JP2023102582A - Caulking device and method for manufacturing molded product - Google Patents

Abstract

To provide a caulking device that prevents a work from being damaged when a tip of a punch comes close to the work, and a method for manufacturing a molded product by caulking.SOLUTION: A thermal caulking device 20 includes: a flame 23; a punch holder 26 that can move up and down with respect to the frame; a punch 10 attached to the punch holder 26 and having a pressing part 17 at its tip capable of pressing a convex part of a fixing member; and a work upper surface stopper 40 mechanically coupled with a punch holder extension 27 extending from holder body 261 of the punch holder 26. The work upper surface stopper 40 has an inner wall facing a tip of the punch 10 through a gap and has a contact surface 48 that can contact the upper surface of the convex part protruding side of a fixed object and that prevents an occurrence of damage to the fixed object when the pressing part 17 approaches the upper surface. As a result, the punch does not bite into the work without being affected by the dimensions of the work.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a caulking device and a method for manufacturing a molded product by caulking.

BACKGROUND ART Conventionally, a turret punch press for punching and processing a metal plate is known.
The punching press disclosed in Patent Document 1 moves a ram to cooperate with a punch and a die to punch a workpiece. This punch is provided with a punch position adjusting device that regulates the movement stroke of the punch by forming a projection on the head of the punch and moving a regulator plate that has a hole that fits into the projection.
This punch position adjusting device regulates the amount of movement of the punch via a regulator plate, and changes the feed clearance of the punch according to the plate thickness and material of the work.

JP-A-9-192755

According to the punching press of Patent Document 1, a punch position adjusting device with a movable regulator plate is driven to regulate the movement stroke of the punch. The feed clearance can be adjusted by operating the punch position adjusting device according to the plate thickness, material, etc. of the work and regulating the movement stroke of the punch.

In this punching press, a punch position adjusting device is provided separately from the punch driving device as a device for regulating the punch movement stroke during punching, so that the device becomes complicated and large. Also, the workpiece is punched by punching.

The present invention is similar to Patent Document 1 in that it punches, but instead of punching the work, the fixing member corresponding to the work and the object to be fixed are caulked and fixed, and the problem to be solved is different from that of Patent Document 1.

An object of the present invention is to provide a caulking device and a method for manufacturing a molded product by caulking that prevents the work from being damaged due to approach of the tip of the punch to the work when the fixing member and the object are joined by a boss formed by inserting the projection of the fixing member into the hole of the object and crushing the projection from the top surface side.

A crimping device according to a first aspect of the present invention is a crimping device for crimping and fixing a fixing member (2) made of resin having a projection (4) and an object (3) having a hole into which the projection is inserted, comprising: a frame (23); a punch holder (26) vertically movable with respect to the frame; and a work upper surface stopper which is rigidly coupled, the work upper surface stopper has an inner wall (50) facing the tip of the punch through a gap, and has an abutting surface (48) which is capable of coming into contact with the upper surface (33) of the object to be fixed on the projecting side of the projecting portion and prevents the object to be fixed from being damaged when the pressing portion approaches the upper surface.

A method for manufacturing a molded product according to a second aspect of the present invention is a method for manufacturing a molded product by caulking, comprising the steps of: carrying in a work (1) in which a hole (6) of an object (3) is inserted into a projection (4) of a fixing member (2); a step of contacting a pressing portion (17) of a solid cylindrical punch (10) against a top surface (5) of the projection of the fixing member to start pressurization; The work upper stopper (40) contacts the upper surface (33) of the workpiece so as to restrict the pressing portion from biting into the workpiece before the contact, the step of canceling the operation of pressing the pressing portion against the workpiece after the contact, and the step of shifting to the operation of separating the punch and the workpiece upper surface stopper from the workpiece.

A method for manufacturing a molded product according to a third aspect of the present invention is a method for manufacturing a molded product by heat crimping, comprising the steps of: carrying in a workpiece (1) in which a hole (6) of an object (3) is inserted into a convex portion (4) of a fixing member (2); a step of contacting a pressing portion (17) of a heated solid cylindrical punch (10) against the top surface of the convex portion of the fixing member to start pressurization; The work upper stopper (40) contacts the upper surface of the workpiece (33) so as to restrict the pressing portion from biting into the workpiece before the contact, the step of terminating the thermal crimping operation after the contact, the step of canceling the operation of pressing the pressing portion against the workpiece after completion, and the step of shifting to the operation of separating the punch and the upper workpiece stopper from the workpiece.

