JPH0358934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an installation structure for a hydraulic brake on a tractor.

Generally, small tractors use dry internal expansion brakes, but with this, the link mechanisms such as the brake rods that make up the operation system are unsightly exposed outside the case, and inspection and maintenance are troublesome. Not only that, but there are also problems in that it becomes difficult to secure a simple and spacious suspension area for the cockpit, and that it also imposes restrictions on the installation of the cabin and other layouts.

Therefore, wet-type (oil-immersed) brakes, which are nearly maintenance-free, are being introduced to small tractors, but in most of these brakes are operated using ball cams or other mechanical actuators. It's summery. Therefore, the structure of the brake device is still complex, and the reliability and efficiency of brake performance have not yet been fundamentally improved.

The present invention solves these problems and also
This hydraulic brake is designed to be installed in a tractor body in an extremely rational and stable manner.

Hereinafter, the specific configuration of the present invention will be described in detail based on the illustrated embodiment. In FIGS. 1 and 2 showing the installation state of the hydraulic brake, 10 is the tractor body, 11 is the pedal from above the cockpit. 12, and is connected to a brake hydraulic cylinder, which will be described later, via a brake pressure oil supply/discharge pipe 13. The system of the conduit 13 is stationary and can be freely buried inside the tractor body 10, so the leg area of the cockpit can be secured as wide as possible, and a cabin etc. can be installed above the seat. In doing so, there will be no restrictions on space.

A is the center case of the tractor body 10, and as is clear from the enlarged view in FIG.
The built-in chamber a is divided into a substantially U-shaped cross section, and the adjacent lateral position is divided into a partition wall 15.
As a result, they are interconnected as a reduction gear built-in chamber b that opens outward and has a substantially U-shaped cross section. and,
The opening surface of the built-in chamber b substantially corresponds to the opening surface of the axle case B so that it can be joined. Reference numeral 16 denotes a differential gear shaft that extends outward from the differential case 17 of the differential device 14 in a horizontally suspended state, and its projecting end extends beyond the built-in chamber b and extends into the axle case B. At the same time, a so-called multi-plate brake disc 18 is spline-fitted to the protruding end portion thereof.

A differential bearing case 19 is fitted onto the partition wall 15 of the center case A, and the intermediate portion of the differential gear shaft 16 is also supported by the bearing 20 of the differential bearing case. 21 is a bolt for fixing the differential bearing case 19, and 22 is an axle supported at a lower position of the axle case B, which is kept horizontally suspended in two stages parallel to the differential gear shaft 16, above and below. By meshing reduction gears 23 and 24 on both shafts 16 and 22, the shafts are connected to each other so as to be able to freely decelerate and rotate. As is clear from the diagram, both of the reduction gears 23 and 24 are housed in the built-in chamber b of the center case A.

Further, 25 is a hydraulic cylinder which is also integrally and continuously projecting from the upper part of the axle case B, and is opened so as to face the brake disc 18 on the differential gear shaft 16 in a substantially concentric state. Reference numeral 26 denotes a sealing material fitted to the inner circumferential surface of the piston, which keeps the brake piston, which will be described later, in an oil-tight state. 27 is an air bleed plug, and it goes without saying that the hydraulic cylinder 25 is opened to communicate with the brake pressure oil conduit 13 described above. In that case, although the hydraulic cylinder 25 is coupled to the axle case B itself in the illustrated example, instead of this, the hydraulic cylinder 25 may be made separate from the axle case B, for example, as shown in FIG. , it may be fitted and fixed into the mounting opening 28 of the axle case B in a closed manner.

In any case, a brake piston 29 that pushes the brake disc 18 is enclosed within the hydraulic cylinder 25, and its hydraulic pressure applies a braking force to the brake disc 18 in proportion to the depression pressure of the pedal 12. It's getting old. The brake piston 29 has a top-hat shape that substantially matches the hydraulic cylinder 25, and its body 30 serves as a slide guide surface for the hydraulic cylinder 25, and the flange 31 that continuously protrudes from the body 30 acts as a brake disc. Each is configured to function as a pressure surface for 18.

Then, pressure oil is supplied to the top surface of the brake piston 29 from the supply/discharge pipe 13 connected to the hydraulic cylinder 25, and the body 30 of the piston 29 slides along the hydraulic cylinder 25. It's becoming like that.

