JPH0942333A - Brake band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a brake band which does not cause projection of lining, suppresses temporal change of a torque capacity, stabilize the torque capacity and improve heat resistance and durability. SOLUTION: Brackets 4 of similar or different shapes 4 are connected to both ends of a bent thin strap 3. A thin frictional member (lining) 2 is adhered to an inner peripheral surface of the bent strap 3. In such a brake band, a first line of the connection of the bracket 4 and the strap 3 is provided such that any projection is not generated on an inner surface of the strap 3 to which the frictional member 2 is adhered by means of spot welding 7 or the like.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an automobile, an agricultural machine,
Alternatively, the present invention relates to a brake band used in a transmission for vehicles such as construction machinery.

[0002]

2. Description of the Related Art In automatic transmissions, multiple disc clutches, brake bands, etc. are used to fix and release input elements such as gears to perform gear shifting. Among them, the brake band is widely used because it has a characteristic that the braking force is different even when the same acting force is applied depending on the braking direction of the drum, and has a preferable characteristic of smoothing the upshift.

To facilitate the understanding of this invention, FIG.
The basic structure of the brake band is shown in Fig. 1. The brake band 7 is composed of a curved strap 3 which is a thin steel plate. Brackets 4 and 4'are respectively connected to both ends of the strap 3 so that the curved strap 3 is formed. A porous thin friction material (lining) 2 is adhered to the inner peripheral surface with an adhesive. Among the brackets, the bracket 4 is a working side (apply side) bracket on which a hydraulic pressure for brake operation acts, and the bracket 4'is a fulcrum side (anchor side) bracket. In such a band brake, in the case where the oil groove 5 is provided in the lining and the oil discharge hole 6 is provided in the oil groove 5 in order to improve the oil discharge characteristic between the drum and the lining in the process of fastening the band brake. There is. The action of the brake band will be briefly described with reference to FIG. 4. The brake band 7 surrounds the drum 1, and when the brake is operated, hydraulic pressure is applied to the bracket 4 on the Apply side to tighten the brake band. Reference numeral 4'denotes an anchor side bracket on the opposite fulcrum side. FIG. 5 is an enlarged view showing the structure of the conventional brake band on the apply side, where 1 is a drum and 2 is a drum.
Is a lining, 3 is a strap, 4 is a bracket, 8 is a strut for hydraulically pushing the bracket 4, 9 is a caulking pin for caulking the bracket 4 to the strap 3, and the caulking pin 9 forms a caulking portion 10. As a result, the lining 2 has a convex bulge in the inner diameter direction around the caulking portion 10 due to the bulging of the caulking pin 9, as shown in FIG. The convex swelling of the lining around the caulked portion has a great influence, and the friction torque of the brake band increases.

FIG. 7 shows the torque curve when the band is fastened, with the vertical axis representing the friction torque T and the horizontal axis representing the time t, and the torque curve in the conventional brake band is shown by the chain double-dashed line B. Regarding the lubrication state, the α region at the initial stage of meshing can be divided into a fluid lubrication region, the β region at the middle stage of meshing can be divided into a mixed lubrication region, and the γ region at the final stage of meshing can be divided into a boundary lubrication region. In this meshing region, especially in the friction characteristics of the α region and the β region, the influence of the convex swelling of the lining tip portion is large (the solid line A indicates that a constant torque curve is obtained by the present invention as described later). It shows.).

[0005]

The above-mentioned increase in the friction torque becomes remarkable especially when the drum rotating in the leading direction is tightened and the convex ridge of the lining on the Apply side is large. Therefore, the torque values in the α and β regions vary depending on the degree of swelling at the end of the lining. Also, this excitement is
Since the brake band becomes smaller as it is used, the torque value changes with the lapse of time, resulting in a decrease in reliability. Conventionally, in order to eliminate this point, the lining end surface of the brake band, or
The chamfering of the lining (reference numeral 23 in FIG. 6) was carried out from the end surface of the reininge to around the first caulking portion between the bracket and the strap (the portion indicated by reference numeral 24 in FIG. 4).

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention solves the above problems by crimping a bracket of the same shape or a different shape to both ends of a curved thin strut with an adhesive, and bending the curved bracket. In a brake band in which a thin friction material is adhered to the inner circumferential surface of the strap, the first row of the connection between the bracket and the strap is melted and connected between the parts, as typified by spot welding. By using such a melted material for fixing between the parts, a joining method is adopted in which no convex portion is formed on the inner peripheral surface of the strap to which the friction material is adhered. Further, a joining method is adopted in which a convex portion does not occur on the inner peripheral surface of the strap for adhering the friction material by spot welding or the like between the bracket tip portion and the bracket rising portion serving as a fulcrum of the bracket. The change in torque value due to the convex bulge at the end of the lining as described above uses the conventional caulking connection lining by using the caulking connection of the bracket part that uses a machining method that does not generate a protrusion on the strut surface such as by Sbot welding. It is possible to solve the problem that the elastic deformation due to the convex bulge and the high density is hindered, and the change in the performance due to the variation in the chamfer size can be prevented.

