JP5460555B2 - Method for producing wet friction material - Google Patents

Description

  The present invention relates to a method for producing a wet friction material capable of controlling the characteristics of the wet friction material formed by papermaking.

As a typical method for forming a hollow ring-shaped friction plate as a wet friction material, there is a method in which a wet friction material made into a sheet is punched into a ring shape and manufactured. In this method, the papermaking material in the central portion and the outer peripheral portion becomes scrap, and the usage efficiency of the papermaking material is very low. Therefore, various methods have been proposed as a method for producing a wet friction material.
For example, in a method of directly forming a hollow ring having a shape close to the final product of the wet friction material, a pot method or a bathtub method for minimizing waste is an example.

Since the pot type papermaking stock solution is supplied and dehydrated only as much as necessary for a single piece of papermaking, there is almost no change in concentration, and a paper base material having a stable density can be obtained. However, a long cylinder is required for the inner diameter jig, and there is a problem that the cylinder cannot be moved from dewatering to completion of papermaking. Moreover, there is a problem that the jig becomes large and difficult to handle.
On the other hand, the bath method is not suitable for obtaining a thick paper substrate because the required amount of papermaking stock solution is small, and the concentration of the raw material in the tank gradually decreases. There is a problem that it is necessary.

  Therefore, in Patent Document 1, a hollow disk-like wet friction material is supplied that supplies a papermaking stock solution containing a fiber component and a filler to a papermaking section of a hollow disk-shaped groove and absorbs and dehydrates water from the bottom of the papermaking section. In the production method, the papermaking stock solution is circulated and stirred between the papermaking raw material tank and the raw material tank to keep the concentration constant, and a papermaking jig having a papermaking part having a hollow disk-shaped concave groove, and a lifting suction part. A technique is disclosed in which the papermaking raw material tank is combined and moved up and down, while water is sucked from the stock solution in the papermaking section to make paper, and then dehydrated and dried.

Japanese Patent Application Laid-Open No. 8-337995

  According to the manufacturing method of the present invention, the papermaking stock solution is constantly circulated and stirred between the raw material tank and the papermaking raw material tank, so that the concentration can be kept constant at a constant level. If made into a body, the paper making jig is compact and removable. And it becomes easy to change the set and the productivity is improved.

  However, a hollow disk-shaped wet friction material that absorbs and dehydrates water from the bottom of the papermaking section is supplied by supplying a papermaking stock solution containing a fiber component and a filler to the papermaking section of the hollow disk-shaped concave groove of Patent Document 1. In the method of papermaking, the effect of moisture pulling is added to the influence of gravity during papermaking, and even if the papermaking stock solution is made while stirring, it depends on the specific gravity of the composition of the papermaking components in the papermaking stock solution during the paper making time and during the dewatering. A substance having a large specific gravity in the lower position accumulates at a high density and is laminated. In particular, when paper is made from the base material of the friction material, when the moisture is pulled from the lower side as described above, the component ratio of the upper surface and the lower surface changes, and the lower component density tends to increase.

  Accordingly, the present invention has been made to solve such a problem, and it is an object of the present invention to provide a method for producing a wet friction material that can reduce the influence of gravity and obtain a wet friction material having a desired μ-V characteristic. It is what.

The manufacturing method of the wet friction material according to the invention of claim 1 includes a stirring step of stirring the slurry-like papermaking raw material in which the friction adjusting filler is dispersed in water in a papermaking raw material tank and keeping the concentration constant. The slurry-like papermaking material is supplied from the papermaking material tank, the slurry-like papermaking material is dehydrated to determine its shape, and the friction material whose shape is determined in the friction material-forming step is dried. Having a drying step, and in the friction material forming step, the friction-adjusting filler in the semi-slurry papermaking raw material from which a part of moisture has been removed from the slurry-like papermaking raw material is unevenly distributed by controlling the water flow. It has uneven distribution means.
The “slurry papermaking raw material” here is a cocoon-like mixture in which fiber components such as pulp and various additives are dispersed in water.
In addition, the “semi-slurry papermaking raw material” here is one in which a part of moisture is removed by dehydration or the like from the slurry-like papermaking raw material, and the viscosity becomes higher than that of the “slurry papermaking raw material”. . Here, the stirring step may be any as long as it has a function of stirring the slurry-like papermaking raw material in a papermaking raw material tank and keeping the concentration constant.
In the friction material forming step, the slurry-like papermaking raw material is supplied from the slurry-like papermaking raw material tank, and the slurry-like papermaking raw material is dehydrated to determine the shape of the papermaking raw material. The shape at this time can be various shapes such as a circular shape, a square shape, a rectangular shape, an arc shape, or a shape having a length that specifies only a predetermined width for punching.
Further, the drying step of drying the friction material whose shape is determined in the friction material forming step only needs to be able to dry a wet friction material made of a semi-slurry papermaking material partially dehydrated from the slurry-like papermaking material. A process can be used.

