JP2002130343A - Brake band, method for manufacturing thereof, and adhesion fixture for brake band manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a lining even in case when materials of high porosity are used. SOLUTION: A brake band 10 which is used for braking or releasing of a cylindrical clutch drum of an automatic transmission comprises an annular strap and a lining 13. The lining 13 is fixed on the inside face of the strap 12 and is provided with an oil groove 13a extending in circumferential direction. At least a part (20A) of the periphery of the oil groove 13a of the lining 13 has a higher density than the other part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brake band,
In particular, it relates to a brake band for braking or releasing a cylindrical clutch drum of an automatic transmission.

[0002]

2. Description of the Related Art In an automatic transmission, a plurality of clutch devices and a brake band are provided in order to perform automatic shifting. Further, these clutch devices and brake bands are wet type, that is, hydraulic oil (A
TF).

[0003] A brake band is provided on the outer periphery of a clutch drum constituting a clutch device, and is formed by winding a band-like member into a substantially circular shape, a lining fixed to the inner peripheral surface of the strap, and a strap. And a pair of brackets fixed to both ends of the bracket.

In such a brake band device, the lining is strongly wound around the outer peripheral surface of the clutch drum by moving the pair of brackets so as to approach each other, thereby braking the rotation of the clutch drum.
Then, when the rotation of the clutch drum is stopped, the clutch device is brought into the connected state, and the speed change is performed.

[0005] In order to improve the oil discharge characteristics between the drum and the lining during the tightening process of the brake band, a plurality of oil discharge holes are formed in the brake band. Further, an oil groove is formed in the lining. The oil groove is
A notch formed by punching in the lining and extending long in the rotational direction, and a part thereof overlaps the oil discharge hole.

[0006]

In recent years, in order to improve the performance of a brake band, a low-density lining material having a high porosity has been used.

On the other hand, when a material having a high porosity is used, the strength of the lining is reduced. For this reason, it is assumed that chipping or peeling occurs in, for example, a portion around the oil groove of the lining. The peeling of the lining increases the variation in the fastening torque of the brake band.

[0008] It is an object of the present invention to improve the durability of the lining even when a material having a high porosity is used.

[0009]

According to the present invention, there is provided a brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, which comprises an annular strap and a lining. . The lining is
It has a groove fixed to the inner surface of the strap and extending in the circumferential direction. At least a portion of the lining around the groove is denser than other portions. The “other part” here refers to a part that functions as a friction surface of the lining.

[0010] In this brake band, at least a portion around the groove of the lining has a high density.
While the brake performance as a whole is maintained, peeling or the like at the portion around the groove is less likely to occur.

[0011] In the brake band according to the second aspect, in the first aspect, the part is one end in a circumferential direction of the groove.
In this brake band, at least the circumference of one end in the circumferential direction of the groove is higher in density than the other parts, so that it is most effective in preventing the lining from peeling off.

According to a third aspect of the present invention, there is provided a brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, the brake band including an annular strap and a lining. The lining has a circumferentially extending groove secured to the inner surface of the strap. The whole area around the groove of the lining is denser than other parts.

In this brake band, peeling is hard to occur around the entire groove. According to a fourth aspect of the present invention, there is provided a brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, the brake band including an annular strap and a lining. The lining is fixed to the inner surface of the strap. At least one circumferential edge of the lining is denser than the other parts.

In this brake band, at least one circumferential edge of the lining has a higher density than the other portion, so that peeling or the like at the circumferential edge hardly occurs. In the brake band described in claim 5, in claim 4, the circumferential side edges of the lining have a higher density than other portions.

In this brake band, since the circumferential side edges of the lining are denser than other portions, peeling or the like at the circumferential side edges hardly occurs. A method of manufacturing a brake band according to a sixth aspect is a method of manufacturing a brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, and includes the following steps.

◎ Preparation step for preparing an annular strap and lining ◎ Adhesion step of winding the strap and lining around the outer peripheral surface of a cylindrical bonding jig and bonding them together ◎ Densification to increase the density of a part of the lining Process In this method of manufacturing a brake band, since the density of a part of the lining is high, peeling or the like at a predetermined portion is less likely to occur while maintaining the overall braking performance.

According to a seventh aspect of the present invention, in the sixth aspect, the high density step is performed simultaneously with the bonding step. In this manufacturing method, since the density of a part of the lining is increased simultaneously with the bonding of the strap and the lining, the manufacture of the brake band is easy.

An adhesive jig for producing a brake band according to claim 8 is an adhesive jig for producing a brake band for adhering an annular strap and a lining to each other,
It has a cylindrical body. The main body has an outer peripheral surface around which the strap and the lining are wound, and a projection formed on the outer peripheral surface for increasing the density of a part of the lining.