According to the crimping device according to the first aspect of the present invention, the tip of the punch descends after crimping is started, and the top surface of the convex portion is pressed. At this time, the contact surface of the work top surface stopper mechanically coupled to the punch holder abuts the work top surface of the workpiece to be fixed.
As a result, when the tip of the punch approaches the workpiece during operation of the caulking device, the contact surface (lower surface) of the stopper for upper surface of the workpiece mechanically coupled to the punch holder contacts the upper surface of the workpiece before the tip of the pressing portion of the tip of the punch contacts the upper surface of the workpiece.
Therefore, the punch can be lowered by the stroke amount required for crimping. The punch does not bite into the workpiece without being affected by uneven dimensions of the workpiece or pallet.

Even if the height of the upper surface of the work with respect to the caulking device is uneven, the position of the lower end of the tip of the punch is constant with respect to the upper surface of the work. As a result, it is possible to prevent the occurrence of damage such as burrs at the time of caulking and fixing.

1 is a front view of a crimping device according to a first embodiment of the present invention; FIG. FIG. 4 is an enlarged cross-sectional view of the tip of the punch of the crimping device according to the first embodiment of the present invention; FIG. 4 is an enlarged cross-sectional view of a workpiece upper surface stopper of the crimping device according to the first embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged schematic cross-sectional view of a main part of a crimping device according to a first embodiment of the present invention; FIG. 2 is a perspective view of the work upper surface stopper of the first embodiment of the present invention; It shows the operation of the main part of the caulking device according to the first embodiment of the present invention, (A) is a schematic cross-sectional view before pressing, and (B) is a schematic cross-sectional view after pressing. FIG. 4 is a schematic explanatory diagram showing steps of operation of the first embodiment of the present invention; FIG. 7B is an enlarged schematic explanatory view of the VIII portion of FIG. 7B; FIG. 7C is an enlarged schematic explanatory view of the IX portion of FIG. 7C; Explanatory drawing explaining burr generation of the crimping|crimping apparatus which concerns on a comparative form.

A crimping device and a method for manufacturing a molded product according to multiple embodiments of the present invention will be described below with reference to the drawings. In addition, the same code|symbol is attached|subjected to the substantially same structural part in several embodiment, and description is abbreviate|omitted.

(First embodiment)
A crimping device and a method for manufacturing a molded product according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 9. FIG.

The crimping device of the present embodiment is a heat crimping device that manufactures a molded product by heat crimping and fixing. This heat caulking device is a device using an electrothermal punch.

As shown in FIG. 1, the heat crimping device 20 has a frame 23 that can be moved up and down by a drive unit 22 attached to a base 21 . A linear guide 25 is provided movably relative to a guide rail 24 formed on the side surface of the frame 23 , and a punch folder 26 is fixed to the linear guide 25 .

The punch folder 26 is urged downward as shown in FIG.
A solid cylindrical punch 10 is fixed to a punch holder 26 . As shown in FIG. 6A, the tip 12 of the punch 10 thermally welds the work 1 to fix the fixing member 2 and the object 3 to be fixed by heat caulking.

Although the workpiece is not shown in FIG. 1, the punch holder 26 includes a holder body 261 having a portion for fixing the punch 10, and a punch holder extension portion 27 extending downward from another portion of the holder body 261 along the axial direction of the punch 10 near the punch 10.

The punch holder extension part 27 is formed so as to extend in the direction in which the tip part 12 of the punch 10 presses the workpiece. One end 41 of a work upper surface stopper 40 is fixed to the lower end of the punch holder extension 27 .

