JPS583689Y2 - Tractor propulsion shaft inertial slip prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing a propulsion shaft from idling due to inertia in a tractor transmission mechanism.

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

However, in this case, even if the main clutch is disengaged to cut off the 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.

This invention was devised to prevent such idling of the propulsion shaft, and its purpose is to simplify the structure of the outer periphery of the propulsion shaft by using a brake band to brake the propulsion shaft. It is also an object of the present invention to provide a braking device for preventing slippage of a propulsion shaft in which the action of the brake band is performed in a well-balanced manner.

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 attached to the rear of an engine (not shown) mounted on the front of the tractor body. A drive 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.

4 is a PTO spline-fitted to this PTO drive shaft 2.
This is a clutch hub, and a PTO friction plate 5 is attached to this clutch hub 4, and a PTO pressure plate 6 at the rear of the friction plate 5 applies pressure to the flywheel 3, and this pressure plate 6 is connected to a PTO release lever 8 via a PTO clutch release.

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.

Also, at its front end, a main clutch friction plate 12 is attached to a main clutch hub 11, similar to the PTO drive shaft 2 described above, and is brought into pressure contact with the engine flywheel 3 by a main clutch pressure plate 13. The main clutch pressure plate 13 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,
A PTO release hub 25 is externally fitted onto this release sleeve 23 via a bearing 24, 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 moved. , thereby moving the PTO pressure plate 6 and cutting off power transmission to the PTO drive shaft 2.

26 is a PTO release shaft rotatably supported by the clutch housing 1 and rotated by a PTO clutch lever 27, as shown in FIG. 2; 28 is a PTO release yoke attached to the series shaft 26;
By rotating the clutch lever 27, 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. 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 is rotated, thereby causing the main clutch release sleeve 20 to slide. It looks like this.

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

Next, reference numeral 32 shown in FIG. 2 is a lever shaft rotatably fitted on one side of the main clutch release shaft 29, and on the outside of the clutch housing 1.
A driven plate 33 is spline-fitted to the lever shaft 32, and a drive shaft 34 is disposed on the outside of the driven plate 33.
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 the drive shaft 34, and the drive plate 36 and the driven plate 33 are integrally connected together by bolts 3γ. It is fixed.

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 fixed 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.

Next, 41 is a roughly U-shaped lever bracket having flanges 42 and 43 attached on the left and right, and a sleeve guide is attached to the support wall 19 below the propulsion shaft 9 by bolts 44 and 45 at the flange 42 and 43 parts. It is fixed together with 16.

Reference numeral 46 designates a shaft support member that is formed in a generally U-shape and has an L-shaped flange portion 47 extending upward from the center portion of the shaft support member. , is fixed to the lever bracket 41 in a suspended state, and a support shaft 49 is attached to the U-shaped portion, and a flat plate-shaped cam lever 50 is attached to the support shaft 49.
It is attached at the center of the front and back so that it can move up and down.

Reference numeral 51 denotes a spring receiver extending rearward from the shaft supporting member 46, into which the upper end of a spring shaft 52 whose lower end is attached to the cam lever 50 is inserted for vertical movement. .

Reference numeral 53 denotes a compression spring fitted onto the spring shaft 52. In this way, the compression spring 53 is placed between the spring receiver 51 and the cam lever 50 at the center of the left and right sides of the cam lever 50.
3, which biases the cam lever 50 so as to constantly rotate it in the clockwise direction in FIG.

The front end of the cam lever 50 has a front and rear flat portion 54°5 on one of its left and right sides, that is, on the right side in FIG.
5 and a central recess 56, the cam 57 is brought into constant contact with the roller 40 of the brake lever 38 by the elastic force of the compression spring 53.

Further, at the other end, that is, the rear end of the cam lever 50, a brake fixing piece 58 is extended on the opposite side of the cam 57, that is, on the left side in FIG.

59 is a rib provided on the lower surface of the cam lever 50; 60 is a rib provided on the lower surface of the cam lever 50;
A rib provided inside the brake fixing piece 58 is shown.

On the other hand, 61 is a brake drum as a brake receiver that is spline-fitted to the propulsion shaft 9 above the rear end of the cam lever 50, and is configured to rotate integrally with the propulsion shaft 9 in this way. , whose outer peripheral surface is used as a brake receiving surface 62.

