JPH0251719B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for molding a brake pad,
In particular, the present invention relates to a method for preforming brake pads used for braking automobile wheels.

[Conventional technology]

Brake pads are mainly used in automobiles, and are made by integrally bonding a backing member made of insulating fiber material to the back of a brake pad body made of semi-metallic material, and integrally providing a boss protruding toward the rear on the back of this backing member. Used in disc brakes. The boss on the back side of the backing member of this type of brake pad is formed of the same insulating fiber material as the backing member, and a back metal having holes is attached to the back of the backing member using the boss.

Conventionally, when molding such brake pads, a mold is first filled with semi-metallic material powder, and then insulating fiber material powder is filled in a layer above and below the semi-metallic material. , they are pressed from above so that an integral boss is formed on top of the layer of insulating fabric, and this operation is all done manually. After this preforming, the brake pads are fitted between hot platens and press-formed at, for example, 200°C and a pressure of 250 tons to form the final product.

[Problem that the invention seeks to solve]

In the conventional brake pad preforming method described above, press forming is performed with the boss protruding from the back facing upward, and therefore, the boss is formed with a downward opening on the lower surface of the press ram, etc. that descends during the press forming stage. However, with this configuration, no matter how much pressure is applied to the press ram, it is not possible to sufficiently push the insulating fiber material powder into the boss-forming recess, and the formed boss The density is insufficient and the strength is low. Since the boss has the role of supporting the back metal behind the bucking member, low strength of the boss is fatal to the brake pad.

The present invention aims to solve the above-mentioned problems of the prior art.

[Means for solving problems]

To achieve this objective, according to the invention:
A mold configured to have a recessed hole for forming a boss on the bottom is prepared, a powder of insulating fiber material is supplied from above into this mold, and a boss pushing rod is lowered from above into the recessed hole to form the recess. After compacting the insulating fiber material in the hole and smoothing the upper surface of the insulating fiber material, the entire insulating fiber material is temporarily pressed from above, and then the semi-metallic material powder is poured into the mold from above. After covering the top surface of the insulating fiber material supplied from above and temporarily pressed, and then leveling the top surface of the semi-metallic material, the press ram is lowered from above into the mold, and the space between the bottom of the mold and the ram is lowered into the mold. A preformed brake pad is obtained by compression molding the insulating fiber material and the semimetallic material, and then the brake pad is removed from the mold to obtain a molded brake pad.

By doing this, it is possible to first put the powder of the insulating fiber material into the boss forming concave hole that opens upward and tamp it down, thereby increasing the density and strength of the boss part to be formed and uniformly forming it. can do.

In addition, in the combined invention, the bottom of the mold is opened, the molded brake pad is extruded downward from the bottom of the mold, and the brake pad is placed on a receiving tray below the mold with the boss facing downward. While holding the brake pad on the receiving tray, turn the receiving tray over, and then place the brake pad on the receiving part with the boss facing upward.

By doing so, it is possible to prevent the comparatively weak boss after the preforming from coming into contact with the mounting surface and being damaged in the subsequent conveyance process.

[Example] The method of the present invention and the apparatus used to implement the method will be described below with reference to the drawings.

FIG. 2 shows an example of a brake pad to be made by the method of the present invention. In the figure, SM is the brake pad body made of semi-metallic material, which is pressed against the surface of the brake disc during braking. Semi-metallic material is a granular material of impermeable metal material, for example, made of finely cut stainless steel wire of small diameter. Behind the brake pad main body SM is a backing member made of insulating fiber material.
The BM is integrally joined, and a plurality of bosses BS are protruded from the back surface thereof, and the back metal P is supported on the back surface of the backing member BM using the bosses BS. The insulating fiber material is, for example, a mixture of asbestos, cashew dust, metal powder, and others, and is in powder form before being molded. FIG. 1 generally shows an apparatus for carrying out the method of the present invention, with which a brake pad excluding the back metal P is preformed. This device consists of a press and mold opening station Z, a filling and temporary pressing station A, a receiving tray retreating station B, and a receiving tray reversing station C.
It has