Further, the uneven distribution means in the friction material forming step is a water absorption device provided on the upper surface side of the semi-slurry papermaking raw material, and the friction adjusting filler contained in the semi-slurry papermaking raw material by the water absorption device. It is unevenly distributed on the upper surface side.
And the water absorption method of said water absorption apparatus does not specify the means at all. As the method, it is possible to use means for sucking and removing moisture from the upper surface side of the semi-slurry papermaking raw material.
Here, the water absorption from the upper surface in the friction material forming step is preferably one that can be continuously processed and one that can absorb water uniformly in terms of area in order to increase productivity.

According to a second aspect of the present invention, there is provided a wet friction material manufacturing method comprising: in the friction material forming step, a dehydrator on the lower surface side of the semi-slurry papermaking material; The ratio of the dehydration pressure from the lower surface is within the range of water absorption pressure / dehydration pressure = 1/100 to 1/1.
If the ratio between the water absorption pressure and the dewatering pressure is too lower than the water absorption pressure / dewatering pressure = 1/100, it is difficult to pull up the friction adjusting filler of the semi-slurry papermaking raw material to the upper surface side. .
Further, when the ratio of the water absorption pressure and the dewatering pressure is too high exceeding the water absorption pressure / dehydration pressure = 1/1, the friction adjusting filler of the semi-slurry papermaking material is removed by water absorption. .
And the said dehydration method by a dehydrator does not specify the means at all. As the method, it is possible to use a means for sucking and removing moisture from the lower surface side of the semi-slurry papermaking raw material.
Here, the dehydration from the lower surface in the friction material forming step may be any one that can be continuously processed in order to increase productivity.

In the method for producing a wet friction material according to the invention of claim 3 , the semi-slurry papermaking raw material in the friction material forming step has a moisture content immediately before water absorption from the upper surface in the range of 85.0% to 99.5%. The water content immediately after water absorption is in the range of 70.0 to 95.0%.

The method for producing a wet friction material according to claim 1 comprises a stirring step of stirring a slurry-like papermaking raw material in which a friction-adjusting filler is dispersed in water in a papermaking raw material tank and keeping the concentration constant, and the papermaking The slurry-like papermaking raw material is supplied from the raw material tank, the frictional material forming step for dehydrating the slurry-like papermaking raw material to determine its shape, and the drying step for drying the friction material whose shape has been determined in the friction material forming step And having the uneven distribution means for unevenly distributing the friction adjusting filler of the semi-slurry papermaking raw material from which a part of moisture has been removed from the slurry papermaking raw material by controlling the water flow in the friction material forming step. Is.
Therefore, since the friction adjusting filler of the semi-slurry papermaking raw material from which a part of moisture is removed from the slurry-like papermaking raw material is unevenly distributed by controlling the water flow, for example, in the slurry-like papermaking raw material Thus, diatomaceous earth or the like contained as a friction adjusting filler for increasing the friction coefficient μ can be pulled up to the upper surface side of the papermaking raw material to obtain a wet friction material with μ-V characteristics having a high μ on the upper surface side. Moreover, it can also be set as the wet friction material of arbitrary micro-V characteristics also as a whole.

Further, the uneven distribution means for unevenly distributing the friction adjusting filler is a water absorption device provided on the upper surface side of the semi-slurry papermaking raw material.
In the friction material forming step, the water flow is controlled by absorbing the water of the semi-slurry papermaking raw material with the water absorption device, and the semi-slurry papermaking raw material from which a part of the water content of the slurry-like papermaking raw material is removed The friction adjusting filler is unevenly distributed on the upper surface side, for example, diatomaceous earth contained as a friction adjusting filler for increasing the friction coefficient μ in the slurry-like paper raw material, for example, the upper surface of the paper raw material. The wet friction material having a friction surface having a μ-V characteristic with a high μ on the upper surface side can be obtained. Moreover, it can also be set as the wet friction material of arbitrary micro-V characteristics also as a whole.

