JP6986802B1 - Heating part structure of resin heat molding equipment and resin heat molding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an adverse effect of heat transfer by a clamp on a work when a thermoplastic resin material (work) smaller than a mold is held by a clamp and heated in molding a resin molded product. Provided are a heating portion structure of a resin heat molding apparatus capable of heating with a more uniform temperature distribution, and a resin heat molding apparatus. SOLUTION: In a heating unit, a clamp group intermittently clamps a work holding band that requires holding of a clamp on one side forming an outer edge of the work in a form of dividing the work holding band into one or more based on a clamp holding reference pitch P. It is arranged and configured. The clamp holding reference pitch P consists of a holding region P1 that is attached to the clamp alone and receives the clamp, and a local non-holding region P2 that is next to the holding region P1 and is not clamped. Is formed by satisfying the condition of 0 <K ≦ 25 (%) of the clamp portion occupancy rate K = P1 / (P1 + P2) occupied by the holding portion region P1 in the clamp holding reference pitch P. [Selection diagram] FIG. 11

Description

The present invention relates to a heating part structure of a resin heat molding apparatus that heats and forms a thermoplastic resin material in the manufacture of a resin molded product, and a resin heat molding apparatus.

Among plastic products, there are resin molded products made of thermoplastic resin materials, and the resin molded products are widely used not only in the industrial field but also in various industrial fields. The resin molded product is manufactured by using, for example, a heat molding device and a trimming device, depending on the specifications such as the shape and the application of the product. In the heat molding process, the heat forming apparatus heats a work made of a thermoplastic resin material and holds the end portion thereof outside the mold, with respect to the central portion of the work inside the mold. A semi-molded product is manufactured by molding according to the mold shape.

In the trimming step after the heat molding step, the trimming device takes out the main part of the molded product, which will be the product later, from the semi-molded product. Perform trimming. In the manufacturing method in which such trimming of unnecessary parts of the molded product is performed after the heat molding step, the finishing accuracy of the product depends on the trimming accuracy of the semi-molded product. Generally, it is not as strict as finishing accuracy. The trimmed parts that do not require molded products are disposed of as scrap.

By the way, in recent years, the influence of plastic products on the environment has begun to be considered in the industrial world from the viewpoint of environmental protection and resource protection. As one of such countermeasures, in addition to the technology to control the amount of waste of the unnecessary part of the molded product, the heat molding technology to manufacture the product (resin molded product) without performing the trimming process is available among the manufacturing industry. Attention has been paid. In the heat molding technology, a resin molded product can be manufactured by supplying the entire work whose size is smaller than the mold into the mold and molding this work according to the shape of the mold. This is because it is possible to eliminate the disposal of. On the other hand, in the heat forming technique, the heat forming accuracy of the work becomes the finishing accuracy of the product as it is, so that more accurate forming is required as compared with the case of going through the trimming step. A molding technique for a thermoplastic resin material to which such a heat molding technique is applied is disclosed in, for example, Patent Document 1.

In Patent Document 1, a synthetic resin sheet having a size smaller than that of a mold is placed on a rotating belt accompanied by heating, and the entire rotating belt device is moved to a position directly above the lower mold, and then the rotating belt is used. On one end side of the device, the retracted clamp is moved and placed sideways on the rotary belt device, and the synthetic resin is held in a state where one end of the synthetic resin sheet sent out by the rotary belt is gripped by this clamp. This is a method of transporting a heat-softened resin sheet in which the sheet can be released from the rotary belt device and covered on the lower mold. In Patent Document 1, after the clamp opens the synthetic resin sheet at the molding positions of the upper mold and the lower mold, the entire rotary belt device is retracted to the other end side of the rotary belt device, and the clamp is retracted to the retracted position. After being moved, the synthetic resin sheet is formed by matching the upper mold and the lower mold.

On the other hand, in the heat forming process, when the work is heat-treated before molding, heating the entire work at a more uniform temperature is one of the factors in the molding conditions for improving the accuracy of the work. For example, Patent Document 2 also discloses that the heating of the above-mentioned material is made uniform.

In Patent Document 2, when a fiber-reinforced composite sheet mainly composed of a thermoplastic resin sheet is heated by an infrared rod-shaped heater in molding a three-dimensional molded product, the heating area is divided into several vertical and horizontal blocks, and each block is used. It is a sheet heating device that uniformly heats the entire fiber-reinforced composite sheet to the molding heating temperature range by controlling the temperature of the heater.

Japanese Unexamined Patent Publication No. 2000-326328 Japanese Unexamined Patent Publication No. 11-268111

As in Patent Document 1, especially when a work having a size smaller than a mold is heat-molded to manufacture a resin molded product, the work is not originally provided with a scrap fee to be disposed of in association with the molding process. In addition, since it may be provided in a small size, it is necessary to make effective use of the entire heated work as much as possible for molding. Therefore, in the resin heat molding apparatus, in the heat treatment of the work to be applied before molding, the heating unit must heat the entire work up to the end at a more uniform temperature in order to prevent the product from becoming defective.

Further, in the heat forming step, the work is set in the mold and molded without wrinkles or twists, so that the work must be inevitably stretched in the heating part. However, a clamp is required to keep the work in an stretched state. However, in the heating portion, the work is heated by the heater while the end portion is held by the clamp, so that the heat supplied from the heater is applied to the end portion of the work held by the clamp. It is difficult to transfer heat due to its existence. Therefore, when an attempt is made to heat-mold a work having a size smaller than a mold to manufacture a resin molded product, the clamp adversely affects the heat transfer of the heated work, and the entire work before molding is heated to a uniform temperature. There was a problem that it could not be heated due to the distribution. It should be noted that Patent Document 2 does not describe in what manner the fiber-reinforced composite sheet (work) is held in the mold at the time of molding.

The present invention has been made to solve the above problems, and when molding a resin molded product, when a thermoplastic resin material (work) having a size smaller than that of a mold is held by a clamp and heated. It is an object of the present invention to provide a heating part structure of a resin heat forming apparatus capable of suppressing the influence of heat transfer exerted by a clamp on the work and heating the entire work with a more uniform temperature distribution, and a resin heat forming apparatus. And.

In order to achieve the above object, the heating part structure of the resin heat molding apparatus according to the present invention has the following configuration.

(1) A size smaller than the mold for a resin heat-molding device that molds a flat plate-shaped work made of a thermoplastic resin material with a pair of upper and lower molds under a heated state. In the heating part structure of the resin heating molding apparatus including a heating part for heating the work by a heating means, a clamp group including at least one clamp having a clamp capable of gripping or releasing the work. , The work can be arranged in the heating portion together with the work, and in the heating portion, the clamp group holds the work that needs to be held by the clamp at one side of the end including the outer edge of the work, which forms the outer edge. The band is configured by intermittently arranging the clamps in an arrangement form in which the band is partitioned by at least one clamp holding reference pitch P based on the reference clamp holding reference pitch P, and the clamp holding reference. The pitch P is a local portion of the work that is attached to the clamp and is held by the clamp, and is next to the holding region P1 and the holding region P1 that are distances along the one side. , The part of the work locally that is not held by the clamp, and is one pitch of the work holding band composed of the non-holding portion region P2 which is the distance along the one side. Among the clamp holding reference pitch P, the clamp portion is formed in such a manner that the condition 0 <K ≦ 25 (%) of the clamp portion occupancy rate K = P1 / (P1 + P2) occupying the holding portion area P1 is satisfied. And.
(2) In the heating portion structure of the resin heat forming apparatus according to (1), the clamp connects two support portions arranged in parallel to each other and a connecting portion at a distance corresponding to the thickness of the work. It is formed by connecting in a U shape, and while the clamp holds the work, the direction orthogonal to the height direction along the thickness direction of the work is directed to the outer edge side of the work with respect to the clamp. When the width direction extends and the depth direction extends from the outer edge of the work to the inside of the surface of the work, the support portion holds the size of the work in the width direction smaller than the depth direction. It is characterized in that it is formed up to twice the thickness as an upper limit.
(3) In the heating unit structure of the resin heat molding apparatus according to (1) or (2), the heating means is a heater that heats the work by radiant heat.

Further, in order to achieve the above object, the resin heat molding apparatus according to the present invention has the following configurations.

(4) When a flat plate-shaped work made of a thermoplastic resin material is molded with a pair of upper and lower molds under a heated state, the work having a size smaller than the mold is used. In a resin heat molding apparatus provided with a heating portion that is heated by a heating means, the heating portion is configured by the heating portion structure of the resin heat molding apparatus according to any one of (1) to (3). It is characterized by.

The structure of the heating portion of the resin heat molding apparatus according to the present invention having the above configuration, and the actions and effects of the resin heat molding apparatus will be described.

(1) A size smaller than the mold for a resin heat-molding device that molds a flat plate-shaped work made of a thermoplastic resin material with a pair of upper and lower molds under a heated state. In the heating part structure of the resin heat forming apparatus provided with a heating part for heating the work by a heating means, a clamp group consisting of at least one clamp having a clamp capable of gripping or releasing the work is a work. In the heating section, the clamp group sets the work holding band that needs to be held by the clamp at one side of the end including the outer edge of the work, which is the outer edge, as a reference clamp holding reference. Based on the pitch P, the clamps are arranged intermittently by an arrangement form partitioned by at least one clamp holding reference pitch P, and the clamp holding reference pitch P is attached to a single clamp and is a single unit. A part of the local work that is held by the clamp, the holding area P1 that is the distance along one side, and a part of the local work that is next to the holding area P1 and is not held by the clamp, on one side. It is one pitch of the work holding band consisting of the non-holding part area P2 which is the distance along the clamp, and the clamp has the clamp part occupancy rate K = P1 / (which occupies the holding part area P1 in the clamp holding reference pitch P). It is characterized in that it is formed in an embodiment satisfying the condition 0 <K ≦ 25 (%) of P1 + P2).

Due to this feature, the heat received from the heating means is easily propagated from the portion sandwiching the workpiece holding portion by the clamp through the inner layer of the work to the bottom of the workpiece holding portion. Therefore, even if there is a part where the work is held by the clamp, the heat from the heating means can be transferred to the work in the same way as the part which is not held by the clamp. The work can be heated at a temperature within a suitable molding temperature range.

Therefore, according to the heating portion structure of the resin heat molding apparatus according to the present invention and the resin heat molding apparatus, a thermoplastic resin material (work) having a size smaller than that of the mold is held by a clamp when molding the resin molded product. When heating the work, the effect of heat transfer exerted by the clamp is suppressed, and the entire work can be heated with a more uniform temperature distribution, which is an excellent effect.

In the heating part structure of the resin heat forming apparatus according to the present invention and the resin heat forming apparatus, the concept of the flat plate-shaped work is that in the present invention, the work (thermoplastic resin material) to be thermoformed by the resin heating forming apparatus is used. It is not classified according to its thickness, and even if it is a thermoplastic resin material having a thickness of 1 mm or less and a thickness in the sheet-like category, it is collectively referred to as a flat plate-shaped work.

In the heating portion structure of the resin heat forming apparatus described in (2), the clamp has a U-shape between two supporting portions arranged in parallel with each other and a connecting portion at a distance corresponding to the thickness of the work. Formed by connecting, under the state where the clamp holds the work, the direction orthogonal to the height direction along the thickness direction of the work with respect to the clamp is the width direction extending toward the outer edge side of the work and the work from the outer edge of the work. The support portion is characterized in that the size in the width direction is smaller than that in the depth direction and is formed up to twice the thickness of the workpiece to be held, when the depth direction extends inward to the inside of the surface. And.