As shown in FIG. 2, the tip 12 of the punch 10 is formed with an annular tapered surface 13 whose outer wall is tapered and an annular tapered surface 14 whose inner wall is widened forward. The bottom surface of tip 12 of punch 10 has a concave curved surface 15 . The curved surface 15 of the punch 10 can press the top surface of the protrusion 3 of the fixing member 1 . A pressing portion 17 formed at the tip 12 of the punch 10 forms an annular convex portion 16 at the tip 12 of the punch 10 . The annular convex portion 16 is formed by the annular tapered surface 13 of the outer wall and the annular tapered surface 14 of the inner wall.

One end 41 of the work upper surface stopper 40 is joined to the lower end of the punch holder extension 27, and the other end 42 has a notch 43 as shown in FIG. 1 and 4, the tip portion 12 of the punch 10 shown in FIG. 2 is positioned in the space formed by the notch portion 43. As shown in FIGS.
The work upper surface stopper 40 has an inner wall 50 facing a part of the tip portion 12 of the punch 10 with a gap therebetween.

The inner wall 50 faces a portion of the outer wall of the distal end portion 12 of the punch 10 through a gap, and as shown in FIGS.
The abutting portion 47 has a radially inward projecting portion 471 and a lower surface forming the abutting surface 48 . The inner wall 50 faces the outer wall of the tip portion 12 of the punch 10 with a gap therebetween.

The outer surface of the contact portion 47 forms a contact surface 48 . The contact surface 48 is capable of coming into contact with the upper surface 33 of the fixed object 3 on the projecting side of the projection 4 . As a result, when the punch 10 descends and approaches the workpiece during operation of the caulking device, the difference (displacement) between the position level of the punch tip and the upper surface position level of the object to be fixed regulates the separation distance between the punch tip position and the upper surface position of the object to be fixed.

The notch 43 forms a thin portion 49 . When the molded article having the workpiece has a complicated shape, the thin portion 49 can enter the space by utilizing the gap or small space of the complicated shape portion.

The notch portion 43 of the work upper surface stopper 40 forms a space for allowing insertion of the tip portion 12 of the punch 10 and a space for avoiding interference with the fixed object 3 .

As a result, the tip portion 12 of the punch 10 can approach the object 3 to be fixed without interfering with the specific diameter portion 7 such as the protrusion of the object 3 to be fixed on the work side. Therefore, it is possible to widen the allowable range of workpiece shapes that can be thermally crimped and fixed.

A PLC (Programmable Logic Controller) as a control device (not shown) controls power supply to the punch 10 and temperature control of the pressing portion 17 of the punch 10 . The punch 10 is heated by controlling the amount of power supplied to the punch 10 via a transformer according to a predetermined procedure.

Next, the action will be described.
A workpiece 1 to be joined is composed of a fixing member 2 made of thermoplastic resin and an object to be fixed 3 made of thermoplastic resin. The fixing member 2 has a convex portion 4 on its outer surface, and the fixed object 3 has a hole 6 into which the convex portion 4 is fitted. The workpiece 1 is in a state in which the convex portion of the fixing member is inserted into the hole of the object to be fixed. The workpiece in this state corresponds to the molded product 70 before molding.

FIG. 6A shows a state in which the tip of the punch 10 of the heat crimping device 20 is in contact with the top surface 5 of the projection 3 of the fixing member 2. FIG.
FIG. 6B shows a state in which the protruding portion of the convex portion 4 pressed by the pressing portion 11 at the tip of the punch 10 is thermally melted and deformed to become the boss portion 8 from the state shown in FIG. 6A. In this state, the fixing member 2 and the object to be fixed 3 are caulked together. A workpiece in this state corresponds to a molded product after molding.
(About operation)

Next, the operation of the heat crimping device of this embodiment will be described with reference to FIGS. 6, 7, 8 and 9. FIG.

The work is carried in below the heat crimping device 20 in a state in which the protrusions 4 of the fixed object 3 are inserted into the holes 6 of the fixing member 2 .

A molded product 70 before molding, which corresponds to a work having a plurality of projections 4, is placed on a pallet 80 and carried under the heat crimping device 20, as shown in FIG. 7(A).

As shown in FIG. 7(A), the tip portion 12 of the punch 10 of the heat crimping device 20 is at an initial position in the sky before starting the crimping operation. Before starting the crimping operation, a pallet 80 on which a molded article 70 before molding is placed is carried under the punch 10 .

