JPS59529Y2 - Chain tension device in chain transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improvement of a chain tension device in a chain transmission.

Two sprockets are rotatably housed and held in a case with a predetermined distance between their axes, and a chain is hung between both sprockets to form a chain transmission case. A chino transmission device has a configuration in which a drive shaft and a driven shaft whose center-to-center distance matches the distance between the center centers of the drive shaft and the driven shaft are inserted into a hole, thereby interlockingly connecting the two shafts. ,well known.

By the way, in such a chain transmission device, if the distance between the drive and driven shafts does not match the distance between the centers of the two sprockets on the chain transmission case side, fitting and installation cannot be performed properly. However, in reality, it is not possible to make them exactly match due to manufacturing errors, so both sprockets on the chain transmission case side are held in the case so that they can move within a eugenic range, thereby making it easier to insert and install the sprockets. In some cases, the distance between the axes of both sprockets is corrected to match the distance between the axes of the two shafts.

On the other hand, the chain that is hung between the sprockets in the chain transmission case is tightened by a tightener to prevent problems such as pulsation. Since the tightener is placed in contact with the loose side of the chain to tension the chain, as mentioned above, both sprockets that are being held will be pulled toward each other by the tensioned chain, resulting in an arbitrary situation. As a result, a problem arises in that it becomes difficult to insert both sprockets into the drive shaft and the driven shaft.

Therefore, the present invention is implemented in a chain transmission device in which a sprocket in a chain transmission case is removably inserted into a drive shaft and a driven shaft that are provided at a predetermined center-to-center distance. The purpose is to provide a tensioning device that can properly tension the sprockets without adversely affecting the maintenance of the center-to-axis distance between the sprockets.

Hereinafter, specific examples of the present invention will be explained in detail based on the drawings.

The illustrated embodiment shows a case where the device of the present invention is implemented in the tilling transmission part of a tiller. The power of the engine 4 mounted on the frame 3 extending forward from the mission case 1 is transmitted to the axle through the transmission device inside the mission case so that the axle rotates, and the engine is operated rearward and upward from the top of the mission case. '%
Furthermore, a rotary tiller 7 is attached to the connection part 6 on the rear side of the transmission case, and this passive shaft (driven shaft 8) is connected to the PTO shaft (driving shaft) on the mission case side. between the shaft 9) and the chino transmission case 1.
They are constructed in such a way that they are interlocked and connected by a chino transmission mechanism B housed in the chino transmission mechanism B.

Accordingly, the present invention is implemented in a chino transmission mechanism B that interlocks and connects the drive shaft 9 and the driven shaft 8, and is configured in detail as follows.

First, the drive shaft 9 and the driven shaft 8 in the tiller are provided so as to maintain a predetermined distance l between their axes, and the ends of each shaft protrude outward in parallel from the mission case 1 and the rotary tiller. let

On the other hand, two sprockets 12.12a are housed inside the chino transmission case 10, and the chino 14 is wound between these sprockets (12.12a). A shaft hole 11 into which the above-mentioned drive shaft 9 and driven shaft 8 can be inserted in common. lla, and have different numbers of teeth, and mounting portions 13, 13 are provided on the boss portions of the respective sprockets (12, 12a), and the mounting portions 13.13 are attached to the transmission case. (12) are held in the transmission case 10 so as to be freely rotatable by fitting them into the holding parts installed in the transmission case 10;
．． The center-to-center distance of 12a is made to match the center-to-center distance 1 between the drive shaft 9 and the driven shaft 8 described above.

In other words, the sprockets (12.12a) are held in the chaino transmission case 10 with a distance of 1 between their axes. There is an installation state where the hole 11 a is inserted into the drive shaft 9 and the two shafts 8 and 9 are interlocked, and conversely, the shaft hole 11 a of the sprocket H2a is inserted into the driven shaft 8 and the shaft of the other sprocket 12 is connected. The transmission case 10 can be rotated 180 degrees between the installation state in which the hole 11 is inserted into the drive shaft 9, and in either installation state, the transmission case 10 is attached to both sprockets 12.12a. The turned chino 14 is configured such that the homologous upper side becomes the slack side.