The method for producing a wet friction material according to claim 2 has a dehydrator on the lower surface side of the semi-slurry papermaking raw material in the friction material forming step, and the water absorption pressure from the upper surface and the lower surface of the semi-slurry papermaking raw material. The ratio of the dehydration pressure is the water absorption pressure / dehydration pressure = 1/100 to 1/1. Thus, by defining the water absorption pressure ratio with respect to the dewatering pressure, the friction adjusting filler in the semi-slurry papermaking raw material can be unevenly distributed at a desired position.
Furthermore, the dehydration method using the above dehydrator does not specify any means. As the method, it is possible to use a means for sucking and removing moisture from the lower surface side of the semi-slurry papermaking raw material.
Here, the dehydration from the lower surface in the friction material forming step may be performed so long as continuous drying treatment is possible in order to increase productivity.
Moreover, the density of the upper and lower surfaces of the wet friction material can be set to an arbitrary density by water absorption from the upper surface of the papermaking raw material and dehydration from the lower surface.

In the method for producing a wet friction material according to claim 3 , the semi-slurry papermaking raw material in the friction material forming step has a moisture content in the range of 85.0% to 99.5% immediately before water absorption from the upper surface, The moisture content immediately after water absorption is in the range of 70.0% to 95.0%. Here, when the water content of the semi-slurry papermaking raw material exceeds 99.5% and is too high, the friction-adjusting filler of the semi-slurry papermaking raw material flows out together with the water flow due to the water absorption. . On the other hand, if it is lower than 85.0%, the viscosity of the semi-slurry papermaking raw material becomes too high, making it difficult for the friction adjusting filler to move and making it difficult to obtain the desired uneven distribution. Moreover, if the moisture content immediately after water absorption is in the range of 70.0% to 95.0%, it is easy to maintain the specified shape, and the handling of the semi-slurry papermaking raw material becomes easy.
Thus, by adjusting the moisture content immediately before and after water absorption from the upper surface of the semi-slurry papermaking raw material, the friction material in which the friction adjusting filler is unevenly distributed can be efficiently produced continuously.

FIG. 1 is a production process diagram illustrating a method for producing a wet friction material according to a first embodiment of the present invention. 2A is a water absorbing roller for a wet friction material according to the first embodiment of the present invention, FIG. 2A is a perspective view thereof, and FIG. 2B is a longitudinal sectional view of an essential part showing a longitudinal section in the length direction. is there. FIG. 3 is an explanatory diagram showing the ash content ratio of the wet friction material manufactured by the upper water absorbing device according to the method of manufacturing the wet friction material according to the first embodiment of the present invention. FIG. 4 is an explanatory diagram showing μ-V characteristics of the wet friction material manufactured by the upper water absorbing device according to the method of manufacturing the wet friction material according to the first embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, the same symbols and the same reference numerals are the same or corresponding functional parts in the drawings, and therefore, redundant description is omitted here.

[Embodiment 1]
In FIG. 1, a papermaking raw material tank 1 containing a slurry-like papermaking raw material 10 which is made into a wet friction material by papermaking has a predetermined volume, and is a slurry-like papermaking raw material contained by stirring means 12 rotated by an electric motor 11. 10 is agitated constantly or as needed. Further, the papermaking raw material tank 1 is provided with a circulation pump 13 so that the slurry-like papermaking raw material 10 accommodated in the papermaking raw material tank 1 is not easily affected by the specific gravity, or the opposite direction. The slurry-like papermaking raw material 10 is maintained in a uniformly distributed state.

  Further, an adjustment tank 2 is externally connected to the papermaking raw material tank 1, and the adjustment tank 2 mixes raw materials for papermaking and a wet friction material to obtain a predetermined concentration. Also in the adjustment tank 2, an electric stirring means and a circulation means (not shown) are provided as necessary. In addition, a circulation path is formed in the adjustment tank 2 so that paper residues, for example, moisture, binder, etc. can be reused via the feedback pump 21 if necessary. It has returned to.

