JPS581375Y2 - Tractor propulsion shaft inertial slip prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tractor transmission mechanism, particularly to a device for preventing a propulsion shaft from idling due to inertia when the main clutch is disengaged.

Generally, in the power transmission mechanism of an agricultural tractor, a main clutch is interposed between the engine flywheel portion and the propulsion shaft, and the power from the propulsion shaft to the transmission mechanism is interrupted or interrupted by important operation of the main clutch.

However, in this case, even if the main clutch is disengaged to cut off power from the engine, the propulsion shaft will still be idling due to its inertia, which will impede gear shifting operations and cause unpleasant gear noises when shifting. This has the disadvantage of easily causing gear damage.

In order to eliminate such inconveniences, conventionally, the propulsion shaft is braked in conjunction with important clutch operations, thereby preventing the propulsion shaft from idling due to inertia.

As a means for performing braking in this manner, for example, a brake receiver is provided on the propulsion shaft, and a brake that is linked to the disengagement of the clutch is configured to act on the brake receiver, which is a distant relative. In general, a disc is used as a brake receiver, and in such a structure, it is necessary to slide or rotate the brake that acts on this disc in the axial direction. This requires a large amount of space around the outer periphery of the shaft, which may be difficult to implement, especially in a double clutch type in which a large number of members are arranged around the outer periphery of the propulsion shaft.

On the other hand, there is a so-called drum brake that does not use a disc, but such drum brakes require the braking device that acts on the braking drum to be moved in the diametrical direction of the propulsion shaft. However, the operation of the clutch operating tool that operates in the axial direction of the propulsion shaft must be converted and transmitted in the diametrical direction, which has the disadvantage that the interlocking links become complicated.

The present invention was made with the aim of solving these conventional problems. First, the present invention eliminates the need to move the braking device or brake receiver in the axial direction, and uses a drum brake with good braking effect. Moreover, even when such a drum brake is used, the interlocking relationship between the brake shoe acting on the brake drum and the clutch disengagement tool is simple.

The configuration of the present invention will be explained below based on the drawings showing one embodiment.

In FIGS. 1 and 2, reference numeral 1 denotes a clutch housing that is attached to the rear of an engine (not shown) mounted on the front of the tractor body. A shaft 2 is supported passing through the clutch housing 1, and its front end is loosely fitted and supported by an engine flywheel 3 portion.

Reference numeral 4 denotes a clutch hub that is spline-fitted to the PTO drive shaft 2. A PTO friction plate 5 is attached to this clutch hub, and a PTO pressure plate 6 at the rear of the PTO friction plate 5 moves the PTO friction plate 5 into a flywheel. This PPTO pressure plate 6 is designed to apply pressure to three parts.
PTO release lever 8 via O clutch release 7
connected to.

On the other hand, a cylindrical propulsion shaft 9 is fitted onto the PTO drive shaft 2 so as to be relatively rotatable. A transmission gear is attached to the.

In addition, a main clutch hub 11 is spline-fitted to the front end of the main clutch hub 11 in the same manner as the PTO drive shaft 2 described above, and a main clutch friction plate 12 is attached to the main clutch hub 11. The main clutch pressure plate 13 is in pressure contact with the engine flywheel 3, and is connected to a main clutch release lever 15 via a main clutch release 14.

Reference numeral 16 denotes a sleeve guide fitted externally to the above-mentioned propulsion shaft 9 via bearings 17 and 1B. ing.

A main clutch release sleeve 20 is slidably fitted onto the sleeve guide 16, and a main clutch release hub 22 is fitted onto the release sleeve 20 via a bearing 21. By sliding it forward, the main clutch release lever 15 supported on the flywheel 3 is rotated, thereby moving the main clutch pressure plate 13 and disengaging the main clutch.

