JP2005069411A - Segment type frictional material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain sufficient reduction in drag torque at such positions that lubrication oil amount is large and lubrication oil is difficult to be drained in segment type friction material. <P>SOLUTION: Two edges with R in a reverse direction to a core 2 of a segment piece 3 are brought into contact so as to become an inner periphery 5b and an outer periphery 5a in the segment type friction material 1. The drainage capability of ATF is extraordinarily improved by lost motion of a disk 1 as shown with an arrow because the R which is ascent in the oil groove direction 4 is provided with the inner periphery 5b, and the width of the outer periphery opening portion of a gap 4 as an oil groove is made larger than the width of an inner periphery opening portion, resulting in extraordinary reduction in the drag torque of the lubrication oil. Besides, ATF drained on a disc 1 outer periphery side collides with an inner surface of an automatic transmission device case 10 as shown with the arrow and is to be returned to the disc 1 side. However, the ATF is easy to be drained to the outside of the periphery due to the R shape of which the both edges are ascent toward the outer periphery side of the outer periphery 5a of the segment piece 3, thus extraordinarily reducing the drag torque of the lubrication oil. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a wet friction material that obtains torque by applying high pressure to the opposite surface in a state immersed in oil, and a friction material base material cut into segment pieces on a flat plate ring-shaped metal core on both sides It is related with the segment type friction material adhere | attached on.

  In recent years, as a wet friction material, a flat plate ring-shaped cored bar 12 as shown in FIG. 5 is formed along a flat ring shape with the aim of reducing costs by improving material yield and reducing fuel consumption in vehicles by reducing drag torque. The friction material base material 13 cut into segment pieces is sequentially arranged with an adhesive at intervals to become oil grooves 14 and bonded over the entire circumference, and the friction material base material 13 similarly cut into segment pieces is also attached to the back surface. A segment type friction material 11 formed by bonding has been developed. FIG. 5 is a plan view showing a partial configuration of a conventional segment type friction material. Such a segment type friction material 11 is a friction material member provided with a plurality of or a single friction plate used in an automatic transmission (hereinafter also referred to as “AT”) such as an automobile or a transmission such as a motorcycle. It can be used for combined devices.

  As an example, wet hydraulic clutches are used in automatic transmissions for automobiles, etc., and multiple segment type friction materials and multiple separator plates are alternately stacked, and torque is transmitted by pressure-contacting both plates with hydraulic pressure. In order to absorb friction heat generated when shifting from the non-fastened state to the fastened state and to prevent wear of the friction material, lubricating oil (Automatic Transmission Fluid, automatic transmission) is provided between both plates. Lubricating oil, hereinafter also referred to as “ATF”). However, the distance between the segment type friction material and the separator plate is set small in order to increase the response of the hydraulic clutch, and the segment type friction material is used to ensure a sufficient torque transmission capacity when the hydraulic clutch is engaged. The total area of the oil passage that occupies above is limited. As a result, there is a problem that when the hydraulic clutch is not engaged, the lubricating oil remaining between the segment type friction material and the separator plate is difficult to be discharged, and drag torque due to the lubricating oil is generated due to the relative rotation of both plates.

Therefore, in the invention described in Patent Document 1, the segment pieces are arranged in two stages on the inside and outside of the wet friction plate (segment type friction material), and at least a part of the inner periphery of the segment piece is a radius that faces the delay side in the rotational direction. By inclining radially outward toward the radially inner end of the directional oil passage, lubricating oil can be effectively guided to the radially inner end of the radial oil passage.
JP 2002-340071 A

  However, in the technique described in Patent Document 1, the radial oil passages are narrow and parallel to each other. On the other hand, as shown in FIG. When the relationship between the groove width ratio (a / b) of the outer peripheral opening a and the inner peripheral opening b and the drag torque reduction rate was tested, the groove width ratio (a / b) = 1.0, that is, parallel. There was only a torque reduction rate of about 30%, and only half the effect of the groove width ratio (a / b) = 3.0, 4.0 was obtained. FIG. 7 is a diagram showing the relationship between the outer / inner groove width ratio and drag torque reduction rate in a conventional segment type friction material. In addition, in the technique described in Patent Document 1, segment pieces that have been cut into small pieces are bonded to the inner and outer stages, and the drag torque due to sufficient lubricating oil can be reduced despite the increased manufacturing cost. There was a problem that it was not made.

  Furthermore, as shown in FIG. 6, in a conventional segment type friction material, the relationship between the size of the outer inner circumference R of the segment piece (the same size of the outer inner circumference R) and the drag torque reduction rate was tested. It has been found that the drag torque can be sufficiently reduced when R = 80 mm or less. FIG. 6 is a diagram showing the relationship between the size of the outer inner circumference R and the drag torque reduction rate in the conventional segment type friction material. However, the conventional segment type may increase the drag torque on the part where the amount of lubricating oil in the AT is relatively large or the part where the ATF is difficult to escape (is easy to accumulate) due to its structure. .

