JP4886407B2 - Outsert molding method for belt with protrusions - Google Patents

Description

  The present invention relates to an outsert molding method for a belt with protrusions.

  The toothed belt 2 is formed by an inner peripheral tooth portion provided with a plurality of teeth 12 at predetermined intervals in the belt longitudinal direction and an outer peripheral back portion 14. Such a toothed belt 2 is driven to run by being suspended on a toothed pulley. When this belt 2 is used for transporting a card or paper, the card or paper is locked. Protruding bodies 4 for feeding are formed on the belt 2 by molding with resin (see, for example, Patent Document 1).

FIG. 3 shows an example in which a protrusion 4 is provided on the back surface of the belt 2 by resin molding. The belt 2 is formed by molding teeth 12 and a back portion 14 with an elastomer such as polyurethane. The support projection 1 is integrally provided on the back portion 14 of the second projection. Then, the belt 2 produced by projecting the support projection 1 on the back surface is set in a molding die 3 for injection molding, and injection molding is performed. The belt 2 is set so that the support protrusion 1 is disposed in the cavity 15 provided in the molding die 3 as shown in FIG. 4, and the thermoplastic resin is injected into the cavity 15 through the gate 16. Thus, the protrusion 4 can be formed. The projection 4 is formed in an outsert manner with the bifurcated joint 5 formed at its base sandwiching both sides of the support projection 1 in the longitudinal direction of the belt. As shown in FIG. The body 4 can be provided to stand on the back surface of the belt 2.
JP 2001-341157 A

  The protrusion 4 formed on the back surface of the belt 2 often has an asymmetric shape on the left and right sides of the belt in the longitudinal direction with the support protrusion 1 interposed therebetween. Therefore, the cavity 15 of the molding die 3 is similarly supported. It is formed in an asymmetric shape across the part 1. As described above, when the shape of the cavity 15 is asymmetric with respect to the support protrusion 1, the resin is injected into the cavity 15 of the molding die 3 as described above, and the protrusion is formed on the support protrusion 1 of the belt 2. When the body 4 is outsert-molded, the flow of the resin injected from the gate 16 in the cavity 15 is different on the left and right of the support protrusion 1 as shown by the arrows in FIG. The flow rate balance of the resin becomes unbalanced on the left and right. Here, the belt 2 itself is fixed in the molding die 3, but the support protrusion 1 is in a free state in the cavity 15, so that the flow rate balance of the resin is lost on the left and right sides of the support protrusion 1. When a difference occurs in the pressure acting on both the left and right sides of the protrusion 1, the support protrusion 1 is deformed so as to tilt to either the left or right.

Then, when the protrusion 4 is outsert-molded in such a state that the support protrusion 1 is inclined, the support protrusion 1 is moved in the traveling direction of the belt 2 (in FIG. 5 by an arrow as shown in FIG. 5A, for example). When the protrusion 4 is outsert-molded in a state of being tilted to the position shown in FIG. 5B, the protrusion 4 is reversed as shown in FIG. 5B due to the restoration of the support protrusion 1 after being removed from the molding die 3. When the belt 2 falls down in the direction opposite to the traveling direction of the belt 2 , the lower surface of the front portion of the protrusion 4 peels off from the back surface of the belt 2 and floats. The problem that there is a possibility of being caught is caused.

Further, for example, as shown in FIG. 6A, when the projection 4 is outsert-molded in a state where the support protrusion 1 is inclined in the direction opposite to the traveling direction of the belt 2 (indicated by an arrow in FIG. 6), a molding die is formed. As shown in FIG. 6B, the protrusion 4 is reversed in the moving direction of the belt 2 as shown in FIG. The distance L between the claw 17 and the back surface of the belt 2 is reduced, and there is a problem in that the number of papers that can be transported decreases when transporting papers and the like.

  The present invention has been made in view of the above points, and can be outsert-molded to the support protrusion in a correct standing state without falling down the protrusion, and the protrusion is attached to the support protrusion of the belt with high strength. It is an object of the present invention to provide an outsert molding method for a belt with protrusions that can be outsert molded.

