JP2532788Y2 - Braking device in tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to a brake device in an agricultural tractor.

(B) Conventional technology Conventionally, a transmission case is provided at the rear of the fuselage, and the rear wheels are driven through a rear axle case provided with a brake by a differential mechanism in the transmission case, and the brake is manually operated. A tractor in which a brake cam is rotated and operated by a tool is already known.

(C) Problems to be Solved by the Invention The known tractor brake device has a high cost because it has no special means for mounting the return spring of the brake cam and has a special locking portion. Also,
Since the rear axle case receives a large load from the rear wheels, it had to be constructed firmly to obtain sufficient strength.

(D) Means for Solving the Problems In the present invention, the transmission case 7 and the rear axle case 25 are provided at the rear of the fuselage, and the rear axle case 25 in which the brake 33 is interposed by the differential mechanism in the transmission case 7 is provided. In a tractor that drives the rear wheels via the rear axle case 25, a plurality of ribs 43 with a plurality of protrusions spaced apart in the circumferential direction are provided on the inner peripheral surface near the brake 33 at the base 25a of the rear axle case 25. The ribs 43 are protruded to form a receiving surface 43a of the brake cam 35 of the brake 33, and a ring 46 is fitted and mounted in a slit 45 formed in the inner end of the rib 43, and the ring 46 and the brake By extending the return spring 47 to the cam 35, the above-mentioned problem was solved and the transmission case was reinforced.

(E) Action When the brake cam is rotated by a manual operation tool such as a brake pedal, the brake is differentially operated, and when the manual operation tool is released, the brake cam is returned and rotated by the return spring, so that the brake is not operated.

Then, the rib for holding the receiving surface of the brake cam and one end of the return spring reinforces the rear axle case.

(F) Embodiment One embodiment of the present invention will be described with reference to the drawings. An engine 2 is mounted on a front part of a stepped portion 1a of a chassis 1 and a front axle case 4 of a front wheel 3 is supported thereunder. An auxiliary step 6 is provided vertically on the side of the vehicle, a transmission case 7 is mounted on the rear, and a front wheel speed-up switching lever 10, an ultra-low speed switching lever 11, a sub-transmission lever 12, A main shift lever 13 and a shuttle shift lever 14 are provided, and a differential lock pedal and a PTO
A shift lever 15 is provided.

An operation panel 16 erected at the front of Step 5 is equipped with an accelerator lever 17 and a steering handle 18, a clutch pedal 19 on the left side, and left and right brake pedals 20, 20 on the right side.
Are respectively suspended, and a foot accelerator pedal 21 is provided on the outside.

Reference numeral 22 denotes a propeller shaft connecting the engine 2 and the transmission case 7 via a universal joint.
Is a front wheel drive shaft. Reference numeral 25 denotes a rear axle case screwed to both sides of the transmission case 7, and the outer ends of differential shafts 27, 27 extending from the differential mechanism 26 to both sides are bearings 28.
The gear 29 meshes with the large gear 32 of the wheel 31 of the rear wheel 30, and a disc brake 33 is interposed between the differential shaft 27 and the base 25a of the rear axle case 25. A plurality of arc-shaped inclined grooves 36 are provided on the outer surface of 35, and a ball 37 is interposed between these inclined grooves 36 and the spherical hole formed in the case, and is supported on the rear axle case 25.
An arm 39 is fixed to the inner end of 38, and a projection 40 at the tip of the arm 39 is fitted into the hole of the brake cam 35 and linked and linked,
A brake arm 41 attached to the outer end of the support shaft 38 is operatively connected to the brake pedal 20 by a longitudinal rod and a vertical brake rod 42.

At the base 25a of the rear axle case 25 (in the vicinity of the outside of the disk brake 33), a plurality of (for example, three) ribs with projections spaced in the circumferential direction are provided on the inner peripheral surface in the vicinity of the brake opposite to the brake. 43 ...
And the receiving surface 43a of the brake cam 35. A circumferential slit 45 is formed in the inner end of each of the ribs 43, and a ring 46 is fitted and mounted in each of the slits 45. Hole 35a
And a return spring 47 is stretched.

Reference numeral 48 denotes a differential lock body which is spline-fitted to one differential shaft 27 and is urged by a spring 50.When the differential lock pedal is depressed, the swing arm 52 pushes the differential lock body 48 against the spring 50. To engage the claws on the inner end surface thereof with the claws on the outer end surface of the shaft support portion of the differential case 52, whereby the differential lock is performed.

Thus, when the brake pedal 20 is depressed, the support shaft 38 rotates through the brake rod 42 and the like, and the arm at the inner end thereof
39 rotates against the return spring 47, whereby the brake cam 35 is pushed out by the ball 37, so that the disk brake 33 operates and the differential shaft 27 is braked.

When the foot is released from the brake pedal 20, the brake cam 35 is returned and rotated by the return spring 47, so that the braking action of the disk brake 33 is stopped.

Also, each rib 43... Holds a ring 46 on which an end of a return spring 47 is hooked by a slit 45 thereof and a base portion of the rear axle case 25 where the largest load is applied.
Reinforce 25a.

(G) Effects of the Invention As described above, the present invention provides the transmission case 7 and the rear axle case 25 at the rear portion of the fuselage, and the rear axle case 25 provided with a brake or interposed by the differential mechanism in the transmission case 7. In a tractor that drives wheels, a base 25a of the rear axle case 25 is used.
A plurality of ribs 43 with a plurality of protrusions are provided on the inner peripheral surface in the vicinity of the surface facing the brake so as to protrude to form a receiving surface 43a for the brake cam 35 of the brake, and these ribs are provided. A ring 46 is fitted and fitted to a slit 45 formed in the inner end of the rib 43, and a return spring 47 is stretched between the ring 46 and the brake cam 35. Ring on the slit 45
With a very simple structure of mounting the 46, the return spring 47 of the brake cam 35 can be hooked and held, so that the cost can be reduced and the weight can be reduced.

Moreover, the base portion 25a of the rear axle case 25 can be reinforced while the rib 43 is also used as the receiving surface 43a of the brake cam 35.

[Brief description of the drawings]

1 is a cross-sectional view of a rear wheel drive unit, FIG. 2 is a cross-sectional view of a rib, FIG. 3 is a side view of a tractor, and FIG. It is a rear view of an operation part. 1 ... chassis, 7 ... mission case, 25 ... rear axle case, 25a ... base, 27 ... differential shaft, 33 ...
Disc brake, 35… Brake cam, 43… Rib, 45…
… Slit, 46 …… Ring, 47 …… Return spring

Claims (1)

(57) [Scope of request for utility model registration] 1. A transmission case 7 and a rear axle case 25 are provided at a rear portion of an airframe, and a rear wheel is driven by a differential mechanism in the transmission case 7 via a rear axle case 25 in which a brake 33 is interposed. In the tractor, a plurality of ribs 43 with a plurality of protrusions spaced apart in the circumferential direction are protruded from an inner peripheral surface of the base portion 25a of the rear axle case 25 near the brake 33 so as to protrude therefrom. 35, and a ring 46 is fitted and mounted on a slit 45 formed in the inner end of the rib 43, and a return spring 47 is stretched on the ring 46 and the brake cam 35. A brake device for a tractor, characterized in that: