JP3082573B2 - Brake band - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake band used in a vehicle automatic transmission and the like.

[0002]

2. Description of the Related Art In an automatic transmission such as an automobile, a gear shift is performed by connecting and disconnecting input elements of a planetary gear train and fixing and releasing a reaction force element. Band brakes are used in addition to one-way clutches and the like. In particular, band brakes can provide higher static torque capacity than multi-plate brakes of the same size, and because the torque capacity varies depending on the direction in which the drum is braked, the shift characteristics that are favorable as a release element in upshifts can be obtained Therefore, it is widely used as a reaction force element. Such a band brake is used in an ATF (Automatic Transmission Fluid) as a lubricating oil together with other transmission mechanism elements.

FIG. 19 is an explanatory view showing a general structure of this type of band brake.

In FIG. 19, reference numeral 1 denotes a brake drum which is an engagement element, and 2 denotes a brake band. The brake band 2 includes a flexible back metal 3 formed in a band shape from a thin steel plate or the like, and a wet friction material 4 adhered to almost the entire inner peripheral surface. In general, a paper-based friction material is used. Brackets 5 and 6 are provided at both ends of the back metal 3 of the brake band 2, and both ends of the brake band 2 are connected to the servo actuator 7 and the anchor 8 via these brackets 5 and 6, respectively. And the servo actuator 7
, And the operating force is applied to one end of the brake band 2 via the apply side bracket 5, whereby the brake band 2 is tightened around the drum 1 and engages with the drum 1. As shown in the drawing, the direction of rotation of the drum 1 is "forward rotation" is a rotation direction in which the brake band 2 is in a leading state and a self-tightening (self-energy) action is exerted thereon, and "reverse rotation" is This is the rotation direction in which the brake band 2 enters the trailing state, and the anti-tightening (deenergization) action acts on this.

[0005] Fig. 20 shows an example of a conventional brake band 2 used for such a band brake.
That is, it is a perspective view shown from the friction engagement surface side. In FIG. 20, the side to which the actuation force of the actuator 7 is applied (apply side) is shown on the left side, and the side locked to the anchor 8 (anchor side) is shown on the right side.

[0006] As shown in FIG.
In order to discharge oil (oil film) between the drum 1 and the wet friction material 4 during the braking operation to the outside of the friction engagement region, it is usual to provide an oil groove 9 and an oil hole 10. The oil groove 9 is generally formed by punching out and cutting out the wet friction material 4. For this reason, the back metal 3 is exposed in the portion where the oil groove 9 is provided. The oil grooves 9 are usually provided at appropriate intervals along the length direction of the band 2. The oil hole 10 is formed in the back metal 3 in communication with the oil groove 9, and is generally provided at the center in the length direction of the oil groove 9. By providing such an oil groove 9 and an oil hole 10, oil (oil film) between the drum 1 and the wet friction material 4 is discharged to the outer peripheral side of the back metal 3 via the oil groove 9, and as a result, the brake band 2 and the drum 1 is improved, and the engagement torque of the brake is increased. In addition, in FIG.
For the alignment when bonding the wet friction material 4 with
It is a center hole formed therethrough. This center hole 11 also promotes oil discharge between the drum 1 and the wet friction material 4.

[0007] These oil grooves 9 and oil holes 1
0 are arranged so as to be evenly distributed in the length direction of the brake band 2, so that the patterns on the apply side and the anchor side are formed symmetrically with respect to the center.

[0008]

As described above, by providing the brake band with the oil discharging means such as the oil groove and the oil hole, the oil (oil film) discharging characteristic between the wet friction material and the drum during the braking operation can be improved. That is, the oil film breaking characteristics are improved, and the engagement torque can be increased. At the same time, the oil discharge characteristics increase as the sum of the opening areas of the oil discharge means increases, and the oil discharge characteristics decrease as the sum of the open areas decreases. By increasing or decreasing
The engagement torque can also be adjusted by changing the oil discharge characteristics.

When the brake drum, which is an engagement element of the brake band, is used in normal rotation and reverse rotation, a self-energy action generates an engagement torque higher than the actual operating force during normal rotation, and conversely, during reverse rotation. An engagement torque lower than the actual operating force is generated by the deenergization action. The difference in engagement torque between the forward rotation and the reverse rotation as described above makes it possible to obtain favorable shift characteristics such as smooth upshifting.

However, the difference between the engagement torque at the time of forward rotation and the engagement torque at the time of reverse rotation generally tends to be too large from an ideal point of view. That is, if the engagement torque at the time of forward rotation is optimally set, the engagement torque at the time of reverse rotation will be insufficient, and sufficient quick engagement will not be obtained. In such a case, there is a tendency that the engagement torque at the time becomes excessive, a sufficiently smooth engagement cannot be obtained, and a shift shock occurs.

Conversely, depending on the type of automatic transmission, etc., especially when the drum brake is operated with a relatively low operating force, the difference in engagement torque between forward rotation and reverse rotation tends to be too small. There were cases.

In such a case, optimizing both the engagement torque at the time of normal rotation and the rotation at the time of reverse rotation means that the operating force applied to the brake band is controlled independently during the normal rotation and the reverse rotation. It is possible. However, such control is actually quite difficult and also leads to a significant increase in the cost of the device.

On the other hand, as a prior art of this kind, Japanese Utility Model Laid-Open No.
-47559, Japanese Utility Model Laid-Open No. 2-103534, etc.
Technology.

Japanese Utility Model Laid-Open Publication No. 5-47559 discloses a brake system.
Braking on the lining bonded to the inner surface of Kiband
When the ram rotates in one direction, oil is applied when the brake is applied.
Forms a sump and in the other direction of rotation, the oil is eliminated
The technology for providing oil grooves, oil sumps, etc. is disclosed.
ing. However, in this type of technology, the engagement torque during forward rotation is reduced.
If the torque is set optimally, the engagement torque during reverse rotation will be insufficient.
And sufficient quick engagement cannot be obtained.
If the torque is set optimally, the engagement torque during forward rotation will be excessive.
And it is not possible to obtain a sufficiently smooth engagement.
Problems such as occurrence will not be solved.

