JPH063160A - Supporting apparatus for rotary encoder - Google Patents

Abstract

PURPOSE:To obtain a supporting device of a rotary encoder which is easily assembled and prevents the plastic deformation of the rotary encoder. CONSTITUTION:The supporting device is provided with a rotary encoder 13 and a pair of hubs 11, 12 fixed via the rotary encoder 13 to a rotary body 2 in the rotational direction, but slidably meshed with the rotary body 2 in the axial direction. A plurality of engaging hooks 21 which are elastically bendable are formed in one hub 11, and also an engaging part 24 is formed in the other hub 12. The rotary encoder 13 and hubs 11, 12 are meshed with the rotary body 2. The engaging hook 21 protruding from one hub 11 is engage resiliently with the engaging part 24 of the other hub 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary encoder supporting device used in a detecting device for detecting a rotation angle of a rotating body.

[0002]

2. Description of the Related Art In order to detect a rotation angle of a rotating body, a rotary encoder having a hole to be detected along a circumference is fixed to the rotating body, and a photoelectric detector is made to face the hole to be detected of the rotary encoder. There is a detection device in which a photoelectric detector counts the passage of the detected hole when the rotary encoder rotates. A conventional example of a rotary encoder supporting device used for the detecting device is shown in FIGS.

That is, there are provided a rotating body (shaft) 30 driven by a motor, a hub 31 and a rotary encoder 32 each made of metal such as aluminum. The rotary encoder 32 has a fitting hole 33 fitted into the hub 31, a plurality of locking claws 34 arranged on the inner peripheral edge of the fitting hole 33, and a large number of covered members formed along the circumference. The detection hole 35 is formed. Also,
The hub 31 is formed with a flange 36 that presses one surface of the rotary encoder 32 and a boss 37 that projects from the flange 36. The hub 31 is the rotating body 3
Pressed into 0. The fitting hole 33 of the rotary encoder 32 is fitted into the boss 37 of the hub 31, but at the time of fitting, the locking claw 34 elastically bends and bites into the outer peripheral surface of the boss 37. It is fixed to the hub 31. Therefore, when the rotating body 30 is rotated,
The hub 31 and the rotary encoder 32 also rotate integrally, and the detected hole 35 is detected by the photoelectric detector.

[0004]

In the conventional example, since the locking claw 34 receives a large resistance from the boss 37 when the rotary encoder 32 is fitted to the hub 31, it is difficult to replace the rotary encoder 32. In addition, since the inner peripheral edge of the fitting hole 33 of the rotary encoder 32 is partially subjected to an unbalanced load due to the engagement of the locking claw 34 and the boss 37, the rotary encoder 32 is plastically deformed so as to undulate a flat surface. . As a result, there is a problem in that the position of the hole to be detected 35 is displaced and the accuracy of detecting the rotation angle is reduced.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a fitting hole fitted in the central portion of a rotating body, a plurality of through holes arranged around the fitting hole, and a detected object formed in the outer peripheral portion are provided. A rotary encoder having a hole; a pair of hubs sandwiched between the rotary encoders and fixed to the rotating body in the rotational direction and slidably fitted in the axial direction; It is configured by a plurality of elastically bendable locking claws protruding from the through hole, and a locking portion formed on the other hub and locked by the locking claw.

[0006]

The rotary encoder is paired with the rotary encoder by fitting the rotary encoder and the pair of hubs and elastically locking the locking claws protruding from one hub to the locking portions of the other hub. It can be easily assembled to the rotating body while being held by the hub. In this assembled state, both sides of the rotary encoder are evenly held by the entire opposing surfaces of the pair of hubs, so that the rotary encoder is not subjected to an unbalanced load in the circumferential direction, thus preventing plastic deformation of the rotary encoder. be able to.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 and 3, reference numeral 1 is an encoder frame. The encoder frame 1 is formed with bearings 3 and 4 for rotatably holding a rotating shaft 2 which is a rotating body, and a compartment 5, and a lower portion of the compartment 5 is closed by a cover 6. The pulley 7 and the belt stopper 8 are press-fitted on the upper portion of the rotary shaft 2 so as to rotate integrally. The belt 9 wound around the pulley 7 is restricted in its widthwise movement by a collar 10 formed at one end of the pulley 7 and a belt stopper 8. A pair of hubs 11 and 12 are press-fitted to the lower part of the rotary shaft 2, and a rotary encoder 13 is fitted in a state of being sandwiched between these hubs 11 and 12. These hubs 1
1, 12, the rotary encoder 13, the transmission type photoelectric detector 14 for detecting a detection target hole (described later) of the rotary encoder 13, and the wiring substrate 15 fixed to the photoelectric detector 14 are the same as those described above. It is housed in chamber 5. Further, the cover 6 is formed with an outlet 16 for drawing out a flexible cable (not shown) connected to the wiring board 15. The hubs 11 and 12 are made of elastic synthetic resin, and the rotary encoder 13 is made of a polyester resin film.

As shown in FIG. 3, at the center of the rotary encoder 13, a fitting hole 1 fitted into the rotary shaft 2 is provided.
7 are formed, and three through holes 18 and an oval-shaped positioning hole 19 that is long in the radial direction are formed in the periphery thereof, and a large number of detected holes 13a are formed in the peripheral edge. Further, a press-fitting hole 20 that is press-fitted into the rotary shaft 2 is formed at the center of the upper hub 11, and three locking claws 21 to be inserted into the through hole 18 and the positioning hole are formed around the press-fitting hole 20. A circular protrusion 22 having an outer diameter dimension corresponding to the width dimension of 19
(See FIGS. 1 and 2) are formed. Furthermore, FIG.
As shown in FIG. 5, a flexible portion 25 that elastically bends in the vertical direction is formed on the lower hub 12. A press-fitting hole 20 that is press-fitted into the rotary shaft 2 is formed at the center of the flexible portion 25, and three square holes 23 through which the locking claw 21 penetrates are formed around the press-fitting hole 20. These square holes 2
As shown in FIG. 1, a locking portion 24 that is locked to the tip of the locking claw 21 is formed on the lower edge of the locking member 3.