This device has a bed 2 on station Z, and on this bed 2 there is a bed in the longitudinal direction of the device (first
A horizontal support plate 3 is fixed in the left-right direction in the figure, and a longitudinal guide 4 is provided thereon. As shown in FIG. 3 when viewed in the - line direction of FIG. 1, a pair of guides 4 are provided along both longitudinal edges of the horizontal support plate 3. As shown in FIG. A sliding member 5 is provided between the pair of guides 4 so as to be slidable in the longitudinal direction (direction perpendicular to the paper plane of FIG. 3). A lower mold device 7, which constitutes the bottom of the brake pad mold, is held on the sliding member 5 by a holding member 6.

The lower mold device 7 has a lower platen 8 and an upper platen 9 as shown in FIG.
is the guide column 1 established on the lower platen 8.
It is possible to move up and down while being guided by 0,
A spring 11 is provided to resist the lowering of the upper platen 9. A middle mold 12 forming a part of the lower mold device 7 is integrally provided on the upper platen 9, and a recessed hole 13 is provided at the top of the middle mold 12. This recessed hole 13 opens upward and serves to form the boss BS of the brake pad as described below.

In FIGS. 1 and 3, reference numeral 15 denotes an outer mold for molding brake pads, which has molding cavities 15a that open upward. In the illustrated example, two cavities 15a are provided, the same as the number of middle molds 12. The bottom of each cavity 15a is normally closed by fitting the middle mold 12 into the cavity from below. Therefore, a boss forming concave hole 13 that opens upward is provided at the bottom of each cavity. The outer mold 15 is movable between a position at station A, as shown by the phantom line in FIG. 1, and a position at station Z, as shown by the solid line, by a support and conveyance mechanism (not shown). Further, the outer mold 15 can also be moved upward at the station Z as described later.

A push-up rod 16 is provided in the station Z so as to vertically move through the pair of guides 4. The lower ends of these push-up rods 16 are moved upward by the operation of a vertical drive mechanism (not shown), and the push-up rods 16 are pushed upward via the projecting portions 17 of the outer mold 15 as described below.

The station Z is also provided with plate bodies 18 arranged in a tree shape on the outside of the guide 4, and a stopper 19 bent inward is provided at the upper end of each plate body 18.

In the station Z, a press ram 21 is mounted above a predetermined position of the outer mold 15 in a cavity 15a of the outer mold.
are provided corresponding to each. Ram 21
has a clamping surface 21a at the lower end, and is lowered and inserted into the corresponding cavity 15a during molding,
The molded product is pressed between the medium die 12.

A quantitative supply chute 23 is provided so as to be movable between a position directly above the outer mold 15 at station A and a position remote therefrom. As shown in FIG. 5A, the chute 23 is connected to the outer mold cavity 15.
It is provided with chute portions 23a corresponding to each of a. Each chute portion 23a of the chute 23
An opening/closing plate 24 is provided to be able to slide in the horizontal direction, and for sliding displacement of the opening/closing plate 24, the opening/closing plate 24 is fixed to the tip of the piston rod of the air cylinder 25. When the piston rod is extended, the opening/closing plate 24 closes the bottom of the chute portion 23a, and when the piston rod is retracted, the bottom of the chute portion 23a is opened. As shown in FIG.
is adapted to be moved onto the outer mold 15 with a certain amount of material filled inside.

As shown in FIG. 1, an air cylinder 28 is fixedly provided to the bed 2 in the region of a receiving tray retraction station B provided subsequent to the press/mold opening station Z. The tip of the piston rod 29 of the air cylinder 28 is connected to the right end of the sliding member 5 in the drawing. Further, a rising end plate 31 is fixed near the right end of the sliding member 5 in the figure, and a horizontal support plate 32 is fixed to this end plate 31. Therefore, support plate 3
2 moves together with the sliding member 5.