Due to this feature, the clamp can be gripped or released from the work with a simple structure, and can be versatilely adapted to the size and shape of the work to be held. Moreover, even if the heat generated by the heating means is transferred to the work under the heating of the work held by the clamp, it is possible to prevent the clamp from becoming an obstructive factor that blocks the heat transfer to the work. Therefore, the entire work can be heated at a temperature suitable for molding by a mold.

In the heating unit structure of the resin heat molding apparatus described in (3), the heating means is a heater that heats the work by radiant heat.

Due to this feature, the work can be heated at a uniform temperature regardless of the presence or absence of a holding portion of the work by the clamp.

(4) When a flat plate-shaped work made of a thermoplastic resin material is molded with a pair of upper and lower molds under a heated state, the work having a size smaller than the mold is used. In a resin heat molding apparatus provided with a heating portion that is heated by a heating means, the heating portion is configured by the heating portion structure of the resin heat molding apparatus according to any one of (1) to (3). It is a feature.

Due to this feature, a work smaller than the mold is molded to manufacture a resin molded product. Therefore, after heat molding a work larger than the mold, trimming of unnecessary parts of the molded product caused by heating is performed. In comparison, the thermoplastic resin material used as a material is hardly disposed of. Therefore, the resin heat molding apparatus according to the present invention can be an environmentally friendly apparatus on the earth from the viewpoint of environmental protection, resource protection, etc., and can contribute to global efforts to reduce the disposal of plastic products.

It is a top view which shows the main part of the clamp group configured in the transport part of the heat molding apparatus which concerns on embodiment. It is a side view of the transport part shown in FIG. 1, and is the explanatory view which shows the non-grip state of a work by a clamp group. It is a side view of the transport part shown in FIG. 1, and is explanatory drawing which shows the gripping state of the work by a clamp group. It is a figure which shows the clamp which constitutes the clamp group by the heat molding apparatus which concerns on embodiment, (a) is the side view, (b) is the plan view. It is explanatory drawing which shows typically the structure of the heating part and the movement of a transfer part in the heat molding apparatus which concerns on embodiment. Regarding the work to be heated by the heating unit of the heat molding apparatus according to the embodiment, (a) is a plan view showing how the work is held and heated by the clamps according to the first and second embodiments, and (b) is shown in (a). It is a figure which shows the temperature distribution of the work in the heated state under the heating condition of the shown work. It is a schematic diagram for demonstrating the concept of the clamp holding reference pitch P used in the calculation of the clamp part occupancy rate K about the heating part of the heat molding apparatus which concerns on embodiment. In the production of the resin molded product, (a) is an explanatory view showing how the work heated under the heating conditions of the work shown in FIG. 6 is molded by a mold, and (b) is taken out from the mold. It is a top view which shows the resin molded product. Regarding the work to be heated by the heating unit of the heat forming apparatus according to the embodiment, (a) is a plan view showing how the work is held and heated by the clamp according to the comparative example, and (b) is the work shown in (a). It is a figure which shows the temperature distribution of the work in the heated state under the heating condition. In the production of the resin molded product, (a) is an explanatory view showing a state in which a work heated under the heating conditions of the work shown in FIG. 9 is molded by a mold, and (b) is taken out from the mold. It is a top view which shows the molding defective product. It is explanatory drawing which shows the state of heating a work by the heating part of the heat forming apparatus which concerns on embodiment, using the clamps of Examples 1, 2 and comparative examples, and the influence of heat transfer on a work is about every clamp. It is a schematic diagram which shows in comparison with. It is the result of the investigation test in which the work was held and heated by the clamps according to Examples 1 and 2, and the clamp portion occupancy rate K in the work and the temperature T of the heat-transferred sample (work). It is a graph which shows the relationship. FIG. 1 is a first process diagram showing a state in which a work gripped by a clamp is conveyed to a mold matching position in a process of manufacturing a resin molded product by a heat molding apparatus according to an embodiment. Following the first process chart shown in FIG. 13, it is a second process chart showing a state in which the lower mold is raised to the contact start position with the work. Following the second process diagram shown in FIG. 14, it is a third process diagram showing a state in which the lower mold has reached the support state position, and is a diagram showing immediately before the work is released from being gripped by the clamp. It is explanatory drawing about the support state position of the lower mold illustrated in FIG. It is a chart diagram showing the relationship between the speed and the position of the work regarding the behavior of the lower mold with respect to the manufacturing process of the resin molded product by the heat molding apparatus according to the embodiment, and (a) is the behavior of the lower mold according to Reference Example 1. , (B) shows the behavior of the lower mold according to Reference Example 2, respectively. Following the third process diagram shown in FIG. 15, it is a fourth process diagram showing a state in which the clamp is retracted from the mold after the gripping of the work by the clamp is completed. Following the fourth process diagram shown in FIG. 18, it is a fifth process diagram showing a state in which a work is molded with a mold to manufacture a resin molded product.

Hereinafter, the structure of the heating portion of the resin heat molding apparatus according to the present invention and the embodiment in which the resin heat molding apparatus is embodied will be described in detail with reference to the drawings. Hereinafter, since the heating portion structure of the resin heat molding apparatus according to the present invention is typically configured in the present embodiment as the resin heat molding apparatus according to the present invention, the resin heat forming apparatus according to the present embodiment is described as a representative. Will be mainly explained.

The resin heat-molding apparatus according to the present invention is an apparatus for producing a resin-molded product in which a work made of a thermoplastic resin material is molded by a pair of upper and lower dies under a heated state. Therefore, a workpiece having a size smaller than that of a mold and formed in a flat plate shape is targeted for molding. In this resin heat forming apparatus, the work is heated by the heating means in the heating portion while being held by the clamp. The structure of the heating portion of the resin heat molding apparatus according to the present invention is intended for equipment for manufacturing resin molded products, for example, the heating portion of an existing resin heat molding apparatus similar to the resin heat molding apparatus according to the present invention. In addition, it can be modified and incorporated, or it can be incorporated into a part of a new device that fulfills another function.

