder chamber 32 is discharged to the outside from the second port 36 in a state where the pressure fluid is not supplied via the communication passage 38.

At this time, the loss ring 20 is displaced while being slidably abutted against the inner wall surface 12a of the cylinder chamber 26 by the outer peripheral surface 58a.

Further, since the piston 16 abuts against the end surface of the piston rod cover 14, it becomes the displacement end position of the piston 16 in the fluid pressure cylinder 10.

On the other hand, when the piston 16 located at the position of the displacement end is displaced from the piston rod cover 14 in the direction of departure (arrow A direction), the pressure fluid supply source (not shown) is supplied to the first port. The pressure fluid of the port 22 is supplied to the second port 36 under the switching action of a switching valve (not shown), and the first port 22 is set to a state in which the pressure fluid is not supplied.

The pressure flow system supplied to the second port 36 is introduced into the second cylinder chamber 32 via the communication passage 38, and the piston 16 is pressed in the direction away from the piston rod cover 14 (arrow A direction), whereby the piston 16 is provided. It will be displaced in the direction away from the aforementioned piston rod cover 14. Similarly, in this case, the loss ring 20 is displaced while the outer peripheral surface 58a is in sliding contact with the inner wall surface 12a of the cylinder chamber 26, and the inner peripheral surface 58b is in contact with the bottom of the third annular groove 52. The state of the wall. Further, the pressure flow system in the first cylinder chamber 28 is discharged from the first port 22 to the outside via the communication passage 24.

Further, the piston 16 abuts on the closed one end side (arrow A direction) of the cylinder tube 12, whereby the piston 16 in the fluid pressure cylinder 10 is returned to the initial position (refer to Fig. 1).

Then, for example, in a direction orthogonal to the axis of the piston rod 18 (vertical In the direction), a load is applied to the other end portion of the piston rod 18, and the piston rod 18 and the piston 16 are inclined with respect to the axis of the cylinder tube 12. In this case, the description will be made with reference to Figs. 5 and 6 .

When the load F (refer to FIG. 5) is applied as described above, the other end portion of the piston rod 18 is pushed downward, and the portion supported by the piston rod cover 14 serves as a fulcrum to become the other end. The portion is tilted downward to a predetermined angle. Thereby, the one end portion of the piston rod 18 and the piston 16 connected to the one end portion pass through a clearance provided between the outer circumferential surface 58a of the piston 16 and the inner wall surface 12a of the cylinder chamber 26, thereby becoming a cylinder chamber. The inside of 26 is inclined upward by a predetermined angle.

At this time, since the inner circumferential surface 58b of the loss ring 20 protrudes in the radial direction in a cross-sectional arc shape, the loss ring 20 is in a state in which the outer circumferential surface 58a is kept in surface contact with the inner wall surface 12a of the cylinder tube 12. The inner circumferential surface 58b is a fulcrum and is inclined to move inside the third annular groove 52. In other words, when the piston 16 is inclined with respect to the axis of the cylinder tube 12, the loss ring 20 is inclined with respect to the piston 16 by a predetermined angle so as to maintain the abutment state with the inner wall surface 12a of the cylinder tube 12, so that the foregoing The contact area of the inner peripheral surface 58b with the outer peripheral surface 58a of the aforementioned loss ring 20 does not change.

In other words, since the loss ring 20 is tilted from the axis substantially parallel to the axis of the piston 16 so as to be inclined with respect to the axis, the outer peripheral surface 58a of the loss ring 20 can be constantly grounded to the inner wall surface of the cylinder tube 12. 12a.

As a result, even if the load F is applied to the other end portion of the piston rod 18 for unknown reasons, causing the aforementioned piston 16 to tilt in the cylinder chamber 26, The contact area between the loss ring 20 and the cylinder tube 12 can be constantly set to be constant, as compared with the case where the piston rod 18 and the piston 16 are disposed coaxially with the axis of the cylinder tube 12 (see FIG. 1). Here, an increase in the contact pressure applied to the loss ring 20 when abutting against the cylinder tube 12 can be suppressed. That is, a stable contact area can be obtained without changing the contact area of the loss ring 20 with respect to the cylinder tube 12.