In the outsert molding method for a belt with protrusions according to claim 1 of the present invention, a belt 2 having a support protrusion 1 integrally projecting on the back surface is formed into a molding die 3 formed by two mold parts 18 and 19. said resin molding die 3 by injection, the out protrusions 4 on both sides in the belt longitudinal direction of the supporting projections 1 in bifurcated state sandwiched at the junction 5 of the base in the injected resin concert with sets by molding, when integrally provided by standing the protrusion 4 on the back of the belt 2, the through-hole 6 penetrating in the longitudinal direction of the belt to the supporting protrusions 1 provided, of the support projections 1 set the both sides of the belt width direction while fixing the support projections 1 hold two mold parts 18, 19 of the molding die 3 belt 2 to the molding die 3, said forming die 3 the injection to the resin to the support projection 1 The serial protrusions 4 together with the outsert molding, connecting integrating a resin filled with the joining portion 5 which is formed so as to sandwich both surfaces in the belt longitudinal direction of the supporting projection 1 in the through hole 6 It is characterized by doing.

  According to the present invention, the belt 2 is set on the molding die 3 with the supporting projections 1 fixed by pressing both side surfaces of the supporting projections 1 in the belt width direction within the molding die 3. Even if the flow of the injected resin in the molding die 3 is different on the left and right sides of the support protrusion 1 and the pressure on the left and right sides of the support protrusion 1 is different, the support protrusion 1 does not tilt. The body 4 can be outsert-molded, and the protrusion 4 can be outsert-molded on the support protrusion 1 in the correct standing state. Also, a through hole 6 that penetrates the support protrusion 1 in the belt longitudinal direction is provided, and a joint portion 5 that is molded so as to sandwich both surfaces of the support protrusion 1 in the belt longitudinal direction, and a resin that fills the through hole 6. Can be integrated with the support protrusion 1 by the resin molded in the through-hole 6 of the support protrusion 1, and the bifurcated joint 5 of the base of the protrusion 4 can be integrated. The protrusion 4 does not come off the support protrusion 1, and it is possible to obtain high attachment strength of the protrusion 4 that is outsert-molded on the support protrusion 1, and to apply stress to the protrusion 4 in the longitudinal direction of the belt. It is possible to firmly prevent the protrusion 4 from falling in the longitudinal direction of the belt even if acts.

The invention of claim 2, in claim 1, each of the two mold parts 18, 19 of the molding die 3, projecting a pair of pins 7 which faces the tip of the pair of pins 7 in which it characterized in that to set the belt 2 in the molding die 3 while fixing the support projections 1 presses both sides of the supporting protrusion 1.

  According to the present invention, the support projection 1 can be fixed so that the support projection 1 is sandwiched between the pair of pins 7 provided on the molding die 3, and the belt 2 is set on the molding die 3. When the mold is clamped, the support protrusion 1 can be fixed at the same time.

The invention of claim 3, in claim 2, the protruding dimension of the pin 7 from the inner surface of the mold portions 18, 19 of the molding die 3, of the type 18, 19 of the molding die 3 it is characterized in that setting the 0.3~1.5mm longer dimension than the gap dimension between the sides of the inner surface and the support projection 1.

  According to this invention, the support protrusion 1 can be reliably fixed by the pin 7 without excessively deforming the support protrusion 1.

According to the present invention, even if the flow of the injected resin in the molding die 3 is different on the left and right of the support protrusion 1, the support protrusion 1 is inclined even if the pressure on the left and right sides of the support protrusion 1 is different. The protrusion 4 can be outsert-molded without such a situation, and the protrusion 4 can be outsert-molded on the support protrusion 1 in the correct standing state. The joint 5 can be integrated with the support protrusion 1 by the resin molded in the through-hole 6 of the support protrusion 1, and the protrusion 4 can be prevented from being detached from the support protrusion 1. it is possible to obtain high attachment strength of outsert molded protrusions 4 in part 1, firmly prevent that that the protrusions 4 the belt longitudinal stress to the protrusions 4 acts collapses in the longitudinal direction of the belt It is something that can be done.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The belt 2 is formed of an inner peripheral tooth portion provided with a plurality of teeth 12 at a predetermined interval in the belt longitudinal direction (traveling direction of the belt 2), and an outer peripheral side back portion 14 in which a core wire is embedded. The teeth 12 and the back portion 14 are made of an elastomer such as polyurethane. Support protrusions 1 are integrally provided on the back portion 14 of the belt 2 at a plurality of locations along the longitudinal direction of the belt. The support protrusion 1 is formed so as to cover the entire width in the belt width direction.