In the papermaking container 3, a return roller 40 at the end of the papermaking conveyor 4 is disposed in the papermaking container 31, and the slurry-like papermaking raw material 10 supplied from the papermaking raw material tank 1 is drawn up while making paper. The residue made in the paper making container 3 is stored in the residue tank 33. The residue stored in the residue tank 33 is sent to the adjustment tank 2 so that it can be reused via the return pump 21 in the circulation path.
In addition, the papermaking raw material tank 1, the adjustment tank 2, and the papermaking container 31 can be combined and used only as the papermaking raw material tank 1, or can be separated. In particular, in the case where a circulation path is formed so that it can be reused via the return pump 21, the paper-making raw material 10 is replenished in accordance with the return amount to produce the slurry-like paper-making raw material 10.

In the paper making conveyor 4, a paper making belt 4A formed of a metal net or a synthetic resin net is hung on dehydrating rollers 41, 42, 43, 44, 45, a separation roller 46, guide rollers 47, 49a, 49b, and a tension roller 48. It has been.
The dewatering rollers 41,..., 45 remove water from the lower surface side of the papermaking belt 4A, and absorb the water from the upper surface as the uneven distribution means described later. It is paired with 73, 74, 75. That is, the dewatering rollers 41, 42, 43, 44, 45 and the papermaking belt 4A are lower parts of the present embodiment having a function of dewatering from the lower surface of the slurry-like papermaking raw material 10 or the semi-slurry papermaking raw material 6 with reduced water content. A dehydrator 8 is configured.

  The separation roller 46 supplies compressed air from the inside when moving the friction material 61 dehydrated from the semi-slurry papermaking raw material 6 and made into a specific shape from the papermaking belt 4A to the drying conveyor 5, 53 is a separation mechanism that separates and guides the friction material 61 from the papermaking belt 4A, separates the friction material 61 from the papermaking belt 4A, and places the friction material 61 on the drying belt 50 of the drying conveyor 5 including the conveying rollers 51 and 52. 9 and presents the peeling step of the present embodiment. For this reason, the separation roller 46 is connected to a compressor or the like that generates compressed air (not shown) in order to peel the friction material 61 from the papermaking belt 4A. This peeling step may or may not be necessary depending on the degree of dewatering of the paper-form slurry-like paper raw material 10, and is left to the friction material 61 depending on the degree of dewatering, and is necessarily required. is not.

The tension roller 48 applies a predetermined tension to the papermaking belt 4A of the papermaking conveyor 4, and makes the tension of the papermaking belt 4A a predetermined state by an elastic force.
The guide rollers 47, 49a, 49b are for guiding to determine the path of the paper making conveyor 4, and are provided in a necessary number.

  As shown in FIG. 2, the water-absorbing rollers 71, 72, 73, 74, and 75 have innumerable perforations 7a formed on the outer periphery of the cylindrical shape, and the perforation area with respect to the entire area, that is, the perforation rate is predetermined. Although it is set to a value, it is determined by an empirical rule according to specific gravity, density, layer thickness, and the like. The water-absorbing rollers 71,..., 75 of the present embodiment are made of stainless steel and have a cylindrical shape, and are not easily bent by an external force. Rotating force is transmitted to the water absorbing rollers 71,..., 75 by a water absorbing belt 7A composed of a V belt to which a rotating force is applied outside (not shown). Therefore, each of the guide rollers 76 and 77 is rotated at a constant speed by the water absorbing belt 7A formed of a V belt. The upper water-absorbing device 7 of this embodiment having water-absorbing rollers 71, 72, 73, 74, 75 and having a function of absorbing water from the upper surface of the semi-slurry papermaking raw material 6 with a reduced amount of water is constituted.

  As described above, the water-absorbing rollers 71,..., 75 of the upper water-absorbing device 7 include the cylinder 7b in which the perforations 7a are formed, the one supporting shaft 7c and the suction-side supporting shaft 7d serving as the rotation shaft of the cylinder 7b. Have. On the outer periphery of the cylinder 7b, a shielding plate 7e that opens about 90 to 120 degrees is provided. The shielding plate 7e has an open lower end, that is, an outer peripheral surface parallel to the length direction, and covers only the upper surface of the cylinder 7b with the support shaft 7c and the suction side support shaft 7d as rotation axes. Yes. Therefore, even if the cylinder 7b rotates, the shielding plate 7e having an opening of about 90 to 120 degrees on the lower side covers the upper surface so that only the perforated 7a formed on the lower side of the cylinder functions. It has become. In addition, the hole 7a of this Embodiment can use a hole, a net | network, etc. of a circular hole, an oblong hole, + character shape.

