JPS60241563A - Driving device using self-propelled roller - Google Patents

Abstract

PURPOSE:To accomplish precise ffeed by always applying equal contact pressure to two self-propelled rollers. CONSTITUTION:In case of scanning, a driving shaft 12 is rotated by a driving source such as a motor or the like, so that self-propelled rollers 13A, 13B contacting each other with a pitch angle of theta are respectively rotated in roller support frames 14A, 14B. As designated contact pressure is applied to the self-propelled rollers by a spring 18, the self-propelled rollers are moved in a designated direction on the same principle as the axial movement caused by rotation of a screw, and a scanning table 10 connected to the rollers is moved in a body along guide shafts 11A, 11B. In this arrangement, even if there is a difference in parallel degree to the guide shafts and either eccentricity or cylindrical degree of the driving shaft 12, the roller 10 can be moved smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a drive device such as a scanning device that performs precision feeding by a self-propelled roller drive method using two self-propelled rollers.

(Technical background of the invention and its problems) A drive system using self-propelled rollers is generally popular as a rotational motion-linear motion conversion method using static friction.
Compared to screw feeding methods, it is cheaper, and wire,
Compared to a method that uses a belt or the like to pull it, it can be driven with more precision.

Figure 1 shows a conventional example of a scanning device using a self-propelled roller.
A scanning table 1 having a recording head (not shown) etc. is parallel to two
It is fitted and supported by the book guide shafts 4^, 4B, and can freely move in the axial direction. Self-propelled rollers 3A, 3 arranged to sandwich the drive shaft 2
B is rotatable on shafts 5A and 5B whose both ends are supported by bearings on the four parts of the L surface of the scanning table l, and the self-propelled rollers 3A and 3B are rotated relative to the drive shaft 2 as shown in FIG. 2(A). As shown in the figure, they are in contact with each other at an angle of pitch angle θ, such as a screw. Further, the two self-propelled rollers 3A and 3B are in contact with the drive shaft 2 in opposing positions as shown in FIG. 2(B). That is, assuming a screw having a pitch angle θ, the two self-propelled rollers 3^ and 3B are in contact with the drive shaft 2 along the screw groove.

Here, when the drive shaft 2 is rotated, for example, in the N direction shown in the figure, the self-propelled rollers 3A and 3B, which are inclined at a pitch angle θ and are in contact with each other with a predetermined contact pressure, rotate in the NA and NB force directions, respectively. Similar to the operation of the screw, the scanning table 1, which is connected to the self-propelled rollers 3A and 3B via rotating shafts 5A and 5B, moves along the guide shafts 4A and 4B. Furthermore, when the direction of rotation of the drive shaft 2 is reversed, the direction of movement of the scanning table 1 is also reversed. In this case, if there is a deviation in eccentricity or cylindricity of the drive shaft 2, or a deviation in parallelism with respect to the guide shafts 4A and 4B, the two self-propelled ports 3A and 3
The contact pressure of B against the drive shaft 2 changes, and one of the two self-propelled rollers is strongly pressed against the drive shaft 2, while the other is pressed against the drive shaft 2 weakly. This has the disadvantage that the frictional force changes, causing speed fluctuations and making precise feeding difficult.

(Object of the Invention) An object of the present invention is to provide a drive device using self-propelled rollers that has a structure that always applies the same contact pressure to two self-propelled rollers and enables precise feeding.

(Summary of the invention) This invention relates to a drive device using self-propelled rollers,
A drive shaft that rotates during operation, a base that is movable along a guide shaft that is arranged parallel to the drive shaft, and two self-propelled units that are arranged opposite to each other so as to sandwich the drive shaft. Laura and
Two roller supports each rotatably support these two self-propelled rollers, and one end of each is rotatably or movably connected to a base, and these self-propelled rollers are connected to a drive shaft. The elastic member is mounted on a roller support body so as to be pressed into contact with the roller support member.

(Embodiment of the Invention) FIGS. 3(A) and 3(B) show an embodiment of the present invention, in which a scanning table l serving as a base has an L-shaped structure.
O is fitted and supported by two guide shafts 11A and 11B arranged in parallel at its bottom, and can move freely in the axial direction. Self-propelled rollers 13A arranged vertically to face each other,
13B is a self-propelled roller shaft 15A that is supported by roller support frames 14A and 14B via bearings (not shown), respectively;
It is rotatable at 158. Roller support frame 14A
.

14B is a U-shaped housing and is a self-propelled roller 13^.

The roller support frames 14A and 14B are connected to the upright portion of the scanning table l by shafts 18A and 18B, respectively, and the shafts 16A and
It is designed to be able to rotate using 16B as a fulcrum. Note that the self-propelled rollers 13A and 13B are tilted by the pitch angle θ as shown in FIG.
is in contact with And roller support frames 14A, 14
Pins 17A and 1? are respectively installed on the top of B. A spring 18 is installed between H and pulls the roller support frames 14A and 14B with a predetermined elastic force,
A and 138 are pressed against the drive shaft. Note that the self-propelled rollers 13A and 13B in FIG. 3(A)
Actually, as shown in FIG. 2(B), the surface of the axis of the self-propelled roller appears depending on the pitch angle θ, but it is omitted here.