32 is the projecting flange 3 of the brake piston 29
1 is a brake cover plate that sandwiches the brake disc 18 on the differential gear shaft 16, and this is a brake cover plate that connects the opening surface of the reduction gear built-in chamber b in the center case A and the opening surface of the axle case B. The bolts 33 are inserted between the center case A and the axle case B, and are simultaneously tightened together using bolts 33 for attaching the axle case B to the center case A. Through the interposition of the brake cover plate 32, the built-in chambers b of the reduction gears 23 and 24 are completely covered, and the brake is installed between the brake cover plate 32 and the hydraulic cylinder 25. The room c is divided into sections. However, in operation, the oil for dissipating the frictional heat of the brake is convected between the plurality of chambers a, b, and c through the oil communication ports s1 and s2 formed in the brake cover plate 32 and the partition wall 15, respectively. Needless to say, it has become like this.

This brake cover plate 32 also serves as a case for bearings 34 and 35 for supporting the midway portions of both the differential gear shaft 16 and the axle 22, and in particular, the long axle 22, in addition to this bearing 35, has both inner and outer ends thereof. are supported by the bearings 36 and 37, so the assembled state is excellent in stability, and the assembly work can be done by simply using the bolts 33 and 37.
This can be done efficiently by using both. The support bearing 36 at the inner end of the partition wall 15
It is fitted in and is prevented from coming off by a presser plate 38. 39 is a fixing bolt for the holding plate 38, 40 is a collar, 41 is a sealing material,
Needless to say, the axle 42 is attached to the outer end of the axle 22 extending from the axle case B.

In particular, the brake cover plate 32 in the illustrated example extends rearward and downward in an extended manner, and also has the function of supporting a lower link 43 in a three-point link mechanism for towing a work machine or the like.
That is, in FIG. 2, reference numeral 44 is a projecting extension of the brake cover plate 32, which faces the lateral wall surface 45 of the center case A so as to maintain a constant gap W therebetween. Then, the center case A and the brake cover plate 32
The pivot pin 4 of the lower link 43
6 is suspended horizontally. 47 is a collar inserted into the pivot pin 46 to regulate the constant gap W; 48
Similarly, it is a roll pin for preventing the pivot pin 46 from coming off. According to the extension of the brake cover plate 32, the pivot pin 46 of the lower link 43 is connected to the protruding extension portion 4 of the brake cover plate 32.
4 and the lateral wall surface portion 45 of the center case A, so that it can be mounted stably and effectively in a so-called both-side supported state.

As described above, in the present invention, the tractor body 10
The differential gear shaft 16 coming out from the differential device 14 built into the center case A of the 1000 and the axle 22 coming out of the axle case B attached to the center case A are kept in a horizontally parallel state with two upper and lower stages. The brake disc 18 is fitted to the protruding end of the differential gear shaft 16, and both shafts 16, 2
2 is connected to the axle 2 by the meshing of the reduction gears 23 and 24.
2, in which the built-in chambers b of the reduction gears 23 and 24 are moved to the lateral position of the center case A, and the cross section is approximately U-shaped with an opening facing the opening of the axle case B. On the other hand, the brake disc 18 on the differential gear shaft 16
The hydraulic cylinder 25 for enclosing the brake piston 29 that provides braking force to the brake disc 1
As an opening form facing substantially concentrically with 8,
The hydraulic cylinder 25 and the tractor body 1 are installed in a part of the axle case B.
The top-hat type brake piston 29 is sealed in the hydraulic cylinder 25 and is connected to the master cylinder 11 which is operated by pressing the pedal 12 from above the driver's seat of the driver 0 through a brake pressure oil supply and discharge pipe 13. overhanging flange 3
1 and the brake cover plate 32 sandwiching the brake disc 18, the deceleration gear 23,
The brake cover plate 32 is inserted and fixed between the opening surface of the center case A and the opening surface of the axle case B, and is fitted into the brake cover plate 32 with a size that can completely partition the built-in chamber b of 24. A pair of upper and lower bearings 34 and 35 support both the intermediate portions of the differential gear shaft 16 and the axle 22, and control that is proportional to the depression pressure of the pedal 12 is achieved only by the hydraulic pressure fed into the hydraulic cylinder 25. Since it is provided that power is applied to the brake disc 18, the problems of the prior art mentioned at the beginning can be completely overcome.

In other words, the conventional means of applying braking force to the brake disc using a ball cam or other mechanical actuator described at the beginning requires a large number of operating parts, so it is still structurally difficult to use as a brake device. If it is complicated and there are variations in the machining accuracy and assembly accuracy of the operating parts, the reliability and stability of the brake performance will decrease, but in the case of the present invention, the brake disc 18 is operated only by hydraulic pressure. When the pedal 12 is depressed from above the cockpit of the tractor body 10, a braking force proportional to the pedal pressure is efficiently applied to the brake disc 18 through the sliding action of the hydraulic cylinder 25. As a result, a stable braking effect without variation can be obtained at all times, and the reliability of the braking performance is extremely excellent.The necessary configuration for this purpose is extremely simple and sufficient.

