JPH06226778A - Member with eye part at end and manufacture thereof - Google Patents

Abstract

PURPOSE:To accurately form an inner surface of a hold when a bush is press injected in the hole of a resin eye part provided by injection molding, and to easily release it from a mold. CONSTITUTION:An eye part 12 is provided at an end 25 of a leaf spring body 11 made of FRP. The part 12 is so molded in a shape for enclosing the end 25 of the body 11 by injection molding. A metal collar 35 is provided at an inner periphery 34 of the part 12 of an end cylindrical part 32 of the part 12. Both end faces 90, 91 of the collar 35 are exposed with both sides of the part 32. The collar 35 is mounted at a pin of a mold before the part 12 is injection molded, and the faces 90, 91 of the collar 35 are brought into close contact with the inner surface of the mold at the time of clamping the molds. The resin injected in the molds is cured thereby to stick the resin of the periphery 34 to the outer periphery of the collar 35 to fix the collar 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member such as an FRP leaf spring having an eyeball portion at the end of a member body and a method for manufacturing the member.

[0002]

2. Description of the Related Art In a leaf spring device used in a vehicle suspension system, a fiber reinforced plastic (F
The use of leaf springs made of (RP) is desired. In the leaf spring for suspension, an eyeball portion for connecting to a member on the vehicle body side is provided at an end of a strip-shaped leaf spring body, but a leaf spring made of FRP is a unidirectional reinforcing fiber by a filament winding method or the like. Since the molding is performed with the tension of the plate spring substantially constant, it is difficult to integrally form the eyeball part having a small radius of curvature around the end of the leaf spring body. For this reason, normally, an eyeball component made separately from the leaf spring body is fixed to the leaf spring body by a fastening component such as a bolt or a washer.

However, in order to fix the eyeball component with a fastening component such as a bolt, it is necessary to form a hole for inserting the bolt or the like in the leaf spring body and tighten the nut with a nut or the like. Therefore, it may be difficult to completely fix the eyeball component. In addition, there is a problem that cracks may occur starting from the holes formed in the leaf spring body.

Therefore, the present inventors have considered forming the eyeball portion on the end portion of the leaf spring body by injection molding. The mold for molding the eyeball portion used in this case has an opening for an outsert into which the end of the leaf spring body is inserted and a space (cavity) for molding the eyeball portion. The eyeball portion is injection-molded with the end portion of the leaf spring body inserted in the portion.

[0005]

Since the resin eyeball part molded by the above-mentioned injection molding undergoes a considerably large temperature change in the molding process, it is necessary to change the temperature of the resin to obtain a predetermined product size. It is necessary to design the mold and the like in consideration of shrinkage and the amount of shrinkage when the resin cures. However, the shrinkage behavior of the resin does not always follow the calculation, and therefore some dimensional error is unavoidable. This tolerance is considerably larger than that of metal products such as inserts or outsert steels used in injection molding.

Therefore, when the bush is press-fitted into the hole of the resin eyeball after molding, the dimensional relationship between the inner diameter of the hole and the outer diameter of the bush becomes a problem. That is, even if the outer peripheral surface of the bush is machined with high precision, press-fitting of the bush is impossible if the inner diameter of the eyeball hole is too small, and conversely, if the inner diameter of the hole is too large, the bush cannot be securely fixed. Causes problems such as.

Further, when a pin is provided on the mold for forming the hole of the eyeball portion, the hardened resin adheres to the pin and the hardened resin shrinks to some extent to tighten the pin. As a result, there is a problem in that the pin is less likely to come off the hole of the eyeball portion when the die is released, and the die release becomes difficult.

Therefore, an object of the present invention is to provide a hole having an inner surface finished with high precision in the eyeball part in a case where the eyeball part is provided by injection molding at the end of the member body such as a FRP leaf spring. It is an object of the present invention to provide a member having an eyeball part that can be removed and can be easily removed from the mold, and a method for manufacturing the member.

