JP2023116938A - Workpiece gripping device - Google Patents

Abstract

To provide a workpiece gripping device that grips a resin sheet when heat is applied from the periphery of the resin sheet, and can suppress occurrence of "wrinkles" and "distortion" in the resin sheet, requires only a smaller "marginal part for gripping", and further improves material yield.SOLUTION: A workpiece gripping device 1 for gripping a resin sheet W when heat is applied from the periphery of the resin sheet W, has plate-like gripping surface members (an upper gripping surface member 40 and a lower gripping surface member 50) that sandwich and grip each of facing edge portions of the resin sheet W with continuous surfaces between a space from one end to the other end. The gripping surface member has heat transmission structures (heat transmitting parts 41 and 51 which are hole portions) in which at least a part of applied heat is transmitted toward sandwiched portions of the resin sheet W when heat is applied from the periphery of the gripped resin sheet W.SELECTED DRAWING: Figure 1

Description

The present invention relates to a workpiece gripping device that grips a resin sheet.

2. Description of the Related Art Conventionally, various resin sheet products have been manufactured by hot press molding in which a thermoplastic resin sheet is heated to soften and then press molded.

For example, Patent Document 1 discloses a developed skin having a two-layer structure of a skin layer such as a woven fabric and a sheet layer of a thermoplastic resin sheet, or the skin layer, the sheet layer, and an elastic layer such as urethane foam. A method for shaping an epidermis using an expanded epidermis having a three-layer structure is disclosed. A "gripping margin" for gripping with a chuck is provided on the periphery of the developed skin, and the developed skin is slightly larger in size by the "gripping margin". A plurality of chucks are used to grip a plurality of "holding margins" at "points". After the heater is moved to the lower side of the unfolded skin held by a plurality of chucks to heat the unfolded skin, the heater is retracted and press molding is performed. During press molding, a lower mold having a rod-shaped protruding member that is urged upward by an elastic body is raised and brought close to the developed skin, and the tip of the protruding member supports the deployed skin. After that, the grip of the chuck is released and the chuck is released, and press molding is performed by the upper die and the lower die. The protruding member urged upward is buried in the lower mold during pressing.

JP-A-11-115041

In the skin shaping method described in Patent Document 1, when heating a developed skin body (corresponding to a resin sheet), a plurality of "points" on the peripheral edge of the developed skin body are radially formed by each of a plurality of chucks. Since it is gripped as if it is being pulled, "wrinkles" and "distortion" are likely to occur around the gripped "point". Furthermore, immediately before pressing, the spread skin body heated by the heater and softened is placed on and held on the rod-shaped protruding member, so that at this time as well, wrinkles or creases appear around the support points of the protruding member. "Distortion" is likely to occur.

In order to suppress the occurrence of these "wrinkles" and "distortion", multiple points on the periphery of the resin sheet should be grasped at "points (intermittent positions between one end and the other end)" and pulled radially. It is preferable to grip each of the opposing edges of the resin sheet from one end to the other end by a "plane (a continuous plane between one end and the other end)" instead of gripping the resin sheet directly. Then, after heating in the state of being held by a chuck, the support of the resin sheet is changed from being held by a chuck to being supported by a bar-shaped protruding member during pressing, but "wrinkles" and "distortion" occur. In order to suppress this, it is preferable to perform press molding by heating while being gripped by "surfaces (surfaces continuous from one end to the other end)". However, when the opposing edges of the resin sheet are gripped by a "surface (a surface continuous from one end to the other end)", the area of the resin sheet covered by the gripping member becomes relatively large. When heated by a heater or the like, it is difficult for the heat to be transmitted to the portion and the resin sheet in the vicinity thereof. For this reason, it is necessary to increase the "gripping margin" in the outward direction, resulting in a large portion to be discarded after hot press molding (lowering the material yield).

The present invention has been invented in view of such a point, and is a workpiece gripping device that grips a resin sheet when heat is applied from the periphery of the resin sheet. An object of the present invention is to provide a workpiece gripping device capable of suppressing the occurrence of "distortion", requiring a smaller "gripping margin", and further improving material yield.

