JPH0339855B2 - - Google Patents

Abstract

PURPOSE:To aim at miniaturization in size and structure, by installing a hydraulic cylinder in an axle case concentrically with the brake disc attached to a differential gear shaft end part in a differential gear, while a making a brake piston inside the hydraulic cylinder manually operatable via a slide pin. CONSTITUTION:A differential gear shaft 16 in the differential gear 14 housed in a built-in chamber (a) at the center of a center case A if a tractor machine body is installed so as to project somewhat more outward than a setting surface between the center case A and an axle case B, and a brake disc 18 is connected to this projected end part with a spline. A hydraulic cylinder 25 to be opened so as to be concentrically opposed to this disc 18 is solidly formed in an upper part of the axle case B as one body, and a brake piston 27 is fitly installed in the inner part. In addition, a slide pin 41 pushing a flange part 29 of this piston 27 is fitted in the axle case B so as to be paralleled with an axial line of the cylinder 25, while this pin 41 is made retractable by hand with operation of a lever 45 via a wire 46 and an operating arm 42.

Description

[Detailed description of the invention] The present invention relates to improvements in parking brake devices.

Hydraulic brakes have the advantage of being maintenance-free, so they are being adopted not only for large vehicles such as tractors but also for small vehicles, but they cannot be used as parking brakes to maintain the brake in a locked state for long periods of time. Therefore, a mechanical parking brake must be installed.

However, in terms of its operation and arrangement, the conventional parking brake is installed completely separately from the above-mentioned hydraulic brake, and its structure is also quite complicated. Therefore, although it may be a large vehicle that is not subject to space constraints, it cannot be organically or rationally attached to a small vehicle.

In view of these problems, the present invention aims to improve the performance and efficiency of the hydraulic brake, and by applying special measures to the brake piston, it can be easily and easily operated while utilizing the hydraulic acting part on the brake disc. Moreover, it is possible to rationally attach a parking brake.

Hereinafter, the structure of the present invention will be specifically described in detail based on the illustrated embodiment. FIGS. 1 and 2 illustrate a hydraulic brake device applied to a tractor, and 10
1 is a vehicle body, and 11 is a master cylinder operated by pressing a pedal 12 from above the driver's seat, and is connected to a brake hydraulic cylinder to be described later through a brake pressure oil supply/discharge pipe 13. The system of the conduit 13 is stationary and can be freely buried within the vehicle body 10, so that the leg area of the cockpit is as wide as possible, and a cabin etc. can be installed above the seat. For this,
You will not be subject to that space constraint.

A is the center case of the vehicle body 10, and as is clear from the enlarged view in FIG.
It is divided into a roughly U-shaped cross section, and
Similarly, the adjacent lateral position is connected by a partition wall 15 as a reduction gear built-in chamber b having a substantially U-shaped cross section. 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 to the opening surface of the axle case B. 16 is a differential case 17 of the differential gear 14
The differential gear shaft is extended horizontally outward from the shaft, and its projecting end extends beyond the built-in chamber b and into the axle case B, and the projecting end has a so-called A multi-plate brake disc 18 is spline-fitted.

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. It goes without saying that 26 has a sealing material fitted to its inner circumferential surface, and that the hydraulic cylinder 25 has a communicating opening with the brake pressure oil conduit 13 described above.

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 piston 27 has an overall top-hat or cylinder-hat shape substantially corresponding to the hydraulic cylinder 25, and its body 28 is similar to the hydraulic cylinder 25.
A flange 29, which also continuously protrudes from the body 28, is set to function as a slide guide surface for the brake disc 18, and as a pressure surface for the brake disc 18. However, as long as it has the flange 29 for pressurizing the disk, it is also possible to adopt an integral body having a shape other than that shown in the drawings, or an assembly structure of two divided bodies.

30 is a partition plate which, together with the special flange 29 of the piston 27, sandwiches the brake disc 18 on the differential gear shaft 16. The bolts 31 are inserted between the joints of the axle case B and the opening surface of the center case A, and the axle case B is fastened to the center case A at the same time using bolts 31 for attaching the axle case B to the center case A. Due to the interposition of the flat partition plate 30, the built-in chambers b of the reduction gears 23 and 24 are also completely covered due to the support structure, and the built-in chambers b and the hydraulic cylinder 25 are also isolated from each other. It is divided into states. However, the frictional heat release oil of the brake is
It goes without saying that convection flows between the chambers through the oil communication ports s1 and s2 formed in the partition plate 30 and the partition wall 15, respectively.

This partition plate 30 also serves as a case for bearings 32 and 33 for supporting the midway portions of both the differential gear shaft 16 and the axle 22, and in particular, the long axle 22 serves as a case for both the inner and outer ends of the bearing 33. Since it is supported by bearings 34 and 35, its assembled state is excellent in stability, and the assembly work can be carried out efficiently because the bolt 31 is also used. The support bearing 34 at the inner end is fitted into the partition wall 15 and is prevented from coming off by a presser plate 36. 37 is a fixing bolt for the holding plate 38;
8 is a collar, 39 is a sealing material, and a wheel 4 is attached to the outer end of the axle 22 that comes out from the axle case B.
Needless to say, 0 is attached.