[0009]

A member having an eyeball portion of the present invention developed to achieve the above object is an elongated member body made of fiber reinforced plastic, metal or ceramics, and a member body by injection molding. A resin-made eyeball portion provided at an end portion of the eyeball portion, and the eyeball portion has a base portion having a shape that encloses the end portion of the member main body, and an eyeball inner periphery formed integrally with the base portion and extending in the width direction of the base portion. A terminal tubular portion having a surface, and further on the inner peripheral surface of the eyeball,
The metal collar has both end surfaces exposed on both sides of the terminal tubular portion and is adhered to the resin on the inner peripheral surface of the eyeball by being inserted during injection molding of the eyeball portion.

Further, the manufacturing method of the present invention comprises a member having an elongated member body made of fiber reinforced plastic, metal or ceramics, and an eyeball part formed by injection molding so as to wrap around the end of the member body. A method for manufacturing, wherein a pin is provided on one of a pair of molds having a cavity for molding an eyeball part into which the end of the member main body is inserted, the pin is covered with a metal collar, and the mold is closed. By bringing both end surfaces of the collar into close contact with the inner surface of the mold by injecting a molten resin for molding the eyeball into the cavity and curing the resin, the molded eyeball is demolded together with the collar. It is characterized by doing.

[0011]

[Function] The member main body is molded in a predetermined shape in advance,
The end of the member main body is inserted (outsert) into the cavity of the mold, and the mold is closed while the pins of the mold are covered with the collar. By closing the mold, both end surfaces of the collar come into close contact with the inner surface of the mold, so that a seal is formed between the both end surfaces of the collar and the inner surface of the mold.

As described above, in the state where the collar is inserted in the predetermined position in the mold, the injection molding machine injects the molten resin for molding the eyeball portion into the cavity and applies the predetermined injection holding pressure. Thus, the molten resin is filled in the cavity. The molten resin that has reached the collar is prevented from entering the inside of the collar by the sealing action due to the close contact of both end surfaces of the collar and the inner surface of the mold. When the resin is hardened, the resin on the inner peripheral surface of the eyeball and the outer peripheral surface of the collar are bonded to each other, and the hardened resin shrinks to some extent, so that the pin is externally tightened. Therefore, the collar and the eyeball portion are firmly integrated.

The pin existing inside the collar at the time of injection molding moves in the demolding direction together with one of the molds at the time of demolding, but since the resin does not enter the inside of the collar, the resin sticks to the pin. Nothing. Therefore, an excessive load is not applied when removing the pin, and the mold can be easily released.

Since the inner surface of the metal collar provided on the eyeball portion by the above-mentioned insert molding can be finished with high precision in advance before the insert, when the bush is attached to the eyeball portion after molding, the collar The bush can be pressed into the inside of the machine without any problem.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The leaf spring device 10 for vehicle suspension shown in FIG. 2 is a belt-shaped F as an example of a member main body.
The leaf spring main body 11 made of RP and a pair of eyeball portions 12 provided at both ends of the leaf spring main body 11 are provided. An axle support member 13 is provided at an intermediate portion of the leaf spring body 11 in the longitudinal direction.
4 are supported.

The one eyeball portion 12 located on the left side in FIG. 2 is connected to the bracket 20 on the vehicle body side, and a load in the front-rear direction, the up-down direction, or the twist is applied while the vehicle is running. The other eyeball portion 12 located on the right side of FIG.
It is supported by a bracket 22 on the vehicle body side via a supporting member 21 such as a shackle. The support member 21 swings in the front-rear direction with a change in span when the leaf spring body 11 bends in the vertical direction.

An example of the leaf spring main body 11 is an epoxy resin as a matrix reinforced by a large number of glass fibers along the longitudinal direction of the leaf spring main body 11. The part is formed in a curved shape so as to be convex downward.

As an example of a method for manufacturing the leaf spring body 11,
A well-known filament winding method can be applied, but a pull forming method or another manufacturing method may be adopted. When the leaf spring main body 11 is manufactured by the filament winding method, the glass roving is passed through a resin impregnation tank containing the matrix resin before being cured, and the resin impregnated glass roving is wound around a rotating mold until a predetermined thickness is obtained. Then, the plate spring main body 11 having a predetermined shape is formed by removing the mold after heating for a predetermined time in the curing furnace.

