JP2504177Y2 - Cylinder-Shaft Shake Prevention Device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating device having a cylinder shaft that moves forward in the longitudinal axis direction, and relates to a shaft deviation preventing device for a cylinder shaft that prevents the shaft deviation of the cylinder shaft.

[0002]

2. Description of the Related Art Conventionally, as a device for polishing a workpiece, a reciprocating device has been known which reciprocates a cylinder shaft having a grinding tool 11 such as a grindstone fixed at its tip end at a high speed along the longitudinal axis. Therefore, the applicant of the present invention also applied for Japanese Patent Application No. 1-1.
No. 73112 proposes a fluid drive device that uses a fluid such as air as a power source to reciprocate a cylinder shaft (see FIG. 1).

In the figure, a fluid drive system 1 includes a main spool 3 for switching a supply path of a pressure fluid, and a power unit 4 for reciprocating by a fluid supplied through a fluid supply path switched by the main spool 3. , Power unit 4
And a sub-spool 5 that operates the main spool 3 to switch the fluid supply path.

On the upper surface of the main body 2 of the fluid drive unit 1, there is an intake member 6 for injecting air, which is a fluid for driving the power unit 4, through a pipe 6a, and in the vicinity of the intake member 6, It has first and second control knobs 7 and 8 for adjusting the operating speed of the power unit 4. Further, a mounting shank 2a for fixing the fluid drive device 1 to the lathe is provided on the side surface of the main body 2.

The power unit 4 is composed of a cylinder body 9 and a grinding tool 11 fixed to the tip thereof, and a cylinder shaft 10 which reciprocates in the cylinder body 9, and the front and rear portions of the cylinder body 9. Is provided with a ring-shaped bearing portion 12, and each bearing portion 12 presses the cylinder shaft 10 .
It is slidably supported without Rukoto (Figure 5). A seal projection 13 having a flange structure is provided on the outer peripheral portion of the center of the cylinder shaft 10, and the seal projection 13 divides the fluid storage chamber into a front chamber 14a and a rear chamber 14b.

A front inlet / outlet hole 15a and a rear inlet / outlet hole 15b communicate with the front chamber 14a and the rear chamber 14b, respectively, and the front chamber 14a and the rear chamber 14b are alternately filled with fluid through them. The fluid pressure thus filled causes the cylinder shaft 10 to reciprocate back and forth.

[0007]

However, since sliding friction is exerted on the bearing portion 12 of the cylinder shaft 10 which reciprocates in this manner, the bearing portion 12 is used for a long period of time.
However, there is a drawback in that the clearance between the cylinder shaft 10 and the bearing portion 12, that is, the radial play (backlash) is increased, and axial reciprocation occurs in the reciprocating cylinder shaft.

On the other hand, when grinding or cutting is performed using such a reciprocating device, the grinding cost is smaller than the cutting, and the load applied is extremely small.
High precision is required. Therefore, if the cylinder shaft is shaken as described above, it is not possible to grind with high precision, and therefore the life of the reciprocating device is relatively short.

In addition, when the cylinder shaft is shaken in this way, the bearing part may be replaced with a new one, but there is a problem in that the replacement work is troublesome.

The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to improve the performance of a cylinder shaft even when the bearing part wears due to use and the clearance between the bearing part and the cylinder shaft increases. An object of the present invention is to provide a shaft shake preventing device for a cylinder shaft that prevents shake.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above object, and its gist is to allow a cylinder shaft that reciprocates in the longitudinal axis direction to be slidable without pressing the cylinder shaft. in the reciprocating device provided with a ring-shaped shaft <br/> receiving portion which supports the, put on the bearing portion
And the sliding bearing is incorporated in the mounting chamber which is formed only on one side of one of the radial that, and a pressing member for pressing against the sliding bearing in the radial direction opposite the side of the cylinder shaft, wherein The sliding bearing part, which receives the pressing force of the pressing member, contacts the reciprocating cylinder shaft with low friction while holding the cylinder shaft in the bearing part.
In the axial deviation preventing device for a cylinder shaft, the axial deviation of the cylinder shaft is prevented by constantly pressing it toward the opposite side in the radial direction .

[0012]

[Action] the cylinder shaft, collected a sliding bearing
It is slidably supported by a bearing unit incorporated in the mounting chamber . If the bearing is used for a long time in this state, the clearance between the cylinder shaft and the bearing increases due to wear of the bearing. At this time, the cylinder shaft is
Since the sliding bearing portion, which receives a pressing force from the pressing member, constantly pushes the bearing portion toward the radially opposite side, the shaft center slightly moves, but the bearing portion and the sliding bearing located in this direction are slightly moved. While being supported by the partial pressure of the part, it continues a stable reciprocating motion with no shaft wobbling.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cylinder shaft shake prevention device according to the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a sectional view taken along line II-II of FIG. In the figure, the shaft shake prevention device comprises a case main body 20 and a pressing portion 30 that presses the case main body 20 toward the radially opposite side of the cylinder shaft 10 (see FIG. 3).