First, the work will be briefly explained. FIG. 1 is a plan view showing a main part of a clamp group configured in a transport part of the heat molding apparatus according to the embodiment. The work 50 is made of a thermoplastic resin material such as polypropylene (abbreviated as PP: polypropylene, acrylic resin (abbreviated as PMMA: acrylic resin), polyacetal (abbreviated as POM: polyacetal), polycarbonate (abbreviated as PC: polycarbonate)). The work 50 has a size smaller than that of the mold 10 so that it can be completely fitted in the mold 10 at the time of molding.

For convenience of explanation, in the present embodiment, the work 50 is a flat plate having a quadrangular contour as shown in FIG. 1, and as an example, has a plate thickness of about 1 mm to a dozen mm and a side length of several. It is a material formed to a size of about tens to several hundreds of mm. In the present embodiment, the concept of the flat plate-shaped work 50 does not divide the work (thermoplastic resin material) 50 thermoformed by the thermoforming apparatus 1 according to its thickness, for example, the thickness is 1 mm or less, even if the sheet is 1 mm or less. Even if the thickness of the thermoplastic resin material is in the category of the shape, it is generically called a flat plate-shaped work. Further, since the work 50 has different shapes such as contour, plate thickness, and size according to the specifications of the resin molded product (product) to be molded, the shape such as contour, plate thickness, and size is the present implementation. It is not limited to the form and can be changed as appropriate.

FIG. 2 is a side view of the transport portion shown in FIG. 1, an explanatory view showing a non-grasping state of the work by the clamp group, and FIG. 3 is an explanatory view showing a gripping state of the work by the clamp group. FIG. 5 is an explanatory diagram schematically showing the configuration of the heating unit and the movement of the transport unit in the heat molding apparatus according to the embodiment. In FIG. 1, the left-right direction is the horizontal direction (moving direction of the transport unit 20) HZ of the heat forming apparatus 1 (corresponding to the resin heating forming apparatus of the present invention), and in each of the drawings after FIG. 2, FIG. Follow the defined direction. Further, in FIG. 5, the vertical direction is defined as the vertical direction VT of the heat forming apparatus 1, and each of the drawings after FIG. 6 also follows the direction defined in FIG.

Next, the heat molding apparatus 1 will be described. As shown in FIGS. 1 and 5, the heat molding apparatus 1 includes a drive unit 2, a control unit 3, a mold 10 paired with an upper mold 11 and a lower mold 12, a transport unit 20, a clamp group 30, and a heating unit. It is equipped with 40 mag.

As shown in FIG. 5, in the heat molding apparatus 1, the transport unit 20 is configured to be movable along the transport line FL between the retracted position X1 and the mold matching position X2. The retracted position X1 is in the heating unit 40 away from the mold 10. The mold matching position X2 is a position in the mold 10 on which the work 50 can be placed on the upper surface 12a of the lower mold 12 corresponding to the mold matching with the upper mold 11.

The heating unit 40 is a portion in which the work 50 is preliminarily heated to a temperature required for molding by a heater 41 (heating means) when the work 50 is molded by the mold 10 under a heated state. The heater 41 is an infrared heater that heats the work 50 by radiant heat. The heater 41 is provided with an electromagnetic wave irradiation surface that is sufficiently larger than the area of the plane of the work 50 (see FIG. 1) so that the radiant heat can be enjoyed by the entire plane of the work 50 (see FIG. 1).

As shown in FIGS. 1 to 3, a clamp group 30 is arranged in the transport unit 20. As the transport unit 20 moves between the retracted position X1 and the mold matching position X2, the clamp group 30 can be arranged in the heating unit 40 together with the work 50. The clamp group 30 is composed of at least one clamp 31, and the clamp 31 is formed so as to be able to grip or release the end portion 51 of the work 50.

As shown in FIGS. 1 to 3, the clamp group 30 is arranged in a pair on both sides of the horizontal HZ sandwiching the arrangement position of the work 50 in a facing arrangement, and faces the flat plate-shaped work 50. It is possible to hold the ends 51 together. In the transport unit 20, the clamp groups 30 on both sides select an operation of separating the clamp groups 30 from each other as shown in FIG. 2 and an operation of approaching each other as shown in FIG. 3 based on the arrangement position of the work 50. Can be done.

Specifically, when the clamp groups 30 are close to each other, in the clamp group 30, the clamp 31 grips the end portion 51 of the work 50. Further, when the clamp groups 30 are separated from each other, the clamp 31 releases the grip of the end portion 51 of the work 50. When the work 50 is held by gripping the end portion 51 by the clamp group 30 at the retracted position X1, the work 50 is matched by moving the transport portion 20 while holding the end portion 51 by the clamp group 30. It is transported to position X2 and supplied to the mold 10.

Next, the configuration of the clamp 31 will be described with reference to FIG. 4A and 4B are views showing clamps constituting a clamp group in the heat molding apparatus according to the embodiment, where FIG. 4A is a side view and FIG. 4B is a plan view thereof. In the present embodiment, as illustrated in FIG. 4, the clamp 31 connects two support portions 32, 32 arranged in parallel to each other and a connection portion 33 at a distance corresponding to the thickness t of the work 50. It is formed by connecting them in the shape of a. The clamp 31 is made of a material having excellent thermal conductivity, such as metal.

Here, under the state where the clamp 31 holds the work 50, the work 50 is oriented in a direction orthogonal to the height direction CH along the thickness direction of the work 50 (vertical direction in FIG. 4A) with respect to the clamp 31. The width direction CW extending in the outer edge 50F side (in the vertical direction in FIGS. 4B) and the depth extending from the outer edge 50F of the work 50 to the inside of the surface of the work 50 (in the middle of FIGS. 4A and 4B, left side). Defined as direction CL. In the clamp 31, the support portion 32 has a width length m (0 <m), which is the size of the CW in the width direction, smaller than the depth length n (0 <n <m), which is the size of the CL in the depth direction. It is formed up to twice the thickness 2 of the work 50 to be held (m ≦ 2t) as an upper limit.