  Therefore, the present invention provides a sufficient drag torque reducing effect even in a portion where the amount of lubricating oil is large or where the lubricating oil is difficult to escape, and a segment that can be manufactured in a short time by reducing the size of the segment piece. It is an object to provide a type friction material.

  The segment type friction material according to the invention of claim 1 is a segment type friction material formed by adhering a friction material base material cut into segment pieces along the flat plate ring shape to a flat plate ring shape metal core on both sides. The segment piece has two opposite sides with an R in the same direction, and the segment piece is adjacent to the cored bar so that the center of the R faces the outer peripheral side and becomes an oil groove. The width of the outer peripheral opening in the gap with the matching segment piece is larger than the width of the inner peripheral opening.

  The segment type friction material according to the invention of claim 2 is the same as that of the structure of claim 1, but the size of R applied to two opposite sides of the segment piece is the same.

  A segment type friction material according to a third aspect of the present invention is the structure of the first or second aspect, wherein the width of the outer peripheral opening in the gap with the adjacent segment piece serving as the oil groove is the same as that of the inner peripheral opening. The width is 1.5 times or more.

  A segment type friction material according to a fourth aspect of the present invention is the segment type friction material according to any one of the first to third aspects, wherein the width of the outer peripheral opening in the gap between the adjacent segment pieces to be the oil grooves is the inner diameter. The width of the circumferential opening is about 2.0 times to about 3.0 times.

  A segment type friction material according to a fifth aspect of the invention is the segment type friction material according to any one of the first to fourth aspects, wherein R is added to four corners of the segment piece.

  A segment type friction material according to a sixth aspect of the present invention is the segment type friction material according to any one of the first to fifth aspects, wherein the R of the two opposite sides of the segment piece is the radius of the outer periphery of the cored bar. Is smaller than that.

  In the segment type friction material according to the invention of claim 1, R opposite to the core metal is attached to the two opposite sides of the segment piece, and these two sides are bonded so as to constitute an inner periphery and an outer periphery. Yes. Therefore, the width of the outer peripheral opening of the gap between the segment piece inner periphery and the adjacent segment piece that becomes the oil groove is made larger than the width of the inner peripheral opening. As a result, the ATF discharge performance due to the idling of the disk (segment type friction material) is greatly improved, and the drag torque due to the lubricating oil can be greatly reduced.

  Also, the ATF discharged to the outer peripheral side of the disc (segment type friction material) collides with the inner surface of the automatic transmission case and tries to return to the disc side. It becomes easy to be discharged outside. Further, since the ring-shaped portion of the core bar is full in width and can be formed into a large segment piece, the number of segment pieces can be reduced, the time for cutting and bonding can be shortened, and the cost can be reduced. .

  In this way, a segment type that can achieve a sufficient drag torque reduction effect even in areas where the amount of lubricating oil is large or where lubricating oil is difficult to escape, and can be manufactured in a short time by reducing the size of the segment piece. It becomes a friction material.

  Since the segment type friction material according to the invention of claim 2 has the same size of R attached to the two opposite sides of the segment piece, the two opposite sides when the segment piece is cut out from the friction material substrate. There is no need to replace the cutting blade. For this reason, the process of cutting out the segment piece can be completed in a short time, and the manufacturing process of the segment type friction material can be shortened.

  In this way, a sufficient drag torque reduction effect can be obtained, and the segment type friction material can be manufactured in a shorter time and the cost can be reduced.

  The segment type friction material according to the invention of claim 3 is such that the width of the outer peripheral opening is 1.5 times or more the width of the inner peripheral opening, and as a result of repeated experiments by the present inventors, It has been found that the effect of reducing drag torque appears significantly by increasing the width of the portion to about 1.5 times the width of the inner peripheral opening.

  In this way, a segment type friction material can be obtained that has a sufficient drag torque reduction effect.

  In the segment type friction material according to the invention of claim 4, the width of the outer peripheral opening is about 2.0 to about 3.0 times the width of the inner peripheral opening. As a result, it has been found that the effect of reducing drag torque appears more remarkably. If the area of the segment piece is reduced too much, the friction area will be reduced and the performance of the segment type friction material will be inconvenient, but the width of the outer peripheral opening will be from about 2.0 times the width of the inner peripheral opening. If it is about 0 times, the drag torque due to the lubricating oil can be most appropriately suppressed without reducing the performance as a friction material.

  In this way, a segment type friction material can be obtained in which a more remarkable drag torque reduction effect can be obtained, and the segment piece can be enlarged to be manufactured in a short time and cost can be reduced.