As shown in FIGS. 6 and 7, a bearing 33 is fixed near the right end of the support plate 32 in the drawings, a pivot 34 is rotatably inserted through this, and a pinion 35 is attached to the end of the pivot 34. A vertical rack 36 is engaged with the pinion 35. The rack 36 is guided by a guide 37, and the lower end of the rack 36 is fixed to the upper end of the piston rod of an air cylinder 38 in the vertical direction. Therefore, by expanding and contracting the air cylinder 38, the pivot 34
rotates.

The pivot 34 has a rising portion 40 at one end of the reversing plate 40.
a is fixed, and the reversing plate 40 can be rotated from the solid line position to the imaginary line position in FIG. 6 by rotation of the pivot shaft 34, and can be reversed up and down. One end of an air cylinder 42 is fixed to a bracket 41 fixed to one end of the reversing plate 40, and the other end of the air cylinder 42 is also connected to the reversing plate 4 by another bracket 43.
Fixed above 0. A cover plate 46 is fixed to the tip of the piston rod 44 of the air cylinder 42 via a mounting plate 45.

On the other hand, a molded brake pad receiving tray 49 is fixed on the reversing plate 40. The receiving tray 49 has a receiving surface 50 and has an open top surface,
Moreover, as shown in FIG. 7, two are provided side by side. When the air cylinder 42 is extended from the state shown in FIGS. 6 and 7, the cover plate 46 moves forward and
The upper surface of the two receiving trays 49 is covered.

Next, it will be explained how to carry out the method of the present invention using the apparatus described above.

At the beginning of the method of the invention, the piston rod 29 of the cylinder 28 is first projected in FIG. 1, and the sliding member 5 connected thereto is moved along the guide 4 to the left in the figure. As a result, the lower mold device 7 on the sliding member 5 comes to be located at the station A as shown by the imaginary line in FIG. An outer mold 15 is positioned on the lower mold device 7 so that the middle mold 12 is fitted into the bottom of the cavity 15a as shown in FIG. 5A. Next, the quantitative supply chute 23, which is supplied with a predetermined amount of the heat insulating fiber material BM measured in advance, is positioned on the outer mold 15 as shown in FIG. 5A. As mentioned above, the heat insulating fiber material BM is a powdered mixture of asbestos, cashew dust, metal powder, and others.

When the piston rod of the cylinder 25 is moved back in this state, the opening/closing plate 24 moves back and the chute 23
The bottom of the mold opens and a certain amount of insulation fiber material BM is inserted into the outer mold 15.
is supplied into each cavity 15a. At this time,
A medium-sized concave hole 13 forming the bottom of the cavity
Insulating fiber material BM is also inserted inside, and the same fiber material (hereinafter referred to as
(referred to as raw material) has the shape shown in FIG. 5B.

Next, the quantitative supply chute 23 is withdrawn from the position above the outer mold, and the head 55 having the boss thrust rod 54 is moved above the outer mold as shown in FIG. It is lowered so that it enters each. As a result, the raw material BM is particularly compacted within the concave hole 13,
The shape is as shown in FIG. 8B. This results in
The tip of the boss BS formed in the recessed hole becomes particularly dense.

The boss thrusting rod 54 then rises and retreats from above the outer mold 15, and then, as shown in FIG. 9A,
A head 57 with a leveling device 56 for the upper surface of the raw material BM descends. The leveling device 56 is composed of a large number of leveling needles 60 suspended from a support plate 61. The support plate 61, as shown in FIG. 10, is composed of a lower plate 62, an upper plate 63, and an elastic plate 64, such as a rubber plate, sandwiched between them, and the lower plate 62 is shown in FIG. It has leveling needle insertion holes 65 and tightening bolt insertion holes 66 which are randomly arranged as shown in FIG. Insert the leveling needle 60 from above to the bottom through any number of holes 65 in the lower plate 62, bring the lower surface of the leveling needle's head 60a into contact with the upper surface of the lower plate 62, and then let the leveling needle escape downward. prevent,
Next, sandwich the elastic plate 64 and place the lower plate 62 on the lower side of the upper plate 63, so that the tightening bolt insertion hole 66 and the upper plate 63 are aligned.
The leveling needle 60 is installed in the state shown in FIG. 10 by inserting a bolt into a similar hole (not shown) provided in and tightening both the upper and lower plates.