The case body 20 is a cylinder shaft 1.
It is equipped with a ball bearing 21 as a sliding bearing portion for bearing 0 with low friction.
Is fixed by a fixing pin 22 penetrating the case body 20,
It is rotatably fixed to the case body 20. Further, a positioning pin 23 penetrates through the case body 20 at a portion facing the fixed pin 22, and the case body 20 has a mechanism that is rotatable around the positioning pin 23. Incidentally, the case body 20, a ring-shaped bearing portion 12 that of which is disposed in front and rear of the cylinder shaft
It is rotatably fixed to the bearing portion 12 by the positioning pin 23 which is disposed in the mounting chamber 12a formed only on one side in the radial direction and which penetrates the outer peripheral portion of the bearing portion 12. (Fig. 4).

Further, the pressing portion 30 is a preload spring cap 31 screwed to the side surface of the main body 2 of the fluid drive device 1, and a spring 33 as a pressing member for exerting a reaction force on the preload spring cap 31 via an adjusting washer 32. And a cylindrical preload spring receiver 34 whose tip contacts the case body 20, and the preload spring receiver 34 receives the pressing force of the spring 33.
The main body case 20 is pressed by. Therefore, the ball bearing 21 of the main body case 20 that receives this pressing force supports the cylinder shaft 10 in a pressed state.

The shaft shake preventing device constructed as described above is
The outer peripheral portion of the ball bearing 21 is brought into contact with the outer peripheral portion of the cylinder shaft 10, and the bearing portion 12 and the cylinder shaft 1 are caused by a relatively small frictional force due to rolling.
0 is slidably supported.

When the fluid drive unit is used in this state,
Sliding friction acts on the bearing portion 12 due to the reciprocating movement of the cylinder shaft 10, and the bearing portion 12 is abraded. And, the gap between the cylinder shaft 10 and the bearing portion 12 increases due to long-term use. When the gap is increased in this manner, the main body case 10 is rotated about the positioning pin 23 in each direction in the arrow X direction because it is pressed by the preload spring receiver 34 that receives the pressing force of the spring 33. Go. Therefore, the cylinder shaft 1
Reference numeral 0 denotes a front portion and a rear portion thereof, which are constantly pressed against the radial opposite sides of the shaft shake preventing device, and the shaft center is slightly moved, but the bearing portion 12 located in the pressing direction and the ball bearing of the case body 20. While being supported by 21 and
Continues stable reciprocating motion without shaft shake.

At the time of grinding, the cylindrical grinding tool 11
Since the outer peripheral surface of is brought into contact with the surface to be ground, a force acts on the grinding tool 11 inward in the radial direction as indicated by arrows Y1 and Y2. Therefore, a load is applied to the tip of the reciprocating cylinder shaft 10 in a direction perpendicular to the reciprocating direction, and even when this load acts, the shaft 10 does not move in the radial direction. It is necessary to set the spring force of the spring 33.

In this embodiment, the ball bearing 21 is exemplified as a member for supporting the cylinder shaft 10 with low friction, but the member is not particularly limited as long as it is a member for supporting the cylinder shaft 10 slidably with low friction. . Further, the case main body 20 has a mechanism that is rotatable around the positioning pin 23 that penetrates the case main body 20, but the mechanism is not limited to this. Ball bearing 2
Any mechanism capable of sliding 1 (sliding bearing) may be used.

[0021]

[Effect] The shaft deviation preventing device of the reciprocating device according to the present invention is mounted on the bearing portion with respect to the reciprocating cylinder shaft.
A sliding bearing contact with a low friction built from only chamber, and a pressing member for pressing the sliding bearing toward the cylinder shaft radially opposing side, receives the pressing force of the pressing member The sliding bearing allows the reciprocating cylinder shaft to move in the radial direction of the bearing.
It is always pressed toward the opposite side . Therefore, even when the bearing portion is worn due to use and the gap between the cylinder shaft and the bearing portion increases, the cylinder shaft is opposed in the radial direction by the sliding bearing portion that receives the pressing force from the pressing member. Side shaft is constantly pressed and the shaft center moves a little, but it is supported by the bearing part located in this direction and the partial pressing of the slide bearing part, and a stable reciprocation without shaft shake occurs. It is possible to keep moving.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an appearance of a reciprocating device.

FIG. 2 is a schematic cross-sectional view showing a developed II-II line cross section in FIG.

FIG. 3 is an enlarged view showing the inside of line III of FIG. 2 in an enlarged manner.

FIG. 4 is an exploded perspective view showing a mounted state of the shaft shake preventing device.

FIG. 5 is a partial cross-sectional view showing a cylinder shaft support mechanism in a conventional reciprocating device.

[Explanation of symbols]

 10 Cylinder shaft 21 Ball bearing (slip bearing) 33 Spring (pressing member)

Claims (1)

(57) [Scope of utility model registration request] 1. A reciprocating device comprising a cylinder shaft which reciprocates in a longitudinal axis direction and a ring-shaped bearing portion which slidably supports the cylinder shaft without pressing the cylinder shaft . On one side in the radial direction
A sliding bearing part built into the mounting chamber formed only ,
And a pressing member for pressing against the sliding bearing in the radial direction opposite the side of the cylinder shaft, sliding bearing which receives the pressing force of said pressing member, in the reciprocating to the cylinder shaft and the low friction A shaft shake prevention device for a cylinder shaft, which prevents the shaft shake of the cylinder shaft by constantly pressing the cylinder shaft toward the radially opposite side of the bearing portion while abutting.