The following parking brakes are also effectively attached to the above-mentioned hydraulic brakes. That is, to explain this based on Figure 2, 4
Reference numeral 1 denotes a slide pin that pushes the disk pressurizing flange 29 of the brake piston 27, and extends horizontally through the axle case B so as to be able to slide freely in parallel to the action center line of the piston 27 or the hydraulic cylinder 25. The inner end thereof is in contact with the flange 29, and the outer end thereof is exposed outside the axle case B.

The contact position with the flange 29 can be freely selected, but in particular, when the brake piston 27 is plastically worked into the above-mentioned top-hat shape from a steel plate with a uniform wall thickness as shown in the illustration, hydraulic pressure is required. When braking the brake disc 18, the flange 29
The protruding tip position is elastically deformed in a warped shape, and the brake disc 18
Therefore, in order to effectively prevent this, it is preferable to orient the slide pin 41 so as to contact the protruding tip of the flange 29 as much as possible. It is also conceivable that the inner end portion of the slide pin 41 that comes into contact with the slide pin 41 extends out in the shape of a head with a large diameter.

Reference numeral 42 designates an operating arm that acts as a lever on the slide pin 41 in the direction in which the flange 29 is pushed.One end of the arm is pivotally connected to the axle case B by a fulcrum shaft 43, and from the middle part thereof The bulged working protrusion 44 is in contact with the outer end of the slide pin 41. In this respect, the operating protrusion 44 and the slide pin 41 of the operating arm 42 are
Pivotal connections, such as pins, may be used as long as they are operatively connected.

A wire or other cable 46 that is pulled and operated by a lever 45 or the like from the driver's seat of the vehicle body 10 is connected to the other end of the operating arm 42 . Reference numeral 47 denotes a base for connection thereof, and since it is positioned and supported by the axle case B, the operation arm 42 can be stably screwed.
It is effective to set the cap 47 and other parts so that the sliding amount of the slide pin 41 can be adjusted.

As described above, in the present invention, the axle case B is attached to the side of the center case A in a closed state, and the differential gear shaft 16 is directed into the axle case B from the differential device 14 built in the center case A. When attaching a parking brake to the hydraulic brake in a hydraulic brake device that uses hydraulic pressure to brake a brake disc 18 fitted to the protruding end of the brake disc 18, it is especially important to Hydraulic cylinder 2 installed in the axle case B
5, a brake piston 27 consisting of a body 28 for a slide guide for the cylinder 25 and a flange 29 for pressurizing the brake disk protruding from the body is enclosed, and a slide pin 41 for pushing the flange 29 is inserted into the axle case. The brake disc 18 is set to be held in a locked braking state from outside the axle case B by the lever action of an operating arm 42 which is passed through the axle case B and whose slide pin 41 is pivotally supported on the axle case B. Therefore, it has the effect of completely eliminating the problems mentioned at the beginning.

In other words, the slide pin 41 is connected to the flange 29 of the brake piston 27 for pressurizing the brake disc.
Since the parking brake is configured to push and move, it is possible to rationally and simply attach a parking brake while making effective use of the hydraulic action section.
Also, even with this setting, the brake piston 27
Since the body part 28 can slide with the hydraulic cylinder 25, there is no risk of brake pressure oil leaking out, and the operating arm 42 that exerts a lever action on the slide pin 41 can be organically moved near the hydraulic cylinder 25. Since the hydraulic cylinder 25 is also provided in a part of the axle case B, it can be especially applied to small tractors, forklifts, and other vehicles that are subject to space constraints. It can be said that it can be very effective.

[Brief explanation of drawings]

The figures illustrate the present invention applied to a tractor, with FIG. 1 being an overall schematic side view showing the operating system of the hydraulic brake, and FIG. 2 being an enlarged sectional view of the main parts including the parking brake. A...Center case, B...Axle case, 1
4... Differential device, 16... Differential gear shaft, 18...
Brake disc, 22...Axle, 25...Hydraulic cylinder, 27...Brake piston, 41...
...Slide pin, 42...Operation arm, 46...
cable.

Claims (1)

[Claims] 1. Axle case B to the side position of center case A
is mounted in a closed state, and the differential gear shaft 16 is projected from the differential device 14 built in the center case A toward the inside of the axle case B, and the brake disc 18 fitted to the projected end is braked by hydraulic pressure. In a hydraulic brake system, a hydraulic cylinder 25 facing the brake disc 18 is provided in the axle case B, and into the hydraulic cylinder 25, a body part 28 for a slide guide for the cylinder 25 and a body part 28 for pressurizing the brake disc protruding from the cylinder 25 are provided. A brake piston 27 consisting of a flange 29 is enclosed, and the flange 29
A pushing slide pin 41 is passed through the axle case B, and the lever action of the operating arm 42, which has the slide pin 41 pivoted to the axle case B, locks the brake disc 18 from outside the axle case B. A parking brake device characterized in that the parking brake device is set so as to be maintained in the same state. 2 One end of the operating arm 42 is pivotally connected to the axle case B, and a cable 46 that can be pulled and operated from the driver's seat on the vehicle body 10 is connected to the other end, and the middle part of the operating arm 42 is connected to the slide pin 41. A parking brake device according to claim 1, characterized in that the parking brake device is operatively connected to a parking brake device.