The reinforcing fibers used in the leaf spring body 11 may be inorganic fibers such as carbon fibers, organic fibers such as aramid fibers, or metal fibers instead of glass fibers. Matrix resin, instead of epoxy,
Unsaturated polyester, phenol resin, etc. may be used as long as it is a thermosetting resin.

The eyeball portion 12 is formed into a shape as shown in FIGS. The eyeball portion 12 is an injection-molded product of a resin reinforced with short fibers, and has a leaf spring body 11
A base portion 30 having a shape that encloses the entire circumference of the end portion 25 and a cylindrical terminal tubular portion 32 located outside the end surface 31 of the leaf spring body 11 are integrally formed. Further, reinforcing ribs 33 are integrally formed so as to connect the upper and lower surfaces of the base portion 30 and the terminal attachment portion 32.

An eyeball inner peripheral surface 34 extending along the width direction of the base portion 30 is formed on the terminal tubular portion 32, and a metal collar 35 is provided on the eyeball inner peripheral surface 34. Color 3
An example of the material of No. 5 is steel, but an aluminum alloy or other metal may be used depending on the case. The thickness of the collar 35 is preferably 2 mm or more. Both end surfaces 90, 91 of the collar 35 are exposed on both sides of the terminal tubular portion 32.

A bush 37 is inserted into the through hole 36 along the axial direction of the collar 35 so as to be connected to the support member 21 such as the bracket 20 or the shackle shown in FIG. Therefore, the inner peripheral surface of the through hole 36 of the collar 35 is preliminarily finished to have a predetermined inner diameter according to the outer diameter of the bush 37.

The bush 37 shown in FIG. 1 has a rubber cushioning member 38 provided between an outer cylinder and an inner cylinder made of metal, and the outer diameter of the bush 37 is set so that it can be press-fitted into the collar 35. is there. A connecting pin (not shown) is inserted into the hole 39 of the bush 37. The bush 37 may be a simple rubber bush or a well-known metal bush in addition to the above configuration.

The eyeball portion 12 is a matrix made of a thermoplastic resin such as nylon 66 (polyhexamethylene adipamide) mixed with a large number of short glass fibers as reinforcing fibers, and has a glass content of 30 wt. % ~ 60
The range is wt%. The glass content of this example is 4
It is 5 wt%. An example of the fiber diameter is 20 μm, and an example of the fiber length is 200 μm. The short fibers may be carbon fibers, ceramic fibers, or organic fibers other than glass. As the matrix resin used for the eyeball portion 12, a material that is lightweight and has excellent corrosion resistance is suitable, but as long as it can be injection-molded, nylon 66
However, an appropriate thermoplastic resin can be used.

As shown in FIG. 4, tapered portions 40 are formed on both sides of the eyeball portion 12 so that the width B2 of the terminal tubular portion 32 is narrower than the width B1 of the base portion 30 of the eyeball portion 12. It is provided. On both sides of the end portion 25 of the leaf spring body 11, there are formed tapered surfaces 41 corresponding to the tapered portions 40 so that the plate width on the end surface 31 side is narrowed. By doing so, the width B2 of the terminal tubular portion 32 becomes equal to the width B3 of the leaf spring main body 11, so that the bracket 20 and the supporting member 21 such as the shackle can be attached to the vehicle body without any problem even if they are conventional. You can When the width B1 of the base portion 30 and the width B2 of the terminal tubular portion 32 may be equal to each other, the end portion 25 of the leaf spring main body 11 may also have a straight shape, and thus the tapered surface 41 need not be provided.