In such a structure, the rotary encoder 13 and the pair of hubs 11 and 12 are fitted to the rotary shaft 2, and the locking claws 21 projecting from the upper hub 11 are provided through the through holes 18 of the rotary encoder 13 to the hub. A state in which the rotary encoder 13 is sandwiched by the pair of hubs 11 and 12 by being inserted into the square holes 23 of 12 and elastically locking the locking claws 21 to the locking portions 24 of the lower hub 12. It can be easily assembled to the rotary shaft 2. In this assembled state, by setting the length of the locking claw 21 to be slightly shorter, the locking claw 21 and the locking part 24 are elastically bent in the flexible portion 25 of the hub 12. The hubs 11 and 12 can be firmly locked to each other, so that the holding force of the hubs 11 and 12 with respect to the rotary encoder 13 can be increased. In addition, the rotary encoder 13 has a circular hub 1 on both sides.
Since the entire opposing surfaces of 1 and 12 are sandwiched uniformly, the rotary encoder 13 is not subjected to an unbalanced load in the circumferential direction, and therefore the plastic deformation of the rotary encoder 13 can be prevented. Further, in this embodiment, since the rotary encoder 13 is formed of a film having a high elasticity such as polyester resin, it can be formed thinner than the conventional one, and has sufficient rigidity to withstand deformation. Can be made. Further, the relative position of the hub 11 and the rotary encoder 13 in the rotational direction is accurately determined by the fitting of the protrusion 22 and the positioning hole 19.

An example of detecting the rotation angle of the rotary shaft 2 is shown in FIG. A carrier shaft 28 that slidably holds a carrier 27 is provided on a frame 26 of the printer.
The encoder frame 1 is fixed to one side of the frame 26, and a forward and reverse rotatable motor 29 is mounted to the other side of the frame 26. This motor 2
The belt 9 is wound around a pulley (not shown) driven by 9 and a pulley 7 held by the encoder frame 1 together with the rotating shaft 2. A part of the belt 9 is fixed to the carrier 27.

Therefore, by driving the motor 29, the left and right pulleys rotate together with the belt 9, and the carrier 27 moves. In this process, printing is performed by the print head mounted on the carrier 27. At this time, the rotary shaft 2
Hubs 11 and 12 press-fitted into the hub and these hubs 11 and 1
The rotary encoder 13 held by 2 rotates integrally with the rotary encoder 13, and the detected hole 13a of the rotary encoder 13 is counted by the photoelectric detector 14. However, as described above, the plastic deformation of the rotary encoder 13 is prevented. Therefore, the movement amount of the carrier 27 and the detection accuracy of the stop position can be improved.

When positioning at least one of the locking pawls 21 of the hub 11 and one of the through holes 18 of the rotary encoder 13 in the rotational direction of both, Rotary encoder 1
The positioning hole 19 of No. 3 and the protrusion 22 of the hub 11 may be omitted. Further, the press-fitting method is adopted as a method of fixing the hubs 11 and 12 to the rotating shaft 2 in the rotating direction and slidably fitting in the axial direction, but at least a part of the rotating shaft 2 is polygonal or irregularly shaped. Alternatively, the hubs 11 and 12 may be formed with holes corresponding to the shape.

[0013]

As described above, according to the present invention, of the hubs fitted to the rotary shaft and facing each other with the rotary encoder interposed therebetween, one hub is provided with a plurality of elastically bendable locking claws. Since the locking portions to be locked by these locking claws are formed on the other hub, the rotary encoder and the pair of hubs are fitted to the rotating body, and the locking claws protruding from the one hub are By elastically locking it to the locking part of the hub, the rotary encoder can be easily assembled to the rotating body while being held by the pair of hubs, and in this assembled state, both sides of the rotary encoder are Since the rotary encoders are evenly held on the entire opposing surfaces of the pair of hubs, the rotary encoder is not subjected to an unbalanced load in the circumferential direction, and therefore plastic deformation of the rotary encoder can be prevented. , An effect such as it is possible to improve the detection accuracy of the rotation angle.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention.

FIG. 2 is a perspective view of one hub seen from the back side.

FIG. 3 is an exploded perspective view.

FIG. 4 is a perspective view showing an example of mounting on a printer.

FIG. 5 is an exploded perspective view showing a conventional example.

FIG. 6 is a front view showing a fitted state of a hub and a rotary encoder.

FIG. 7 is a perspective view showing a part of a rotary encoder.

[Explanation of symbols]

 2 Rotating Body 11, 12 Hub 13 Rotary Encoder 13a Detected Hole 18 Through Hole 21 Locking Claw 24 Locking Part

Claims (1)

[Claims] 1. A rotary encoder having a fitting hole fitted in a central portion of a rotating body, a plurality of through holes arranged around the fitting hole, and a detected hole formed in an outer peripheral portion of the rotary encoder. A pair of hubs, which are fixed in the rotating direction and slidably fitted in the axial direction by sandwiching the rotary encoder between them, and an elastic member formed in one of the hubs and protruding from the through hole. A rotary encoder support device, comprising: a plurality of locking claws that can be flexibly bent, and a locking part formed on the other hub and locked by the locking claw.