The pressure oil supply and discharge pipe line 13 for the hydraulic cylinder 25 can also be installed as an extremely simple piping system in a space-saving manner between the master cylinder 11 and the master cylinder 11 which is operated by pressing the pedal 12, as described at the beginning. All of the problems with the internal expansion type brake device can also be solved.

Further, in the present invention, the hydraulic cylinder 25 for enclosing the brake piston 29 is partially installed in the axle case B in the form of an opening facing the brake disc 18 on the differential gear shaft 16 in a substantially concentric manner. Since the brake installation chamber c is defined by the brake cover plate 32 inserted and fixed between the opening surface of the axle case B and the opening surface of the center case A, the axle case B can be effectively used. The entire brake system can be incorporated into the brake installation chamber c in a very rational and compact manner, which is extremely useful for downsizing the tractor.

Further, the brake cover plate 32 forms a pressure-receiving surface of the brake disc 18, and together with this, the brake piston 29 that sandwiches the brake disc 18 has an overall top-hat shape with an overhanging flange 31 that serves as its pressure-applying surface. It is shaped,
Since the body portion 30 is designed to slide correctly along the hydraulic cylinder 25, there is no risk of the brake piston 29 being biased into an incorrect posture, and the necessary slide stroke length can be easily secured. This makes it possible to apply uniform pressing braking force to the brake disc 18 at all times.

Further, the built-in chamber b of the reduction gears 23 and 24 is formed on the side of the center case A in a substantially U-shaped cross section with an opening facing the opening of the axle case B. , B, a brake cover plate 32 having a size that can partition the entire gear built-in chamber b is inserted and fixed, and a pair of upper and lower bearings 34 are fitted to the brake cover plate 32. , 35, both the intermediate parts of the upper differential gear shaft 16 and the lower axle 22 are simultaneously supported, so the assembly rigidity of the center case A and axle case B and the assembly rigidity of the brake device are significantly reduced. The differential gear shaft 16 can be improved
Brake disc 1 fitted to the protruding end of
8 and its braking action by the brake piston 29 can also be kept extremely stable and smooth.

Moreover, since the brake cover plate 32 is separate and independent from the center case A and the axle case B, the axle with the brake device installed in advance can be placed inside the brake installation chamber c divided by the center case A and the axle case B. As a unit body with case B, each axle case B can be easily assembled to the center case A.

At that time, if the bolts 33 for attaching the axle case B to the center case A are also used to tighten and fix the brake cover plate 32 together,
The assembly workability can be further improved.

Further, the brake cover plate 32 is inserted between the center case A and the axle case B, which face each other, so as to cover the entire reduction gear built-in chamber b. It is also possible to extend the brake cover plate 32 to the side wall 4 of the center case A without any support.
5 and the pivot pin 4 of the lower link 43 for towing the work equipment, the pivot pin 4 of the lower link 43 for towing the work equipment
If the brake cover plate 6 is mounted horizontally, the brake cover plate 32 can be used effectively and its lower link 43 can also be supported rationally.

In that case, as described above, the brake cover plate 32 is a large integral part that partitions the entire reduction gear built-in chamber b, so it has excellent support strength for the lower link 43, and the pivot pin 46 is attached to the brake cover plate 32. Since it is horizontally suspended between the extension part 44 of the plate 32 and the lateral wall surface part 45 of the center case A, there is no risk of the lower link 43 accidentally coming off.

[Brief explanation of drawings]

Fig. 1 is an overall schematic side view showing the operating system of the present invention, Fig. 2 is an enlarged sectional view of the main parts, Fig. 3 is a sectional view showing a partial modification of Fig. 2, and Fig. 4 is a lower link. FIG. A...Center case, B...Axle case, W
...Constant gap, 10...Tractor body, 14...
... Differential device, 16 ... Differential gear shaft, 18 ... Brake disk, 22 ... Axle, 23, 24 ... Reduction gear, 25 ... Hydraulic cylinder, 29 ... Brake piston, 32 ... Brake cover plate, 33...Bolt, 43...Lower link, 4
6... Pivot pin.