Further, 23 is a PTO release sleeve slidably fitted onto the main clutch release sleeve 20,
This PTO release sleeve 23 is connected to the PTO release sleeve 23 via a bearing 24.
The TO release hub 25 is fitted onto the outside, and as in the case of the main clutch, by sliding the release sleeve 23 forward, the PTO release lever 8 supported on the flywheel 3 is rotated, and the PTO is applied. The pressure plate 6 is moved to cut off power transmission to the PTO drive shaft 2.

26 is a PTO release shaft rotated by a PTO clutch lever 27 rotatably supported by the clutch housing 1, and 28 is a PTO release yoke attached to the release shaft 26, as shown in FIG.
By rotating the clutch lever 21, the yoke 28 is rotated, thereby causing the PTO release sleeve 23 to slide.

On the other hand, 29 is a main clutch release shaft which is also rotatably supported by the clutch housing 1 and is equipped with a main clutch release yoke 30. As shown in FIG. 2, on the outside of the clutch housing 1, A main clutch lever 31 is attached to this shaft 29, and by rotating this main clutch lever 31, the main clutch release shaft 29 and yoke 30 are rotated, thereby causing the main clutch release sleeve 20 to slide. It is designed to let you do so.

The main clutch lever 31 is configured to rotate in conjunction with a clutch pedal (not shown).

Next □, 32 shown in FIG. 2 is a lever shaft that is rotatably fitted onto the main clutch release shaft 29, and a driven plate 33 is spline-fitted to this lever shaft 32 on the outside of the clutch housing 1. Further, on the outside of this driven plate 33, a drive shaft 34 is fitted onto the outer end of the release shaft 29 and fixed with a pin 35, and a drive plate 36 is fixed to this drive shaft 34, and this drive The plate 36 and the driven plate 33 are fixed together by bolts 31.

On the other hand, 38 is a brake lever attached to the lever shaft 32 in the clutch housing 1, and a roller shaft 39 is attached to the tip of the brake lever 38 extending downward, as shown in FIG. A roller 40 is rotatably attached to the roller shaft 39.

41 is a fixed plate to which the roller shaft 39 is attached on the outside of the roller 40.

Next, 42 is a mounting plate fixed to the support wall 19 with bolts 43 below the propulsion shaft 9, and a shaft support cylinder 44 is attached to the end of the mounting plate 42 on the side of the brake lever 38. A cam shaft 45 is rotatably fitted into this shaft support cylinder 44, and a cam lever 46 is integrally attached to this cam shaft 45.

47 is a long hole formed in the mounting plate 42 for inserting the J bolt 43.

One end of this cam lever 46 is formed with a cam surface 48 as shown in FIG. , the cam lever 46 is configured to rotate in the counterclockwise direction in FIG.

Further, a suppression plate 49 is attached to the other end of the cam lever 46 in a horizontal state.

On the other hand, a brake shaft 50 is fixed to the other end of the mounting plate 42 , and one end of a brake shoe 51 as an arc-shaped brake tool is rotatably supported on this brake shaft 50 . The other end bypasses the lower part of the propulsion shaft 9 and extends to the other side, and a pressing rod 52 is fitted into the tip thereof so as to be movable up and down, and the lower end of the pressing rod 52 is attached to the suppressing plate 49 of the cam lever 46. .

53 is a spring damper fitted onto the press rod 52 between the press plate 49 and the brake shoe 51.

Therefore, the brake shoe 51 is rotatable up and down about the brake shaft 50, and the cam lever 46 connected to the brake shoe 51 via the spring damper 53 is always clocked by the weight of the brake shoe 51. As a result, the cam surface 48 is constantly pressed against the roller 40 of the brake lever 38.

Reference numeral 54 designates a brake drum serving as a brake receiver that is spline-fitted to the propulsion shaft 9 above the brake shoe 51, and has an annular brake receiving surface 55 on its outer peripheral surface.

Reference numeral 56 shown in FIG.
By rotating the lining 56 upward about 0, the lining 56 is brought into pressure contact with the brake receiving surface 55, thereby braking the propulsion shaft 9.