In order to solve the above problems, a first invention of the present invention is a workpiece gripping device that grips a resin sheet when heat is applied from the periphery of the resin sheet, wherein the resin sheets are opposed to each other. It has a plate-shaped gripping surface member that grips each of the edge portions with a continuous surface between one end and the other end, and the gripping surface member receives heat from the periphery of the gripped resin sheet. The workpiece gripping device has a heat transmission structure that transmits at least a part of the applied heat toward the resin sheet at the sandwiched portion when the heat is applied.

Next, a second aspect of the present invention is the work gripping device according to the first aspect, wherein the heat transmission structure of the gripping surface member sandwiches heat applied from the periphery of the resin sheet. A heat transmitting portion that is a plurality of holes that transmit toward the resin sheet at the location where the heat is applied, and the heat applied from the periphery of the resin sheet around the heat transmitting portion of the grip surface member, and a non-heat-transmitting portion that does not transmit toward the resin sheet at the sandwiched portion.

Next, a third aspect of the present invention is the workpiece gripping device according to the second aspect, wherein the non-heat-transmissive portion is subjected to heat absorption processing for absorbing heat applied from the periphery of the resin sheet. It is a workpiece gripping device, which is a heat absorbing part provided.

Next, a fourth aspect of the present invention is the workpiece gripping device according to any one of the first to third aspects, wherein the gripping surface member is a plate having a plurality of holes formed therein. It is a workpiece gripping device that is a punching metal with a shape.

According to the first invention, the gripping surface member grips each of the opposing edges of the resin sheet by sandwiching them with surfaces that are continuous from one end to the other end, so that "wrinkles" and "wrinkles" It is possible to suppress the occurrence of "distortion". Furthermore, since the gripping surface member has a heat-permeable structure, it is possible to apply heat to the resin sheet at the portion covered with the gripping surface member, and the "gripping margin" can be further reduced. Therefore, material yield can be further improved.

According to the second invention, it is possible to relatively easily realize a heat transmission structure that transmits at least part of the heat applied from the periphery of the resin sheet.

According to the third invention, even if the non-heat-transmitting portion does not transmit heat applied from the periphery of the resin sheet, the heat is absorbed by the heat-absorbing portion subjected to heat-absorbing processing, so that the heat is sandwiched. It is possible to appropriately transfer heat to the resin sheet that is in place. In other words, the non-heat-transmitting part can transmit heat indirectly even if it cannot directly transmit heat, so it may or may not be a non-heat-transmitting part that is not subjected to heat absorption processing. In comparison, heat can be transferred to the resin sheet more efficiently.

According to the fourth invention, the grip surface member can be easily realized and procured.

It is a perspective view explaining the example of the whole structure of a workpiece|work holding|gripping apparatus. It is the figure which looked at the work holding|gripping apparatus shown in FIG. 1 from the II direction. FIG. 4 is a perspective view illustrating an example of a rotating mechanism that rotates an upper gripping surface member; FIG. 4 is an external view of an upper gripping surface member and a lower gripping surface member; It is a figure explaining the example of the heating process before pressing in a hot press process. It is a figure explaining the example of the press process after the heating in a hot-press process. FIG. 2 is a cross-sectional view taken along line VII-VII in FIG. 1, and is a diagram for explaining a heat-transmitting portion (hole) and a non-heat-transmitting portion of a gripping surface member gripping a resin sheet therebetween.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated using drawing. Note that the X-axis, Y-axis, and Z-axis in each drawing are orthogonal to each other. The Z-axis direction indicates the vertically upward direction, and indicates the thickness direction of the resin sheet W and the gripping direction (the direction in which the resin sheet W is sandwiched) by the workpiece gripping device 1 . Moreover, the X-axis direction indicates the horizontal direction, and indicates the depth direction of the resin sheet W and the workpiece gripping device 1 . Moreover, the Y-axis direction indicates the horizontal direction, and indicates the width direction of the resin sheet W and the workpiece gripping device 1 .

● [Overall configuration of workpiece gripping device 1 (Figs. 1 to 4)]
The overall configuration of the workpiece gripping device 1 will be described with reference to FIGS. 1 to 4. FIG. The workpiece gripping device 1 is a device that grips a thermoplastic resin sheet W when heat is applied from the periphery of the thermoplastic resin sheet W in a hot press process or the like. Further, in the following description, a substantially rectangular resin sheet W will be described as an example. The resin sheet W is a thermoplastic resin sheet, such as PC (polycarbonate), PA6 (polyamide 6), PA66 (polyamide 66), ABS (acrylonitrile, butadiene, styrene copolymer synthetic resin), PP (polypropylene), PPS. (polyphenylene sulfide), PMMA (polymethyl methacrylate) and the like. In this embodiment, a PC (polycarbonate) resin sheet W having a substantially rectangular shape will be described as an example.

As shown in FIG. 1, the workpiece gripping device 1 connected to the transfer arm 10 or the like has a base member 20, a rotating arm 30, an upper gripping surface member 40, a lower gripping surface member 50, and the like.

As shown in FIG. 1 , the base member 20 has a substantially rectangular parallelepiped plate shape, one edge of which is connected to the transfer arm 10 , and is movable in various directions by the transfer arm 10 . The base member 20 is also provided with a support 21 that supports a rotating shaft member 22 rotating around a rotating axis 22J parallel to the X-axis direction.

Further, as shown in FIG. 1, the lower gripping surface member 50 is provided on the other edge of the base member 20 (the edge on the opposite side of the transport arm 10). Further, as shown in FIG. 1, a plurality of rotating arms 30 are attached to the rotating shaft member 22 at appropriate intervals along the rotating axis 22J. The tip of each rotating arm 30 is connected to the upper gripping surface member 40 . As shown in FIG. 2, the rotating arm 30 rotates integrally with the rotating shaft member 22 to sandwich and grip the resin sheet W between the upper gripping surface member 40 and the lower gripping surface member 50. and a "release position" where the grip of the resin sheet W is released.

The upper gripping surface member 40 and the lower gripping surface member 50 correspond to gripping surface members, and each of the facing edge portions of the resin sheet W is sandwiched between surfaces that are continuous from one end to the other end. It is a thin plate-shaped member to be gripped. The upper gripping surface member 40 and the lower gripping surface member 50 are, for example, stainless steel plates having a thickness of about 2 to 3 [mm]. As shown in FIG. 4, the upper gripping surface member 40 and the lower gripping surface member 50 transmit at least part of the heat applied from the periphery of the resin sheet W toward the resin sheet W at the sandwiched portion. Heat transmitting portions 41 and 51, which are a plurality of holes, are formed. In addition, the surroundings of the heat transmitting portions 41 and 51 in the upper gripping surface member 40 and the lower gripping surface member 50 are non-thermal heat-transmitting members that do not transmit heat applied from the surroundings of the resin sheet W toward the resin sheet W at the sandwiched portion. Transmissive portions 42 and 52 are provided. The heat transmitting portions 41 and 51 and the non-heat transmitting portions 42 and 52 form a heat transmitting structure that transmits at least part of the applied heat toward the resin sheets W sandwiched therebetween.

For the upper gripping surface member 40 and the lower gripping surface member 50, for example, a plate-like punching metal having a plurality of holes, a plate-like expanded metal, a wire mesh, or the like can be used. This embodiment shows an example of using a punching metal.

As shown in FIG. 3 , a relay arm 23 is connected to one end of the rotating shaft member 22 . A rod 25 extending from an actuator 24 provided on the base member 20 is connected to the relay arm 23 . The actuator 24 is, for example, an air cylinder, and uses compressed air supplied from a pipe 26 to expand and contract the rod 25 . The expanded and contracted rod 25 rotates the rotation shaft member 22 around the rotation axis 22J via the relay arm 23 . Further, the rod 25 is pulled in a direction in which the rod is shortened by an elastic body 25A. The elastic body 25A is, for example, a spring. One end of the elastic body 25A is connected to a rod arm 25C connected to the rod 25, and the other end of the elastic body 25A is connected to an elastic body support portion 25B provided on the base member 20. It is

As a result, when compressed air is supplied from the pipe 26 to the actuator 24, the rod 25 moves in the lengthening direction and rotates so that the upper gripping surface member 40 moves to the "release position (see FIG. 2)." The driving shaft member 22 is rotated. Further, when the supply of compressed air from the pipe 26 to the actuator 24 is stopped, the rod 25 is pulled by the elastic body 25A and moves in the direction in which the rod 25 becomes shorter, and the upper gripping surface member 40 reaches the "gripping position (Fig. 2)”, the rotating shaft member 22 is rotated. Further, the gripping force (gripping strength) when the resin sheet W is sandwiched and gripped by the upper gripping surface member 40 and the lower gripping surface member 50 at the "gripping position (see FIG. 2)" can be adjusted by the elastic body 25A.

● [Example of heating process (Fig. 5) and pressing process (Fig. 6) in hot press working and effect of the present invention (Fig. 7)]
Next, referring to FIGS. 5 and 6, heat is applied from the periphery of the resin sheet W gripped by the workpiece gripping device 1 [heating step], and the heated resin sheet W is press-molded [pressing step]. An example of a hot press process having .

In the [heating process] shown in FIG. 5 , the lower mold 80 and the upper mold 90 are separated from each other, and the resin sheet W gripped by the workpiece gripping device 1 is arranged between the lower mold 80 and the upper mold 90 . As shown in [Pressing process] in FIG. This is the edge of the resin sheet W (opposing edge) that does not interfere with the upper die 90 . The portion (edge) of the resin sheet W sandwiched between the upper gripping surface member 40 and the lower gripping surface member 50 is the "gripping margin", and in the example of FIG. It is equivalent to "shiro".

In the [heating step], as shown in FIG. 5, the heater H1 is placed (moved) between the resin sheet W gripped by the workpiece gripping device 1 and the lower die 80, and gripped by the workpiece gripping device 1. A heater H2 is arranged (moved) between the resin sheet W and the upper die 90, and heat is applied to the resin sheet W from the heaters H1 and H2. The heaters H1 and H2 are IR heaters (far infrared heaters), for example, and radiate heat (infrared rays) toward the resin sheet W. As shown in FIG.

As shown in FIG. 7, at a portion of the resin sheet W gripped by the upper gripping surface member 40, the heat (infrared rays) radiated from the heater H2 is transmitted through the heat transmitting portion 41 (hole portion) and The sheet W is directly irradiated to heat the resin sheet W. Similarly, at the portion of the resin sheet W gripped by the lower gripping surface member 50, the heat (infrared rays) radiated from the heater H1 is transmitted through the heat transmitting portion 51 (hole) and directly to the resin sheet W. The resin sheet W is heated by direct irradiation.

As shown in FIG. 7, the heat (infrared rays) radiated from the heater H2 and applied to the non-heat-transmissive portion 42 of the upper gripping surface member 40 is not directly applied to the resin sheet W. As shown in FIG. However, the heat of the resin sheet W at the heat transmitting portion 41 heated by the heat transmitted through the heat transmitting portion 41 propagates to the resin sheet W at the portion held by the adjacent non-heat transmitting portion 42. heat is transferred. Further, the non-heat-transmitting portion 42 is coated with a black-body spray to form a heat-absorbing portion 43 that has undergone a heat-absorbing process to absorb heat. The heat from the can be indirectly transferred to the resin sheet W. Similarly, the heat (infrared rays) radiated from the heater H1 and applied to the non-heat-transmissive portion 52 of the lower gripping surface member 50 is not directly applied to the resin sheet W. As shown in FIG. However, the heat of the resin sheet W at the heat transmitting portion 51 heated by the heat transmitted through the heat transmitting portion 51 propagates to the resin sheet W at the portion held by the adjacent non-heat transmitting portion 52. heat is transferred. Further, the non-heat-transmitting portion 52 is coated with a black-body spray to form a heat-absorbing portion 53 that has undergone a heat-absorbing process to absorb heat. The heat from the can be indirectly transferred to the resin sheet W. Note that the heat absorbing portions 43 and 53 are not limited to the case where the black body spray is applied, and any configuration that enhances the heat absorbing property of the non-heat transmitting portions 42 and 52 may be used.