When this jig is used, the strap and the lining are wrapped around the outer peripheral surface and adhered to each other, and a part of the lining is crushed by the projection to increase the density. As described above, since the density of a part of the lining increases simultaneously with the bonding of the strap and the lining, the manufacture of the brake band is easy.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment (1) Configuration FIG. 1 shows a longitudinal sectional view of a brake band device 1 to which an embodiment of the present invention is adopted.

The brake band device 1 includes a brake band 10 that abuts on the outer periphery of a clutch drum (not shown) constituting the clutch device to brake the drum, and one end 10a of the brake band 10 to the other end 10a of the brake band 10.
b, the piston stem 5 for bringing the inner peripheral surface of the brake band 10 into contact with the clutch drum, the anchor stem 6 for fixing the other end 10b of the brake band 10 to the housing 9, and the piston stem 5 operating. And a driving unit 2 for causing the driving unit 2 to operate.

The drive section 2 has a plurality of oil chambers, and the movement of the piston stem 5 is controlled by supplying hydraulic oil to each oil chamber or draining hydraulic oil from each oil chamber. It has become.

Next, based on FIG.
0 will be described in detail. As shown in FIG. 2, the brake band 10 includes a strap 12 for tightening the surface of the clutch drum, a lining 13 that can abut on the outer peripheral surface of the clutch drum, and a pair of straps 12 fixed to both ends of the strap 12. It has brackets 14a and 14b.

The strap 12 is a belt-shaped steel material formed in an arc shape. The strap 12 is made of, for example, 0.5 to 0.75 mm thick spring steel made of SK5. The strap 12 has a plurality of through holes 12a for allowing oil on the clutch drum surface to escape in the circumferential direction. Is formed.
The through holes 12a are circular and are arranged at regular intervals in the circumferential direction near the center in the width direction.

As shown in FIG. 2, the lining 13 has a circumferential direction and a width direction orthogonal to the circumferential direction.
This is a belt-shaped friction member having a thickness of about 1 mm and formed to a length similar to that of the belt-shaped friction member. The lining 13 is connected to the strap 12
Is attached to the inner peripheral surface of the clutch drum and can be brought into contact with the clutch drum. The lining 13 is a strap 1
Similarly to 2, a plurality of oil grooves 13a are formed in the circumferential direction for releasing the lubricating oil on the clutch drum surface. The oil grooves 13 a have a long hole shape extending in the circumferential direction, and are arranged at equal intervals in the circumferential direction near the center in the width direction of the lining 13. In this embodiment, the oil grooves are arranged on a straight line, but a plurality of oil grooves may be arranged in the width direction. Oil groove 13
“a” is provided so that when the lining 13 is attached to the strap 12, a part of the lining 13 overlaps with the through hole 12a provided in the strap 12. Specifically, the through hole 12
a is located at the center of the oil groove 13a. Thereby, the through hole 12a communicates with the inside of the brake band 10, and the lubricating oil on the clutch drum surface can be discharged to the outer peripheral direction of the brake band 10 through the through hole 12a.

The oil groove 13a is a portion punched in the axial direction, and exposes the inner surface of the strap 12 at that portion. That is, the oil groove 13a is
Is a shallow groove with the inner side surface as the bottom surface and the cross section of the lining 13 as the side surface.

The material of the lining 13 will be described.
The lining 13 is a wet friction member containing at least a fiber component and a thermosetting resin component. First, raw paper is manufactured by blending various friction modifiers and the like with natural pulp and organic synthetic fibers and making paper. Next, the raw paper is impregnated with a binding resin such as a phenolic resin and cured to complete the lining. As a result, the lining 13 in the present embodiment has a void of 50% or more in the entire volume, that is, the porosity is 50% or more. In addition, although the porosity of the lining 13 is generally 35 to 65%, in the present invention, a lining composed of a low-density material having a porosity of 50% or more, more preferably 50 to 65% is used. Is preferred.

In the lining 13, a high density portion 20A is formed around the oil groove 13a. Oil groove 1
The portion around 3a refers to the groove edge and a fixed portion outside the groove edge. The high-density portion 20A is formed around the entire circumference of the oil groove 13a and has a constant width. High density part 20
A has a higher density than other portions, and has improved durability. The high-density portion 20A is densified by being crushed in a manufacturing method described later, and has a slightly lower and concave shape than other portions. High density part 2
The plate thickness T2 of 0A (the thickness of the portion in contact with the oil groove 13a) is
The thickness is preferably in the range of 98 to 50% of the thickness T1 (finished thickness) of the other portions, and more preferably in the range of 95 to 75%. Accordingly, the porosity of the high-density portion 20A decreases and becomes lower than the porosity of the other portions.