  The suction side support shaft 7d is provided with a suction pipe 7g positioned so that the suction port 7f is always positioned below the cylinder 7b. Further, the suction pipe 7g is integrally attached to the shielding plate 7e, and as long as the shielding plate 7e covers the upper position of the water absorption rollers 71,... 75, the suction port 7f is the dehydration roller 71,. -It is located in the lowest position of 75 cylinders 7b. The opposite side of the suction pipe 7g of the suction side support shaft 7d to the suction port 7f is connected to a suction pump (not shown) and contains moisture and moisture inside the cylinder 7b of the water suction rollers 71,. The air is exhausted.

  The support shaft 7c has a recessed groove 7h formed at the end on the cylinder 7b side, and is fitted with a projecting portion formed on the inner side of the reinforcing member 7i welded to the end of the cylinder 7b. A key 7k is inserted into the key groove 7j of the support shaft 7c, and a V-belt pulley 7m is attached. Accordingly, when the V-belt pulley 7m rotates, the support shaft 7c rotates, and the cylinder 7b rotates through the recessed groove 7h and the reinforcing member 7i. At this time, the shielding plate 7e remains stopped at a fixed position without rotating.

A reinforcing member 7p is also welded to the end portion on the cylinder 7b side of the suction side support shaft 7d, and a suction tube 7g is inserted therein. An intake / exhaust pipe 7q is connected to the end of the suction pipe 7g, and is fixed by a lock nut 7r. The suction pipe 7g is attached to a fixed frame 7s, and the shielding plate 7e, the suction pipe 7g, and the intake / exhaust pipe 7q are fixed integrally.
Therefore, when the cylinder 7b rotates, the reinforcing member 7p rotates around the suction side support shaft 7d, and the shielding plate 7e remains stopped at a fixed position without rotating.

The manufacturing method of the wet friction material of the present embodiment configured as described above is manufactured by the following steps.
First, a stirring process is performed in which a slurry-like papermaking raw material 10 containing a friction adjusting filler such as diatomaceous earth is placed in a papermaking raw material tank 1 and circulated by a circulation pump 13 and stirred by stirring means 12 to keep its concentration constant. Have. At this time, the papermaking raw material tank 1, the adjustment tank 2 and the papermaking container 31 can be used alone as the papermaking raw material tank 1, or the papermaking raw material tank 1 and the adjustment tank 2, the adjustment tank 2 and the papermaking container 31, The papermaking material tank 1 and the papermaking container 31 may be integrated, or they may be separated from each other. In particular, in the case where a circulation path is formed so that it can be reused via the feedback pump 21, it is sufficient that the papermaking raw material can be supplied according to the feedback amount.

  Also, the slurry-like papermaking raw material 10 stirred in the papermaking raw material tank 1 is supplied from the papermaking raw material tank 1, and the slurry-like papermaking raw material 10 is made by the papermaking conveyor 4 so that its shape is specified only by a predetermined width. It has the friction material formation process defined as a shape. That is, the return roller 40 at the end of the papermaking conveyor 4 is disposed in the papermaking container 31, and the slurry-like papermaking raw material 10 supplied from the papermaking raw material tank 1 is pulled up while making paper and supplied from the papermaking raw material tank 1. The slurry-like papermaking raw material 10 is made into a predetermined shape while papermaking. At this time, if a flexible plate state is arranged at a specific position of the papermaking conveyor 4 so as to form a circular shape, a square shape, a rectangular shape, an arc shape, or a predetermined shape for punching, a specific shape can be obtained. A wet friction material 61 having a shape can be obtained.

  In the friction material forming step, water absorbing rollers 71,..., 75, etc. are applied from the upper surface of the semi-slurry papermaking raw material 6 from which a part of moisture is removed from the slurry-like papermaking raw material 10 by the papermaking belt 4A of the papermaking conveyor 4. The upper water-absorbing device 7 has water absorption on the upper surface side of the semi-slurry papermaking raw material 6, so that the friction of diatomaceous earth or the like is caused by the flow of water in the semi-slurry papermaking raw material 6 toward the water-absorbing rollers 71,. The adjustment filler is restrained from moving toward the lower surface of the paper conveyor 4 toward the papermaking belt 4A. At this time, the water flow is controlled by adjusting the suction force of the water absorption rollers 71,..., 75, and the friction adjustment filler such as diatomaceous earth is unevenly distributed at a desired position such as the upper surface side of the semi-slurry papermaking raw material 6. Can do. Therefore, the upper water absorption device having the water absorption rollers 71,..., 75, etc. constitutes the uneven distribution means.

