JPS60241564A - Self-propelled roller driving device - Google Patents

Abstract

PURPOSE:To accomplish low-priced and precise scanning feed by using three or more self-propelled rollers to always obtain designated contact pressure. CONSTITUTION:When a driving shaft 2 is rotated in one direction, self-propelled rollers 3A-3C contacting one another with a pitch angle of theta are respectively rotated in a designated direction by shafts 4A-4C, and further a self-propelled roller support portion 1 is moved in a designated direction by rotation of the driving shaft 2 on the same principle as the movement of a screw caused by rotation of the screw, because suitable contact pressure is applied to the rollers. Thus, a scanning portion 10 connected by a transmission member 11 is also moved in direction of an arrow X1 or X2 to perform a specified scanning. In this arrangement, even if there is an eccentric shifting of the driving shaft 2 or the assembling accuracy is bad, the driving shaft 2 is located at the central point formed by three self-propelled rollers, so that the shaft is uniformly brought into contact with the rollers.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a self-propelled roller drive device capable of performing precise scanning and feeding using a self-propelled roller drive method using a plurality of self-propelled rollers.

(Technical background of the invention and its problems) A drive system using self-propelled rollers is generally used as a rotary motion-linear motion conversion method using static friction, and is cheaper than a screw feeding method etc. Moreover, compared to the method of pulling with wires, belts, etc., it can be provided with higher accuracy.

FIGS. 1(A) and 1(B) show an example of a scanning mechanism using a conventional self-propelled roller drive device, in which the self-propelled roller 3
A and 3B are arranged to sandwich the drive shaft 2,
Shafts 4A and 4B are supported at both ends by bearings or the like in a cylindrical self-propelled support portion 1 extending concentrically through the drive shaft 2.
It can be rotated freely. In addition, the self-propelled a-ra support part 1
A scanning section 10 to which an image output head and the like are attached via a transmission member 11 is vertically disposed below. has been done. Note that the guide shafts 12 and 13 are also parallel to the drive shaft 2. The self-propelled rollers 3A and 3B pivotally supported by the self-propelled roller support section 1 are driven by a drive shaft 2.
As shown in FIG. 2(A), the two self-propelled rollers 3
A and 3B are in contact with the drive shaft 2, respectively, in a positional relationship as shown in FIG. That is, assuming a screw with a pitch angle of 0, the two self-propelled rollers 3A and 3B are in contact with the drive shaft 2 with a predetermined contact pressure along the screw groove.

Here, when the drive shaft 2 is rotated in one direction by a drive source such as a morph, the self-propelled rollers 3^ and 3B, which are inclined at a pinch angle θ and are in contact with each other with a predetermined contact pressure, rotate the drive shaft 2. By rotating in accordance with this, the self-propelled roller support portion l, on which the self-propelled rollers 3A and 3B are supported, moves along the axial direction of the drive shaft 2 in the same manner as the operation of a screw. Therefore, the scanning unit IO, which is vertically installed on the self-propelled roller support unit 1 by the transmission member 11, also moves, and the scanning unit IO
2 and 13-, thereby allowing scanning to be performed. In this case, the scanning unit 10
3, the self-propelled roller support part 1 does not rotate due to rotation of the drive shaft 2. In addition, drive shaft 2
By switching the rotation direction of the self-propelled roller support part l
can change the direction of movement of the scanning unit 10.
can move in the X, direction or the x2 direction.

In this case, if the centers of the respective axes of the self-propelled rollers 3A, 3B and the drive shaft 2 are not always aligned on the same line, the self-propelled rollers 3A, 3B and the drive shaft 2 must Since contact pressure cannot be obtained or there is no contact, it becomes impossible to drive. Therefore, self-propelled rollers 3A, 3
A sharp fall prevention mechanism is required to prevent B from separating from the drive shaft 2, and high machining accuracy and assembly accuracy are required, so it is difficult to perform precision feeding at a low cost. Ta.

(Object of the Invention) An object of the present invention is to provide a self-propelled roller drive device that uses three or more self-propelled rollers to constantly obtain a predetermined contact pressure and that enables inexpensive and precise scanning feed. It is about providing.

(Summary of the Invention) The present invention relates to a self-propelled roller drive device, which is composed of a rotating drive shaft and a self-propelled roller support portion that pivotally supports at least three self-propelled rollers. On the other hand, they are arranged at positions shifted by a predetermined angle from each other to provide a predetermined contact pressure, and are inclined at a predetermined angle with respect to the axial direction of the drive shaft.