In Japanese Utility Model Laid-Open No. 2-103534,
Is the lining near the end of the brake drum on the apply side.
The entire area of the oil discharge means in the area is near the anchor end
Larger than the total area of the oil discharge means in the lining area of
Disclosed is a brake band that is characterized by a sharpness.
However, according to experiments by the inventors, the brake drum
The meaning near the ply side end is unknown, but
Oil near the edge in the lining area near the anchor side edge
Engagement during normal rotation, even if it is larger than the total area of the
If the torque is set optimally, the engagement torque during reverse rotation will be insufficient.
The engagement torque cannot be obtained quickly enough,
If the torque is set optimally, the engagement torque during forward rotation will be excessive.
Solves the problem that a sufficiently smooth engagement cannot be obtained.
The characteristics could not be changed to such an extent that they could be erased.

Therefore, the present invention provides a brake drum having a normal rotation.
Brake that can set the difference in engagement torque between
The purpose is to provide Kiband.

[0017]

A breaker according to claim 1.
The band has a band-shaped flexible backing metal and the backing metal.
The wet friction material adhered to the inner peripheral surface
Oil between the brake drum and the wet friction material
Discharge outside the engagement area, and
The oil discharge characteristics are relatively high on the anchor side
Brake band with oil drain means
The oil discharging means is formed on the wet friction material.
Oil groove, which is formed in the back metal in communication with the oil groove.
Oil hole, the wet friction material and the back metal
Including the formed through hole, the oil groove and the oil hole
Actuation force applied to at least one of the number, size and arrangement
In the longitudinal direction of the wet friction material and the back metal
By making the difference between the lie side and the anchor side,
It sets the oil discharge characteristics of the ply side and the anchor side.
is there.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have proposed an oil groove and an oil hole.
As a result of repeated studies focusing on the pattern of
The engagement characteristics at the time of brake operation are
Is mainly due to the oil drainage
Output characteristics, and when the brake drum rotates in reverse,
Mainly oil discharge characteristics by the oil discharge means on the anchor side
Was found to have an effect. And of the oil discharge means
Set the pattern appropriately between the apply side and the anchor side.
Independently controls the engagement torque during forward rotation and reverse rotation
Make sure you do.

Therefore, the pattern of the oil discharging means is changed.
The oil discharge characteristics are differentiated between the apply side and the anchor side.
Be relatively higher on the anchor side than on the apply side.
In other words, the oil discharge characteristics are set to the apply side rather than the anchor side.
By making it relatively low in the normal rotation and reverse rotation
That the difference in engagement torque at the time of
Also, the oil discharge characteristic is more on the apply side than on the anchor side.
Relatively high, i.e., improve oil discharge characteristics.
To make it relatively lower on the anchor side than on the rye side
Therefore, the difference between the engagement torque at the time of forward rotation and the torque at the time of reverse rotation is increased.
Confirmed that it can be done.

Therefore, the brake bar according to claim 1 is provided.
The band has a band-shaped flexible backing metal and an inner peripheral surface of the backing metal.
Adhesive wet friction material and vibration during braking
Oil between the drum and wet friction material outside the frictional engagement area
Oil discharging means for discharging, to which the operating force is applied
Oil discharge characteristics are different on the anchor side than on the apply side.
Oil drain means raised in height,
The oil discharge means is an oil groove or oil groove formed in the wet friction material.
Oil hole formed on the back metal in communication with the oil groove, wet friction material
And any of the through holes formed through the back metal
And their number, size, or arrangement
The difference between the applied side and the anchor side
The oil discharge characteristics compared to the applied side.
Can be relatively high on the
Relative to the apply side than the anchor side
Can also be higher. Therefore, the apply side and the
The oil discharge characteristics on the anchor side can be set .

For example, oil discharge by oil discharge means
Properties, anchor side from the Apply side actuating force is applied
Is relatively high in
The operating force is relatively low on the applied side.
So, as can be seen from the examples below,
It is possible to lower the engagement torque during forward rotation of the bouquet drum.
At the same time as increasing the engagement torque during reverse rotation of the brake drum.
Engagement between forward and reverse rotation
The difference in torque can be reduced. This is
The engagement characteristics during key operation are mainly
The oil discharge characteristics of the apply side affect the
When the drum is rotating in reverse, the oil discharge characteristics mainly on the anchor side
Because it has an effect.

Further , the oil discharging means is formed of a wet friction material.
Formed oil groove, formed on the back metal in communication with the oil groove
Through the oil hole, wet friction material and back metal
It shall consist of at least one of the through holes.
The number, size or arrangement of these oil drains
The difference between the applied side and the anchor side
The oil discharge characteristics compared to the applied side.
Relatively high on the tanker side (oil drainage
Output characteristics are relatively lower on the apply side than on the anchor side
), The engagement torque at the time of forward rotation and reverse rotation
The difference in luck can be reduced.

[0023]

Embodiments of the present invention will be described below.

First Embodiment FIG. 1 is a plan view showing a friction engagement surface of a brake band according to a first embodiment of the present invention, together with a conventional example and a comparative example. 1A shows the first embodiment, FIG. 1B shows a conventional example,
(C) is a comparative example.

In FIG. 1A, the same reference numerals as those of the conventional example shown in FIGS. 19 and 20 indicate the same or corresponding parts.
As in the conventional example, the brake band 2 of the present embodiment includes a band-shaped flexible backing metal 3 (only a part thereof appears on the rear side in the figure, so that the backing metal 3 is located on the inner peripheral surface side). That is, it is constituted by the wet friction material 4 adhered to almost the entire surface on the engagement surface side. The brake band 2 is formed with a total of four oil grooves 9 formed of notches of the wet friction material 4, and further, at the center of the oil grooves 9, oil holes 10 penetrating the back metal 3 are provided. Is formed. Also,
In the center of the brake band 2, a wet friction material 4 and a back metal 3
A center hole 11 for alignment at the time of adhesive bonding is provided through these.

In FIG. 1, the friction engagement surface of the brake band 2 has a side on which the actuation force of the actuator is applied (apply side) on the left side and a side on which it is locked by the anchor (anchor side). It is described on the right side (similarly in the following figures). The drawing also shows the direction of rotation of the brake drum, and the drum rotates in the direction from the anchor side to the apply side during normal rotation and in the direction from the apply side to the anchor side during reverse rotation.

