JPS6324281Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a belt tension adjustment device in a belt transmission mechanism.

BACKGROUND ART Conventionally, belt tension adjustment devices include those shown in FIGS. 4 and 5, for example. this is,
One end (upper end) of the support plate 22 that rotatably supports the driven pulley 21 is fastened to the fixed side member 23 by a tightening bolt 24, and the fixed side member 23
An adjustment bolt 27 to which an operating piece 26 is fixed is connected to an adjustment nut 28 on an adjustment bar 25 fixed to the adjustment bar 25.
The other end of the support plate 22 is fastened to the adjustment bar 25 together with the operating piece 26 by a mounting bolt 29, and the adjustment bar 25 has a circumference centered around the tightening bolt 24. Mounting bolt 2 in direction
A long hole 31 is formed to allow movement of the support plate 22 by rotating the adjustment nut 28 and screwing it relative to the adjustment bolt 27.
is adapted to be rotated around the tightening bolt 24, and by the rotation of the support plate 22,
The tension of the belt 33 that is hung between the driving pulley 32 and the vertical pulley 21 on the stationary member 23 is adjusted.

Problems to be Solved by the Invention However, in the above-mentioned conventional technology, as the adjusting nut 28 is screwed, the adjusting bolt 27 is axially moved, and the axial tip a of the bolt 27 is moved to the fifth position.
Since the adjustment bolt 27 protrudes to the right as indicated by the arrow in the figure, there is a problem that the adjustment bolt 27 may interfere with other peripheral members. In addition, the support plate 22 is attached to the adjustment bar 25 with the mounting bolt 2.
9, the mounting bolt 29 tends to loosen because it is not prevented from rotating with other parts, and when tightening the mounting bolt 29, the seat surface of the mounting bolt 29 A torsional force (bending load) acts on the actuating piece 26 that is in contact with the supporting plate 2, causing the actuating piece 26 and the adjustment bolt 27 to bend unnecessarily.
There was a problem that 2 was insufficiently fixed. Incidentally, a document disclosing a structure in which the support plate 22 is fastened to the adjuster bar 25 with a mounting bolt and a mounting nut includes, for example, Japanese Unexamined Utility Model Publication No. 187955/1987. Also in this document,
No measures had been taken to prevent the nut from loosening.

Means for Solving the Problems This invention was proposed by focusing on the problems in the conventional technology as described above. The adjustment bar is fastened to a member by a tightening bolt and is fixed to the stationary member, and is rotatably provided with an adjustment bolt to which an operating piece that is movable in the longitudinal direction of the adjustment bar is threaded. The other end of the support plate is fastened together with the operating piece by a mounting bolt, and the adjustment bar is formed with a long hole that allows movement of the mounting bolt in a circumferential direction around the tightening bolt. In the belt tension adjustment device, the support plate is configured to be able to rotate around the tightening bolt by rotating the adjustment bolt, and the actuating piece has an adjustment bar that is in contact with a side surface of the adjustment bar, A guide piece for guiding the movement of the actuating piece in the longitudinal direction of the adjustment bar, and a guide hole extending in the width direction of the adjustment bar so that the mounting bolt can be loosely inserted therein are provided. The main feature is that a female thread is formed at the end into which the lower end of the mounting bolt can be screwed, and a contact surface between the tip of the adjustment bar and the adjustment bolt is formed flat.

According to the belt adjustment device using the above means, when the adjustment bolt is rotated, the support plate is rotated around the tightening bolt as the operating piece is threaded on the axis of the adjustment bolt, and the belt is adjusted. Tension is adjusted. In addition, the operating piece is fixed to the adjustment bar by the mounting bolt while being prevented from rotating through the guide piece, so when tightening the mounting bolt, no bending load is applied to the adjustment bolt. It turns out.

Embodiment Hereinafter, an embodiment of this invention will be described based on the drawings.