When gripping the work 50 on the clamp 31, when releasing the gripped work 50 from the clamp 31, and while gripping, as shown in FIG. 4A, in particular, the support portion 32 of the clamp 31. Contact the surface of the work 50. Therefore, the portion of the clamp 31 that comes into contact with the surface of the work 50 is subjected to surface treatment with a high surface roughness equivalent to, for example, Rz (10-point average roughness) of 6.3S or more, and slidability is improved. It is preferable that the clamp 31 is provided with measures for suppressing damage to the surface of the work 50, such as applying an enhanced coating coating treatment to the surface.

In the heating unit 40, the work 50 is heated under the state of being held by the clamp group 30. Therefore, it is necessary to form the clamp group 30 by the clamp 31 in a manner suitable for heating the work 50.

Next, the relationship between the clamp group 30 and the clamp 31 constituting the clamp group 30 will be described. 6A and 6B are plan views showing a work to be heated by the heating portion of the heat forming apparatus according to the embodiment, in which FIG. 6A shows a state in which the work is held and heated by the clamps according to the first and second embodiments, and FIG. 6B is a plan view. It is a figure which shows the temperature distribution of the work in the heated state under the heating condition of the work shown in (a). FIG. 7 is a schematic diagram for explaining the concept of the clamp holding reference pitch P used in the calculation of the clamp portion occupancy rate K with respect to the heating portion of the heat forming apparatus according to the embodiment.

In the heating unit 40 of the heat molding apparatus 1 according to the present embodiment (the heating portion structure of the resin heat forming apparatus according to the present embodiment), as shown in FIG. 6A, the clamp group 30 is the outer edge 50F of the work 50. The work holding band 51Q that needs to be held by the clamp 31 is partitioned by at least one clamp holding reference pitch P based on the reference clamp holding reference pitch P on one side of the end portion 51 forming the outer edge 50F. Clamps 31 are arranged intermittently according to the arrangement form.

As shown in FIG. 7, the clamp holding reference pitch P is a part of a local work that is attached to a single clamp 31 and is held by the single clamp 31, and is a holding portion area P1 that is a distance along one side. Next to the holding portion area P1, it is a local work portion that is not held by the clamp 31, and is one pitch of the work holding band consisting of the non-holding portion area P2 which is the distance along one side. The clamp 31 is formed in such a manner that the condition 0 <K ≦ 25 (%) of the clamp portion occupancy rate K = P1 / (P1 + P2) occupying the holding portion region P1 in the clamp holding reference pitch P is satisfied.

In the case of the single clamp 31 illustrated in FIG. 4, as shown in FIGS. 4 and 7, the holding portion area P1 corresponds to the width length m of the supporting portion 32. Further, with respect to the work holding band 51Q, the number of sections according to the clamp holding reference pitch P depends on the shape of the work 50, the heating conditions of the work 50 in the heating unit 40, the molding conditions of the work 50 in the mold 10, and the like. Set.

This will be described in detail. When the heater 41 heats the work 50 held by the clamp group 30 (clamp 31), the heater 41 irradiates the entire work 50 with an electromagnetic wave and uses the radiant heat as shown in FIGS. 4 and 6. Tell 50. At this time, in the work 50, the irradiation of the electromagnetic wave by the heater 41 is blocked at the holding portion of the clamp 31 in the work holding band 51Q due to the presence of the individual clamps 31 forming the clamp group 30. Therefore, of the work 50, the holding portion of the clamp 31 cannot be directly irradiated with electromagnetic waves from the heater 41.

In the heat forming apparatus 1 (heated portion structure of the resin heating forming apparatus according to the present embodiment), the condition 0 <K ≦ 25 (%) of the clamp portion occupancy rate K is satisfied (see FIGS. 6 (a) and 7). When the clamp 31 is formed with the width length m of the support portion 32 in the above, the temperature distribution of the work 50 heated by the heater 41 is formed by the mold 10 as shown in FIG. 6 (b). The suitable temperature is a molding temperature band of 50H having a temperature range within a set allowable range.

8A and 8B are explanatory views showing a state in which a work heated under the heating conditions of the work shown in FIG. 6 is molded by a mold in the production of a resin molded product, and FIG. 8B is an explanatory view. It is a top view which shows the resin molded article taken out from a mold. When the work 50, which has been entirely heated in the molding temperature band 50H, is molded by the mold 10 based on the manufacturing process of the resin molded product 60 described later, as shown in FIG. 8A, the work holding of the work 50 is held. The portion of the band 51Q also easily follows the mold shape of the mold 10, and as shown in FIG. 8B, the resin molded product 60 having a desired shape is molded.

9A and 9B are plan views showing a work to be heated by a heating portion of the heat forming apparatus according to the embodiment, in which FIG. 9A shows a state in which the work is held and heated by a clamp according to a comparative example, and FIG. It is a figure which shows the temperature distribution of the work in the heated state under the heating condition of the work shown in (1). 10A and 10B are explanatory views showing a state in which a work heated under the heating conditions of the work shown in FIG. 9 is molded by a mold in manufacturing a resin molded product, and FIG. 10B is an explanatory view. It is a top view which shows the molding defective product taken out from a mold.

However, when the clamp 31 is formed with the width length m of the support portion 32 under the condition that the clamp portion occupancy rate K exceeds 25% with respect to the work holding band 51Q, the work 50 heated by the heater 41. As shown in FIG. 8B, the temperature distribution of the above is the molding temperature band 50H at the center of the work 50, but the low temperature band 50C in the work holding band 51Q. The temperature in the low temperature zone 50C is low outside the molding temperature zone 50H, which is unsuitable for molding by the mold 10.