Next, 63 is the same as the lever bracket 41 described above.
It is a locking bracket fixed to the support wall 19 with bolts 45.64 together with the sleeve guide 16, and this locking bracket 63 is provided on the opposite side of the brake fixing piece 58, and has a brake lock on its upper side. A shaft 65 is provided to protrude.

Reference numeral 66 denotes a brake band having one end locked to this brake locking shaft 65, and the other end of this brake band 66 detours above the brake drum 61 to the other side, that is, the left side in FIG. The brake fixing piece 58 extends further downward and is fixed to the brake fixing piece 58 described above.

67 is a fixed shaft for fixing this brake band 66, and 68 is a lining attached to the inside of the brake band 66.

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 series 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 spaced apart from the flywheel 3 part and takes a posture on the main clutch side.

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

At this time, the roller 40 that was in contact with the rear flat surface 55 of the cam 57 moves forward with the rotation of the brake lever 38 and is fitted into the central recess 56, so that the compression spring 53 is resilient. The cam lever 50 rotates clockwise in FIG. 1 due to the force, pulls the brake band 66 downward, and presses the lining 68 against the brake receiving surface 62 of the brake drum 61.
As a result, the propulsion shaft 9 is prevented from idling and stopped.

Then, when the clutch pedal is further depressed, roller 40
Since the cam lever 50 comes out of the recess 56 and comes into contact with the front flat part 54, the cam lever 50 rotates in the opposite direction (counterclockwise in FIG. 1) against the elastic force of the compression spring 53, and the brake band 66 is separated from the braking drum 61, and the braking force on the propulsion shaft 9 is released.

Therefore, if the gear change operation is performed at this point, that is, when the clutch pedal is depressed the deepest, the gear change gear (not shown) attached to the propulsion shaft 9 will not be in a fixed state.
Gear shifting operations can be performed easily.

The present invention has the above-mentioned configuration. By using a brake drum and a brake band in this way, it is only necessary to provide a brake drum around the outer circumference of the propulsion shaft, which takes up less space around the propulsion shaft compared to a disc type. However, on the other hand, it is necessary to pull the brake band in the radial direction, so the movement of the main clutch side, which normally rotates or slides in the axial direction, is reduced in the radial direction. It is necessary to change the direction, making the link mechanism complicated, but
In the present invention, since cams are used for these interlocking relationships, conversion of such operations is easy, there is no need to use complicated links, and the structure is simple and easy to design.

In particular, in the present invention, in such a cam interlocking mechanism, a cam is attached to one end of the cam lever, a brake band is attached to the other end of the cam, and a spring receiver provided at an appropriate location and the cam lever are attached to the other end of the cam lever. Compression springs are installed between the left and right centers to provide a well-balanced arrangement, and since these operations are performed by compression springs, the relationship between them is stable, unlike when using tension springs, etc. This allows for well-balanced and reliable operation.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a clutch housing portion showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A--A. 9...propulsion shaft, 38...braking lever,
50...Cam lever, 51...Spring holder, 53...Compression spring, 57...Cam,
61... Brake drum, 66... Brake band.

Claims (1)

[Scope of utility model registration request] In a tractor transmission mechanism in which a main clutch is provided between the prime mover and the propulsion shaft, and power is transmitted to the propulsion shaft via this main clutch, the brake drum provided on the propulsion shaft and the brake drum that acts on the The brake band comprises a brake band that performs a braking action, a cam lever that rotates around a support shaft provided on an appropriate support, and a brake lever that rotates in conjunction with a disengagement operating tool of the main clutch, A cam is formed on one left and right side of one end of the cam lever, and one end of a brake band is attached to the other end of the cam lever, and a spring holder provided at an appropriate location and a cam on the left and right sides of the cam lever are attached to the other end of the cam lever. A compression spring is provided between the center and the cam lever, which acts in the direction of rotating the cam lever in one direction around the support shaft to bring the brake band into pressure contact with the brake drum, and in the direction of constantly bringing the cam into contact with the tip of the brake lever. In addition, when the disengagement tool of the main clutch is operated in the clutch disengagement direction on the contact surface of the cam with the brake lever, the cam lever is rotated by the force of the compression spring, and the brake band is attached to the brake drum. An inertial slip prevention device for a tractor propulsion shaft, characterized in that it is formed on a cam surface that is brought into pressure contact.