Thereby, in the fluid pressure cylinder 10, the sliding resistance when the piston 16 is displaced in the axial direction (arrows A and B directions) can be avoided, and the piston 16 can be made by the loss ring 20 and The piston rod 18 is smoothly and stably displaced in the axial direction of the cylinder tube 12 (arrows A and B directions).

Next, the loss ring 100 of the second embodiment and the fluid pressure cylinder 102 to which the loss ring 100 is applied are shown in Fig. 7. The same components as those of the fluid pressure cylinder 10 to which the loss ring 20 is applied in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the wear ring 100 of the second embodiment, the outer peripheral surface 104a of the main body portion 104 has a groove portion (lubrication groove) 106 into which the lubricant S can be filled, which is different from the loss ring 20 of the first embodiment. Further, the inner circumferential surface 104b of the loss ring 100 is formed in substantially the same shape as the loss ring 20 of the first embodiment.

The groove portion 106 is formed, for example, in a rectangular cross section, and is formed in an annular shape along the outer circumferential surface 104a of the main body portion 104, and is provided in a width dimension along the axial direction (arrows A and B directions) of the main body portion 104. Central Department.

Further, the cross-sectional shape of the groove portion 106 is not limited to a rectangular shape. For example, the loss ring 100a shown in Fig. 8 may be used as a groove portion (for lubrication). The groove 106a faces the inner peripheral side of the main body portion 104 and has a tapered cross-sectional triangle shape. When the outer peripheral surface 104a of the main body portion 104 abuts against the inner wall surface 12a of the cylinder tube 12, the lubricant S is sealed inside the groove portions 106 and 106a.

Further, the groove portion 106 is not limited to a single arrangement with respect to the outer circumferential surface 104a of the main body portion 104. For example, the loss ring 100b as shown in Fig. 9 may be spaced apart from each other in the center in the width direction of the main body portion 104. At a predetermined interval, a group of grooves (lubrication grooves) 106b are arranged side by side at a position close to the side walls 62a, 62b. In this case, the filling amount of the lubricant S filled in the groove portion 106b can be set to be equal by setting the sectional area of the group of the groove portions 106b to be substantially equal to the sectional area of the single groove portion 106.

In a state in which the loss rings 100, 100a, and 100b are mounted on the piston 16, the outer circumferential surface 104a is in surface contact and abuts against the inner wall surface 12a of the cylinder tube 12, and is filled in the groove portions 106, 106a, 106b. The lubricant S performs lubrication between the piston 16 and the cylinder tube 12, so that the piston 16 can be displaced more smoothly along the cylinder tube 12.

Further, the loss ring used in the linear motion device of the present invention is not limited to the above embodiment, and various configurations can of course be employed without departing from the gist of the present invention.

10, 102‧‧‧ fluid pressure cylinder

12‧‧‧Cylinder tube

12a‧‧‧ inner wall

14‧‧‧Piston rod cover

16‧‧‧Piston (displacement)

18‧‧‧ piston rod

20, 100, 100a, 100b‧‧‧ loss ring

22‧‧‧1st Pass

24‧‧‧Connected Road

26‧‧‧Cylinder room

28‧‧‧1st cylinder room

32‧‧‧2nd cylinder room

34‧‧‧ Sealing members

36‧‧‧2nd entrance

38‧‧‧Connected Road

40‧‧‧ piston rod hole

42‧‧‧ bushing

44‧‧‧Piston rod washer

46‧‧‧Piston hole

48‧‧‧1st annular groove

50‧‧‧2nd annular groove

52‧‧‧3rd annular groove

54‧‧‧ piston washer

56‧‧‧ magnet

58, 104‧‧‧ Body Department

58a, 104a‧‧‧ outer perimeter

58b, 104b‧‧‧ inner circumference

60‧‧‧ gap

62a, 62b‧‧‧ side wall

64‧‧‧Chamfering

106, 106a, 106b‧‧‧ditch (lubrication ditch)

S‧‧‧Lubricant

Fig. 1 is an overall cross-sectional view showing a fluid pressure cylinder using a loss ring according to a first embodiment of the present invention.