Claims (1)

[Claims] 1. A differential gear shaft 1 extending from a differential device 14 built in the center case A of the tractor body 10.
6 and the axle 22 protruding from the axle case B attached to the center case A are maintained in a horizontally parallel state of two upper and lower stages, and the brake disc 18 is fitted to the protruding end of the differential gear shaft 16, and the above-mentioned Both shafts 16, 2
2 is connected to the axle 2 by the meshing of the reduction gears 23 and 24.
2, in which the built-in chambers b of the reduction gears 23 and 24 are moved to the lateral position of the center case A, and the cross section is approximately U-shaped with an opening facing the opening of the axle case B. On the other hand, the brake disc 18 on the differential gear shaft 16
The hydraulic cylinder 25 for enclosing the brake piston 29 that provides braking force to the brake disc 1
As an opening form facing substantially concentrically with 8,
The hydraulic cylinder 25 and the tractor body 1 are installed in a part of the axle case B.
The top-hat type brake piston 29 is sealed in the hydraulic cylinder 25 and is connected to the master cylinder 11 which is operated by pressing the pedal 12 from above the driver's seat of the driver 0 through a brake pressure oil supply and discharge pipe 13. overhanging flange 3
1 and the brake cover plate 32 sandwiching the brake disc 18, the deceleration gear 23,
The brake cover plate 32 is inserted and fixed between the opening surface of the center case A and the opening surface of the axle case B, and is fitted into the brake cover plate 32 with a size that can completely partition the built-in chamber b of 24. A pair of upper and lower bearings 34 and 35 support both the intermediate portions of the differential gear shaft 16 and the axle 22, and control that is proportional to the depression pressure of the pedal 12 is achieved only by the hydraulic pressure fed into the hydraulic cylinder 25. An installation structure for a hydraulic brake in a tractor, characterized in that power is applied to a brake disc 18. 2 Connect the hydraulic cylinder 25 to the brake piston 29
As a top hat type substantially corresponding to the above, it is formed so as to extend continuously and integrally from a part of the axle case B, and the supply and discharge pipe line 13 for brake pressure oil is connected in communication with the projecting top surface of the hydraulic cylinder 25. An installation structure for a hydraulic brake in a tractor according to claim 1, characterized in that: 3. The hydraulic cylinder 25 is made as a separate object from the axle case B in a top-hat shape that substantially corresponds to the brake piston 29, and then fitted into the mounting hole 28 provided in a part of the axle case B in a closed state. At the same time, a brake pressure oil supply and discharge pipe 1 is installed on the top surface of the hydraulic cylinder 25 exposed from the axle case B.
3. An installation structure for a hydraulic brake in a tractor according to claim 1, wherein the hydraulic brakes are connected in communication with each other. 4 Attach the brake cover plate 32 to the center case A with the mounting bolts 3 of the axle case B.
3, and is fixed to the center case A simultaneously with the axle case B. 5 Differential gear shaft 1 coming out from the differential device 14 built in the center case A of the tractor body 10
6 and the axle 22 protruding from the axle case B attached to the center case A are maintained in a horizontally parallel state of two upper and lower stages, and the brake disc 18 is fitted to the protruding end of the differential gear shaft 16, and the above-mentioned Both shafts 16, 2
2 is connected to the axle 2 by the meshing of the reduction gears 23 and 24.
2, in which the built-in chambers b of the reduction gears 23 and 24 are moved to the lateral position of the center case A, and the cross section is approximately U-shaped with an opening facing the opening of the axle case B. On the other hand, the brake disc 18 on the differential gear shaft 16
The hydraulic cylinder 25 for enclosing the brake piston 29 that provides braking force to the brake disc 1
As an opening form facing substantially concentrically with 8,
The hydraulic cylinder 25 and the tractor body 1 are installed in a part of the axle case B.
The top-hat type brake piston 29 is sealed in the hydraulic cylinder 25 and is connected to the master cylinder 11 which is operated by pressing the pedal 12 from above the driver's seat of the driver 0 through a brake pressure oil supply and discharge pipe 13. overhanging flange 3
1 and the brake cover plate 32 sandwiching the brake disc 18, the deceleration gear 23,
It is inserted and fixed between the opening surface of the center case A and the opening surface of the axle case B, and is fed into the hydraulic cylinder 25 with a size that can partition the built-in chamber b of 24 as a whole. A braking force proportional to the depression pressure of the pedal 12 is applied to the brake disc 18 only by hydraulic pressure, and a pair of upper and lower bearings 34 and 35 fitted to the brake cover plate 32 is used to control the differential gear shaft 16 and the axle. By supporting both middle portions of the brake cover plate 22 and extending the brake cover plate 32 so as to extend rearward and downward, the extended portion 44 is extended between the side wall portion 45 of the center case A for a certain period of time. The pivot pin 4 of the lower link 43 for towing the work equipment is disposed between the horizontal wall surface portion 45 and the extension portion 44 so as to face each other so as to maintain the angle W.
An installation structure for a hydraulic brake in a tractor, characterized in that 6 is horizontally mounted.