JP7348704B2 - cylinder device - Google Patents

Description

The present invention relates to a cylinder device.

The applicant has filed a patent application for a fluid cylinder such as an air bearing type cylinder, and has obtained a patent right (Patent Document 1). This fluid cylinder has a cylinder body and a shaft member supported within the cylinder body, and is able to stroke (advance and retreat) in the axial direction while rotating the shaft member by the action of fluid. A rotary vane is attached to the shaft member, and the action of fluid on the rotary vane causes the shaft member provided with the rotary vane to rotate.

Patent No. 6456565

The fluid cylinder disclosed in Patent Document 1 includes rotating blades provided on a shaft member, and the shaft member is actively rotated by the action of fluid on the rotating blades.

In response to this, the present inventor focused on the need for a cylinder device that allows stroke (advance and retreat) in the axial direction while suppressing (prohibiting) rotation of the shaft member, and developed such a cylinder device. In order to make this a reality, we have continued to conduct further research.

For example, fluid cylinders such as air bearing cylinders support the shaft member in a floating state, so they have low resistance.However, because of the low resistance, they are vulnerable to external forces (disturbances) in the rotational direction, and when the shaft member rotates, accurate operation control is possible. becomes difficult. On the other hand, it is conceivable to attach the shaft member to another member in order to suppress the rotation of the shaft member, but in that case, the premise of a fluid cylinder that the shaft member is supported in a floating state will be destroyed (the characteristics cannot be utilized ). In this way, with conventional cylinder devices (fluid cylinders), it is difficult to reduce the resistance during the stroke of the shaft member and to suppress the rotation of the shaft member (both are in a trade-off relationship). there were).

The present invention has been made based on the awareness of the above problems, and an object of the present invention is to obtain a cylinder device that can smoothly stroke (advance and retreat) a shaft member and suppress rotation of the shaft member.

The cylinder device of this embodiment includes a first cylinder body, a second cylinder body, a first shaft member supported inside the first cylinder body, and a first cylinder body supported inside the second cylinder body. a second shaft member supported, a first bearing supported around the first shaft member inside the first cylinder body, and a first bearing supported around the first shaft member inside the second cylinder body; a second bearing supported around the shaft member; the first cylinder body and the second cylinder body are arranged continuously in the axial direction; The second shaft member is arranged continuously in the axial direction so that their center axes are shifted from each other, so that the second shaft member is connected to the first shaft member inside the first cylinder body and the second cylinder body. Rotation of the second shaft member is suppressed, and the first cylinder body has a small diameter cylindrical portion located on the inner surface on the side closer to the second cylinder body in the axial direction, and It has a large diameter cylindrical part which is located on the inner surface of the far side and has an open end face on the side opposite to the second cylinder main body of the first cylinder body, and the inner surface of the small diameter cylindrical part and the second cylinder main body are open. A clearance is provided between the outer surfaces of the first shaft member, and the inner surface of the large diameter cylindrical portion, the end surface of the first cylinder body opposite to the second cylinder body, is open. It is characterized in that a first bearing is fitted, and the first shaft member is fitted into the inner surface of the first bearing.
The shape of the outer surface of the first shaft member and the inner surface of the first bearing, and the shape of the outer surface of the second shaft member and the inner surface of the second bearing are substantially circular when viewed in cross section. , a clearance between the outer surface of the first shaft member and the inner surface of the first bearing, and a clearance between the outer surface of the second shaft member and the inner surface of the second bearing are It may be set to suppress integral rotation of the shaft member and the second shaft member.
The shape of the outer surface of the first shaft member and the inner surface of the first bearing, and the shape of the outer surface of the second shaft member and the inner surface of the second bearing are, when viewed in cross section, the shape of the outer surface of the first shaft member and the inner surface of the first bearing. The shaft member may be set to a non-circular shape that suppresses integral rotation of the shaft member and the second shaft member.
The shape of the outer surface of the first shaft member and the inner surface of the first cylinder body, and the shape of the outer surface of the second shaft member and the inner surface of the second cylinder body are approximately circular when viewed in cross section. The clearance between the outer surface of the first shaft member and the inner surface of the first cylinder body, and the clearance between the outer surface of the second shaft member and the inner surface of the second cylinder body are: It may be set to suppress integral rotation of the first shaft member and the second shaft member.
The center axes of the first cylinder body and the second cylinder body may be shifted from each other.
The first shaft member and the second shaft member may be formed from separate members, and the first cylinder body and the second cylinder body may be formed from separate members.

1 is a diagram showing an example of the external configuration of a cylinder device according to the present embodiment. It is a diagram showing an example of the internal configuration of the cylinder device according to the present embodiment, and depicts a protruding state of the piston rod. It is a diagram showing an example of the internal configuration of the cylinder device according to the present embodiment, and depicts a stored state of the piston rod. It is a figure which shows an example of the shape and clearance of the outer surface of a piston rod, and the inner surface of an air bearing. It is a figure showing an example of the shape of the outer surface of a piston rod, and the inner surface of an air bearing.

The cylinder device 1 according to this embodiment will be described in detail with reference to FIGS. 1 to 5. Here, as the cylinder device 1, an air bearing type cylinder that strokes a piston rod (shaft member) 20 (moves forward and backward in the left-right direction in the figure) by the action of air will be exemplified and explained. However, the cylinder device 1 can also be applied to a fluid cylinder that utilizes the action of a fluid other than air (for example, liquid).

FIG. 1 is a diagram showing an example of the external configuration of a cylinder device 1 according to this embodiment. FIG. 2 is a diagram showing an example of the internal configuration of the cylinder device 1 according to the present embodiment, and depicts a protruding state of the piston rod 20. FIG. 3 is a diagram showing an example of the internal configuration of the cylinder device 1 according to the present embodiment, and depicts a stored state of the piston rod 20. Note that although the silhouette of the cylinder device 1 is different between FIG. 1, FIG. 2, and FIG. 3, this is for convenience of drawing. Characteristic parts of the cylinder device 1 according to this embodiment are clearly expressed in FIGS. 2 and 3.

As shown in FIG. 1, the cylinder device 1 includes a cylinder body 10 and a piston rod (shaft member) 20 supported inside the cylinder body 10. The cylinder body 10 is provided with an exhaust port 30 for discharging air from the inside of the cylinder body 10 to the outside. Further, a cable 40 is connected to the cylinder body 10 for transmitting information (signal) regarding the forward and backward positions of the piston rod 20 to an external device (not shown).

As shown in FIGS. 2 and 3, the cylinder body 10 includes a first cylinder body 10A located on the left side of the figure and a second cylinder body 10B located on the right side of the figure. The first cylinder body 10A and the second cylinder body 10B may be integrally molded, or they may be molded separately and then joined by various joining means (for example, screwing). Good too.

The piston rod (shaft member) 20 has a first piston rod (shaft member) 20A located on the left side in the figure, and a second piston rod (shaft member) 20B located on the right side in the figure. There is. The first piston rod 20A and the second piston rod 20B may be integrally molded, or may be molded separately and then connected by various connecting means (for example, screwing). Good too.

By configuring the first cylinder body 10A and the second cylinder body 10B from separate members, and by configuring the first piston rod 20A and the second piston rod 20B from separate members, a "rotation suppression mechanism" described later can be realized. It is possible to simplify the configuration and ease of assembly of the mounted cylinder device 1.

The first cylinder body 10A is a cylindrical member with a relatively small diameter (compared to the second cylinder body 10B), and the second cylinder body 10B has a relatively large diameter (compared to the first cylinder body 10A). It is a cylindrical member.

The first piston rod 20A is a solid (rod-shaped) member with a relatively smaller diameter (than the second piston rod 20B), and the second piston rod 20B is relatively (than the first piston rod 20A) ) It is a large diameter solid (rod-shaped) member.

A first piston rod 20A is supported in a cylindrical space inside the first cylinder body 10A. A second piston rod 20B is supported in the cylindrical space inside the second cylinder body 10B.