  At the same time, a dehydration step is performed by the lower dehydrator 8 having dewatering rollers 41,. In particular, since the lower dewatering device 8 is dewatered by the dewatering rollers 41,..., 45 via the papermaking belt 4A of the papermaking conveyor 4, the lower dewatering is determined by the dewatering ability of the papermaking belt 4A. In addition, since the water absorption capability of the water absorption rollers 71,..., 75 is determined by the exhaust capability of the upper water absorption device 7, in particular, only the upper water absorption device 7 acts strongly, or conversely, the lower dewatering device 8 is strongly activated. It can be made to act.

  Here, in the present embodiment, the dewatering from the slurry papermaking raw material 10 to the semi-slurry papermaking raw material 6 is performed by dehydration from the papermaking belt 4A. For example, the water absorption rollers 71 and 72 on the inlet side absorb water. The semi-slurry papermaking raw material 6 may be obtained by the dewatering rollers 41 and 42 without being operated. Here, the water absorption from the upper surface side with respect to the semi-slurry papermaking raw material 6 starts the water absorption when the moisture content of the semi-slurry papermaking raw material 6 falls within the range of 85.5% to 99.5%. If the water content of the semi-slurry papermaking raw material 6 is lower than 85.5%, the viscosity of the semi-slurry papermaking raw material 6 becomes too high, and the friction adjustment filler such as diatomaceous earth is difficult to move due to the water flow caused by water absorption and is unevenly distributed. It becomes difficult to let you. Further, when the water content of the semi-slurry papermaking raw material 6 exceeds 99.5%, the friction adjusting filler such as diatomaceous earth in the semi-slurry papermaking raw material 6 is put together with water in the water absorption rollers 71,. It is absorbed and it becomes difficult to secure the necessary amount of the friction adjusting filler at a desired position. That is, when the water content of the semi-slurry papermaking raw material 6 is in the range of 85.5% to 99.5%, the viscosity of the semi-slurry papermaking raw material 6 becomes appropriate and is included in the semi-slurry papermaking raw material 6. Since the friction adjusting filler such as diatomaceous earth is movable while receiving an appropriate resistance, it is difficult to be absorbed into the water absorption rollers 71,. It becomes easy to control the uneven distribution in the papermaking raw material 6.

  As described above, in the embodiment of the present invention, water absorption on the upper surface of the semi-slurry papermaking raw material 6 and dehydration are performed from the lower surface. That is, by appropriately setting the water absorption pressure / dehydration pressure ratio between the upper water absorption device 7 and the lower dewatering device 8, for example, diatomaceous earth contained as a friction adjustment filler for increasing the friction coefficient μ is used as a papermaking raw material. The wet friction material having a μ-V characteristic with a high μ on the upper surface side can be obtained. Moreover, it can also be set as the wet friction material of arbitrary micro-V characteristics also as a whole. Furthermore, the shape of the friction material 61 which becomes the base material of the wet friction material is specified by passing water absorption on the upper surface of the semi-slurry papermaking raw material 6 and dehydration from the lower surface. Here, the water absorption pressure is preferably in the range of 1 kPa to 50 kPa, and the dehydration pressure is preferably in the range of 50 kPa to 100 kPa. If the water absorption pressure is less than 1 kPa, the water flow by suction is weak and it is difficult to dispose the friction adjusting filler (diatomaceous earth in this embodiment) on the upper surface, and if it exceeds 50 kPa, the friction adjusting filler is formed together with the water flow by suction. It becomes easy to be sucked into the water absorption roller. From this, it can be said that the ratio of water absorption pressure / dehydration pressure is preferably in the range of 1/100 to 1/1.