These oil grooves 9 and oil holes 10 are
As described above, the oil (oil film) between the wet friction material 4 and the drum at the time of the braking operation is discharged out of the friction engagement region,
Thereby, the engagement characteristics between the brake band 2 and the brake drum are enhanced. Here, the present embodiment is based on the oil groove 9 and the oil hole 10 based on the conventional example of FIG. 1B in which the engagement torque at the time of reverse rotation of the drum under a predetermined operating force is an optimum value. Is changed to reduce the engagement torque during normal rotation of the brake drum by about 10%, so that an optimal feeling during shifting can be obtained.

That is, in the present embodiment, in the conventional brake band 2 of FIG. 1B, the length of the two oil grooves 9 located closer to the apply side than the center of the center hole 11 is set to 2
/ 3. For this reason, in the present embodiment, the pattern of the oil groove 9 is formed asymmetrically between the apply side and the anchor side about the center in the length direction of the band 2. The diameter of the oil hole 10 and others are the same as in the conventional example, and are symmetrical between the apply side and the anchor side.

The following Table 1 shows the brake band 2 of this embodiment.
2 shows the results of measurement of the engagement characteristics (initial engagement torque) of the conventional example and the comparative example. In the comparative example, as shown in FIG. 1C, the length of the conventional oil groove 9 in FIG. 1B is all ２.

[0030]

[Table 1]

As shown in the results of Table 1, according to the brake band of the present embodiment, the engagement torque at the time of normal rotation is reduced without reducing the engagement torque at the time of reverse rotation of the conventional brake band. Value could be reduced. On the other hand, in the comparative example (c) in which all of the oil grooves 9 are 2/3 of the conventional example, the engagement torque at the time of the forward rotation can be reduced to the target value, but at the same time, at the time of the reverse rotation, The engagement torque also decreased.

From the relationship between the pattern of the oil groove 9 and the engagement torque characteristic in these examples, the conventional example, and the comparative example, the engagement characteristic during normal rotation of the brake drum mainly depends on the pattern on the apply side. It can be seen that the pattern on the anchor side mainly affects the engagement characteristics at the time of reverse rotation of the brake drum. Therefore, by appropriately adjusting the pattern on the apply side and the pattern on the anchor side, the engagement characteristics of the brake drum during normal rotation and reverse rotation are independently controlled,
You can see that it can be set.

As described above, the brake band 2 of this embodiment is
Is a band-shaped flexible back metal 3, a wet friction material 4 adhered to the inner peripheral surface of the back metal 3, and an oil (oil film) between the wet friction material and the drum during braking operation. An oil groove 9 and an oil hole 10 are provided, and the area of the oil groove 9 is made different between the apply side to which the operating force is applied and the anchor side, and is larger on the anchor side than on the apply side (the apply side is larger than the anchor side). Side is smaller than the anchor side). For this reason, the oil discharge characteristic is enhanced on the anchor side rather than on the apply side (lower on the apply side than on the anchor side), and as a result, the difference in the engagement torque between the forward rotation and the reverse rotation of the drum can be reduced. As a result, the engagement torque during forward rotation of the drum can be reduced, and the engagement torque during reverse rotation of the drum can be maintained high. The adjustment of the engagement torque to the target value can be easily performed only by changing the opening area of the oil groove 9, and the engagement torque in either the forward rotation or the reverse rotation is optimal. By adjusting the engagement torque, it is easier to adjust the engagement torque.

As described above, by changing the pattern of the oil groove 9 between the apply side and the anchor side, the difference in the engagement torque between the forward rotation and the reverse rotation can be reduced. Value can be adjusted. Changing the pattern of the oil groove 9 between the apply side and the anchor side in this manner can be performed in various modes. A typical example is shown below.

Second Embodiment FIG. 2 is a plan view showing a friction engagement surface of a brake band according to a second embodiment of the present invention. In the figure, the same or corresponding parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 2, in the brake band 2 of this embodiment, the oil grooves 9 of the same size
One band is formed on the apply side and two on the anchor side from the longitudinal center of the band 2 provided with 1. The pattern of the oil groove 9 corresponds to the pattern of the oil groove 9 symmetrical to the left and right of the conventional brake band 2 shown in FIG.

As described above, since the number of the oil grooves 9 is smaller on the apply side than on the anchor side, the total opening area thereof is larger on the anchor side than on the apply side. Also the anchor side is higher. According to the present embodiment, similarly to the first embodiment, the engagement torque at the time of normal rotation can be reduced while maintaining the engagement torque at the time of reverse rotation.

Third Embodiment FIG. 3 is a plan view showing a friction engagement surface of a brake band according to a third embodiment of the present invention.

As shown in FIG. 3, the brake band 2 of this embodiment has two oil grooves 9 of the same size on the apply side and four on the anchor side. That is, the pattern of the oil groove 9 is different from the pattern of the oil groove 9 of the conventional brake band 2 shown in FIG. The number of oil grooves 9 is increased.

Therefore, according to the pattern of the oil grooves 9, the total opening area of the oil grooves 9 on the anchor side is increased, and the oil discharge characteristics on the anchor side are enhanced. Therefore, the engagement torque at the time of reverse rotation can be increased while maintaining the engagement torque at the time of drum forward rotation. By appropriately reducing the braking force, the first
It is possible to obtain substantially the same engagement torque value as in the embodiment.

Fourth Embodiment FIG. 4 is a plan view showing a friction engagement surface of a brake band according to a fourth embodiment of the present invention.

As shown in FIG. 4, the brake band 2 of this embodiment does not have the oil groove 9 formed on the apply side of the center of the band. Therefore, in the case of this embodiment,
The engagement torque during forward rotation can be reduced to the maximum. However, on the anchor side, as in the first and second embodiments, 2
Since the oil grooves 9 are provided, the engagement torque at the time of reverse rotation can be maintained as it is.

The oil grooves 9 of the first to fourth embodiments are formed in parallel to the length direction of the brake band 2, and such oil grooves 9 are formed in the width direction of the brake band 2. Or it can be formed inclined with respect to the length direction of the brake band 2.