The first cylinder body 10A has a small diameter cylindrical portion 11A located on the right side in the figure and a large diameter cylindrical portion 12A located on the left side in the figure. A certain amount of radial clearance is provided between the inner surface of the small diameter cylindrical portion 11A and the outer surface of the first piston rod 20A. A first air bearing (first bearing) 50A is fitted into the large diameter cylindrical portion 12A. The outer surface of the first piston rod 20A is positioned (fitted) on the inner surface of the first air bearing 50A with a minimum clearance (micro clearance). That is, the first air bearing 50A is supported around the first piston rod 20A. A storage air supply hole 13A penetrating in the radial direction is formed in the small diameter cylindrical portion 11A. The large diameter cylindrical portion 12A is formed with an air bearing intake port 14A and an air bearing exhaust port 15A that penetrate in the radial direction. Air bearing intake port 14A is located on the left side, and air bearing exhaust port 15A is located on the right side.

The second cylinder body 10B has a small-diameter cylindrical portion 11B located on both left and right sides in the figure, and a large-diameter cylindrical portion 12B located in the center of the figure. A certain amount of radial clearance is provided between the small diameter cylindrical portion 11B and the outer surface of the second piston rod 20B. A second air bearing (second bearing) 50B is fitted into the large diameter cylindrical portion 12B. The outer surface of the second piston rod 20B is located (fitted) on the inner surface of the second air bearing 50B with a minimum clearance (micro clearance). That is, the second air bearing 50B is supported around the second piston rod 20B. A protruding air supply hole 13B penetrating in the radial direction is formed in a portion of the small diameter cylindrical portion 11B on the right side of the large diameter cylindrical portion 12B. The large diameter cylindrical portion 12B is formed with an air bearing intake port 14B, an air bearing exhaust port 15B, and an air bearing exhaust port 16B that penetrate in the radial direction. The air bearing intake port 14B is located in the center, the air bearing exhaust port 15B is located on the right side, and the air bearing exhaust port 16B is located on the left side (air bearing intake port 14B is located in the air bearing exhaust port 15B). and is sandwiched from the left and right by the air bearing exhaust port 16B).

Here, since the outer surface of the second piston rod 20B fits into the inner surface of the second air bearing 50B with a minimum clearance, the cylinder body 10 (the first cylinder body 10A and the second cylinder body 10B) The internal space is a right side space SR on the right side of the fitting part of the second air bearing 50B and the second piston rod 20B, and a right side space SR on the left side of the fitting part of the second air bearing 50B and the second piston rod 20B. It is divided into a left side space SL.

In order to shield the right side space SR and the left side space SL and ensure a pressure difference (stroke force) between them, the air bearing exhaust port 15B exhausts the air for the air bearing taken in by the air bearing intake port 14B. This prevents the air for the air bearing from coming into contact with the air in the right side space SR (thereby, the right side space SR can be reliably pressurized). In addition, the air bearing exhaust port 16B exhausts the air bearing air taken in by the air bearing intake port 14B to avoid mixing the air bearing air with the air in the left side space SL (thereby, the air bearing air in the left side space SL is (can be reliably pressurized). Further, the air bearing exhaust port 15A exhausts the air bearing air taken in by the air bearing intake port 14A and seals the fitting portion between the first air bearing 50A and the first piston rod 20A. Mixing of the air bearing air and the air in the left side space SL is avoided (thereby, the left side space SL can be reliably pressurized).

In this way, when the right side space SR and the left side space SL are shielded and the pressure difference (stroke force) can be secured between them, when the protruding air is drawn from the protruding air supply hole 13B and supplied to the right side space SR, The piston rod 20 is in a state of protruding to the left with respect to the cylinder body 10 (FIG. 2), and when storage air is drawn from the storage air supply hole 13A and supplied to the left side space SL, the piston rod 20 is projected to the left with respect to the cylinder body 10. It will be stored on the right side (Figure 3). That is, the piston rod 20 moves back and forth in the left-right direction with respect to the cylinder body 10.