On the other hand, the molding die 3 is formed of a plurality of mold parts 18 and 19 as shown in FIGS. 1A and 1B, and a molding recess is formed on each parting surface of the mold parts 18 and 19. A place 20 is formed. In this molding die 3, the mold parts 18 and 19 are opened, the belt 2 is set in the molding recess 20, and then the mold parts 18 and 19 are closed. A cavity 15 that can be filled with resin is formed between the back surface of the belt 2 and the molding recess 20 . In the portion where the cavity 15 is formed, the pins 7 protrude from the inner surfaces of the mold portions 18 and 19, respectively. As shown in FIG. 1B, each pin 7 protrudes with its tip opposed. Further, a gate 16 is provided in one mold part 18, and the gate 16 is opened in the cavity 15.

When the belt 2 is set on the molding die 3 and clamped as shown in FIG. 1, the pins 7 are pressed against both side surfaces in the belt width direction of the support protrusion 1 disposed in the cavity 15, and supported. The support protrusion 1 can be fixed in the cavity 15 by sandwiching the protrusion 1 between the tips of the pins 7. After the belt 2 is set in the molding die 3 in this way, when a thermoplastic resin such as polyacetal is injected into the molding die 3 from the injection molding machine, the resin flows into the cavity 15 from the gate 16 and is filled, The protrusion 4 can be outsert-molded on the support protrusion 1 by the resin filled in the cavity 15 .

  At this time, when the resin is injected from the gate 16 into the cavity 15, the flow of the resin in the cavity 15 is different between the left and right sides of the support protrusion 1 as shown by the arrows in FIG. If the flow rate balance of the resin is unbalanced on the left and right sides of 1, the pressure acting on both the left and right sides of the support protrusion 1 in the longitudinal direction of the belt will be different. Since it is sandwiched and fixed in the cavity 15, it is possible to prevent the support protrusion 1 from being deformed and tilted by this pressure difference. Therefore, the protrusion 4 can be outsert-molded on the support protrusion 1 in a state without inclination deformation.

  FIG. 2A shows a belt with protrusions in which the protrusions 4 are formed on the back surface of the belt 2 as described above. Since the protrusion 4 is outsert-molded on the support protrusion 1 in a state where there is no inclination deformation, the support protrusion 1 is not deformed so as to be restored to its original state after being removed from the molding die 3. As shown in FIGS. 5B and 6B, the protrusion 4 does not fall down, and the protrusion 4 can be formed in a correct standing state.

  Here, the projecting dimensions of the pins 7 from the inner surfaces of the mold parts 18 and 19 of the molding die 3 are set between the inner surfaces of the mold parts 18 and 19 and the side surfaces of the support protrusion 1 in the cavity 15. It is preferable to set the dimension 0.3 to 1.5 mm longer than the dimension of the clearance (clearance) on the mold design. When the protrusion dimension of the pin 7 is less than the gap dimension between the inner surfaces of the mold parts 18 and 19 and the side surface of the support protrusion 1 +0.3 mm, the fixing strength when the support protrusion 1 is fixed between the pins 7 is fixed. In particular, when the width of the support protrusion 1 is formed to be small within the range of manufacturing error, the support protrusion 1 may not be fixed with the pin 7, and the outsert molding may occur. In this case, the support protrusion 1 may be prevented from tilting, and the protrusion 4 may not be formed in a correct standing state. On the contrary, when the projecting dimension of the pin 7 becomes larger than the gap dimension +1.5 mm between the inner surfaces of the mold parts 18 and 19 and the side surface of the supporting projection 1, the supporting projection 1 is supported when sandwiched between the pins 7. The protrusion 1 is greatly compressed and deformed, and this deformation reaches the belt 2, so that resin flows into the side surface of the belt 2, and there is a risk that burrs and width dimension defects may occur. The protrusion dimension of the pin 7 is most preferably a dimension that allows the support protrusion 1 to be lightly compressed while allowing manufacturing errors in the width dimension of the support protrusion 1. The gap size between the inner surface and the side surface of the support protrusion 1 is most preferably about +0.3 to 0.5 mm.

