JPS6123962Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a chain tensioner equipped with a hydraulic shock absorption mechanism, and more specifically to an oil filtering device for the tensioner.

For example, a side-drive type rotary tiller that is towed by an agricultural tractor uses a chain transmission mechanism as a power transmission means between the drive shaft and the claw shaft, and the transmission mechanism is housed in a chain case. It is said to be an oil bath type. Tension is applied to the chain of the transmission mechanism via a tightener by a tensioner provided within the chain case.

The chain tensioner needs to press the tightener against the chain and absorb the impact applied through the tightener.For this purpose, a piston is slidably provided in the cylinder, and the piston is pressed against the tightener by a spring. At the same time, a system has been devised in which oil is supplied to a cylinder hole into which a piston is inserted, and the shock applied to the piston is absorbed by squeezing and flowing out the oil.

By the way, the oil used for this shock absorption is the lubricating oil in the chain case, but this oil contains foreign matter such as iron powder, and in order for the shock absorption mechanism to operate properly, foreign matter must be removed. Therefore, it is necessary to install a filter in the oil storage tank provided at the top of the cylinder. However, since this filter must filter minute foreign matter, it has fine mesh, and if it is simply installed at the upper opening of the oil storage tank, the oil that is scraped up and circulated by the rotation of the chain will be filtered out by the filter. The oil film on the top surface prevents oil from penetrating and accumulating in the oil storage tank. Therefore, the oil storage tank needs to have a structure that can store enough oil, and the filter needs to be replaced because it gets clogged.

Therefore, the present invention was devised in view of the above-mentioned problems, and the purpose of the present invention is to provide a cylinder tightener that can sufficiently store oil in the oil storage tank and can also supply filtered oil to the cylinder. shall be. Therefore, the feature is that the bottomed cylinder hole of the tensioner body is filled with oil, and the piston that presses the chain is slidably fitted, and the body has an oil storage tank. A supply hole is provided that communicates the bottom of the oil storage tank with the cylinder hole, and a check valve that allows oil to flow only from the oil storage tank to the cylinder hole is interposed in the supply hole. A cylindrical weir with an upward opening is erected around the opening at the bottom of the tank.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In Fig. 1, 1 is a chain transmission mechanism of a side drive type rotary cultivating device, 2 and 3 are drive shafts and pawl shafts parallel to each other, and 4 and 5 are sprockets provided on drive shaft 2 and pawl shaft 3, respectively. , 6 are chains wound around the sprockets 4 and 5, and the sprockets 4 and 5, the chain 6, etc. are surrounded by a chain case 7.

Inside the chain case 7, a tightener 8 that is pressed against the chain 6 is pivotally supported by a pin 9, and a tensioner 11 that presses the tightener 8 against the chain 6 is provided. The oil 10 thus produced can be supplied to the tensioner 11 by the chain 6 rotating in the direction of arrow a.

As shown in FIG. 2, the tensioner 11 has a tensioner body 13 that is detachably fixed to the inner surface of the case 7 via bolts 12, and an oil storage tank 14 that is open from above is integrally formed in the upper part of the body 13. has been done.

A piston 16 whose tip abuts on the tightener 8 is slidably fitted into a bottomed cylinder hole 15 bored in the lower part of the tensioner body 13. The piston 16 is pressed toward the tightener 8 by a spring 17 built into the cylinder hole 15.

18 is a hole bored in the tensioner body 13 so as to be approximately concentric with the cylinder hole 15 and communicate with the cylinder hole 15, and a cylindrical valve seat body 19 is inserted into the hole 18.
The insertion has been fixed. An oil passage 20 that opens into the cylinder hole 15 is provided in the valve seat body 19, and the opening of the cylinder hole 15 of the passage 20 serves as a valve seat 21. A ball 22 contacts this valve seat 21 to constitute a check valve 23. The ball 22 is pressed against the valve seat 21 by a spring 24, and the spring 24 is held by a spring holder 25, which holds the spring 1 for pressing the piston 16.
It is held at 7.

The tensioner main body 13 is provided with a supply hole 26 that communicates the bottom of the oil storage tank 14 with the oil passage 20 . A cylindrical weir 27 with an upward opening is erected around the opening of the supply hole 26 at the bottom of the oil storage tank 14 . In the drawing, the weir 27 is formed by threading a pipe into the supply hole 26. The opening at the top of the weir 27 does not protrude beyond the oil storage tank 14 and is located below the oil level stored in the oil storage tank 14. The opening of the weir 27 is covered with a spherical filter member 28. The filter member 28 is detachably attached to the weir 27 and is made of fine wire mesh, porous material, or the like.