When the piston rod 20 protrudes to the left with respect to the cylinder body 10 (FIG. 2), the step portion 10C between the first cylinder body 10A and the second cylinder body 10B, and the first piston rod 20A and the second The stepped portion 20C of the piston rod 20B abuts against the cylinder body 10 and the protruding end of the piston rod 20 to restrict their positions.

When the piston rod 20 is stored on the right side with respect to the cylinder body 10 (FIG. 3), the storage end position regulating portion 17B of the second cylinder body 10B and the accommodation end position regulating portion 21B of the second piston rod 20B The positions of the housing ends of the cylinder body 10 and the piston rod 20 are regulated.

The cylinder device 1 of this embodiment suppresses (prohibits) rotation of the piston rod 20 (first piston rod 20A and second piston rod 20B) in the axial direction (left and right directions in FIGS. 2 and 3). This allows for strokes (advance and retreat).

Therefore, the piston rod 20 (the first piston rod 20A and the second piston rod 20B) is located inside the cylinder body 10 (the first cylinder body 10A and the second cylinder body 10B). The piston rod 20A and the second piston rod 20B) have a "rotation suppression mechanism" that suppresses rotation.

Specifically, the "rotation suppression mechanism" is configured by shifting the center axis 20AX of the first piston rod 20A and the center axis 20BX of the second piston rod 20B from each other. By shifting the central axis 20AX of the first piston rod 20A and the central axis 20BX of the second piston rod 20B from each other, even if an external force (disturbance) in an unintended rotational direction is applied to the piston rod 20, the piston rod 20 can be Rotation can be suppressed to achieve accurate operation control. In addition, since there is no need to apply other members to suppress the rotation of the piston rod 20, the piston rod 20 is supported in a floating state, reducing resistance to the maximum during stroke (advancing and retracting). The premises (characteristics) of the device (fluid cylinder) 1 can be maintained.

Furthermore, in conjunction with the fact that the central axis 20AX of the first piston rod 20A and the central axis 20BX of the second piston rod 20B are shifted from each other, the central axis 10AX of the first cylinder body 10A and the central axis 10AX of the second cylinder body The center axis 10BX of 10B is shifted from each other. Therefore, the stepped portion 10C of the cylinder body 10 and the stepped portion 20C of the piston rod 20 can be easily brought into contact with each other. In FIGS. 2 and 3, the central axes 10AX and 20AX are located on the same axis, and the central axes 10BX and 20BX are located on the same axis, but this is not the case. For example, the central axes 10AX and 20AX may be located on different axes, and the central axes 10BX and 20BX may be located on different axes. Alternatively, the central axis 10AX of the first cylinder body 10A and the central axis 10BX of the second cylinder body 10B may be coaxially located. That is, it is sufficient that the "rotation suppressing mechanism" is configured by shifting the central axis 20AX of the first piston rod 20A and the central axis 20BX of the second piston rod 20B from each other, and various design changes may be made for other configurations. is possible.

In addition, in FIGS. 2 and 3, the amount of shift between the central axis 20AX of the first piston rod 20A and the central axis 20BX of the second piston rod 20B (the distance in the vertical direction in the figures) is exaggerated. . The amount of shift may be within a range that can suppress the integral rotation of the first piston rod 20A and the second piston rod 20B.

4A is a diagram showing an example of the shape and clearance between the outer surface of the first piston rod 20A and the inner surface of the first air bearing 50A, and FIG. 4B is a diagram showing an example of the shape and clearance between the outer surface of the second piston rod 20B and the inner surface of the first air bearing 50A. It is a figure which shows an example of the shape and clearance of the inner surface of bearing 50B.

As shown in FIG. 4A, the outer surface of the first piston rod 20A and the inner surface of the first air bearing 50A have substantially circular shapes when viewed in cross section. For this reason, an annular clearance is provided between the outer surface of the first piston rod 20A and the inner surface of the first air bearing 50A. The clearance (radial distance) between the outer surface of the first piston rod 20A and the inner surface of the first air bearing 50A can suppress the integral rotation of the first piston rod 20A and the second piston rod 20B. Any range is fine. At least some of the requirements described here can be considered as part of the "rotation suppression mechanism," for example.