  As shown in FIG. 2B, the protrusion 4 is outsert-molded such that the base bifurcated joint 5 sandwiches both surfaces of the support protrusion 1 in the belt longitudinal direction. When the cavity 15 is filled with resin, a part of the resin flows into the through hole 6 of the support protrusion 1, and the through molded portion 22 formed by flowing the resin into the through hole 6 is a bifurcated joint portion. 5 are connected and integrated with each of the joining pieces 23a and 23b. As described above, since the joining pieces 23 a and 23 b of the bifurcated joint 5 at the base of the protrusion 4 are connected and integrated through the through hole 6 of the support protrusion 1, the protrusion 4 is not detached from the support protrusion 1. Further, the attachment strength of the protrusion 4 that is outsert-molded on the support protrusion 1 can be obtained high. Further, a stress in the longitudinal direction of the belt acts on the protrusion 4 at the time of conveyance, and this stress acts as a force for tilting the protrusion 4 in the longitudinal direction of the belt, but sandwiches both surfaces of the support protrusion 1 in the longitudinal direction of the belt. Even if stress in the longitudinal direction of the belt acts on the projecting body 4, the projecting body 4 is obtained by connecting and integrating the formed bifurcated joint 5 with the through-molding section 22 in the through hole 6 that penetrates in the longitudinal direction of the belt. Can be firmly prevented from falling in the longitudinal direction of the belt.

An example of embodiment of this invention is shown, (a) is front sectional drawing of a part of molding die, (b) is side sectional drawing of a part of molding die. The belt with a protrusion shape | molded same as the above is shown, (a) is a partial front view, (b) is a partial front sectional view. It is a partial front view which shows the belt with a protrusion of a prior art example. It is a sectional view of a part of a conventional molding die. The belt with a protrusion of a conventional example is shown, and (a) and (b) are partial front views. The belt with a protrusion of a conventional example is shown, and (a) and (b) are partial front views.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support protrusion 2 Belt 3 Molding die 4 Projection body 5 Joint part 6 Through hole 7 Pin
18 mold parts
19 Mold part

Claims (3)

The belt projecting from the integrally supporting projections on the back, the resin is injected into the molding die while set in the molding die formed of two mold portions, both sides in the belt longitudinal direction of the supporting protrusion by outsert molding a protrusion in the injected resin at a state sandwiched between the bifurcated junction of the base portion, when provided integrally by standing the protrusion on the back of the belt, the support projection wherein the longitudinal direction of the belt in the through hole penetrating provided, wherein the belt both sides of the belt width direction of the supporting projection in a state of fixing the said support projections by pressing the two mold parts of the molding die molding was set in a mold, the projecting body with outsert molded into the support projections by injecting the resin into the molding die, is shaped so as to sandwich both surfaces in the belt longitudinal direction of the supporting protrusion wherein the that the joint Outsert molding method nubbed belt, characterized in that the connecting integrate the resin filled in the through hole. State to each of the two mold parts of the molding die, projecting a pair of pins opposed to fixing the supporting protrusion presses the both side surfaces of the supporting protrusions at the tip of the pair of pins outsert molding method with projections belt according to claim 1, characterized in that to set the belt to the molding die in. The projecting dimension of the pin from the inner surface of the mold portion of the molding die, 0.3 to 1.5 mm than the gap dimension between the sides of the inner surface and the support projection of the mold portion of the molding die 3. The method for forming an outsert of a belt with protrusions according to claim 2, wherein the length is set to a long dimension.

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