  In the present embodiment, the friction material 61 held in a specific shape by appropriately removing water through the water absorption / dehydration process is further transferred to the drying conveyor 5 through the peeling mechanism 9 for peeling from the papermaking belt 4A. Conveying. That is, the friction material 61 that has undergone the water absorption / dehydration process has a peeling process for peeling from the papermaking belt 4A. In this embodiment, the water absorption and dehydration are performed together with the water absorption. However, the water absorption / dehydration process may be performed only with the water absorption roller by individually controlling the water absorption capacity of the water absorption rollers 71,. It is possible. Here, the moisture content of the semi-slurry papermaking raw material 6 immediately after the water absorption is finished is set in the range of 70.0% to 95.0% in the present embodiment. By setting the moisture content within this range, the shape of the semi-slurry papermaking raw material 6 is specified, the shape can be maintained, and handling becomes easy. The semi-slurry papermaking raw material 6 whose shape is specified is the friction material 61. If the water content is reduced from 70.0%, the shape can be easily maintained and handled, but the time spent for the friction material forming process becomes longer, which is disadvantageous in production.

Furthermore, the friction material 61 that has undergone the peeling process is moved to the drying belt 50 that is transported by the transport rollers 51, 52, and the like, and includes a drying process that is dried there.
Therefore, the peeling mechanism 9 that peels from the papermaking belt 4A molds the frictional material 61 by the separation roller 46 and the scrubber 53 to which a compressor or the like that generates compressed air (not shown) is connected in order to peel the frictional material 61 from the papermaking belt 4A. Without causing collapse, the belt can be reliably moved to the drying belt 50 conveyed by the conveyance rollers 51 and 52 and the like.

Here, the dewatering pressure of the lower dewatering device 8 is adjusted to be within 60 kPa to 70 kPa, and the wet pressure manufactured by the wet friction material manufacturing method according to the first embodiment is changed by changing the water absorption pressure of the upper water absorbing device 7. The ash content ratio of the friction material (the friction material 61 that has undergone the drying process), that is, the distribution in the thickness direction of the diatomaceous earth by the ash content survey is shown in FIG. Similarly, FIG. 4 shows μ-V characteristics of the wet friction material manufactured by the upper water absorbing device 7 according to the manufacturing method of the wet friction material according to the first embodiment. Here, the ash content indicates the ratio of the inorganic component remaining when the wet friction material is brought to a high temperature state and the organic components in the wet friction material are decomposed and removed. In this example, the ratio of diatomaceous earth in the wet friction material is shown.
As shown in FIG. 3, ash such as diatomaceous earth in the friction material surface layer portion (depth position 1 mm from the surface) between the upper water absorption pressure 2 kPa and the upper water absorption pressure 50 kPa compared to the overall ash content distribution of the wet friction material. Increase was confirmed, and diatomaceous earth was unevenly distributed on the upper surface.

The μ-V characteristic of the wet friction material shown in FIG. 4 shows the performance under the conditions of a rotational speed of 0-1000-0 rpm, a disk surface pressure of 0.2 MPa, an oil temperature of 100 ° C., and an oil amount of 100 mL / min (ATF = A). evaluated. In particular, between the upper water absorption pressure of 2 kPa and the upper water absorption pressure of 50 kPa, the μ-V characteristics of the wet friction material were good, and a good judder property was obtained.
In the present embodiment, there is no particular problem even if the upper water absorption device 7 and the lower dehydration device 8 are upside down. In this case, a desired amount of the friction adjusting filler is unevenly distributed on the lower surface side.

  As described above, the wet friction material manufacturing method according to the above-described embodiment is configured such that the slurry-like papermaking raw material 10 is placed in the papermaking raw material tank 1 and circulated and stirred to keep its concentration constant, and the slurry from the raw material tank 1 is in a slurry state. For the semi-slurry papermaking raw material 6 supplied with the papermaking raw material 10 and removing a part of the water from the slurry-like papermaking raw material 10, an upper water absorbing device 7 as an uneven distribution means and a lower dewatering device as a dewatering and shape forming means 8, the water absorption from the upper surface of the semi-slurry papermaking raw material 6 and the dehydration from the lower surface are performed, and the friction adjustment filler contained in the semi-slurry papermaking raw material 6 is obtained by using the water flow at the time of water absorption by this series of operations. The arrangement position is made free and formed into a specific shape.