The head 57 of the leveling device 56 is provided with a vibrating device (not shown), and by operating the vibrating device with the lower end of the leveling needle 60 of the leveling device 56 in contact with the upper surface of the raw material BM. Then,
The top surface of the raw material BM is leveled by the tip of the leveling needle 60 as shown in FIG. 9B, and segregation of the raw material is eliminated. Moreover, the thickness of the raw material becomes uniform.

Note that the arrangement of the leveling needles 60 and the number of used leveling needles can be freely changed by removing the lower plate 62, and damaged leveling needles can be replaced immediately.

Next, after raising and retracting the leveling device 56, the press head 68 for temporary pressing is moved as shown in FIG. 12A.
is lowered, and the smoothed raw material BM is temporarily pressed from the upper surface. As a result, the raw material BM is solidified as shown in FIG. 12B. At this time, press head 6
If a protrusion 68a corresponding to the recessed hole 13 is provided on the lower surface of the recessed hole 13, the raw material inside the recessed hole 13 and the vicinity thereof can be compacted more densely.

After the compaction of the heat insulating fiber material BM is completed in this way, the press head 68 for temporary pressing is raised and retracted, and then the same quantity supply chute 23 as shown in FIG. 5A moves above the outer mold 15. . However, the semi-metallic material SM is supplied in a fixed quantity into the fixed quantity supply chute 23 instead of the previously described heat insulating fiber material BM. As mentioned above, the semimetallic material SM is a powdery material of a non-corrosive metal material.

When the opening/closing plate 24 retreats, the semi-metallic material
The SM falls from inside the chute 23 into the outer mold 15 and covers the insulation fiber material BM as shown in FIG. 13B.

Next, the quantitative supply chute 23 is evacuated, and the ninth
The same leveling device 56 as explained in Figure A is lowered into the outer mold as shown in Figure 14A, and the upper surface of the semimetallic material SM is leveled by vibration, eliminating segregation and making the thickness uniform. . The situation thus obtained is shown in Figure 14B.

All the steps described above are performed at station A. After completing the above steps, the first
As the piston of the cylinder 28 shown in the figure retreats, the sliding member 5 is displaced to the right in the figure, and the lower die device 7 on the sliding member 5 moves from the imaginary line position to the solid line position and moves to the station Z. Move. At the same time,
The outer mold 15 is also moved to station Z. Thus, the state shown in FIG. 15 is obtained.

In this state, the above-mentioned press ram 21 is
5, the heat insulating fiber material BM and the semi-metallic material SM are pressed together with the lower mold device 7 and molded. At this time, as shown in FIG.
The upper platen 9 moves down a little while compressing the spring 11.

As described above, the brake pad is preformed within the outer mold 15. To remove the brake pad from the outer mold, the push-up rod 16 is pushed upward by a drive device (not shown) in the state shown in FIG. As a result, the upper end of the push-up rod 16 lifts the outer mold through the overhanging portion 17 of the outer mold, and finally the overhanging portion 17 is brought into contact with the stopper 19 of the upper bent portion of the plate body 18, as shown in FIG. bring it into contact. By this,
The outer mold 15 stops rising, and the middle mold 12 of the lower mold device 7
is exposed. At this time, the molded brake pad is inside the outer mold 15.

Next, the sliding member 5 moves forward as the piston of the cylinder 28 shown in FIG. Thus, a space is left between the plates 18.

The receiving tray 49 is sent into this empty space as shown in FIG. This is cylinder 28
This is done by the advancement of the piston. That is,
As the piston moves forward, the support plate 32 fixed to the sliding member 5 also moves forward, and the receiving tray 49 on the support plate 32 also moves forward and moves below the outer mold 15.