In such a configuration, when the drive shaft IO is first rotated by a drive source such as a motor during scanning, the self-propelled rollers 13A and 13B, which are in contact with each other at a pitch angle θ, rotate in the aforementioned directions with the roller support frames 14A and 14B, respectively. Rotate to.

Since a predetermined contact pressure is applied to the self-propelled rollers 13A and 13B by the spring 18, the self-propelled rollers 13A and 13B move in a predetermined direction in the same way that a screw moves in the axial direction when the screw rotates. The roller support frames +4A, 148 and the scanning table 10 connected to the roller support frames +4A, 148 move together along the guide shafts 11A, IIB. here,
Even if there is a deviation in either the eccentricity or cylindricity of the drive shaft 12 and the parallelism with respect to the guide shafts 11A and 118, the roller support frames +4A and 14B can be rotated via the shafts 16A and 16B, respectively. Therefore, the scanning table lO is the guide shaft 11^.

It can move smoothly along the line 11B as the self-propelled rollers 13A and 13B run. Also, spring 1
8, a predetermined contact pressure is applied between the self-propelled rollers 13A, 13B and the drive shaft 12, so the frictional force between them is constant and the moving speed of the scanning table IO does not change. The material of the self-propelled rollers 13A and 13B used is, for example, metal or rubber, and has appropriate hardness, so that it is also possible to maintain a predetermined frictional force.

FIG. 4 shows another embodiment of the present invention corresponding to FIG. 3(B), in which the scanning table 10^ has a rectangular shape, and a roller support frame 14A is attached to a part of the scanning table 10^. and 14B are installed. This also allows the same scanning as described above, and can be effectively used when there are space constraints depending on the direction. Further, FIG. 5 shows another embodiment of the present invention corresponding to FIG. 3(A),
The roller support frames 14A and 14B are provided with elongated grooves 20A and 20B, and the scanning table 10 is provided with pins 21A and 21B that engage with the grooves. The roller support frames 14^ and 14B are pulled by springs 22, 23, and when eccentricity occurs with respect to the drive shaft 12, the roller support frames 14A.

14B connects the grooves 20^, 20 via the pins 21A, 21B.
The eccentricity is absorbed by the downward movement of B. Furthermore, FIG. 6 shows still another embodiment of the present invention corresponding to FIG. It is rotatably supported on the scanning table 10B. And scanning table 1
Support walls 27 and 28 are provided on both sides of 0B,
Between the wall 27 and the roller support frames 14^ and 14B, the wall 28
Springs 25 and 28 are installed between the roller support frame +4A and the roller support frame +4A, respectively, to apply a stretching force, so that the roller support frames 14A and 14B are pressed against the drive shaft 12. Even with such a structure, the roller support frame 1
Since the pins 4A and 14B can freely rotate around the pin 24, they can perform the same operations as described above.

In the above-mentioned model, the guide shafts that guide the movement of the scanning table 10.10^ are made of two pieces of wood, and are fitted to the bottom of the scanning table, but the number of guide shafts and the positions in which they are fitted are arbitrary. It is. Additionally, the roller support frame does not need to have a frame structure;
Any support can be used as long as it can rotatably connect the self-propelled roller and the scanning table. Further, the position of the spring attached to the roller support body to apply a pressing force to the self-propelled roller may be arbitrary, and an elastic material such as rubber may be used.

(Effect of the invention) According to the drive device of the present invention as described above.

Even if the processing accuracy and assembly accuracy of the drive shaft, guide shaft, and the parts that support them are poor to some extent, there is an advantage that precision feeding with sufficient accuracy is possible and the cost is low.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of a scanning device using a conventional self-propelled roller, Figures 2 (^) and (8) are diagrams showing the relationship between the self-propelled roller and the drive shaft, and Figure 3 (A ) is a side view showing one embodiment of this invention, FIG. 4(B) is a front view thereof, FIG. 4 is a front view showing another embodiment of this invention, and FIGS. It is a figure which shows yet another Example of. 1.10...Scanning table, 2.12...Drive shaft, 3A,
38.13A, 13B... Self-propelled roller, 4A, 4B
, IIA, 11B...Guide shaft, 5A, 5B, 15A
, 15B...Self-propelled roller shaft, 7^, 7B, 14A, 1
4B...roller support frame, 17A, 17B...pin,
18...Spring. Applicant's agent Yuzo Yasugata L 1 Figure 2 Figure θ Figure 3 Figure (A) CB) Figure 4

Claims (1)

[Claims] A drive shaft that rotates during operation, a base that is movable along a guide shaft that is arranged in a W row on this drive shaft, and two bases that are arranged oppositely to sandwich the drive shaft. a self-propelled roller, two roller supports that rotatably support the two self-propelled rollers, and each end of which is rotatably or movably connected to the base; 1. A drive device using a self-propelled roller, comprising an elastic member mounted on the roller support so that the running roller is pressed against the drive shaft.