Next, the drive unit 22 is driven to lower the frame 23, and the punch 10 shown in FIG. 7(A) is lowered to the position shown in FIG. 7(B).
The punch 10 of the heat crimping device 20 is energized, and the heated punch 10 is lowered in the direction of the arrow by the distance a shown in FIG. 7, and as shown in FIG.

Immediately after the start of pressing, the compression coil spring 31 shown in FIG. 1, which corresponds to the biasing means, contracts and bends, after which the tip portion 12 of the punch 10 further descends and is thermally melted and deformed from the top surface 5 of the convex portion, thereby forming the welding boss portion 8 shown in FIG. 6(B).

At this time, the contact surface 48 of the workpiece upper surface stopper 40 mechanically coupled to the holder main body 261 of the punch holder 26 contacts the workpiece upper surface 33 of the fixed object 3 of the workpiece 1 . As a result, when the tip 12 of the punch 10 approaches the work during operation of the heat crimping device 20, the contact surface 48 (lower surface) of the work upper surface stopper 40 mechanically coupled to the punch holder abuts the upper surface 33 of the work before the tip of the pressing portion of the punch tip contacts the upper surface 33 of the work.
Therefore, the punch 10 can be lowered by the stroke amount required for crimping.

As shown in FIGS. 7A, 7B, and 7C, the distance between the top surface 33 of the crimping portion and the upper end of the frame 23 is defined as L1 before the start of crimping, L2 after the punch is lowered and before the start of pressing, and L3 after the punch is lowered and after the end of pressing.

L2<L3<L1

As shown in FIG. 7(C), regarding the difference (displacement) between the position level of the tip of the punch 10 and the position level of the upper surface of the object to be fixed 3, the separation distance between the position of the tip of the punch and the position of the upper surface of the object to be fixed is regulated.

Thus, when the molded product 70 before molding is carried under the heat crimping device, even if the height of the top surface of the work with respect to the heat crimping device is uneven, the position of the lower end of the tip part 12 of the punch 10 is constant with respect to the top surface 33 of the work. As a result, it is possible to prevent the occurrence of burrs during thermal caulking and fixing, as will be described in comparison with a comparative embodiment described later.

In this embodiment, when an object to be fixed is fixed to a thermoplastic resin molded product (resin base material), a crimping convex portion called a welding boss is formed in a part of the thermoplastic resin molded product, the welding boss is inserted into a fixing hole formed on the side of the object to be fixed, and the tip of the welding boss protrudes from the fixing hole. The object to be fixed is thermally caulked to the thermoplastic resin molded product.

Examples of application of the present invention include caulking of bosses of resin cases, caulking of pins of printed circuit boards, caulking of resin lens frames of lenses, assembly of precision molded products and parts, and the like.

(Comparison with comparative form)
The present embodiment will be described in comparison with the comparative embodiment.
A heat crimping device according to a comparative embodiment shown in FIG. 10 differs from the above embodiment in that it does not have a workpiece surface stopper.

In both the comparative embodiment and the present embodiment, after the work is placed on a pallet and carried into the heat crimping device, the punch is lowered from above, the heated pressure surface 65 of the punch is pressed against the convex portion 4 of the work 1, the convex portion 4 is thermally melted and deformed, and the fixing member and the object to be fixed are crimped and fixed.

However, according to the heat crimping device according to the comparative embodiment, as the tip of the punch 60 descends, the annular convex portion 66 at the tip of the punch bites into the upper surface of the object to be fixed, resulting in a biting amount δ shown in FIG.

One of the causes of burr generation is that the height positions (upper surface positions of the objects to be fixed) of the workpieces 1 carried into the lower part of the heat crimping device are not uniform among the workpieces. The upper surface position level of the fixed object of the work is not uniform (uniform) among the works.

In contrast, in this embodiment, in order to prevent the occurrence of burrs, the amount of movement of the lower end of the tip of the punch during operation of the heat crimping device is regulated.

In this embodiment, when the punch moves (lowers) in a direction approaching the work during thermal crimping, the lower surface of the work upper surface stopper contacts the upper surface of the work before the tip of the pressing portion of the punch tip contacts the upper surface of the upper surface of the work (fixed object).