In addition, in FIG. 2, for convenience of explanation, the brake drum 5 is
4 is indicated by a two-dot chain line.

Further, 57 is a rib formed on the lower surface of the brake shoe 51.

Now, to explain the operation of the present invention based on the above configuration,
Now, when you depress the clutch pedal (not shown) and rotate the main clutch lever 31, the main clutch lever release shaft 2
9 and the main clutch release yoke 30 attached thereto rotate, causing the main clutch release sleeve 20 and the main clutch release hub 22 to slide forward, and the release hub 22 rotating the main clutch release lever 15, The main clutch friction plate 12 is separated from the flywheel 3 section to take the main clutch disengaged position.

At the same time, the drive shaft 34 degree drive plate 36 attached to the release shaft 29. The brake lever 38 is rotated forward via the driven plate 33 and lever shaft 32.

As the brake lever 38 rotates, the roller 40 that was in contact with the cam surface 48 of the cam lever 46 moves while being in contact with the cam surface 48, and the cam lever 46 moves while being in contact with the cam surface 48.
is rotated counterclockwise around the fulcrum O, and the pressing plate 49 at the other end rotates the brake shoe 51 upward around its brake shaft 50 via the spring damper 53, and the brake drum 54 is rotated. Since they are brought into pressure contact, the propulsion shaft 9 is prevented from idling due to inertia and is stopped.

Then, after performing the gear shifting operation at this point, when the clutch pedal is released, the brake lever 38 rotates in the original direction.
Since the pushing force exerted on the brake shoe 51 by the cam lever 46 is eliminated, the brake shoe 51 rotates downward around the brake shaft 50 due to its own weight, moves away from the brake receiving surface 55 of the brake drum 54, and moves toward the propulsion shaft. The braking force for 9 will be released.

The present invention is as described above.According to the present invention, a drum is used as a brake receiver, and a brake shoe is applied to the outer periphery of this brake drum to perform braking. It is not necessary to move either the braking device or the braking receiver in the axial direction on the shaft, which requires less space in the axial direction of the propulsion shaft, and since it is a so-called external retractable drum brake, the braking effect is good. .

Additionally, when a drum brake is used in this way, the linkage between the brake shoes that move in the radial direction and the clutch operating tool that rotates or moves in the axial direction becomes complicated.
For example, see Utility Model Application Publication No. 49-9703), since the present invention uses a cam, it is easy to convert axial movement into radial movement, and there is no need to use a complicated link. There is.

When a cam is used in this way, the brake shoe and the clutch operating tool are not directly connected, so a mechanism for returning the brake shoe is required. However, in the present invention, the brake shoe is moved below the brake drum. Since one end of the brake shoe is freely rotatable in the vertical direction, when the clutch is returned, the brake shoe will surely return while following the cam due to its own weight. This device does not have the drawbacks of weakening the braking effect by constructing itself with a spring, has a good overall braking effect, and has a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross-sectional view of a clutch housing portion showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A--A, and FIG. 3 is a bottom view of essential parts. 9...propulsion shaft, 51...braking shoe,
55...Brake receiving surface, 48...Cam surface,
54... Braking drum.

Claims (1)

[Scope of utility model registration request] In a tractor transmission mechanism in which a main clutch is provided between a prime mover and a propulsion shaft, and power is transmitted to the propulsion shaft via the main clutch, a braking drum is attached to the propulsion shaft, and a lower portion of the braking drum is attached to the propulsion shaft. A brake shoe is disposed facing the brake receiving surface on the outer periphery of the brake drum, and has one end pivotally connected and the other end rotating upward in a direction substantially perpendicular to the propulsion shaft axis. The other end is connected to one end of a cam lever that is arranged in the axial direction of the propulsion shaft and rotates in the vertical direction,
An inertial slip prevention device for a tractor propulsion shaft, characterized in that the other end of the cam lever is operatively connected to a disengagement operating tool of a main clutch via a cam.