At the edge of the base portion 30 of the eyeball portion 12, that is, at the base end edge 45 of the eyeball portion, there is provided a sealing material 50 which is continuous over the entire circumference thereof. This sealing material 50 is the eyeball part 1.
It is made of an elastic body such as an O-ring having a heat resistance that does not deteriorate even if it is touched with a molten resin during injection molding of 2, and for example, nitrile rubber, polyfluorinated ethylene, polypropylene, silicone rubber, etc. are suitable. This sealing material 50
Is in close contact with both the surface of the leaf spring body 11 and the base end edge 45 of the eyeball portion, and the back side of the sealing material 50 is the base end edge 4 of the eyeball portion.
It is in a state of being bonded to No. 5.

The eyeball portion 12 is molded using a pair of molds 55, 56 for injection molding as shown in FIGS. One mold 55 is on the fixed side and the other mold 56 is on the moving side. These molds 55, 56 are clamped by a mold clamping device (not shown) from the direction of the arrow in FIG. It As shown in FIG. 6, a resin injection port 61 is provided in a fixed side mounting plate 60 provided in the fixed side mold 55, and an injection molding machine (not shown) is provided in the injection port 61.
The nozzles are designed to be joined.

The dies 55 and 56 are provided with an outsert opening 65 into which the end 25 of the leaf spring body 11 is inserted, and the base 30 and the terminal tubular portion 32 are integrally molded. A molding space (cavity) 66 is provided. Further, as shown in FIG. 7 as a representative of one mold 55, the molds 55 and 56 are provided with a plurality of gates 70 a to 70 e communicating with the cavity 66, a molten resin flow section 71, a spool 72, and the like. There is. Gates 70a-7
0e, the pair of first gates 70a and 70b located near the end face 31 of the leaf spring body are open at positions facing each other with a gap 75 between the end face 31 and the collar 35 interposed therebetween. . The second gates 70c and 70d face the upper and lower surfaces 76 and 77 of the end portion 25 of the leaf spring body.

As shown in FIG. 5, the mold 56 on the moving side is provided.
A pin 80 is projected on the. The collar 35 described above is attached to the pin 80. The length L of the collar 35 is slightly longer than the protruding height H of the pin 80, and is dimensioned so that both end surfaces 90, 91 of the collar 35 can be brought into close contact with the inner surfaces of the molds 55, 56 during mold clamping.

A truncated cone-shaped convex portion 81 is provided on the tip surface of the pin 80. The convex portion 81 faces the tapered concave portion 82 provided in the fixed-side die 55, and the die 55, 5
When the 6 is closed, the convex portion 81 and the concave portion 82 are fitted to each other, so that the centering of the pin 80 with respect to the die 55 is accurately performed.

The seal material 50 is accommodated in a seal material accommodating portion 85 provided on the inner peripheral surface side of the outsert opening portion 65. As shown in FIG. 7, the sealing material 50 is housed in a state in which it is in close contact with the outer peripheral surface of the leaf spring main body 11 and the inner peripheral surface of the sealing material housing portion 85, and is introduced into the cavity 66 during injection molding. Molten resin is used for outsert opening 6
It is designed to prevent leakage from the outside.

Next, a method of manufacturing the eyeball portion 12 using the above-mentioned molds 55 and 56 will be described. The leaf spring body 11 is formed in advance into a predetermined shape in the leaf spring manufacturing process. The seal member 5 is attached to the end 25 of the leaf spring body 11.
Attach 0. Further, a thermosetting adhesive (for example, an epoxy-based, polyurethane-based, polyester-based or polyimide-based adhesive) is applied to the entire surface of the end portion 25 of the leaf spring body 11. This adhesive is hardened by heat when the eyeball part 12 is injection-molded, and the eyeball part 12 and the leaf spring body 11 are cured.
And can be firmly adhered to each other.

Outsert opening 6 of dies 55 and 56
5, the end portion 25 of the leaf spring main body 11 is arranged, and the sealing material 50
Are placed in the sealing material accommodating portion 85. By doing so, the seal material 50 seals the entire circumference between the surface of the leaf spring main body 11 and the inner peripheral surface of the outsert opening 65 during mold clamping. Therefore, even if the outsert has a relatively large dimensional tolerance like the leaf spring body 11 made of FRP, the gap between the leaf spring body 11 and the outsert opening 65 is provided by providing the seal member 50. Is reliably sealed. In addition, the pin 80 is covered with the collar 35. The same thermosetting adhesive as described above is also applied to the outer peripheral surface of the collar 35.