That is, when the low temperature zone 50C is included in the heated work 50, when the resin molded product 60 is manufactured, as shown in FIG. 10A, the work holding band in the low temperature zone 50C of the work 50 51Q is a molding defective portion 61X that is not molded following the mold shape of the mold 10. As a result, as shown in FIG. 10B, the non-defective resin molded product 60 cannot be molded, and the defective molding product 60X including the defective molding portion 61X is molded.

Next, the applicant is for confirming the influence on the heating of the work 50 due to the clamp 31 in holding the work holding band 51Q of the work 50 by the clamp group 30 (clamp 31). A survey test was conducted. In the investigation test, a polycarbonate sample (thickness t = 6 mm) corresponding to the work 50 and three types of clamps formed in different aspects of the clamp site occupancy rate K were used, and each type of clamp was clamped. The held sample (referred to as “sample 50” in FIG. 11 for convenience) is heated by the heater 41 of the heating unit 40, and the temperature of the heated sample 50 and the propagation state of radiant heat at the holding portion by the clamp are described. investigated. The three types of clamps are the first clamp 31A (31), the second clamp 31B (31), and the third clamp 31X. The first clamp 31A was used in the experiment according to Example 1, the second clamp 31B was used in the experiment according to Example 2, and the third clamp 31X was used in the experiment according to Comparative Example. The experimental conditions according to Examples 1, 2 and Comparative Example are all the same except for the difference in the specifications of each clamp.

<Experimental conditions>
FIG. 11 is an explanatory diagram showing a state in which the work is heated by using the clamps according to Examples 1, 2 and Comparative Example in the heating unit of the heat forming apparatus according to the embodiment, and is an explanatory diagram showing the influence of heat transfer on the work. It is a schematic diagram which shows in comparison for each clamp. As shown in FIG. 11, the first clamp 31A is formed based on the clamp portion occupancy rate K = 4. The second clamp 31B is formed based on the clamp portion occupancy rate K = 20. Similar to the clamp 31, the third clamp 31X is formed by connecting the support portions arranged opposite to each other and the connection portion in a U shape based on the clamp portion occupancy rate K = 98.

<Experimental results>
FIG. 12 shows the results of an investigation test in which the work was held and heated by the clamps according to Examples 1 and 2, and the clamp site occupancy rate K in the work and the heat-transferred sample (work). It is a graph which shows the relationship with a temperature T. In the investigation test, when heating the sample 50, the molding temperature band 50H suitable for molding by the mold 10 is between the upper limit side temperature TU and the lower limit side temperature TL, as shown in FIG. 12, and the upper limit side temperature TU. The temperature range between the lower limit side temperature TL and the lower limit side temperature TL is about 10 ° C. as an example.

The results of the survey test were as follows. In the first clamp 31A according to the first embodiment, when the clamp portion occupancy rate is K = 4, the temperature T1 of the sample 50 heated by the heater 41 is an allowable range between the upper limit side temperature TU and the lower limit side temperature TL. It was inside. In the second clamp 31B according to the second embodiment, when the clamp portion occupancy rate is K = 20, the temperature T2 of the sample 50 heated by the heater 41 allows a range of the upper limit side temperature TU and the lower limit side temperature TL. It was inside. In the third clamp 31X according to the comparative example, when the clamp portion occupancy rate is K = 98, the temperature T3 of the sample 50 heated by the heater 41 is out of the allowable range between the upper limit side temperature TU and the lower limit side temperature TL. Met.

<Discussion>
As a consideration of the investigation test, both the first clamp 31A (31) according to the first embodiment and the second clamp 31B (31) according to the second embodiment have the clamp site occupancy with respect to the clamp holding reference pitch P. It is formed by the holding portion region P1 in a state where the upper limit value of K is less than 25%, that is, the width length m of the supporting portion 32. Even if the clamp 31 covers the holding portion of the sample 50 under heating by the heater 41, when the clamp portion occupancy rate is K = 4, 20, as shown in FIG. 11, the sample 50 by the clamp 31 The holding site of is kept relatively small.

Therefore, the radiant heat from the heater 41 propagates from the portion sandwiching the holding portion of the sample 50 by the clamp 31 through the inner layer of the sample 50 to below the holding portion of the sample 50. As a result, even if the portion of the sample 50 is held by the clamp 31, the radiant heat of the heater 41 can be transferred to the sample 50 in the same manner as the portion not held by the clamp 31, so that the influence of the presence of the clamp 31 is suppressed and the upper limit is suppressed. It is presumed that the sample 50 can be heated at a temperature T within the allowable range of the side temperature TU and the lower limit side temperature TL.

On the other hand, in the case of the comparative example, the holding portion region P1 in the state of K = 98 (%), which greatly exceeds the upper limit value 25% of the clamp portion occupancy rate K with respect to the clamp holding reference pitch P, that is, the width of the supporting portion. The third clamp 31X is formed by the length (corresponding to the width length m of the support portion 32 of the clamp 31). When the clamp portion occupancy rate is K = 98 under heating by the heater 41, as shown in FIG. 11, in the third clamp 31X, the width length of the support portion is relatively large, and the holding portion of the sample 50 is , It is in a state of being covered by such a third clamp 31X.

Therefore, the radiant heat from the heater 41 is difficult to propagate from the portion sandwiching the holding portion of the sample 50 by the third clamp 31X through the inner layer under the holding portion of the sample 50. Therefore, even if the radiant heat from the heater 41 is transferred to the sample 50, the third clamp 31X holding the sample 50 becomes an obstructive factor that blocks the propagation of the radiant heat to the sample 50, and the upper limit side temperature TU and the lower limit It is presumed that the sample 50 cannot be heated at a temperature T within the allowable range of the side temperature TL.