29 is a relief hole, which connects the oil storage tank 14 and the cylinder hole 15.
It communicates with A throttle member 30 is inserted into the relief hole 29.
is fitted, and the aperture member 30 is fitted with the stopper 3.
1 prevents the oil from escaping from the relief hole 29 to the oil storage tank 14. The diaphragm member 30 is provided with a small-diameter diaphragm hole 32 that passes through the diaphragm member 30 .

Next, the effects of the tensioner 11 having the above configuration will be explained.

The oil 10 in the lower part of the chain case 7 is scraped up by the chain 6 and enters the oil storage tank 14 through the upper opening of the oil storage tank 14. At this time, since the opening of the oil storage tank 14 is not covered with a filter member as in the conventional case, the oil 10 that has been scraped up can be easily received.

The oil 10 that has entered the oil storage tank 14 is filtered to remove dust such as iron powder by a filter member 28 provided at the top of the weir 27, and flows into the supply hole 26, where the check valve 2
3 and is supplied to the cylinder hole 15. At this time, since a weir 27 is erected around the opening of the supply hole 26, iron powder etc. that have settled at the bottom of the oil storage tank 14 do not directly enter the supply hole 26, and the filter member 28 is placed at the top of the weir 27. Since the iron powder etc. which have precipitated are provided in the filter member 28,
Therefore, clogging is less likely to occur. Further, since the filter member 28 is removably fitted and fixed to the weir 27, the shape of the filter member 28 can be made small, and it is extremely easy to remove it for cleaning.

On the other hand, the piston 16 presses the tightener 8 against the chain 6 by the spring 17, and the pawl shaft 3
An overload is applied to the chain 6, and an abnormal tension is generated in the chain 6 at the time of startup, and an impact is applied to the piston 16 via the tightener 8. The cylinder hole 15 is filled with oil, and the piston 16 due to the impact
As a result of the pushing operation, the oil in the cylinder hole 15 is pressurized and flows from the throttle hole 32 of the throttle member 30 to the oil storage tank 14.
Return to Since oil is squeezed out from this cylinder hole 15, the oil pressure gradually decreases, and the spring 17
The impact applied to the piston 16 is absorbed along with the repulsive force.

When the load decreases, the piston 16 presses the tightener 8 toward the chain 6 due to the restoring force of the spring 17, thereby creating a negative pressure inside the cylinder hole 15, and the ball 22 resists the spring 24.
is separated from the valve seat 21, and the oil 10 in the oil storage tank 14 flows into the cylinder hole 15 through the supply hole 26 and the passage 20, and the cylinder hole 15 is replenished with oil 10.

In the shock absorbing mechanism as described above, the oil 10 in the oil storage tank 14 is filtered by the filter member 28, so that the throttle hole 32 is not clogged and the inside of the cylinder hole 15 is not damaged.

What is shown in FIG. 3 is another embodiment of the present invention, in which a nozzle 33 is installed as a throttle member 30 in the relief hole 29.
is attached, and the tip of the nozzle 33 is directed toward the filter member 28 provided in the weir 27.

According to the one shown in FIG. 3, the oil 10 jetted from the nozzle 33 collides with the filter member 28, and the filter member 28 is automatically cleaned.

Note that the present invention is not limited to the above embodiments.

According to the present invention, since a weir is provided around the supply hole, iron powder, etc. that settle at the bottom of the oil storage tank is blocked by the weir and does not enter the supply hole, so that the function of the tensioner is not impaired. However, it can be put to practical use and exhibits great effects.

[Brief explanation of the drawing]

Fig. 1 is a side cross-sectional view of a chain transmission mechanism of a rotary tiller employing the present invention, Fig. 2 is an enlarged cross-sectional view of the main part, and Fig. 3 is an enlarged cross-sectional view of the main part showing another embodiment of the present invention. be. 6...Chain, 10...Oil, 13...Tensioner body, 14...Oil storage tank, 15...Cylinder hole,
16... Piston, 26... Weir, 28... Filter member.

Claims (1)

[Scope of utility model registration request] In the case where the bottomed cylinder hole 15 of the tensioner main body 13 is filled with oil 10 and a piston 16 that presses the chain 6 is slidably fitted, the main body 13 is provided with an oil storage tank 14, A supply hole 26 is provided that communicates the bottom of the oil storage tank 14 with the cylinder hole 15.
A check valve 23 is interposed to allow the oil 10 to flow only from the cylinder hole 15 to the cylinder hole 15, and an upwardly opening cylindrical weir 2 is provided at the opening periphery of the bottom of the oil storage tank 14 of the supply hole 26.
A chain tensioner characterized by having a number 7 standing upright.