In the conventional case of using a simple plate-like member instead of a punching metal for the upper gripping surface member and the lower gripping surface member, heat was not transmitted to the resin sheet sandwiched between the gripping surface members, so the reference numeral L1 in FIG. (The cut-off portion after hot press molding) was necessary. The length of L1 (the cut-off portion after hot press molding) is the length obtained by adding the length of L3, which is a predetermined distance from the "gripping margin", to the length of the "gripping margin" indicated by L2. is. The length of L3 (the length of a predetermined distance from the "gripping margin") is determined by the material and thickness of the upper gripping surface member, the lower gripping surface member, and the resin sheet, and the length of L3 is, for example, zero. (Length of code L1=Length of code L2).

However, in the present embodiment in which the upper gripping surface member 40 and the lower gripping surface member 50 are made of punching metal, heat can be efficiently transmitted to the resin sheet sandwiched between the gripping surface members. The length (the truncated portion after hot press molding) can be made shorter.

As described above, in the workpiece gripping device 1 described in the present embodiment, each of the facing edge portions of the resin sheet W is gripped by the gripping surface members (the upper gripping surface member 40 and the lower gripping surface member 50). (Surface continuous from one end to the other end)”, it is possible to suppress the occurrence of “wrinkles” and “distortion”. Furthermore, the upper gripping surface member 40 and the lower gripping surface member 50 have the heat transmitting portions 41 and 51, which are holes that transmit heat, so that the heat can be efficiently transmitted to the portions of the sandwiched resin sheet W. Therefore, the "grip margin" can be made smaller, and the material yield can be further improved. In addition, by subjecting the non-heat-transmitting portions 42 and 52 of the upper gripping surface member 40 and the lower gripping surface member 50 to heat absorption processing to form the heat absorption portions 43 and 53, the portion of the sandwiched resin sheet W can be further It can transfer heat efficiently.

● [Others]
The workpiece gripping device 1 of the present invention is not limited to the appearance, configuration, structure, etc. described in the present embodiment, and various modifications, additions, and deletions are possible without changing the gist of the present invention.

In the description of the present embodiment, the upper gripping surface member 40 and the lower gripping surface member 50 are made of plate-shaped punching metal, but they may be made of plate-shaped expanded metal, wire mesh, or the like. In the case of perforated metal, the hole diameter, hole pitch, which is the distance between the centers of adjacent holes, and the opening ratio are determined according to the required holding strength and heat transmittance. is set to

Numerical values used in the description of the present embodiment are only examples, and the present invention is not limited to these numerical values.

REFERENCE SIGNS LIST 1 workpiece gripping device 10 transfer arm 20 base member 21 support 22 rotation shaft member 22J rotation axis 23 relay arm 24 actuator 25 rod 25A elastic body 25B elastic body support 25C rod arm 26 pipe 30 rotation arm 40 upper gripping surface Member (gripping surface member)
41, 51 heat transmitting portions 42, 52 non-heat transmitting portions 43, 53 heat absorbing portions 50 lower gripping surface member (gripping surface member)
80 Lower mold 90 Upper mold H1, H2 Heater L2 Grip margin W Resin sheet

Claims (4)

A workpiece gripping device that grips the resin sheet when heat is applied from the periphery of the resin sheet,
A plate-shaped gripping surface member that grips each of the opposing edges of the resin sheet with a continuous surface between one end and the other end,
The gripping surface member has a heat transmission structure that transmits at least part of the applied heat toward the resin sheet at the sandwiched portion when heat is applied from the periphery of the gripped resin sheet. have a
Work gripping device. The workpiece gripping device according to claim 1,
The heat transmission structure of the gripping surface member includes:
a heat transmitting portion, which is a plurality of holes through which heat applied from the periphery of the resin sheet is transmitted toward the resin sheet sandwiched therebetween;
a non-heat-transmitting portion around the heat-transmitting portion of the gripping surface member, which does not transmit heat applied from the periphery of the resin sheet toward the resin sheet sandwiched therebetween;
have,
Work gripping device. The workpiece gripping device according to claim 2,
The non-heat-transmitting portion is
A heat absorbing portion that has been subjected to a heat absorbing process that absorbs heat applied from the periphery of the resin sheet,
Work gripping device. The workpiece gripping device according to any one of claims 1 to 3,
The gripping surface member is a plate-shaped punching metal having a plurality of holes,
Work gripping device.

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