  In the segment type friction material according to the invention of claim 5, R is given to four corners of the segment piece. As a result, if a larger R is added to the two corners of the outer periphery of the segment piece, the width of the outer periphery opening can be made larger than the width of the inner periphery opening, and the flow of ATF in the opening of the outer periphery can be reduced. It becomes smooth and the effect of reducing drag torque appears remarkably.

  In this way, a segment type friction material can be obtained in which a more remarkable drag torque reduction effect can be obtained, and the segment piece can be enlarged to be manufactured in a short time and cost can be reduced.

  In the segment type friction material according to the invention of claim 6, the size of R on the two opposite sides of the segment piece is made smaller than the radius of the outer periphery of the cored bar. As a result, the R rising in the direction of the oil groove on the inner periphery of the segment piece becomes smaller, and the width of the outer peripheral opening in the gap between adjacent segment pieces that become the oil groove is made larger than the width of the inner peripheral opening. By making it larger, the ATF discharge performance due to the idling of the disk (segment type friction material) can be greatly improved, and the drag torque due to the lubricating oil can be greatly reduced. The ATF discharged to the outer periphery of the disk collides with the inner surface of the automatic transmission case and tries to return to the disk side, but is discharged to the outside by a smaller R shape whose both ends rise toward the outer periphery of the outer periphery of the segment piece. It becomes easy.

  In this way, a segment type friction material can be obtained in which a more remarkable drag torque reduction effect can be obtained, and the segment piece can be enlarged to be manufactured in a short time and cost can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4.

  FIG. 1 is a partial plan view showing a part of a segment type friction material according to an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the relative rotational speed and drag torque at an ATF flow rate of 500 mL / min of the segment type friction material according to the embodiment of the present invention, as compared with the conventional segment type friction material. FIG. 3 is a diagram showing the relationship between the relative rotational speed and drag torque at an ATF flow rate of 1000 mL / min of the segment type friction material according to the embodiment of the present invention, as compared with the conventional segment type friction material. FIG. 4 is a diagram for explaining the ATF discharging effect in the segment type friction material according to the embodiment of the present invention.

  As shown in FIG. 1, the segment type friction material 1 according to this embodiment includes a plurality of segment pieces 3 on a flat ring metal core 2 using an adhesive (thermosetting resin). Are arranged and pasted at intervals of 4 and are similarly pasted to the back surface of the core metal 2 with an adhesive. Here, the outer periphery 5a of the segment piece 3 is provided with R having a size of R1 with the center facing the outer peripheral side, and the inner periphery 5b has an R with the same size R2 with the center facing the outer peripheral side. In addition, four corners are R-shaped 6. Then, the segment piece 3 was fixed to the cored bar 2 for 30 seconds to 90 seconds with a hot press at 230 ° C. to 250 ° C. from both sides to obtain a finished product (segment type friction material 1).

  In this segment type friction material 1, R1 of the outer periphery 5a and R2 of the inner periphery 5b of the segment piece 3 are the same, that is, R1 = R2, and therefore the width of the segment piece 3 is constant. Also, R1 on the outer circumference 5a and R2 on the inner circumference 5b are both made the same as the outer radius (80 mm) of the cored bar 2 (φ160-φ140). Further, the ratio A / B of the width A of the outer peripheral opening and the width B of the inner peripheral opening is about 2.0.

  The relationship between the relative rotational speed and drag torque of the segment type friction material 1 according to this embodiment manufactured as described above was tested in comparison with the conventional segment type friction material 11 shown in FIG. As test conditions, relative rotation speed = 500 to 5000 rpm, ATF oil temperature = 40 ° C., ATF oil amount was tested in two ways, 500 mL / min and 1000 mL / min, and the number of discs = 3 (therefore, the counterpart steel plate disc) Was 4 sheets), and the pack clearance was 0.25 mm / sheet. FIG. 2 shows the result when the ATF flow rate is 500 mL / min, and FIG. 3 shows the result when the ATF flow rate is 1000 mL / min.

  As shown in FIG. 2, when the ATF flow rate is 500 mL / min, a difference has already occurred at the time of the relative rotation speed of 500 rpm, and the drag torque of the segment type friction material 1 is smaller. Thereafter, the drag torque decreases as the relative rotational speed increases. However, the difference gradually opens, and at the relative rotational speed of 5000 rpm, the drag torque of the segment type friction material 1 according to the present embodiment becomes almost zero. On the other hand, the drag torque of the conventional segment type friction material 11 is about 0.4 N · m.

  On the other hand, as shown in FIG. 3, at an ATF flow rate of 1000 mL / min, there is almost no difference at about 0.8 N · m at a relative rotational speed of 500 rpm. Although the drag torque is small, the difference is already wide at the time of the relative rotation speed of 1000 rpm, and at the time of the relative rotation speed of 5000 rpm, the drag torque of the segment type friction material 1 according to the present embodiment is almost zero. On the other hand, the drag torque of the conventional segment type friction material 11 is about 0.4 N · m or more.