In FIGS. 1 and 3, a drive pulley 2 is disposed on the left side of a block 1 corresponding to a stationary member so as to be actively rotatable. The upper end of a diamond-shaped support plate 3 is fastened to the upper right portion of the block 1 with a tightening bolt 4. A driven pulley 5 is rotatably supported in the center of the support plate 3 by a support bolt 6. This driven pulley 5
An endless belt 7 is hung around the drive pulley 2. The base of an adjuster bar 8 is fixed to the lower right portion of the block 1 with a fixing bolt 9. The tip of the adjustment bar 8 projects diagonally upward to the right, and a flat bent piece 10 bent upward is formed at the tip. A through hole 11 is opened in the bent piece 10 upward from the center,
A screw shaft 12a of an adjustment bolt 12 is loosely fitted into the through hole 11 from the upper right toward the lower left. The head 12b of the adjustment bolt 12 is in planar contact with the bent piece 10 of the adjuster bar 8, and the screw shaft 1
An upwardly facing piece 13a of the actuating piece 13, which is formed upward in an L-shaped cross section, is screwed into the upwardly facing piece 2a. Note that the screw hole 13a provided in the upward piece 13a is located at the third position with respect to the longitudinal center line of the adjustment bar 8.
The adjustment bolt 12, which is disposed on the left side in the figure and is screwed into the adjustment bolt in a substantially perpendicular direction, is disposed on the left side surface of the adjustment bar 8 and parallel to the same side surface. The other horizontal piece 13b of the actuating piece 13 is parallel to the upper surface of the adjuster bar 8.

Furthermore, as shown in FIG.
protrudes downward and is formed into a cross-sectional shape as a whole, and an oblong guide hole 13d is provided in the center thereof in the width direction of the adjustment bar 8 (perpendicular to the longitudinal direction of the adjustment bar). The guide pieces 13c, 13c are formed so as to abut on the side surfaces 8a, 8a of the adjustment bar 8 and to straddle the upper surface of the adjustment bar 8, and have the role of guiding the movement of the actuating piece in the longitudinal direction of the adjustment bar. Next, the other end of the support plate 3 is fastened to the adjustment bar 8 together with the operating piece 13 by a mounting bolt 14 . That is, the screw shaft A of the mounting bolt 14 is screwed into a screw hole 3a provided at the other end of the support plate 3.

The support plate 3 is located on the lower surface side of the adjustment bar 8, and the operating piece 13 is arranged on the upper surface side of the adjustment bar 8. That is, the head 14a of the mounting bolt 14 is located on the operating piece 13 side, and the axis A of the mounting bolt 14 is threaded into the screw hole 3a of the support plate 3 through the guide hole 13d of the operating piece 13 and the elongated hole 17 of the adjuster bar 8. are combined. Therefore, the elongated hole 17 of the adjuster bar 8
is formed in an arc shape along the circumference of the movement locus of the screw hole 3a of the support plate 3 with the tightening bolt 4 at the center. In addition, in the figure, 19 and 20 each indicate a washer. In the belt tension adjustment device described above, when adjusting the tension of the belt 7, the tightening bolt 4 and the mounting bolt 14 are each slightly loosened, and then the adjustment bolt 12 is rotated to screw the actuating piece 13 forward. Along with this, the support plate 3 is attached via the mounting bolt 14.
is rotated counterclockwise in FIG. 1 around the tightening bolt 4, and the mounting bolt 14
The screw shaft A slides along the elongated hole 17 of the adjuster bar 8. At this time, the guide pieces 13c, 13c of the actuating piece 13 are connected to the side surface 8a of the adjuster bar 8,
8a, and further, the threaded shaft A of the mounting bolt 14 also slides along the guide piece 13d of the actuating piece 13 in the width direction of the adjuster bar 8.

As a result, the distance between the driving pulley 2 and the driven pulley 5 is expanded or contracted, and the tension of the belt 7 is adjusted. After this, tighten the tightening bolt 4 and the mounting bolt 1.
4, the belt tension adjustment work is completed.

According to the belt tension adjustment device described above, the rotation of the adjustment bolt 12 associated with the rotation of the support plate 3 causes the actuating piece 13 to be screwed on the threaded shaft 12a of the adjustment bolt 12. The support plate 3 can be rotated by rotation without axial movement. Further, the guide pieces 13c, 13c of the actuating piece 13 are connected to the side surface 8 of the adjuster bar 8.
Since it is engaged with the bolts a and 8a in a non-rotating state, the mounting bolt 14 can be securely tightened.
That is, in the past, the mounting bolts were not prevented from rotating with other members, but by locking the guide piece 13c of the actuating piece 13 to the adjustment bar 8 as described above, the mounting bolts 14 do not loosen. Therefore, loosening of the mounting bolts 14 is prevented as much as possible. Further, even when the mounting bolt 14 is tightened, no rotational force is applied due to the rotation stopper, so no bending load is applied to the adjustment bolt 12.