  Accordingly, the upper water absorption device 7 and the lower dewatering device 8 of the slurry-like paper raw material 10 perform water absorption from the upper surface and dehydration from the lower surface. The water flow in the semi-slurry papermaking raw material 6 can be controlled to an appropriate flow by appropriately setting the ratio of the water absorption pressure / dehydration pressure of the paper, for example, for friction adjustment for increasing the friction coefficient μ as the slurry-like papermaking raw material 10 The diatomaceous earth etc. which are contained as a filler can be pulled up to the upper surface side of the slurry-like papermaking raw material 10, and it can be set as the wet friction material of the micro-V characteristic whose upper surface side is high (micro | micron | mu). Moreover, it can also be set as the wet friction material of arbitrary micro-V characteristics also as a whole.

  Further, the moisture content of the semi-slurry papermaking raw material 6 is adjusted within an appropriate range, and the viscosity of the semi-slurry papermaking raw material 6 is absorbed by the upper water absorption device 7 as a friction adjustment filler, and the diatomaceous earth etc. Since water absorption is started after controlling to an appropriate viscosity that is difficult to be removed, diatomaceous earth or the like contained as a friction adjusting filler can be unevenly distributed at a desired position. Further, by setting the moisture content after water absorption to an appropriate moisture content, the semi-slurry papermaking raw material 6 that can be separated from the friction material forming step in a state in which the shape is maintained in a specific shape, and then the friction material 61 is formed. Can do.

And since the water absorption by the upper water absorption apparatus 7 from the upper surface of the slurry-like papermaking raw material 10 of the friction material formation process in the manufacturing method of the wet friction material of the said embodiment performs dehydration drying by suction force, it is continuous. In addition, drying can be performed and productivity efficiency can be increased.
Furthermore, the water absorption from the upper surface and the dewatering from the lower surface of the semi-slurry papermaking raw material in the friction material forming step comprising the upper water absorbing device 7 and the lower dewatering device 8 of the wet friction material manufacturing method of the above embodiment are in the form of a slurry. Since dehydration is performed from the lower surface of the papermaking raw material 10 by perforation with a predetermined perforation rate, and suction water is absorbed from the upper surface of the slurry-like papermaking raw material 10 by perforation with a predetermined perforation rate, continuous dehydration drying is performed. Can increase productivity. Moreover, the density of the upper and lower surfaces of the wet friction material 6 can be set to an arbitrary density by water absorption from the upper surface of the slurry-like papermaking material 10 and dehydration drying from the lower surface.

DESCRIPTION OF SYMBOLS 1 Papermaking raw material tank 3 Papermaking container 4 Papermaking conveyor 4A Papermaking belt 5 Drying conveyor 6 Semi-slurry papermaking raw material 7 Upper water absorption device 8 Lower dehydration device 9 Peeling mechanism 10 Slurry papermaking raw materials 41, 42, 43, 44, 45 Dehydration roller 46 Separation roller 50 Drying belt 71, 72, 73, 74, 75 Water absorption roller

Claims (3)

A slurry process paper material in which a friction adjusting filler is dispersed in water is stirred in a paper material tank, and the concentration is kept constant;
The slurry-like papermaking raw material is supplied from the papermaking raw material tank, a friction material forming step for dehydrating the supplied slurry-like papermaking raw material and determining its shape,
In the method for producing a wet friction material having a drying step of drying the friction material whose shape is determined in the friction material forming step,
The friction material forming step has uneven distribution means for unevenly distributing the friction adjusting filler in the semi-slurry papermaking raw material from which a part of moisture has been removed from the slurry-like papermaking raw material by controlling water flow , And the uneven distribution means is a water absorption device provided on the upper surface side of the semi-slurry papermaking raw material, and the friction adjusting filler of the semi-slurry papermaking raw material is unevenly distributed on the upper surface side by the water absorption device. A method for producing a wet friction material. In the friction material forming step, a dehydrating device is provided on the lower surface side of the semi-slurry papermaking raw material,
According to claim 1, wherein the ratio of the dewatering pressure from water pressure and the lower surface from the upper surface of the semi-slurry paper stock, characterized in that the water pressure / dewatering pressure = 1 / 100-1 / 1 in the range A method for producing a wet friction material. The semi-slurry papermaking raw material in the friction material forming step has a moisture content of 85.5% to 99.5% immediately before water absorption from the upper surface, and a moisture content immediately after water absorption of 70.0% to The method for producing a wet friction material according to claim 1 or 2, wherein the content is within a range of 95.0%.

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