Fifth Embodiment FIG. 5 is a plan view showing a friction engagement surface of a brake band according to a fifth embodiment of the present invention.

As shown in FIG. 5, the brake band 2 of this embodiment has a band-shaped flexible back metal 3, a wet friction material 4 adhered to the inner peripheral surface of the back metal 3, and An oil groove 9 and an oil hole 10 for discharging oil (oil film) between the wet friction material 4 and the drum are included. The oil groove 9 is formed in the wet friction material 4 as being inclined in the length direction of the brake band 2. The oil hole 10 is provided at the center of the oil groove 9 as in the previous embodiments.

The oil groove 9 inclined in the length direction of the brake band 2 can discharge oil between the wet friction material 4 and the brake drum in a wide range in the width direction. It has higher oil discharge characteristics compared to parallel oil grooves of the same size. In the present embodiment, the inclined oil groove 9 is
Two are provided on the apply side and three are provided on the anchor side from the center in the length direction. Therefore, the sum of the opening areas of the oil grooves 9 on the apply side from the center of the brake band 2 is smaller than the sum of the opening areas of the oil grooves 9 in the region on the anchor side. For this reason, similarly to the previous embodiments, the engagement characteristics at the time of forward rotation are relatively low mainly because the discharge characteristics at the apply side are dominant, and the engagement characteristics at the time of reverse rotation are mainly at the anchor side. Is relatively high due to the dominant emission characteristics of
The difference between the engagement torque at the time of forward rotation and the torque at the time of reverse rotation can be reduced.

Sixth Embodiment FIG. 6 is a plan view showing a friction engagement surface of a brake band according to a sixth embodiment of the present invention.

As shown in FIG. 6, in the brake band 2 of the sixth embodiment, the inclined oil grooves 9 are arranged in one direction in the fifth embodiment. Are sequentially changed and arranged in the length direction of the band 2. According to such an arrangement, it is possible to prevent a lateral force or a torsional force from being generated in the brake band 2 during frictional engagement with the brake drum. However, the arrangement as in the fifth embodiment is preferable in that the oil grooves 9 are uniformly distributed.

In this embodiment, two oil grooves 9 are provided on the apply side and four on the anchor side from the longitudinal center of the band 2. Therefore, the oil groove 9
The sum of the opening areas is twice as large on the anchor side as on the apply side, and the oil discharge characteristics on the anchor side are higher than on the apply side. Therefore, similarly, the difference between the engagement torque at the time of forward rotation and the torque at the time of reverse rotation can be reduced.

<Seventh Embodiment> FIG. 7 is a plan view showing a friction engagement surface of a brake band according to a seventh embodiment of the present invention.

As shown in FIG. 7, in the brake band 2 of the present embodiment, the oil groove 9 on the apply side relative to the longitudinal center of the band 2 is parallel to the longitudinal direction of the band 2.
The oil groove 9 on the anchor side is inclined with respect to the length direction of the band 2. In the above embodiments, the sum of the opening areas of the oil grooves on the anchor side is larger than that on the apply side, whereas in this embodiment, the size and number of the oil grooves 9 are different between the apply side and the anchor side. Therefore, the sum of the opening areas of the oil grooves 9 is also substantially equal. However, due to the difference in the arrangement of the oil grooves 9, the oil discharge characteristics on the anchor side are higher than on the apply side. Therefore, according to the present embodiment, similarly to the previous embodiments, it is possible to reduce the difference in the engagement torque between the forward rotation and the reverse rotation of the brake drum.

<Eighth Embodiment> FIG. 8 is a plan view showing a friction engagement surface of a brake band according to an eighth embodiment of the present invention.

According to the pattern of the oil groove 9 of the seventh embodiment, since the oil groove 9 having a high discharge characteristic is provided on the anchor side, the oil discharge characteristic on the anchor side can be made higher than that on the apply side. However, there is a limit to the extent to which it can be raised. Therefore, as shown in FIG. 8, in the brake band 2 of the eighth embodiment, the number of inclined oil grooves 9 on the anchor side is increased to four.

Therefore, according to the present embodiment, the sum of the opening areas of the oil grooves 9 on the anchor side is increased.
The engagement characteristics at the time of reverse rotation can be further enhanced as compared with the case of the seventh embodiment. Moreover, since the oil groove 9 on the anchor side has a high oil discharge characteristic which is inclined with respect to the length direction of the band 2, if the size is the same, the oil groove 9 is larger than that of the third embodiment of FIG. Therefore, a high engagement torque at the time of reverse rotation can be obtained.

In the above embodiment, the pattern of the oil groove 9 is different between the apply side and the anchor side.
The pattern of the oil holes 10 can also be changed.

<Ninth and Tenth Embodiments> FIG. 9 is a plan view showing engagement surfaces of brake bands according to ninth and tenth embodiments of the present invention, together with a conventional example and a comparative example.
9A shows the ninth embodiment, and FIG. 9B shows the first embodiment.
Example 0, (c) is a conventional example, and (d) is a comparative example.

As shown in FIGS. 9A and 9B, the ninth and the first
The brake band 2 according to the embodiment has a band-shaped flexible backing metal 3 and a wet friction material 4 as in the previous embodiments.
And oil grooves 9 and oil holes 10 serving as oil discharging means.
including. The ninth and tenth embodiments are similar to the first embodiment.
As in the case of the embodiment, the pattern of the oil discharging means is changed based on the conventional example of FIG. 9C, and the engagement during forward rotation is maintained while maintaining the engagement torque characteristic at the time of reverse rotation of the brake drum. The purpose is specifically to slightly reduce the torque.

For this reason, in the ninth embodiment of FIG. 9A, the diameter of the oil hole 10 on the apply side from the center of the brake band 2 in the conventional example of FIG. . In the tenth embodiment shown in FIG. 9B, the small-diameter oil hole 10 on the apply side in the ninth embodiment is further shifted toward the anchor side, and is arranged at the anchor-side end of the oil groove 9. It is. The size of the oil groove 9 is not changed, and these are formed symmetrically on the apply side and the anchor side with respect to the center of the band 2.