  The reason why the drag torque of the segment type friction material 1 according to the present embodiment is thus reduced will be described with reference to FIG. As shown in FIG. 4, the opposite two sides 5a and 5b of the segment piece 3 are provided with R in the opposite direction to the cored bar 2, and these two sides are bonded so as to form an inner circumference 5b and an outer circumference 5a. ing. Therefore, an R that rises in the direction of the oil groove 4 is attached to the inner periphery 5b of the segment piece 3, and the width of the outer periphery opening of the gap 4 between the adjacent segment pieces that become the oil groove is set to the width of the inner periphery opening. By making it larger than the width, as shown by the arrow, the ATF discharge performance due to idling of the disk (segment type friction material) is greatly improved, and the drag torque due to the lubricating oil is greatly reduced. Further, the ATF discharged to the outer peripheral side of the disk collides with the inner surface of the automatic transmission case 10 as indicated by an arrow and tries to return to the disk side. However, both ends of the ATF are directed toward the outer peripheral side of the outer periphery 5a of the segment piece 3. Since it is easy to be discharged out of the diameter by the rising R shape, the drag torque due to the lubricating oil is greatly reduced.

  As described above, the segment type friction material 1 of the present embodiment can sufficiently reduce the drag torque and enlarge the segment piece 3 even in a portion where the amount of lubricating oil is large and where the lubricating oil is difficult to escape. The manufacturing can be done in a short time and the cost can be reduced. Furthermore, since the size of R attached to the two opposite sides 5a and 5b of the segment piece 3 is the same, the blade for cutting out the two opposite sides when excising the segment piece 3 from the friction material base material is replaced. There is no need to do. For this reason, the process of cutting out the segment piece can be completed in a short time, and the manufacturing process of the segment type friction material can be shortened.

  In the present embodiment, the Rs of the two opposite sides 5a and 5b of the segment piece 3 of the segment type friction material 1 are the same, but they are not necessarily the same.

  In the present embodiment, the Rs of the two opposite sides 5a and 5b of the segment piece 3 are the same as the radius of the outer periphery of the core metal 2, but may be smaller than the radius of the outer periphery of the core metal 2. .

  In practicing the present invention, the configuration, shape, quantity, material, size, connection relationship, and the like of other portions of the segment type friction material are not limited to the present embodiment.

FIG. 1 is a partial plan view showing a part of a segment type friction material according to an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the relative rotational speed and drag torque at an ATF flow rate of 500 mL / min of the segment type friction material according to the embodiment of the present invention, as compared with the conventional segment type friction material. FIG. 3 is a diagram showing the relationship between the relative rotational speed and drag torque at an ATF flow rate of 1000 mL / min of the segment type friction material according to the embodiment of the present invention, as compared with the conventional segment type friction material. FIG. 4 is a diagram for explaining the ATF discharging effect in the segment type friction material according to the embodiment of the present invention. FIG. 5 is a plan view showing a partial configuration of a conventional segment type friction material. FIG. 6 is a diagram showing the relationship between the size of the outer inner circumference R and the drag torque reduction rate in the conventional segment type friction material. FIG. 7 is a diagram showing the relationship between the outer / inner groove width ratio and drag torque reduction rate in a conventional segment type friction material.

Explanation of symbols

1 Segment type friction material 2 Core metal 3 Segment piece 4 Oil groove (gap)
5a, 5b 2 opposite sides 6 R
A Width of outer periphery opening B Width of inner periphery opening

Claims (6)

A segment type friction material formed by adhering a friction material base material cut into segment pieces along the flat plate ring shape to a flat plate ring-shaped cored bar,
The segment piece has two opposite sides with R in the same direction,
The segment piece is bonded to the core bar so that the center of the R faces the outer peripheral side,
A segment type friction material characterized in that the width of the outer peripheral opening of the gap between adjacent segment pieces to be oil grooves is larger than the width of the inner peripheral opening.   The segment type friction material according to claim 1, wherein the R pieces attached to the two opposite sides of the segment piece have the same size.   The width of the outer peripheral opening of the gap between adjacent segment pieces to be the oil groove is 1.5 times or more the width of the inner peripheral opening. Segment type friction material.   The width of the outer peripheral opening of the gap between the adjacent segment pieces serving as the oil grooves is about 2.0 to about 3.0 times the width of the inner peripheral opening. The segment type friction material according to claim 3.   The segment type friction material according to any one of claims 1 to 4, wherein R is attached to four corners of the segment piece.   The segment type friction material according to any one of claims 1 to 5, wherein a size of R of the two opposite sides of the segment piece is made smaller than a radius of an outer periphery of the cored bar. .

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