As shown in FIG. 4B, the outer surface of the second piston rod 20B and the inner surface of the second air bearing 50B have substantially circular shapes when viewed in cross section. For this reason, an annular clearance is provided between the outer surface of the second piston rod 20B and the inner surface of the second air bearing 50B. The clearance (radial distance) between the outer surface of the second piston rod 20B and the inner surface of the second air bearing 50B can suppress the integral rotation of the first piston rod 20A and the second piston rod 20B. Any range is fine. At least some of the requirements described here can be considered as part of the "rotation suppression mechanism," for example.

FIG. 5A is a diagram showing an example of the shape of the outer surface of the first piston rod 20A and the inner surface of the first air bearing 50A, and FIG. 5B is a diagram showing an example of the shape of the outer surface of the second piston rod 20B and the inner surface of the second air bearing 50B. It is a figure which shows an example of the shape of the inner surface.

As shown in FIG. 5A, the shapes of the outer surface of the first piston rod 20A and the inner surface of the first air bearing 50A are such that, when viewed in cross section, the integral rotation of the first piston rod 20A and the second piston rod 20B is It is set to a non-circular shape (here, a rectangular shape with rounded corners) that suppresses the This non-circular shape is not limited to a rectangular shape with rounded corners, but may be other shapes such as an ellipse. At least some of the requirements described here can be considered as part of the "rotation suppression mechanism," for example.

As shown in FIG. 5B, the shapes of the outer surface of the second piston rod 20B and the inner surface of the second air bearing 50B are such that, when viewed in cross section, the integral rotation of the first piston rod 20A and the second piston rod 20B is It is set to a non-circular shape (here, a rectangular shape with rounded corners) that suppresses the This non-circular shape is not limited to a rectangular shape with rounded corners, but may be other shapes such as an ellipse. At least some of the requirements described here can be considered as part of the "rotation suppression mechanism," for example.

Although detailed cross-sectional shapes are omitted, the outer surface of the first piston rod 20A and the inner surface of the first cylinder body 10A (small diameter cylindrical portion 11A) have a substantially circular shape when viewed in cross section. For this reason, an annular clearance is provided between the outer surface of the first piston rod 20A and the inner surface of the first cylinder body 10A (small diameter cylindrical portion 11A). The clearance (radial distance) between the outer surface of the first piston rod 20A and the inner surface of the first cylinder body 10A (small diameter cylindrical portion 11A) is the distance between the first piston rod 20A and the second piston rod 20B. It may be within a range that can suppress the integral rotation of. At least some of the requirements described here can be considered as part of the "rotation suppression mechanism," for example.

The outer surface of the second piston rod 20B and the inner surface of the second cylinder main body 10B (small diameter cylindrical portion 11B) have a substantially circular shape when viewed in cross section. Therefore, an annular clearance is provided between the outer surface of the second piston rod 20B and the inner surface of the second cylinder body 10B (small diameter cylindrical portion 11B). The clearance (radial distance) between the outer surface of the second piston rod 20B and the inner surface of the second cylinder body 10B (small diameter cylindrical portion 11B) is It may be within a range that can suppress the integral rotation of. At least some of the requirements described here can be considered as part of the "rotation suppression mechanism," for example.

The outer surfaces of the first piston rod 20A and the second piston rod 20B, the inner surfaces of the first air bearing 50A and the second air bearing 50B, the first cylinder body 10A (small diameter cylindrical portion 11A) and the second By making the inner surface of the cylinder body 10B (small diameter cylindrical portion 11B) substantially circular when viewed in cross section, ease of processing and design can be improved. On the other hand, if these shapes are non-circular (for example, a rectangular shape with rounded corners as shown in Figures 5A and 5B), there will be large variations in clearance, and air leakage will occur especially from the corners. This tends to make air control difficult.

As described above, the cylinder device 1 of the present embodiment functions as a rotation suppression mechanism that suppresses the rotation of the piston rod 20 inside the cylinder body 10, by connecting the central axis 20AX of the first piston rod 20A and the second piston rod 20B. The central axes 20BX are shifted from each other. This makes it possible to smoothly stroke (advance and retreat) the piston rod 20 and suppress rotation of the piston rod 20.