The width B of the high-density portion 20A is the oil groove width A.
It is preferable not to exceed 1.5 times. If it exceeds this, the range of the high-density portion 20A becomes too wide, that is, the portion functioning as a friction surface becomes too narrow, and the friction coefficient may not be sufficient. There is no problem if the width of the high-density portion 20A is small, including at least the edge portion of the oil groove 13a. Even if the width B is about 10% of the oil groove width A, a sufficient effect is exhibited.

The brackets 14a and 14b are metal members and are fixed to the outer peripheral surfaces at both ends of the strap 12. The brackets 14a and 14b are members made of, for example, S50C and having a thickness of about 2.3 mm. Bracket 14
Is a stopper 14 in which a part of the bracket 14 is folded back.
c and a plurality of holes 14d formed in the surface of the bracket 14.
And (2) Operation Next, the operation will be briefly described.

Here, the operation of the brake band device 1 will be particularly described. When clutch switching is specified,
The operating oil pressure is transmitted to the drive unit 2 and the piston stem 5
Moves in the clutch drum direction under the control of the drive unit 2. At this time, the piston stem 5 is
0 is pressed so as to approach one end 10a of the brake band 10 to the other end 10b of the brake band 10. Then, since the other end 10b of the brake band 10 is fixed by the anchor stem 6, the diameter of the brake band 10 is reduced and the brake band 10 comes into contact with the outer peripheral surface of the clutch drum. As a result, the clutch drum is braked by friction between the brake band 10 and the clutch drum, and the clutch drum stops. Thus, the clutch device is brought into the connected state.

In the above operation, the ATF existing on the outer peripheral surface of the clutch drum is discharged from the through hole 12a to the outside of the brake band 10, but the AT that cannot be completely discharged is removed.
F flows through the oil groove 13a on both sides in the longitudinal direction. At this time A
The TF collides with the side surface of the oil groove 13a. However, since the strength of the side surface of the oil groove 13a is improved by the high-density portion 20A as described above, the edge portion of the oil groove 13a is not easily chipped or peeled. In particular, the ATF flows on both sides in the longitudinal direction and collides most strongly with the longitudinal end of the oil groove 13a, but since the high-density portion 20A is also formed in that portion, chipping or peeling is unlikely to occur.

On the other hand, the portion other than the edge of the oil groove 13a is a low-density portion having a high porosity, so that the coefficient of friction with the clutch drum is sufficiently high. That is, a sufficiently high fastening torque can be obtained.

Next, when the clutch device shifts from the engaged state to the designated shift state, the piston stem 5 is controlled by the drive unit 2 to move in the direction opposite to the clutch drum, and accordingly, the brake band 10 One end 10a also moves in the direction opposite to the clutch drum. Then, the diameter of the brake band 10 expands to release the clutch drum. (3) Referring to FIGS. 5 and 6, a method of manufacturing the brake band 10, in particular, the lining 1
The step of bonding 3 will be described in detail.

First, the strap 12 and the lining 13
Prepare At this time, the through hole 12a has already been formed in the strap 12, and the oil groove 13a has been formed in the lining 13.

Next, a bonding jig 31 is prepared. Jig 3
Reference numeral 1 denotes a columnar member having an outer peripheral surface 31a and a plurality of protrusions 31b formed thereon. Multiple protrusions 3
1b slightly protrudes in the radial direction from the outer peripheral surface 31a, and is smoothly curved in a radial longitudinal section so as to form, for example, a part of a circle. The plurality of protrusions 31b extend in the circumferential direction and correspond to the oil grooves 13a of the lining 13. However, the projection 31b is generally larger than the oil groove 13a. Specifically, the protrusion 31b is slightly larger than the oil groove 13a in the width direction and the longitudinal direction.

In the bonding step, as shown in FIG. 6, the lining 13 is arranged around the outer peripheral surface 31a of the jig 31, and the strap 12 is arranged around the periphery. An adhesive is disposed between the lining 13 and the strap 12. In this state, the strap 12 and the lining 13 are strongly wound around the jig 31. This operation is similar to the operation of fastening the brake band 10 as a finished product to the drum. As a result, the strap 12 and the lining 13 are bonded to each other. Further, the projection 31b crushes a portion of the lining 13 around the oil groove 13a.