(Embodiment of the invention) In this invention, as shown in FIGS. 3(A) and (B) corresponding to FIGS. 1(A) and (B), three self-propelled rollers 3A, 3B, 3G By supporting the self-propelled rollers 3A to 3C on the self-propelled roller support part 1 and arranging the self-propelled rollers 3A to 3C in three parts on the drive shaft 2, the center positions of the self-propelled rollers 3A to 3C do not deviate from the drive shaft 2. Fixed. Here, self-propelled roller 3
The shafts 4A to 4C of A to 3C are rotatably supported by the self-propelled roller support part 1, and the self-propelled rollers 3A
~3C is the same as explained in the conventional example, as shown in Fig. 2 (A), it is inclined by the pitch angle θ and contacts the drive shaft 2 with a predetermined pressure along the thread groove of the screw. There is. FIG. 4 is a diagram showing the relationship between the drive shaft 2 and the self-propelled rollers 3A to 3C in FIG. 3(B), focusing on the inclination relationship between the self-propelled rollers 3A to 3C and the drive shaft 2. Here, the material of the self-propelled rollers 3A to 3C used is, for example, metal or rubber, and has appropriate hardness, so the contact pressure between the self-propelled rollers 3A to 3C and the drive shaft 2 is moderate. It is designed so that it can be maintained.

In such a configuration, when the drive shaft 2 is first rotated in one direction, the self-propelled roller 3 that is in contact with it at a pitch angle θ
A and 38.3G are axes 4A and 4B, respectively.

4C rotates in a predetermined direction, and appropriate contact pressure is applied, so the rotation of the drive shaft 2 causes the self-propelled roller support l to move in a predetermined direction, based on the same principle that a screw moves when it rotates. move in the direction by the thrust of friction.

As a result, the scanning unit IO connected by the transmission member II
is also moved in the x1 or x2 direction and performs a predetermined stagnation check,
Here, even if the eccentricity of the drive shaft 2 is misaligned or the assembly precision between the self-propelled roller support part l and the drive shaft 2 is poor, the center formed by the three self-propelled rollers 3^ to 3C The drive shaft 2 is present at the point, and the three self-propelled rollers can always be in uniform contact with the drive shaft 2, so
Drive failures caused by contact pressure fluctuations can be eliminated. Furthermore, there is no need for a falling-off prevention mechanism for preventing the self-propelled roller from separating from the drive shaft, as described in the conventional example. and,
Since the contact pressure between the drive shaft 2 and the self-propelled rollers 3A, 3B, 3G made of a material such as metal or rubber having appropriate hardness is maintained at an appropriate level, it is possible to have a predetermined frictional force. Note that the same effect can be achieved even if four or more self-propelled rollers are provided. Furthermore, in the above-described embodiment, if the load on the scanning unit lO vertically disposed on the self-propelled roller support part 1 is large, the self-propelled roller support part l may be tilted with respect to the drive shaft 2 due to unbalanced weight. . In such a case, two sets of self-propelled roller mechanisms 2 are used as shown in FIG.
If 0 and 21 are arranged consecutively in the roller support part IA, the stability in the axial direction of the drive shaft 2 will be increased, so that the scanning part IO
It is possible to prevent tilting due to the load.

(Effects of the Invention) As described above, according to the self-propelled roller drive device of the present invention,
To provide an inexpensive self-propelled roller drive device that enables precision feeding with sufficient accuracy even if the additional accuracy of the drive shaft or self-propelled roller shaft and the assembly accuracy when assembling them are degraded to some extent. be able to.

[Brief explanation of the drawing]

FIG. 1(A) is a front view showing an example of a conventional self-propelled roller drive device, FIG. 1(B) is a side view thereof, and FIGS. 2(A) and (
B) is a diagram showing the relationship between the self-propelled roller and the drive shaft, and Figure 3 (
A) is a front view showing one embodiment of the present invention, and the same figure (B
) is a side view thereof, FIG. 4 is a mechanical diagram thereof, and FIG. 5 is a structural diagram showing another embodiment of the present invention. 1, IA... self-propelled roller support section, 2... drive shaft. 3A, 38.30... Self-propelled roller, 4A, 4B...
Self-propelled roller shaft, 10... Scanning section, +1... Transmission member, 12.13... Guide shaft. Applicant's agent Yu Yasugata 3rd ICA) CB) XI X2 3rd (A) (B) XI-X2

Claims (1)

[Claims] Consisting of a rotating drive shaft and a self-propelled roller support section that pivotally supports at least three self-propelled rollers, each of the self-propelled rollers is disposed at a predetermined position relative to the drive shaft and makes contact with each other by a predetermined angle. A self-propelled roller drive device, characterized in that the drive shaft is applied with pressure and contacts the drive shaft at a predetermined angle with respect to its axial direction.