As shown in FIG. 6, when the molds 55 and 56 are closed and tightened by the mold clamping device, the both end surfaces 90 and 91 of the collar 35 previously attached to the pin 80 are fixed to the molds 55 and 56.
Close to the inner surface of 56. In this state, the injection molding machine injects the plasticized resin for molding the eyeball portion into the cavity 66 through the spool 72 and the gates 70a to 70e.

The air existing in the cavity 66 is
With the injection of the molten resin, a gap (20
To about 30 μm). Since the molten resin cannot pass through such a slight degassing gap, the cavity 66 is filled with the molten resin for molding the eyeball portion without a gap, and a predetermined injection holding pressure is applied. The molten resin reaching the sealing material 50 is prevented from leaking to the outside by the sealing material 50. Also,
The molten resin that has reached the collar 35 is prevented from entering the inside of the collar 35 by the sealing action due to the fact that both end surfaces 90, 91 of the collar are in close contact with the inner surfaces of the molds 55, 56.

During the injection molding, the first gate 70a,
Molten resin injected from the gap 70b into the gap 75 between the end surface 31 of the leaf spring body and the collar 35 is discharged from the gates 70a and 70a.
The injection holding pressure of the molten resin pushed in from b is filled with high density and the high injection holding pressure is maintained. Therefore, it is possible to avoid the occurrence of voids or weld lines exceeding the allowable limit in the resin injected into the gap 75.

Further, at the portion where the base portion 30 is molded, the pressure of the molten resin injected from the second gates 70c and 70d is applied to the upper and lower surfaces 76 and 77 of the end portion 25 of the leaf spring body.
Since it is applied in the direction of pressing, the adhesion between the base portion 30 and the end portion 25 of the leaf spring main body is increased, and the density of the base portion 30 can be increased. Moreover, the end portion 25 is coated with a thermosetting adhesive. In addition, the base portion 30 and the end portion 25 can be strongly bonded to each other. For this reason,
The leaf spring main body 11 and the eyeball portion 12 can be reliably fixed to each other without using a fastening bolt, a clamp component, or the like.

The pin 80 existing inside the collar 35 at the time of injection molding moves in the demolding direction together with the one die 56 at the time of demolding, but since the resin does not enter the inside of the collar 35, No resin sticks to 80. Therefore, when the pin 80 moves in the direction of pulling out from the collar 35, an excessive load is not applied and the mold can be easily released.

The metal collar 35 is inserted into the molds 55 and 56 before injection molding.
Since No. 5 is provided in the terminal tubular portion 32 by injection-molding the eyeball portion 12, problems such as cracks and residual strain that occur when the collar 35 is press-fitted into the eyeball inner peripheral surface 34 after eyeball molding are produced. Can be avoided. This color 35
The resin of the eyeball portion 12 is injection-molded and then contracted to some extent, so that the entire circumference of the collar 35 firmly adheres to the eyeball inner peripheral surface 34, and a thermosetting adhesive is applied to the collar 35. Combined with that, the strength against pull-out is extremely high.

In addition, like the collar 35a shown in FIG.
The both end portions 95 may be shaped so as to spread outward, or flange portions may be provided on the collar to enhance the retaining effect with respect to the inner peripheral surface 34 of the eyeball, as in the collar 35b shown in FIG. In addition, the retaining effect may be enhanced by providing a recess 96 along the circumferential direction on the outer peripheral surface of the collar 35b.

Further, as a collar 35c shown in FIG. 10, a collar 3 is provided as a means for enhancing the anti-rotation effect.
You may provide the recessed part 97 along the axial direction on the outer peripheral surface of 5c. Further, like the collar 35d shown in FIG. 11, even if the convex portion 98 projecting to the outer surface side is provided in the circumferential direction of the collar 35d, the retaining effect can be enhanced. Alternatively, FIG.
2 and collar 35e as shown in FIG.
By providing the convex portion 99 along the axial direction of 5e,
You may make it improve the anti-rotation effect.