Therefore, when the punch moves up and down, since the level difference between the level of the lower surface of the work upper surface stopper and the punch tip position is constant, a constant separation distance is maintained between the punch tip position and the work upper surface position when the punch is lowered with respect to the upper surface of the work. This prevents the tip of the punch from biting into the upper surface of the object to be fixed before the tip of the punch bites into the upper surface of the object to be fixed even if the height of the work placed on the pallet is uneven.
Therefore, damage such as burrs can be prevented from occurring on the upper surface of the workpiece.
(Regarding embodiments of the present invention)

An embodiment of the crimping device according to the first aspect of the present invention is as follows.
The contact surface of the work upper surface stopper is a contact surface that maintains a level equal to or separated from the upper surface (33) of the object to be fixed to such an extent that damage such as burrs is not caused to the object to be fixed when the tip of the pressing portion approaches the surface of the object to be fixed on which the convex portion is formed.
As a result, the tip of the punch can be prevented from biting into the work, burrs can be suppressed, and the quality of the molded product can be improved.

The pressing portion has a pressing surface (15) capable of coming into contact with the top surface (5) of the convex portion, and an annular convex portion (16) formed on the outer ring portion of the pressing surface.
As a result, the convex portion is plastically deformed to form the boss portion, so that the molded product can be crimped and fixed securely.

The crimping device may include biasing means (31) for biasing the punch holder in one direction with respect to the frame.
As a result, it is possible to absorb the impact force when the punch presses, appropriately form the boss portion due to the deformation of the convex portion, and produce a molded product of good quality which is crimped and fixed.

The caulking device may include a linear guide (25) that guides the punch holder so as to be able to move relative to the frame. Combined with the deflection by the urging means, the impact force when the punch is pressed can be absorbed, the boss portion can be properly formed by the deformation of the convex portion, and the crimped and fixed molded product can be manufactured with good quality.

The caulking device comprises a base (21) and a driving part (22) for moving the frame up and down with respect to the base. The vertical movement of the punch is interlocked with the vertical movement of the frame, and the caulking device can be driven.

The work upper surface stopper may have a thin portion (49) that secures a space in the vicinity of the pressing portion of the punch so as not to interfere with the object to be fixed.
As a result, even if the molded article before molding has a complicated shape, if there is a small space around the projection, if the thin-walled portion can be inserted into the space, the work upper surface stopper will perform a stopper function during the crimping operation, so that there is an effect that the crimping device can be highly convenient and can be used for molded articles having complicated shapes before molding.

The work upper surface stopper may have a notch (43) that allows the existence of the protrusion (7) protruding from the upper surface of the fixed part so as not to interfere with the fixed object.
In the same manner as described above, even if the pre-molded product has a complicated shape, if there is a small space around the convex portion, if the thin portion can be inserted into the space, the workpiece upper surface stopper will function as a stopper during the caulking operation.

The crimping device can be applied to a crimping device by heat crimping fixing, in which the punch can be energized to heat the tip of the punch, and the projection can be deformed by heat melting when the pressing portion presses the projection.

In the case of the heat crimping device, the inner wall of the annular convex portion may have an annular tapered inner wall surface (14) that facilitates release after heat crimping. Thereby, the quality of the molded article after molding can be improved.
(Other embodiments)

Although the present invention has been described as a method for manufacturing a molded product by heat caulking, it can also be applied to a caulking device that caulks and fixes an object to be fixed to a fixing member by pressing a pressing portion without heating the punch by energization.

INDUSTRIAL APPLICABILITY The present invention can be applied to a crimping device using a normal temperature punch that does not apply heat.
In the above embodiment, the heat crimping device using an electric heating punch has been described, but in the case of the heat crimping device of the present invention, a heating method other than the electric heat type may be used.

Although the resin material is used for the object to be fixed in the above embodiment of the present invention, it may be a metal material, an inorganic material, or other materials.
The work upper surface stopper shown in the above embodiment shows one embodiment, and the shape of the work upper surface stopper of the present invention is not limited to this, of course.

As described above, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist of the present invention.