The brake band 2 of the comparative example shown in FIG. 9D in which the diameters of the oil holes 10 are all reduced to 1/3 with respect to the brake band 2 having these discharge means patterns.
At the same time, the engagement torque (initial engagement torque) was measured. The results are as follows.

[0060]

[Table 2]

As shown in the results of Table 2, the ninth,
According to the brake band of the tenth embodiment, without reducing the engagement torque at the time of reverse rotation of the conventional brake band,
The engagement torque during forward rotation could be reduced. In particular, according to the tenth embodiment (b), the required target value can be achieved. On the other hand, in the comparative example (d) in which the diameters of all the oil holes 10 were reduced to one third of the conventional example, the engagement torque at the time of the forward rotation could be reduced, but at the same time, the torque at the time of the reverse rotation was reduced. The engagement torque was also reduced.

As described above, in the brake band 2 of the ninth embodiment shown in FIG. 9A, in the first embodiment, the length (opening area) of the oil groove 9 on the apply side is smaller than that on the anchor side. On the other hand, the diameter (opening area) of the oil hole 10 on the apply side is smaller than that on the anchor side. Accordingly, also in this case, the oil discharge characteristics on the apply side, which particularly affect the engagement characteristics of the brake drum at the time of normal rotation, are reduced. Therefore, similarly to the first embodiment, the engagement of the brake drum at the time of normal rotation is reduced. The combined torque can be reduced, and the difference between the engagement torque at the time of forward rotation and the torque at the time of reverse rotation can be reduced.

In the brake band 2 of the tenth embodiment shown in FIG. 2B, the diameter (opening area) of the oil hole 10 on the apply side is reduced so that the oil discharge characteristic is reduced. The position of the oil hole 10 is defined as an end of the oil groove 9 on the anchor side. Therefore,
Since the oil hole 10 is arranged in this manner, when the brake drum rotates forward from the anchor side to the apply side, the oil is discharged in the oil groove 9 because it goes to the closed end on the apply side. It has become difficult. Therefore, at the time of forward rotation, the oil discharge characteristic of the apply side is further reduced, and the engagement torque at the time of forward rotation can be further reduced. At the time of reverse rotation, on the contrary, the oil discharge characteristics are enhanced, but the engagement torque at the time of reverse rotation is not substantially affected by the oil discharge characteristics of the apply side, and therefore does not substantially increase. By changing the arrangement of the oil holes 10 in this manner, the oil discharge characteristics of the apply side at the time of forward rotation can be made lower than that of the anchor side, whereby the difference in engagement torque between the forward rotation and the reverse rotation can be obtained. Can be reduced.

<Eleventh Embodiment> FIG. 10 is a plan view showing a friction engagement surface of a brake band according to an eleventh embodiment of the present invention.

The eleventh embodiment is a modification of the tenth embodiment shown in FIG. That is, as shown in FIG. 10, the brake band 2 of the present embodiment
In the tenth embodiment, the oil grooves 9 are provided at both ends of the oil grooves 9 whereas the oil grooves 9 are provided at the center. By providing the oil holes 10 at both ends of the oil groove 9 along the length direction of the band 2 in this manner, compared to a case where a single oil hole 10 having the same total area is provided at the center of the oil groove 9. As a result, a higher oil discharging effect can be obtained.

In this embodiment, the brake band 2
The sum of the opening areas of the oil holes 10 on the anchor side relative to the center in the length direction is larger than that on the apply side because of the large number of the oil holes 10, and therefore, the oil discharge characteristics are higher on the anchor side than on the apply side. . Moreover, the oil hole 10 on the apply side is formed at the end of the oil groove 9 on the anchor side so that the oil discharge characteristic at the time of forward rotation is low, as in the tenth embodiment. Therefore, according to the present embodiment, the same effects as in the tenth embodiment can be obtained.

<Twelfth Embodiment> FIG. 11 is a plan view showing a friction engagement surface of a brake band according to a twelfth embodiment of the present invention.

As shown in FIG. 11, the brake band 2 of the twelfth embodiment is formed so that the oil groove 9 is further deformed and one end thereof is released to the side end of the wet friction material 4. According to such an oil groove 9, the oil in the oil groove 9 is discharged from the open end to the outside of the frictional engagement region, so that the oil hole 10 is not necessary.

In the brake band 2 of the present embodiment, the oil groove 9 is formed obliquely in the direction of the apply side from the side end of the wet friction material 4 to substantially the center in the width direction thereof. They are arranged in a staggered manner in the length direction, that is, alternately left and right. An oil hole 9 is formed at the closed end of the oil groove 9 in a region on the anchor side from the longitudinal center of the band 2. On the other hand, no oil hole 10 is formed in the oil groove 9 on the apply side. Accordingly, the oil discharge characteristic of the anchor side is higher than that of the apply side having no oil hole 10, and the oil groove 9 of the apply side is closed at the end in the direction of the apply side. Low emission characteristics. Therefore, according to the present embodiment, the first
The same effects as those of the 0th and 11th embodiments can be obtained, and a brake band having a small difference in engagement torque between forward rotation and reverse rotation can be obtained.

<Thirteenth Embodiment> FIG. 12 is a plan view showing a friction engagement surface of a brake band according to a thirteenth embodiment of the present invention.

The brake band 2 of the thirteenth embodiment is a modification of the oil groove 9 of the twelfth embodiment. That is,
As shown in FIG. 12, the oil groove 9 of this embodiment has an L-shape, and is bent at a right angle from a groove portion parallel to the length direction of the brake band 2 and one end thereof to a side end of the wet friction material 4. And an open groove.

As in the case of the twelfth embodiment, the oil groove 9 in the region on the anchor side from the longitudinal center of the band 2 is used.
Has an oil hole 10 at its closed end, whereas the oil groove 9 on the apply side does not have an oil hole 10. The closed end of the oil groove 9 on the apply side is directed toward the apply side. Therefore, the effect of this embodiment is the same as that of the twelfth embodiment, and the difference in engagement torque between the forward rotation and the reverse rotation of the brake drum can be reduced.

<Fourteenth Embodiment> FIG. 13 is a plan view showing a friction engagement surface of a brake band according to a fourteenth embodiment of the present invention.