The point of concern of the present invention is that the strength of the joint portion between the bracket and the strap is reduced. However, when the strength of the brake band is pressed against the bracket, or when a reaction force acts on the fulcrum or point of action of the bracket, a moment is applied to the bracket. Works, and the load concentrates on the joints in the last row.
Therefore, there is no problem even if a joining method, in which the joining method of the tip portions is represented by spot welding, is performed after the parts are melted and then joined. Therefore, the present invention minimizes the effect of the decrease in overall strength and stabilizes the torque capacity,
The heat resistance and durability are improved.

[0008]

1 shows the apply side of a brake band according to a first embodiment of the present invention, in which 1 is a brake drum, 2 is a lining, 3 is a strobe, 4 is a bracket, and 8 is a bracket 4. Struts, 9 are spot weldings in the first row for joining the strap 3 and the bracket 4, and 10 are crimping pins in the last row for crimping the strap 3 and the bracket 4. Further, R indicates the rotation direction of the drum. In addition, 9'is spot welding of another row, 1
0'indicates the caulking pins in the other row. By spot welding the joining of the tip portions of the strap 3 and the bracket 4 in this way, no convex swelling occurs at the tip portion of the lining 2, so that the torque value changes over time and the reliability is impaired. There is no such thing. FIG. 7 shows the change over time in friction torque. The solid line A shows the brake band according to the present invention, and the two-dot chain line B shows the conventional brake band.
In the invention, from the α region at the initial stage of meshing to the γ at the final stage of meshing
It can be seen that the friction torque is substantially constant up to the region. Then, when the strength of the joint between the bracket and the strap is required, the last row where the load concentrates is the conventional caulking joint to minimize the effect of the strength decrease due to spot welding of the tip. In addition, the torque capacity can be stabilized and the heat resistance and durability can be improved.

FIG. 2 shows a second embodiment, and the same reference numerals as those in FIG. 1 indicate the same parts. In the example of the present invention, the tip end of the strap 3 of the bracket 4 is welded (both sides between the bracket tip part and the bracket bulge part are welded in order to increase the welding length in terms of strength). In some cases, reference numeral 11 is a welded portion.). By eliminating the convex portion generated on the strap or the convex bulge or high density portion generated on the tip of the lining, uniform contact can be secured up to the end, and the change in torque capacity over time and design torque Contrary torque waveforms do not increase or decrease and become flat, and variations in individual qualities can be suppressed. Further, although only the Apply side is illustrated in the description of the embodiments, providing the anchor side also leads to more stable quality. Further, as a matter of course, the rotating direction of the drum may be reversed from the example shown in the drawing depending on the use conditions, so that the effect on the anchor side may be high.

[0010]

The brake band according to the present invention has the above-mentioned construction, and the bracket and the tip portion of the strap are connected by a welding method such as spot welding or the like in which a convex portion is not formed on the inner surface of the strap. It is possible to obtain stable torque capacity and improved heat resistance and durability without generating a convex swelling or a high density portion of the lining due to the caulking connection. In addition, it was possible to prevent changes in performance due to variations in the chamfering size of the lining.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a brake band.

FIG. 4 is an explanatory view of the operation of the brake band.

FIG. 5 is an enlarged view of a main part of a conventional brake band.

FIG. 6 is a diagram showing a conventional example.

FIG. 7 is a diagram showing a change over time in friction torque.

[Explanation of symbols]

 1 Brake Drum 2 Lining 3 Strap 4 Bracket 5 Oil Groove 6 Oil Discharge Hole 7 Brake Band 8 Strut 9 First Row Spot Weld 9'Other Row Spot Weld 10 Last Row Caulking Pin 10 'Other Row Caulking Pin 11 Weld 21 21 Tip 23 Chamfer 24 Bracket rise from the bracket tip

Claims (2)

[Claims] 1. A brake band in which a bracket of the same shape or a different shape is caulked to both ends of a curved thin strap with an adhesive, and a thin friction material is adhered to the inner peripheral surface of the curved strap. Adhesion of friction material by using the joining method such as spot welding in which the first row of joining of bracket and strap is melted between parts and joining, or by using melted material such as ordinary welding for fixing parts The brake band is characterized in that the connecting method is such that no convex portion is generated on the inner peripheral surface of the strap. 2. When connecting the bracket and the strap of the brake band, to the inner peripheral surface of the strap for adhering a friction material by spot welding or the like between the tip of the bracket and the bracket rising portion serving as the fulcrum of the bracket or the fulcrum. A brake band characterized by a coupling method that does not generate a convex portion.