Next, the mold 10 will be described. The mold 10 is formed in a mold shape corresponding to the molding shape of the resin molded product 60 (see FIG. 8), which is a product, and the upper mold 11 and the lower mold 12 form a set. The mold 10 is configured so that both the upper mold 11 and the lower mold 12 can be moved up and down or stopped based on the drive unit 2, respectively. The control unit 3 controls the operation of the drive unit 2, the operation control of the transport unit 20, the operation control of the clamp group 30 (holding and releasing the work 50), temperature control of the heater 41 in the heating unit 40, and the work 50. Electrical of the entire heat molding device 1 such as temperature sensors mounted on the temperature control of radiant heat toward (see FIG. 12), various sensors such as photoelectric sensors and proximity sensors, and various sensors mounted on pneumatic equipment. Takes charge of control.

In the mold 10, the mold opening position between the upper mold 11 and the lower mold 12 is set with reference to the transport line FL of the work 50 by the transport unit 20 as shown in FIG. 5, and the upper and lower end positions of the upper mold 11 are set. U1 is above the transport line FL, and the descending end position L1 of the lower die 12 is below the transport line FL. The drive unit 2 and the control unit 3 move the upper mold 11 toward the lower side of the upper descending end position U1 and the lower mold 12 toward the upper side of the lower end position L1.

Next, in manufacturing the resin molded product 60, a control method of the heat molding apparatus 1 will be described. FIG. 13 is a first process diagram showing a state in which the work gripped by the clamp is conveyed to the mold matching position in the process of manufacturing the resin molded product by the heat molding apparatus according to the embodiment.

As shown in FIG. 5, the transport unit 20 transports the work 50 held by the clamp group 30 from the retracted position X1, and as shown in FIG. 13, the work 50 in this state is the mold 10. It is arranged at the mold matching position X2 of. The work 50 is in a state of being softened by being heated to, for example, about one hundred and several tens of degrees in advance by the heating unit 40. Therefore, when the work 50 is supplied to the mold matching position X2 in a state where the end portions 51 on both sides (left and right sides in FIG. 13) are held by the clamp 31 (clamp group 30), the work 50 has a flat plate shape before heating. As shown in FIG. 13, the work 50 is deformed into a shape forming a hanging portion 52 hanging below the clamp group 30.

FIG. 14 is a second process diagram showing a state in which the lower mold is raised to the contact start position with the work, following the first process diagram shown in FIG. FIG. 17 is a chart diagram showing the relationship between the speed and the position of the work regarding the behavior of the lower mold in the manufacturing process of the resin molded product by the heat molding apparatus according to the embodiment, and FIG. 17A is a chart diagram showing the relationship between the speed and the position of the work, and FIG. 17A relates to Reference Example 1. The behavior of the lower mold is shown, and (b) shows the behavior of the lower mold according to Reference Example 2.

After the work 50 is arranged at the mold matching position X2 of the mold 10 as shown in FIG. 13, the control unit 3 transfers the lower mold 12 from the lower end position L1 as shown in FIG. It is raised at a primary speed V1 (0 <V1) toward the work 50 waiting on the FL, and is brought into contact with the bottom 53 of the droop 52 as shown in FIG. When the lower mold 12 reaches the contact start position L2 in contact with the bottom 53 of the hanging portion 52, the control unit 3 starts contact with the bottom 53 of the hanging portion 52 of the lower mold 12 as shown in FIG. With the contact start position L2 as the boundary, the control to change the operation of the lower mold 12 from the primary speed V1 (0 <V1) to the secondary speed V2 (0 <V2 <V1) decelerated by a negative acceleration is performed. This is performed on the drive unit 2.

FIG. 15 is a third process diagram showing a state in which the lower mold has reached the lower support position of the work, following the second process diagram shown in FIG. 14, and is a diagram showing immediately before the work is released from being gripped by the clamp. be. FIG. 16 is an explanatory diagram of the support state position of the lower mold shown in FIG.

In the heat forming apparatus 1, the work 50 with such deformation is placed on the upper surface 12a of the lower mold 12, and then molded by matching with the upper mold 11 of the hanging portion 52 of the work 50. The control unit 3 grips the work 50 by the clamp group 30 at the support state position L3 of the lower mold 12 which has been supported by the contact of the bottom 53 with the lower mold 12 rising toward the upper mold 11. To release. As shown in FIGS. 15 and 16, the support state position L3 is set with respect to the bottom 53 of the hanging portion 52 in contact with the lower mold 12 in the effective contact area S1 of the work 50 that can contact the upper surface 12a of the lower mold 12. It is a position where the ratio S2 / S1 occupying the projected contact area S2 of the bottom 53 of the hanging portion 52 projected on the lower mold 12 side reaches a state satisfying the condition of at least 5%. When this ratio S2 / S1 is less than 5%, when the work 50 from which the end portion 51 is not gripped by the clamp group 30 is placed on the upper surface 12a of the lower die 12 accompanied by the ascending operation, the work 50 is placed. This is because the molding process by the mold 10 may be hindered due to misalignment or the like on the upper surface 12a of the lower mold 12.

This will be described in detail. At the timing when the upper surface 12a of the lower mold 12 first reaches the contact start position L2 at which the bottom 53 of the hanging portion 52 begins to substantially contact, the control unit 3 sets the lower mold 12 to the secondary speed as shown in FIG. Decelerate to V2 (0 <V2 <V1). As a result, the lower die 12 rises at the decelerated secondary speed V2 and approaches the support state position L3.

In the lower mold 12, the heat forming apparatus 1 is a detecting means capable of detecting the state of the upper surface 12a of the lower mold 12 and the hanging portion 52 of the work 50 in detecting the contact start position L2 and the support state position L3. It is preferable to provide it in. As an example of the detection means, the operation points of the lower mold 12 corresponding to the contact start position L2 and the support state position L3 are grasped, and the proximity sensor detects that the lower mold 12 approaches these operation points. It is a means. Further, the control unit 3 is moving at the timing when the light is emitted from the photoelectric sensor in accordance with the position of the bottom 53 of the hanging portion 52 and the upper surface 12a of the lower mold 12 is in a state of interfering with the light. It is a means for controlling the operation of the lower mold 12.