In the fourteenth embodiment, unlike the previous embodiments, the oil discharging means is formed as a through hole 12 formed through the wet friction material 4 and the back metal 3. Therefore, in FIG. 13, the back metal 3 of the brake band 2 does not appear on the surface. According to such a through hole 12, a high cooling effect of the friction engagement surface by oil can be obtained.

In the brake band 2 of the present embodiment, such through holes 12 are provided in a larger number in the region on the anchor side from the longitudinal center of the brake band 2 than in the region on the apply side. That is, the plurality of through holes 1
The sum of the opening areas of the oil discharge means 2 is larger on the anchor side than on the apply side, and the oil discharge characteristics are relatively higher on the anchor side than on the apply side.
Therefore, according to the brake band 2 of the present embodiment, similarly to the previous embodiments, the difference between the engagement torque at the time of normal rotation and the reverse rotation of the brake drum is reduced, and the engagement torque at the time of normal rotation is reduced. At the same time, the engagement torque at the time of reverse rotation can be increased.

The brake band of the present invention which can reduce the difference in engagement torque between the forward rotation and the reverse rotation of the brake drum will be described, and some typical embodiments will be described with respect to the oil discharging means and its pattern. However, the oil discharging means such as the oil groove 9, the oil hole 10, the through hole 12 and the like can be of any other shape, and the oil discharging means may be provided between the brake drum and the wet friction material during the braking operation. Any other oil may be used as long as the oil is discharged outside the friction engagement area.
For example, a hole formed when the bracket is provided on the back metal may be used. Any combination of these oil discharge means is possible.

The pattern composed of these oil discharging means indicates the number, size,
The arrangement and the like are asymmetrically different between the apply side and the anchor side with respect to the longitudinal center of the brake band, so that the oil discharge characteristics of the oil discharge means are relatively higher on the anchor side than on the apply side. Any pattern may be used. In particular, in the embodiment, the patterns of all the regions on the apply side or the anchor side from the center in the longitudinal direction of the brake band are different from each other, but the patterns of only some of these regions may be different from each other. However, the area range where the patterns are different from each other is preferably at least 1/3 or more, more preferably 1/2 or more, of half the length of the band from the end on the apply side or the anchor side. . Most preferably, the patterns of the entire region of half the length of the band, that is, the entire region on the apply side or the anchor side from the longitudinal center of the band are different from each other as in the embodiment. Thereby, a wider range of adjustment of the engagement characteristics is possible.

The purpose of these embodiments is to reduce the difference in engagement torque between the forward rotation and the reverse rotation of the brake drum. If the discharge means in the example is made opposite between the apply side and the anchor side so that the oil discharge characteristic is higher on the apply side than on the anchor side, the difference in the engagement torque between the forward and reverse rotation of the brake drum is reversed. It can be seen that it can be enlarged. This will be described below with reference to examples.

<Fifteenth Embodiment> FIG. 14 is a plan view showing a friction engagement surface of a brake band according to a fifteenth embodiment of the present invention.

As shown in FIG. 14, in the brake band 2 of the fifteenth embodiment, the pattern of the oil discharging means of the first embodiment of FIG. 1A is exactly opposite between the apply side and the anchor side. . That is, similarly to the first embodiment, the brake band 2 of the present embodiment includes a band-shaped flexible back metal 3, a wet friction material 4 adhered to the inner peripheral surface of the back metal 3, and an oil discharging means. And four oil grooves 9 formed in the wet friction material 4. An oil hole 10 penetrating the back metal 3 is formed at the center of each oil groove 9. Here, the two oil grooves 9 located on the anchor side from the center in the length direction of the band 2 having the center hole 11 are shorter in length than the oil groove 9 on the apply side, and are ／ of the length thereof. Is formed.
Therefore, the sum of the opening areas of the oil grooves 9 on the anchor side is 2/3 of that on the apply side, and the oil discharge characteristic on the anchor side is lower than that on the apply side.

The engagement characteristics (initial engagement torque) of this embodiment having the pattern of the oil groove 9 are as follows.
Was measured under the same conditions as in the first embodiment. As a result, the engagement torque at the time of normal rotation of the brake drum was 15 kg · m, and the engagement torque at the time of reverse rotation was 5 kg · m. As described above, the engagement characteristics during the forward rotation of the drum are mainly affected by the oil discharge characteristics on the apply side, and the engagement characteristics during the reverse rotation of the drum are mainly affected by the oil discharge characteristics on the anchor side. In the present embodiment in which the oil discharge characteristic of the side is reduced, the engagement torque at the time of reverse rotation decreases, and the difference between the engagement torque at the time of normal rotation and the engagement torque at the time of reverse rotation of the drum increases.

As described above, by making the oil discharge characteristic on the apply side relatively higher than that on the anchor side, the difference in engagement torque between the forward rotation and the reverse rotation of the brake drum can be increased. In addition, as in the first to fourteenth embodiments, the oil discharge characteristics on the apply side are relatively higher than those on the anchor side, as in the first to fourteenth embodiments. By making the number, size, and arrangement of the oil discharge means different between the apply side and the anchor side, the present invention can be implemented in various modes.
In this case, the first of FIGS. 9B and 10 to 12 is used.
The oil groove 9 having one end closed in the 0th to thirteenth embodiments is disposed with its closed end facing the anchor. Further, it is preferable that the area range in which the pattern of the oil discharging means is different between the apply side and the anchor side is at least 1/3 or more of half the length of the band from the end on the apply side or the anchor side. Has already been described.

As can be seen from the tenth to thirteenth embodiments, the oil groove has different oil discharge characteristics between the forward rotation and the reverse rotation of the brake drum, ie, the brake band. By adopting an oil groove 9 whose one end in the longitudinal direction is open to the side end of the wet friction material 4 or communicates with the oil hole 10 and the other end is closed, the apply side and the anchor side are used. It is possible to reduce the difference between the engagement torques at the time of normal rotation and at the time of reverse rotation without making the oil discharge characteristics different. Hereinafter, a typical example will be described.

<Sixteenth Embodiment> FIG. 15 is a plan view showing a friction engagement surface of a brake band according to a sixteenth embodiment of the present invention.