Effects of the invention In the belt tension adjustment device of the invention, one end of the support plate on which the driven pulley is rotatably supported is fastened to the stationary side member with a tightening bolt, and the belt tension adjustment device is fixed to the stationary side member. The adjustment bar is rotatably provided with an adjustment bolt to which an operating piece that is movable in the longitudinal direction of the adjustment bar is screwed, and the other end of the support plate is fastened to the adjustment bar together with the operating piece by a mounting bolt. , and the adjustment bar is formed with a long hole that allows movement of the mounting bolt in the circumferential direction around the tightening bolt, and by rotating the adjustment bolt, the support plate can be moved around the tightening bolt. In the belt tension adjustment device, the actuating piece includes a guide piece that comes into contact with a side surface of the adjusting bar and guides movement of the actuating piece in the longitudinal direction of the adjusting bar; a guide hole extending in an oval shape in the width direction of the adjustment bar so that a bolt can be loosely inserted therein, and a female screw thread into which a lower end of the mounting bolt can be screwed is formed at the other end of the support plate; In addition, by forming the contact surface between the tip of the adjustment bar and the adjustment bolt into a flat surface, the support plate is rotated by the rotation of the adjustment bolt without any axial movement, which is different from conventional ones. It is possible to solve the problem of interference between the adjusting bolt and surrounding parts, and since the operating piece is prevented from rotating by the adjustment bar, it is possible to prevent the mounting bolt from loosening, and unlike the conventional method, there is no bending load on the adjusting bolt. The support plate can be securely fixed by taking this into consideration. In addition, since the tip of the adjustment bar and the contact surface of the adjustment bolt are flat, it is possible to better eliminate the bending load of the adjustment bolt when tightening the mounting bolt, and at the same time prevent the adjustment bolt from loosening. Moreover, since the lower end of the mounting bolt is screwed into the support plate, parts such as nuts can be saved, and commercially available standard bolts can be used as the mounting bolts, thereby reducing costs. It has the effect of

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of this invention,
Figure 1 is a front view of the belt tension adjustment device, Figure 2 is a sectional view taken along line B-B in Figure 1, and Figure 3 is a line C--
C-line sectional view. 4 and 5 show a conventional example, in which FIG. 4 is a front view of the belt tension adjusting device, and FIG. 5 is a sectional view taken along the line A--A in FIG. 4. DESCRIPTION OF SYMBOLS 1... Block (fixed side member), 3... Support plate, 4... Tightening bolt, 5... Driven pulley, 8... Adjustment bar, 12... Adjustment bolt, 13... Operating piece, 14... Mounting bolts,
13c... Guide piece, 13d... Guide hole, 17
...Long hole.

Claims (1)

[Scope of utility model registration request] One end of the support plate on which the driven pulley is rotatably supported is fastened to the stationary side member with a tightening bolt, and an adjustment bar fixed to the stationary side member is provided with an adjustment bar that is movable in the longitudinal direction. An adjustment bolt to which an operating piece is screwed is rotatably provided, and the other end of the support plate is fastened to the adjustment bar with a mounting bolt together with the operating piece, and an adjustment bolt is provided on the adjustment bar with the tightening bolt as the center. A belt tension adjustment system in which a long hole is formed to allow movement of the mounting bolt in the circumferential direction, and the support plate is rotated around the tightening bolt by rotating the adjustment bolt. In the device, the actuating piece includes a guide piece that comes into contact with a side surface of the adjusting bar and guides movement of the actuating piece in the longitudinal direction of the adjusting bar, and a guide piece that extends in the width direction of the adjusting bar so that the mounting bolt can be inserted loosely therein. A circular guide hole is provided, a female thread is formed at the other end of the support plate into which the lower end of the mounting bolt can be screwed, and the tip of the adjuster bar is in contact with the adjustment bolt. A belt tension adjustment device characterized by having a flat surface.