With the above manufacturing method, the strap 12
And the lining 13 are adhered to each other, and at the same time, a high-density portion 20A is formed around the oil groove 13a of the lining 13, which facilitates manufacture. Second Embodiment As shown in FIG. 7, the high-density portion provided in the lining 13 may be formed only in a part around the oil groove 13a. The high-density portions 20B are formed at portions corresponding to both ends in the longitudinal direction of the oil groove 13a. Thus, even if the high-density portion 20B is formed only at a part of the edge of the oil groove 13a, the same effect as the conventional one can be obtained. It is oil groove 1
This is because, in 3a, the portion where peeling is most likely to occur is the end in the longitudinal direction where the ATF collides most severely, and improving the strength of that portion is the most effective measure against peeling. Third Embodiment As shown in FIG. 8, the high-density portion 20B is formed only on one side in the longitudinal direction (one end in the circumferential direction) of the oil groove 13a.
The high-density portion 20B is a part of the AT that flows in one direction due to rotation of the clutch drum when the brake band 10 is not fastened.
It has a function necessary as a measure against separation of F. In this case, the strength of the end of the oil groove 13a on the side where the high-density portion 20B is not formed is not improved, but a sufficient effect may be ensured depending on the type and use of the brake band 10. . Fourth Embodiment As shown in FIG. 9, a high-density portion provided in the lining 13 may be formed at the longitudinal end. The high-density portion 20C is formed to extend along the width direction. For this reason, peeling at the end of the lining 13 is unlikely to occur. Fifth Embodiment As shown in FIG. 10, the high-density portion 20A of the first embodiment and the high-density portion 20C of the third embodiment may be formed on the same lining 13. In this case, both excellent effects can be obtained. Sixth Embodiment As shown in FIG. 11, the high-density portion 20B of the second embodiment and the high-density portion 20C of the third embodiment may be formed on the same lining 13. In this case, both excellent effects can be obtained. [Other Embodiments] The shape and position of the oil groove are not limited to those in the above embodiment.

[0039]

In the brake band according to the present invention, since the density of at least a portion around the groove of the lining is high, peeling or the like at the portion around the groove hardly occurs while maintaining the overall braking performance. Has become.

[0040]

[Brief description of the drawings]

[0041]

FIG. 1 is a longitudinal sectional view showing a brake band device to which an embodiment of the present invention is applied.

[0042]

FIG. 2 is a perspective view showing the entire brake band.

[0043]

FIG. 3 is a perspective view showing a part of a brake band.

[0044]

FIG. 4 is a vertical sectional view taken along the line IV-IV in FIG. 3;

[0045]

FIG. 5 is a perspective view of a bonding jig.

[0046]

FIG. 6 is a partial cross-sectional view for explaining a step of bonding the strap and the lining.

[0047]

FIG. 7 is a partial plan view of a brake band according to a second embodiment.

[0048]

FIG. 8 is a partial plan view of a brake band according to a third embodiment.

[0049]

FIG. 9 is a partial plan view of a brake band according to a fourth embodiment.

[0050]

FIG. 10 is a partial plan view of a brake band according to a fifth embodiment.

[0051]

FIG. 11 is a partial plan view of a brake band according to a sixth embodiment.

[0052]

[Explanation of symbols]

 Reference Signs List 1 brake band device 10 brake band 12 strap 12a discharge hole 13 lining 13a oil groove 20A to 20C high density part

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[Procedure amendment]

[Submission date] November 9, 2000 (200.11.
9)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Added

[Correction contents]

FIG. 11

Claims (8)

[Claims] 1. A brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, comprising: an annular strap; and a lining fixed to an inner surface of the strap and having a groove extending in a circumferential direction. A brake band, wherein at least a portion of the lining around the groove is denser than other portions. 2. The part is a circumferential end of the groove,
The brake band according to claim 1. 3. A brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, comprising: an annular strap; and a lining fixed to an inner surface of the strap and having a groove extending in a circumferential direction. A brake band, comprising: the entire periphery of the groove of the lining is denser than other parts. 4. A brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, comprising: an annular strap; and a lining fixed to an inner surface of the strap, at least a circle of the lining. One side edge in the circumferential direction is denser than other parts, brake band. 5. The brake band according to claim 4, wherein the circumferential side edges of the lining are denser than other portions. 6. A method of manufacturing a brake band for braking or releasing a cylindrical clutch drum of an automatic transmission, comprising: a step of preparing an annular strap and a lining; and bonding the strap and the lining in a cylindrical shape. A method of manufacturing a brake band, comprising: a bonding step of winding the jig around an outer peripheral surface and bonding the jigs to each other; and a densification step of increasing a density of a part of the lining. 7. The method for manufacturing a brake band according to claim 6, wherein said densification step is performed simultaneously with said bonding step. 8. An adhesive jig for manufacturing a brake band for adhering an annular strap and a lining to each other, comprising: a cylindrical main body; wherein the main body has an outer peripheral surface around which the strap and the lining are wound; A bonding jig for manufacturing a brake band, comprising: a projection formed on the outer peripheral surface to increase a density of a part of the lining.