The present invention is not limited to leaf springs, but is a member such as a tension rod or a lateral rod used in a suspension mechanism of a vehicle, which is a member that receives a load such as bending, tension and compression, and has an elongated shape. The same can be applied as long as it has a terminal part corresponding to the eyeball part at the end of the member body. Further, the material of the member main body is not limited to FRP, and the same applies to metal or ceramics.

[0043]

According to the present invention, in the case where the eyeball portion is formed by injection molding on the end portion of the member main body, the bush is inserted into the hole of the metal collar which is firmly fixed to the eyeball portion. Therefore, even with a resin eyeball part having a relatively large dimensional tolerance after molding, the inner surface of the hole for inserting the bush can be made highly precise, and mold release after molding the eyeball part becomes easy. .

[Brief description of drawings]

FIG. 1 is a perspective view of an end portion of a leaf spring device showing an embodiment of the present invention.

FIG. 2 is a side view of the leaf spring device shown in FIG. 1 attached to a vehicle.

FIG. 3 is a side view showing a partial cross section of an end portion of the leaf spring device shown in FIG.

FIG. 4 is a plan view showing a partial cross section of an end portion of the leaf spring device shown in FIG.

5 is a plan view showing, in a partial cross section, a mold used to mold the eyeball portion of the leaf spring device shown in FIG. 1. FIG.

FIG. 6 is a plan view showing a state in which the mold shown in FIG. 5 is closed in a partial cross section.

7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a sectional view of a part of an eyeball portion showing a modified example of a collar.

FIG. 9 is a side view of an example in which a circumferential recess is provided on the collar.

FIG. 10 is a side view of an example in which a circumferential recess and an axial recess are provided in a collar.

FIG. 11 is a side view of an example in which a collar is provided with a convex portion in a circumferential direction.

FIG. 12 is a side view of an example in which a circumferential convex portion and an axial convex portion are provided on a collar.

13 is a sectional view taken along the line aa in FIG.

[Explanation of symbols]

10 ... Leaf spring device, 11 ... Leaf spring main body (member main body), 1
2 ... Eyeball portion, 25 ... End portion of leaf spring main body, 30 ... Base portion of eyeball portion, 31 ... End surface of leaf spring main body, 32 ... Terminal tubular portion, 3
4 ... Inner peripheral surface of eyeball, 35 ... Collar, 35a to 35e ... Collar, 55, 56 ... Mold, 66 ... Cavity, 80 ... Pin, 90, 91 ... Both end faces of collar.

Claims (3)

[Claims] 1. An elongated member main body made of fiber reinforced plastic, metal or ceramics, and a resin eyeball portion provided at an end portion of the member main body by injection molding, wherein the eyeball portion is the member. A base portion having a shape that encloses the end portion of the main body, and a terminal tubular portion that is integrally formed with the base portion and that has an inner peripheral surface of the eyeball along the width direction of the base portion, and further on the inner peripheral surface of the eyelet, both end surfaces Is provided on both sides of the terminal tubular portion and is equipped with a metal collar adhered to the resin on the inner peripheral surface of the eyeball by being inserted at the time of injection molding of the eyeball portion. Element. 2. A member having an eyeball portion according to claim 1, wherein the outer peripheral surface of the collar is provided with a concave portion or a convex portion for enhancing a retaining effect or a rotation preventing effect with respect to the inner peripheral surface of the eyeball. 3. A method for producing a member having an elongated member body made of fiber reinforced plastic, metal or ceramics, and an eyeball part formed by injection molding so as to wrap around the end of the member body. , A pin is provided on one of a pair of molds having a cavity for molding an eyeball part into which an end of the member main body is inserted, a metal collar is put on the pin, and both ends of the collar are closed by closing the mold. The surface is brought into close contact with the inner surface of the mold, and a molten resin for molding an eyeball portion is injected into the cavity, and after the resin is cured, the formed eyeball portion is released from the mold together with the collar. A method for manufacturing a member having an eyeball portion at its end.