Also, both sprockets! - 12, 123, the tensioner 14 is connected to a tightener 15 made of an elastic material such as a leaf spring.
However, the tightener 15 pivots the mounting base 15b by the pivot pin 16 and tightens the transmission case 1.
The part connected to the mounting base 15b is formed as the chain pressing part 15a, and the free end 15C is attached to the transmission case 1.
The chain pressing portion 15a of the tightener 15 is configured to be in sliding contact with the inner wall surface of the chain at a point P on the starting end side where the chain 14 is wound around the sprocket fitted to the driven shaft 8. 14 rollers from the outside to press it.

Therefore, the sprocket 12.1 in the transmission case 10
When 2a is inserted into the drive shaft and the driven shaft and operates by interlocking and connecting the two shafts, the cheno 14 rotates with the lower side being the tension side and the upper side being the slack side. However, on the loose side, the chain 14 starts to mesh with the sprocket fitted on the driven shaft at the P section in Figure 2, but the chain on the iron part has the pressure part 15a of the tightener contacting the roller from the outside. Since it is elastic and prevents pulsation, it starts to engage the sprocket accurately and operates reliably.

In addition, when changing the transmission ratio between the driving shaft and the driven shaft, the sprocket and the transmission case are removed from both shafts, and the transmission case 10 is rotated 180 degrees to change the position of the sprocket relative to both shafts. The operation of refitting and re-inserting is performed in reverse, but when both sprockets (-12 and 12H) are removed and removed, the elastic force by the tightener 15 is applied only in the vertical direction, so that both sprockets do not touch each other. Since there is no possibility that the cables will be pulled in the approaching direction by the chino, it becomes easy to match the distance between the axes when reinserting them, and the transmission case 10 can be installed easily.

As explained above, in the present invention, in order to house and hold the two sprockets H2, 12a in the case 10 with a predetermined center-to-axis distance l, each sprocket (12.121) is a boss portion of each sprocket. The mounting part 13 formed in the case is freely rotatably fitted and held in the holding part of the case, and both sprockets are attached.
12.12 A chino 14 is hung between a to form a chino transmission case, and the shaft holes 11 and 11a of both sprockets in this chino transmission case are connected to the center-center distance l.
The drive shaft 9 and the driven shaft 8 are installed with a center-to-axis distance that matches
In a chain transmission device that interlocks and connects both shafts by fitting and inserting the chain, the chain 14 in the chain transmission case is tensioned by a tightener 15 that elastically presses only the starting end side that wraps around the driven sprocket. Since this is done, the sprockets 12, 12a in the chain drive case 10 can be attached and detached together with the chain drive shaft 9 and the driven shaft 8, which are provided at a predetermined center-to-center distance. Regardless, it has become possible to properly tension the cheno without adversely affecting the maintenance of the center-to-axis distance between the sprockets.

[Brief explanation of the drawing]

Figure 1 is an overall side view of the device of the present invention applied to a tiller, Figure 2 is an enlarged partial view of the chino transmission device of the present invention, Figure 3 is a vertical cross-sectional view of the main parts of Figure 2, and Figure 4 is It is an explanatory view of the operation of the device of the present invention. 8... Driven shaft, 9... Drive shaft, 10... Transmission case, 11° 11 a... Shaft hole, 12.12 a...
Sprocket, 14...cheno, 15...tightener

Claims (1)

[Scope of utility model registration request] In order to accommodate and hold two sprockets)-12, 12a in the case 10 with a predetermined center-to-axis distance of 1, each sprocket)-12.12a has a mounting portion 13 formed on each boss portion. It is fitted and held in the holding part of the case so that it can rotate freely.
4 to construct a chain transmission case, and insert the shaft holes 11.11a of both sprockets in this chain transmission case.
is inserted into the driving shaft 9 and the driven shaft 8, which are installed with a distance between the shaft centers that matches the distance between the shaft centers 1, thereby interlockingly connecting the two shafts. The chain tensioner 14 in the chain transmission case is tensioned by a tightener 15 that elastically presses only the starting end side that wraps around the driven sprocket.