As shown in FIG. 15, the brake band 2 of the sixteenth embodiment corresponds to the one in which the oil hole 10 is omitted in the twelfth embodiment of FIG. 11, and has a band-shaped flexible back metal 3 and a back metal. 3 is provided with a wet friction material 4 adhered to the inner peripheral surface thereof, and an oil groove 9 formed on the wet friction material 4 as an oil discharging means. The oil groove 9 extends obliquely toward the apply side from the side end of the wet friction material 4 to a substantially central portion in the width direction and terminates.
Therefore, the end of the oil groove 9 on the anchor side is open to the side end of the wet friction material 4, but the end on the apply side is closed. And several, here 6
Such oil grooves 9 of the book are uniformly arranged in a staggered manner, that is, alternately left and right in the length direction of the band. Therefore, the pattern composed of the plurality of oil grooves 9 is the same on the apply side and the anchor side.

As described above, since the end of the oil groove 9 in the direction of the apply side is closed, the oil is not easily discharged at the time of normal rotation in which the brake drum rotates in the direction of the apply side. Conversely, since the end of the oil groove 9 in the anchor-side direction is released, the oil is easily discharged when the brake drum rotates in the reverse direction in the anchor-side direction. Therefore, when the brake drum rotates forward, the oil discharge characteristics are poor, so that the engagement torque is relatively low. When the brake drum rotates in the reverse direction, the oil discharge characteristics are good, so the engagement torque is relatively high. Therefore, the engagement torque at the time of forward rotation can be reduced and the engagement torque at the time of reverse rotation can be increased, and the difference can be reduced.

<Seventeenth Embodiment> FIG. 16 is a plan view showing a friction engagement surface of a brake band according to a seventeenth embodiment of the present invention.

The brake band 2 of the seventeenth embodiment is different from the eleventh embodiment of FIG.
Oil holes 1 on the apply side among the oil holes 10 at both ends
It corresponds to the value excluding 0. And, as shown in FIG.
In the brake band 2 of the present embodiment, the oil grooves 9 are formed so as to extend in parallel with the length direction of the band 2 and are arranged uniformly in the length direction of the band 2. Each oil groove 9 is provided with an oil hole 10 at an end in the direction of the anchor side.

Therefore, according to this pattern, the first
As in the sixth embodiment, when the brake drum rotates forward, the oil discharge characteristics are poor and the engagement torque is relatively low. When the brake drum rotates in reverse, the oil discharge characteristics are good and the engagement torque is relatively high. Become. Therefore, the engagement torque at the time of forward rotation can be reduced and the engagement torque at the time of reverse rotation can be increased, and the difference can be reduced.

<Eighteenth Embodiment> FIG. 17 is a plan view showing a friction engagement surface of a brake band according to an eighteenth embodiment of the present invention.

As shown in FIG. 17, the brake band 2 of the eighteenth embodiment has the same oil groove 9 as the sixth to eighth embodiments of FIGS. 6 to 8, and the oil groove 9 is inclined. Are sequentially changed, and are uniformly arranged in the length direction of the band 2. Each oil groove 9 is provided with an oil hole 10 at the end in the direction of the anchor, but is not provided with an oil hole in the end in the direction of the apply. For this reason, the end of the oil groove 9 on the apply side is in a closed state, and it is difficult for the oil to be discharged when the drum is normally rotated. Therefore, according to the present embodiment, the sixteenth and seventeenth elements can be used.
As in the embodiment, the brake band 2 having a small difference in engagement torque between the forward rotation and the reverse rotation of the drum can be obtained.

<Nineteenth Embodiment> FIG. 18 is a plan view showing a friction engagement surface of a brake band according to a nineteenth embodiment of the present invention.

As shown in FIG. 18, in the brake band of the nineteenth embodiment, the oil grooves of the sixteenth to eighteenth embodiments of FIGS. An oil groove 9 having a bent shape is provided. The oil groove 9 is arranged with its bent portion (corner) facing the apply side, and has oil holes 10 at both ends, which are ends in the anchor side. Therefore, according to the oil groove 9, the oil discharge characteristics during the forward rotation of the brake drum are poor, and the oil discharge characteristics during the reverse rotation of the brake drum are good.
As in the case of the embodiment, the engagement torque at the time of normal rotation can be reduced and the engagement torque at the time of reverse rotation can be increased, and the difference can be reduced. In addition, the oil groove 9 can be disposed with its bent portion (corner portion) directed toward the anchor, but in this case, the oil hole 10 is formed in the bent portion.
Will be provided.

Although several typical examples have been described above, the oil groove 9 may have any other shape, and two or more types may be used in combination. In addition, the size, the number of arrays, and the like can be set as appropriate.

The sixteenth embodiment to the nineteenth embodiment
The brake band 2 of the embodiment includes a band-shaped flexible back metal 3, a wet friction material 4 bonded to an inner peripheral surface of the back metal 3,
An oil hole formed in the wet friction material 4, the end on the apply side to which the operating force is applied is closed, and the end on the anchor side is opened to the side end of the wet friction material 4 or an oil hole formed in the back metal 3. An oil groove 9 communicating with the wet friction material 4
And a plurality of oil grooves 9 uniformly arranged in the longitudinal direction.

Therefore, when the brake drum rotates forward, the engagement torque is relatively low due to poor oil discharge characteristics, and when the brake drum rotates in reverse, the oil discharge characteristics are good. It becomes higher. Therefore, similarly to the first to fourteenth embodiments,
It is possible to obtain a brake band having a small difference in engagement torque between the forward rotation and the reverse rotation of the brake drum.

In these embodiments, if the apply side and the anchor side are reversed, the engagement torque at the time of normal rotation of the brake drum can be increased and the engagement torque at the time of reverse rotation can be reduced. Thus, the difference between the engagement torque at the time of forward rotation and the torque at the time of reverse rotation can be increased. Further, if the oil grooves 9 are arranged symmetrically on the apply side and the anchor side about the longitudinal center of the brake band 2, both the engaging torque at the time of normal rotation and the torque at the time of reverse rotation are increased or both decreased. be able to.

Although the brake band of the present invention has been mainly described for use in an automatic transmission of an automobile,
In practicing the present invention, the present invention is not limited to this application, and can be applied to any other band brake that is used in oil.