In the state shown in Fig. 18, the press ram 2
1 goes down. As a result, the brake pad is pushed downward inside the cavity 15a, and
It is placed on a receiving tray 49 as shown in the figure.
At this time, the brake pad is supported by the receiving tray 49 with its boss B facing downward. The support plate 32 supporting the receiving tray 49 is then retracted back to the position of FIG. 1 by the retraction of the piston of the cylinder 28. Next, the cover plate 46 covers the upper surface of the receiving tray 49 as the piston of the cylinder 42 moves forward as shown in FIG.
5, the reversing plate 40 is reversed to the imaginary line position in FIG. 6 via the pivot 34, and then the receiving tray 49
By retreating the cover plate 46, the brake pad is placed on the receiving portion 70 shown in FIG. 6 with the boss BS facing upward. The receiving section 70 is, for example, a conveyor.

In this way, the pre-formed brake pads are placed with the easily damaged boss facing upwards, and are conveyed on a conveyor, where they are press-formed while being heated between heating plates to become the final product. .

〔effect〕

As described above, in the present invention, a concave hole for forming a boss of a brake pad is provided in the bottom of the outer mold facing upward, a heat insulating fiber material is first supplied into the outer mold, the heat insulating fiber material is put into the concave hole and tamped, Next, the upper surface is smoothed and temporarily pressed, and then semi-metallic material is supplied into the outer mold, smoothed, and then press-formed. As a result, the density and strength of the boss part is increased, and a brake pad with a uniform thickness without segregation is obtained. In addition, in the combined invention, the brake pad can be sent to the final pressing process while preventing damage to the boss portion.

[Brief explanation of drawings]

Fig. 1 is an overall view of the apparatus used in the brake pad molding method of the present invention, Fig. 2 is a sectional view of the brake pad, Fig. 3 is a sectional view taken along the - line in Fig. 1, and Fig. 4 is a front view of the lower die device. Figure 5A is a diagram showing the state of supply of the insulation fiber material into the outer mold, Figure 5B is a diagram showing the shape of the insulation fiber material supplied into the outer mold, and Figure 6 is a diagram showing the preformed brake pad. 7 is a plan view of the same, FIG. 8A is a diagram showing the tamping process using a boss tamping rod, and FIG. 8B is a diagram showing the shape of the insulating fiber material provided by the same process. Figure 9A is a diagram showing the breaking-in process, Figure 9B is a diagram showing the shape of the heat-insulating fiber material provided by the same process, and Figure 10 is a longitudinal cross-sectional view showing the breaking-in needle extraction part of the breaking-in device. , 11th
The figure is a plan view of the lower plate shown in Figure 10, Figure 12A is a diagram showing the temporary pressing process, Figure 12B is a diagram showing the shape of the heat insulating fiber material obtained in the same process, and Figure 13A is a diagram of the semimetallic material. Figure 13B is a diagram showing the supply process, and Figure 14 is a diagram showing the shape of the raw material obtained in the same process.
Figure A is a diagram showing the leveling process of semi-metallic materials.
Figure 14B is a diagram showing the shape of the raw material obtained by the same process, Figure 15 is a diagram showing the state before the start of the press molding process, Figure 16 is a diagram showing the press molding process, and Figure 17 is a diagram of the outer mold. Diagram showing the opening process, No. 18
This figure shows a state where the brake pad after preforming is about to be taken out, and FIG. 19 shows a state where the brake pad has been completely taken out. BS...Boss, SM...Semi-metallic material (brake pad), BM...Insulating fiber material (backing member), Z...Press/mold opening station, A...Filling/temporary pressing station, B... Receiving tray reversing station, C... Receiving tray reversing station, 2... Bed, 4... Guide,
5...Sliding member, 7...Lower die device, 12...Medium die forming part of the lower die, 13...Recessed hole, 15...Outer die, 16...Uplifting rod, 19...Stopper, 21
...Press ram, 23...Quantitative supply chute,
23a...Chute part, 24...Opening/closing plate, 25
...Air cylinder, 28 ...Air cylinder, 32
... Support plate, 34 ... Axis, 35 ... Pinion, 3
6...Rack, 38...Air cylinder, 40...
Reversing plate, 42... Air cylinder, 46... Cover plate, 49... Receiving tray, 54... Boss pushing rod, 56... Leveling device, 60... Leveling needle, 68... Press head for temporary pressing, 70... Receiving part.