Figure 2 is a view showing the vicinity of the loss ring in the fluid pressure cylinder of Figure 1. Magnified section view.

Figure 3 is a front view of the loss ring shown in Figure 2.

Fig. 4 is a cross-sectional view taken along line IV-IV of Fig. 3.

Fig. 5 is an overall cross-sectional view showing a state in which the piston and the piston rod in the fluid pressure cylinder of Fig. 1 are inclined with respect to the axis of the cylinder tube.

Figure 6 is an enlarged cross-sectional view showing the vicinity of the loss ring in the fluid pressure cylinder of Figure 5.

Fig. 7 is an enlarged cross-sectional view showing the vicinity of a loss ring in the second embodiment of the present invention.

Fig. 8 is an enlarged cross-sectional view showing a modification of the loss ring of Fig. 7.

Fig. 9 is an enlarged cross-sectional view showing another modification of the loss ring of Fig. 7.

10‧‧‧ fluid pressure cylinder

12‧‧‧Cylinder tube

12a‧‧‧ inner wall

16‧‧‧Piston (displacement)

20‧‧‧ loss ring

52‧‧‧3rd annular groove

56‧‧‧ magnet

58‧‧‧ Body Department

58a‧‧‧Outer surface

58b‧‧‧ inner circumference

62a, 62b‧‧‧ side wall

64‧‧‧Chamfering

Claims (8)

A loss ring for a linear motion device, the loss ring being a linear motion device having a body (12) and a displacement body (16) disposed in a manner displaceable along the inside of the body (12) (10,102), the groove portion (52) is attached to the outer circumferential surface of the displacement body (16), and abuts against the annular loss ring (20, 100, 100a, 100b) of the inner wall surface of the main body (12). The loss ring (20, 100, 100a, 100b) includes a main body portion (58, 104) formed in an annular shape, and has an outer peripheral surface (58a) that is in contact with the inner wall surface in a planar shape; and a protruding portion is provided in the foregoing The inner peripheral surface (58b) of the main body portion (58, 104) is formed in a cross-sectional shape protruding toward the inner side of the radius, and abuts against the bottom wall of the groove portion (52); wherein the body portion (58, 104) is the aforementioned displacement portion When the body (16) is inclined with respect to the axis of the main body (12), the outer peripheral surface (58a) is inclined to move in the groove portion (52) while maintaining the contact with the inner wall surface; 104) is provided with a lubricant filling, and supplies the aforementioned lubrication between the aforementioned body (12) and the aforementioned displacement body (16) Lubrication grooves (106, 106a, 106b). The loss ring for a linear motion device according to claim 1, wherein the protruding portion is formed to have a circular arc shape. The loss ring for a linear motion device according to claim 2, wherein the protruding portion is in line contact with the groove portion (52) Way to set. The loss ring for a linear motion device according to the first aspect of the invention, wherein the lubrication groove (106, 106a, 106b) is formed on an outer circumferential surface (104a) of the main body portion (104). The loss ring for a linear motion device according to the first aspect of the invention, wherein the lubrication groove (106b) is provided in plural and separated from each other and arranged side by side. The loss ring for a linear motion device according to the fourth aspect of the invention, wherein the lubrication groove (106b) is provided in plural and separated from each other and arranged side by side. The loss ring for a linear motion device according to the first aspect of the invention, wherein the inner peripheral surface (58b, 104b) of the body portion (58, 104) is formed with a set of chamfered portions close to the protruding portion. (64). The loss ring for a linear motion device according to the first aspect of the invention, wherein the lubrication groove (106, 106a, 106b) is formed in a rectangular cross section or toward an inner peripheral side of the main body portion (104). Become a tapered pyramid.