The cylinder device of the present invention is applicable to, for example, a fluid cylinder such as an air bearing type cylinder.

1 Cylinder device (air bearing cylinder, fluid cylinder)
10 Cylinder body 10A First cylinder body 10AX Central axis 11A Small diameter cylinder part 12A Large diameter cylinder part 13A Storage air supply hole 14A Air bearing intake port 15A Air bearing exhaust port 10B Second cylinder body 10BX Central axis 11B Small diameter cylinder part 12B Large diameter cylindrical portion 13B Protruding air supply hole 14B Air bearing intake port 15B Air bearing exhaust port 16B Air bearing exhaust port 17B Storage end position regulation portion 10C Step portion 20 Piston rod (shaft member)
20A First piston rod (shaft member)
20AX center axis (rotation suppression mechanism)
20B Second piston rod (shaft member)
20BX center shaft (rotation suppression mechanism)
21B Storage end position regulation part 20C Step part 30 Discharge port 40 Cable 50A First air bearing (first bearing)
50B Second air bearing (second bearing)
SR Right side space SL Left side space

Claims (6)

a first cylinder body;
a second cylinder body;
a first shaft member supported inside the first cylinder body;
a second shaft member supported inside the second cylinder body;
a first bearing supported around the first shaft member inside the first cylinder body;
a second bearing supported around the second shaft member inside the second cylinder body;
has
The first cylinder body and the second cylinder body are arranged continuously in the axial direction,
The first shaft member and the second shaft member are arranged consecutively in the axial direction so that their center axes are shifted from each other, so that the interior of the first cylinder body and the second cylinder body rotation of the first shaft member and the second shaft member is suppressed;
The first cylinder body includes, in the axial direction, a small diameter cylindrical portion located on an inner surface on a side closer to the second cylinder body, and a small diameter cylindrical portion located on an inner surface on a side farther from the second cylinder body , and a large diameter cylindrical portion with an open end face opposite to the second cylinder body of the cylinder body ;
A clearance is provided between the inner surface of the small diameter cylindrical portion and the outer surface of the first shaft member,
The first bearing is fitted into the inner surface of the large-diameter cylindrical portion of the first cylinder body, the end surface of which is opposite to the second cylinder body is open, and the inner surface of the first bearing is fitted with a the first shaft member is fitted;
A cylinder device characterized by: The shape of the outer surface of the first shaft member and the inner surface of the first bearing, and the shape of the outer surface of the second shaft member and the inner surface of the second bearing are substantially circular when viewed in cross section. ,
The clearance between the outer surface of the first shaft member and the inner surface of the first bearing and the clearance between the outer surface of the second shaft member and the inner surface of the second bearing are configured to suppress integral rotation of the member and the second shaft member;
The cylinder device according to claim 1, characterized in that: The shape of the outer surface of the first shaft member and the inner surface of the first bearing, and the shape of the outer surface of the second shaft member and the inner surface of the second bearing are, when viewed in cross section, the shape of the outer surface of the first shaft member and the inner surface of the first bearing. set in a non-circular shape to suppress integral rotation of the shaft member and the second shaft member,
The cylinder device according to claim 1, characterized in that: The shape of the outer surface of the first shaft member and the inner surface of the first cylinder body, and the shape of the outer surface of the second shaft member and the inner surface of the second cylinder body are approximately circular when viewed in cross section. and
The clearance between the outer surface of the first shaft member and the inner surface of the first cylinder body and the clearance between the outer surface of the second shaft member and the inner surface of the second cylinder body are configured to suppress integral rotation of the shaft member and the second shaft member,
The cylinder device according to any one of claims 1 to 3, characterized in that: The first cylinder body and the second cylinder body have center axes shifted from each other,
The cylinder device according to any one of claims 1 to 4, characterized in that: The first shaft member and the second shaft member are composed of separate members,
The first cylinder body and the second cylinder body are composed of separate members,
The cylinder device according to any one of claims 1 to 5, characterized in that:

Images