1 work,
2 fixing member,
3 object to be fixed,
4 convex part,
5 top surface,
6 holes,
10 punches,
12 tip,
15 curved surface (pressure surface)
16 annular protrusion,
17 pressing part,
20 heat crimping device,
21 base,
22 drive,
23 frames,
25 linear guides,
27 punch holder extension,
31 compression coil spring (biasing means),
33 work upper surface,
40 work upper surface stopper,
43 notch,
48 contact surface,
49 thin portion,
50 inner wall,
70 moldings,
80 pallets.

Claims (13)

A caulking device for caulking and fixing a fixing member (2) made of resin having a projection (4) and an object (3) having a hole into which the projection is inserted,
a frame (23);
a punch holder (26) vertically movable with respect to the frame;
a punch (10) which is attached to the punch holder and has a pressing portion (17) at its tip end capable of pressing the convex portion of the fixing member;
a workpiece upper surface stopper mechanically coupled with the punch holder;
The work upper surface stopper has an inner wall (50) facing the tip of the punch with a gap therebetween, and has a contact surface (48) which is capable of coming into contact with the upper surface (33) of the projecting portion of the object to be fixed and prevents damage to the object to be fixed when the pressing portion approaches the upper surface. 2. A crimping device according to claim 1, comprising an extension (27) of said punch holder, said extension being mechanically coupled to said workpiece upper surface stop. The crimping device according to claim 1 or 2, wherein the contact surface of the work upper surface stopper is such that, when the tip of the pressing portion approaches the surface of the object to be fixed on which the convex portion is formed, the pressing portion maintains a level equal to or separated from the upper surface (33) of the object to be fixed to an extent that the object to be fixed is not damaged such as burrs. 2. The crimping device according to claim 1, wherein said pressing portion has a pressing surface (15) capable of coming into contact with the top surface (5) of said convex portion, and an annular convex portion (16) formed on an outer ring portion of said pressing surface. 2. A crimping device according to claim 1, further comprising biasing means (31) for biasing said punch holder in one direction with respect to said frame. 2. A crimping device according to claim 1, further comprising a linear guide (25) for guiding said punch holder so as to be able to move relative to said frame. 2. A crimping device according to claim 1, comprising a base (21) and a driving part (22) for moving said frame up and down with respect to said base. 2. A crimping device according to claim 1, wherein said workpiece upper surface stopper has a thin portion (49) which secures a space near said pressing portion of said punch so as not to interfere with said object to be fixed. 2. A crimping device according to claim 1, wherein said workpiece upper surface stopper has a notch (43) that allows the presence of a projection (7) protruding from said upper surface of said fixed part so as not to interfere with said fixed object. 2. A crimping device according to claim 1, wherein said punch is energized to heat the tip of said punch, and said convex portion is thermally fused and deformable when said pressing portion presses said convex portion. 11. The crimping device according to claim 10, wherein the inner wall of said annular convex portion has an annular tapered inner wall surface (14) for improving release after heat crimping. A method for manufacturing a molded product by crimping,
a step of loading the workpiece (1) in which the hole (6) of the object to be fixed (3) is inserted into the protrusion (4) of the fixing member (2);
a step of contacting the pressing portion (17) of a solid cylindrical punch (10) against the top surface (5) of the convex portion of the fixing member to start pressurization;
a step of contacting a work top surface stopper (40) with a work top surface (33) so as to restrict the pressing part from biting into the work before the pressing part of the punch contacts the work top surface after the start of pressurization;
a step of canceling the operation of pressing the pressing portion against the work after contact;
and a step of moving the punch and the work upper surface stopper away from the work. A method for manufacturing a molded article by heat caulking, comprising:
a step of loading the workpiece (1) in which the hole (6) of the object to be fixed (3) is inserted into the projection (4) of the fixing member (2);
a step of contacting the pressing portion (17) of a heated solid cylindrical punch (10) against the top surface of the convex portion of the fixing member to start pressurization;
a step of contacting a work top surface stopper (40) with a work top surface (33) so as to restrict the pressing part from biting into the work before the pressing part of the punch contacts the work top surface after the start of pressurization;
a step of terminating the heat crimping operation after contact;
After the end, the step of canceling the operation of pressing the pressing portion against the work;
and a step of moving the punch and the work upper surface stopper away from the work.

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