[0099]

As described above, the brake band according to claim 1 is a band-shaped flexible backing metal, a wet friction material adhered to the inner peripheral surface of the backing metal, and a brake drum when a braking operation is performed. And the oil between the wet friction materials is discharged out of the frictional engagement region, and the oil is applied from the apply side to which the operating force is applied.
The oil discharge characteristics are relatively high on the anchor side
Brake band with oil drain means
The oil discharging means is formed on the wet friction material.
Oil groove, which is formed in the back metal in communication with the oil groove.
Oil hole, the wet friction material and the back metal
Including the formed through hole, the oil groove and the oil hole
Actuation force applied to at least one of the number, size and arrangement
In the longitudinal direction of the wet friction material and the back metal
By making the lie side different from the anchor side,
The oil discharge characteristics are set for the lie side and the anchor side.
is there.

Therefore, the oil discharge characteristics of the oil discharge means are low on the apply side where the engagement characteristics during the forward rotation of the brake drum particularly affect, and the oil discharge characteristics on the anchor side where the engagement characteristics during the reverse rotation of the brake drum particularly affect. Then it can be high,
You can also set the reverse
Arbitrarily set the difference in engagement torque between the forward and reverse rotation of the ram.
Can be Therefore, by simply changing the oil discharge characteristics of the oil discharge means between the apply side and the anchor side, the operating force applied to the brake band can be controlled independently during forward rotation and reverse rotation, and the desired engagement characteristics can be easily achieved. Can be obtained.

Further , the oil discharging means is formed as a wet friction material.
Formed oil groove, formed on the back metal in communication with the oil groove
Through the oil hole, wet friction material and back metal
Including at least one of the through holes,
Apply the number, size, or arrangement of the actuation forces
The difference between the oil side and the anchor side
Characteristics are relatively higher on the anchor side than on the apply side
Or on the contrary, the anchor side is relatively lower than the apply side.
Can be done. Therefore, the number and size of at least one of the oil groove, the oil hole and the through hole,
Or it is different between the apply side and the anchor-side arrangement, blurring
-The difference in engagement torque between forward and reverse rotation of the
The desired engagement characteristics can be easily obtained only by adjusting the pattern of the discharging means such as the oil groove , and complicated control of the actuator for operating the brake band and cost increase are not required.

[Brief description of the drawings]

FIG. 1 is a plan view showing a friction engagement surface of a brake band according to a first embodiment of the present invention, together with a conventional example and a comparative example. FIG. 1A shows the first embodiment, and FIG.
Is a conventional example, and (c) is a comparative example.

FIG. 2 is a plan view showing a friction engagement surface of a brake band according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a friction engagement surface of a brake band according to a third embodiment of the present invention.

FIG. 4 is a plan view showing a friction engagement surface of a brake band according to a fourth embodiment of the present invention.

FIG. 5 is a plan view showing a friction engagement surface of a brake band according to a fifth embodiment of the present invention.

FIG. 6 is a plan view showing a friction engagement surface of a brake band according to a sixth embodiment of the present invention.

FIG. 7 is a plan view showing a friction engagement surface of a brake band according to a seventh embodiment of the present invention.

FIG. 8 is a plan view showing a friction engagement surface of a brake band according to an eighth embodiment of the present invention.

FIG. 9 is a plan view showing friction engagement surfaces of brake bands according to ninth and tenth embodiments of the present invention, together with a conventional example and a comparative example. 9A shows the ninth embodiment, FIG. 9B shows the tenth embodiment, FIG. 9C shows the conventional example, and FIG. 9D shows the comparative example.

FIG. 10 is a plan view showing a friction engagement surface of a brake band according to an eleventh embodiment of the present invention.

FIG. 11 is a plan view showing a friction engagement surface of a brake band according to a twelfth embodiment of the present invention.

FIG. 12 is a plan view showing a friction engagement surface of a brake band according to a thirteenth embodiment of the present invention.

FIG. 13 is a plan view showing a friction engagement surface of a brake band according to a fourteenth embodiment of the present invention.

FIG. 14 is a plan view showing a friction engagement surface of a brake band according to a fifteenth embodiment of the present invention.

FIG. 15 is a plan view showing a friction engagement surface of a brake band according to a sixteenth embodiment of the present invention.

FIG. 16 is a plan view showing a friction engagement surface of a brake band according to a seventeenth embodiment of the present invention.

FIG. 17 is a plan view showing a friction engagement surface of a brake band according to an eighteenth embodiment of the present invention.

FIG. 18 is a plan view showing a friction engagement surface of a brake band according to a nineteenth embodiment of the present invention.

FIG. 19 is an explanatory view showing a general structure of a band brake.

FIG. 20 is a perspective view showing an example of a conventional brake band viewed from a friction engagement surface side.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 brake drum 2 brake band 3 back metal 4 wet friction material 5, 6 bracket 7 servo actuator 8 anchor 9 oil groove (oil discharging means) 10 oil hole (oil discharging means) 11 center hole 12 through hole (oil discharging means)

Continuation of the front page (56) References JP-A-6-307468 (JP, A) JP-A-5-47559 (JP, U) JP-A-2-103534 (JP, U) JP-A-5-47559 (JP) , U) Japanese Utility Model Hei 6-82443 (JP, U)

Claims (1)

(57) [Claims] 1. A band-shaped flexible back metal, a wet friction material adhered to an inner peripheral surface of the back metal, and an oil between a brake drum and the wet friction material during a braking operation is moved out of a friction engagement region. And an oil discharging means whose oil discharging characteristics are made relatively higher on the anchor side than on the apply side to which the operating force is applied, wherein the oil discharging means is formed on the wet friction material. and the oil groove is formed on the back metal in communication with the oil groove, the
Oil hole formed in substantially the center of the length direction of the oil grooves, through the wet friction material and the back metal, the Burekiba
A center hole formed at the center in the longitudinal direction of the
The operating force is applied to the number, size and arrangement of the oil grooves.
By making the difference between the apply side and the anchor side relative to the center hole , the oil discharge characteristics are different from those of the apply side and the anchor side.
A brake band characterized by being relatively changed on the side of the brake.