Claims (1)

[Claims] 1. A brake pad body made of semi-metallic material,
It is integrally joined to the back of the brake pad body,
A method for forming a brake pad comprising a brake pad main body and a backing member made of a heat insulating fiber material having a protruding boss on the opposite surface, the heat insulating fiber being placed in a mold having a concave hole for forming the boss in the bottom surface. The powder of the insulation material is supplied from above, and the boss ramming rod is lowered from above into the recessed hole to compact the insulation fiber material in the recessed hole.Then, after leveling the upper surface of the insulation fiber material, the entire insulation fiber material is tamped. Temporary pressing was applied from above to the mold, and then powder of the semimetallic material was supplied from above into the mold to cover the top surface of the temporarily pressed insulating fiber material, and then the top surface of the semimetallic material was leveled. After that, a press ram is lowered into the mold from above, and the insulating fiber material and semi-metallic material are compression-molded between the bottom of the mold and the ram to obtain a preformed brake pad. A method for molding brake pads that involves removing them from a mold. 2. The upper surface of the insulating fiber material is leveled by suspending a large number of leveling needles inside the mold so that their tips contact the upper surface of the fiber material, and applying vibration to the top surface of the fiber material, as set forth in claim 1. How to mold brake pads. 3. The method of molding a brake pad according to claim 1, wherein the temporary pressing of the insulating fiber material is carried out by lowering a press head for temporary pressing into the inside of the mold. 4 A protrusion is provided on the lower surface of the press head for temporary pressing so as to vertically align with the recessed hole in the bottom of the mold, so that when the press head is lowered, a pressing force is applied to the insulating fiber material inside the recessed hole and directly above the recessed hole. A method for molding a brake pad according to claim 3, wherein the method is as follows. 5 Brake pad body made of semi-metallic material,
It is integrally joined to the back of the brake pad body,
A method for molding a brake pad comprising a backing member made of a heat insulating fiber material and having a protruding boss on the opposite side of the brake pad body, the insulating fiber material being placed in a mold having a concave hole for forming the boss in the bottom surface. powder is supplied from above, and the boss tamping rod is lowered from above into the recessed hole to compact the insulating fiber material in the recessed hole.Then, after leveling the upper surface of the insulating fiber material, it is applied to the entire insulating fiber material. Temporary pressing is performed from above, and then powder of the semi-metallic material is supplied into the mold from above to cover the top surface of the temporarily pressed insulating fiber material, and then the top surface of the semi-metallic material is leveled. , a press ram is lowered into the mold from above, and the insulating fiber material and semi-metallic material are compression-molded between the bottom of the mold and the ram to obtain a preformed brake pad, and then the bottom of the mold is Release and push the brake pad downward from the bottom of the mold.
Place the brake pad on the receiving tray at the bottom of the mold with the boss facing downward, then turn the receiving tray upside down while holding the brake pad on the receiving tray, and place the brake pad with the boss facing upward. A method for molding a brake pad, characterized by placing the brake pad on a receiving part. 6. A method for molding a brake pad according to claim 5, in which the bottom of the mold is formed by a lower mold that can be lowered and has a recessed hole in the upper surface, and the bottom of the mold is opened by relatively lowering the lower mold. . 7. The receiving tray is supported at the tip of an inverting plate whose base is rotatably supported, and the receiving tray is inverted by rotation of the inverting plate.
Brake pad molding method described in section.