<Reference example 1>
In the operation control of the lower die 12 according to Reference Example 1, as shown in FIG. 17A, the lower die 12 rises from the contact start position L2 toward the support state position L3 while decelerating at the secondary speed V2. Then, the control unit 3 stops the ascending operation of the lower mold 12 in accordance with the support state position L3. When the lower mold 12 is stopped, the control unit 3 keeps the lower mold 12 stopped at the support state position L3, separates the clamp groups 30 from each other with respect to the transport unit 20, and ends 51 of the work 50 by the clamp 31. The grip of is released.

<Reference example 2>
Further, in the operation control of the lower die 12 according to Reference Example 2, the lower die 12 continues to rise from the contact start position L2 toward the support state position L3 while decelerating at the secondary speed V2. In the case of Reference Example 2, as shown in FIG. 17B, the secondary velocity V2 is suppressed to be smaller than the threshold velocity v (0 <v <V2) set as the threshold, and the velocity component v0 (0 <v0 <). It is a velocity including a positive acceleration changed from a negative acceleration by changing the direction of the acceleration at the support state position L3 under the movement of the lower mold having v).

The threshold speed v is the end portion 51 of the work 50 at the support state position L3 with respect to the work 50 in which the bottom 53 of the hanging portion 52 is deposited on the upper surface 12a of the lower die 12 that continues to rise. Even if the grip is released, as shown in FIG. 18 described later, the work 50 is placed on the upper surface 12a of the lower mold 12 accompanied by the ascending operation without any misalignment or the like, and there is no problem in the molding process by the mold 10. It means the upper limit speed of the lower die 12 which is within the allowable range on the premise that it can be arranged in an appropriate state. Further, the velocity component v0 means that when the lower die 12 reaches the support state position L3 and the clamp group 30 releases the grip of the end portion 51 of the work 50, the lower die 12 moves toward ascending at a low speed. Means that it is accompanied by.

FIG. 18 is a fourth process diagram showing a state in which the clamp is retracted from the mold after the gripping of the work by the clamp is completed, following the third process diagram shown in FIG. FIG. 19 is a fifth process diagram showing a state in which a work is molded with a mold to manufacture a resin molded product, following the fourth process diagram shown in FIG.

After the lower mold 12 reaches the support state position L3, when the holding of the work 50 by the clamp group 30 (clamp 31) is released at the support state position L3, the control unit 3 shall perform the control unit 3 as shown in FIGS. 17 and 18. At the tertiary speed V3, which is accelerated at a positive acceleration following the secondary speed V2, the lower mold 12 is raised to the molding reference position L4, and the work 50 placed on the upper surface 12a of the lower mold 12 is aligned with the transport line FL. Deploy. After the lower mold 12 reaches the molding reference position L4, as shown in FIG. 19, the control unit 3 lowers the upper mold 11 to the upper mold molding position U2 so that the upper mold 11 and the lower mold 12 are aligned. Will be done. Thus, the work 50 is heated and molded by the upper mold 11 and the lower mold 12, and the resin molded product 60 is manufactured.

Next, the structure of the heating portion of the heat molding apparatus according to the present embodiment and the operation / effect of the heat molding apparatus 1 will be described.

The heating portion structure of the heat molding apparatus according to the present embodiment is a mold 10 in which a flat plate-shaped work 50 made of a thermoplastic resin material is heated and the upper mold 11 and the lower mold 12 form a pair. A clamp capable of gripping or releasing the work 50 in the heating unit structure of the heat forming apparatus including the heating unit 40 for heating the work 50 having a size smaller than the mold 10 with respect to the heat forming apparatus 1 to be molded. A clamp group 30 having 31 and composed of at least one clamp 31 can be arranged in the heating unit 40 together with the work 50. In the heating unit 40, the clamp group 30 is an end portion including the outer edge 50F of the work 50. Of the 51, the work holding band 51Q that needs to be held by the clamp 31 on one side forming the outer edge 50F is partitioned by at least one or more clamp holding reference pitch P based on the reference clamp holding reference pitch P. It is configured by arranging the clamps 31 intermittently, and the clamp holding reference pitch P is a part of the local work 50 that is attached to the clamp 31 and is held by the single clamp 31, and is one side of the outer edge 50F. A non-holding area P1 that is a distance along one side of the outer edge 50F at a site of a local work 50 that is not held by the clamp 31 next to the holding area P1 and the holding area P1. The clamp 31 has a clamp portion occupancy rate K = P1 / (P1 + P2) that occupies the holding portion area P1 in the clamp holding reference pitch P, which is one pitch of the work holding band consisting of P2. It is characterized in that it is formed in an embodiment satisfying 25 (%).

Due to this feature, the heat received from the heater 41 is easily propagated from the portion sandwiching the holding portion of the work 50 by the clamp 31 to the inner layer of the work 50 and below the holding portion of the work 50. Therefore, even if there is a holding portion of the work 50 by the clamp 31, the heat of the heater 41 can be transferred to the work 50 in the same manner as the portion not held by the clamp 31, so that the influence of the presence of the clamp 31 can be suppressed. The work 50 can be heated at a temperature in the molding temperature band 50H suitable for molding by the mold 10.

Therefore, according to the heating portion structure of the heat molding apparatus of the present embodiment, when molding the resin molded product 60, the thermoplastic resin material (work 50) having a size smaller than that of the mold 10 is held by the clamp 31 and heated. In this case, the work 50 can be heated with a more uniform temperature distribution by suppressing the influence of heat transfer exerted by the clamp 31 on the work 50, which is an excellent effect.

According to a survey conducted separately from the above-mentioned survey test, the applicant found that if the clamp site occupancy rate K is up to 25 (%), the temperature transferred to the work 50 by the radiant heat of the heater 41 is. As shown in FIG. 12, it has been confirmed that the temperature is within the upper limit side temperature TU and the lower limit side temperature TL, and that a good resin molded product 60 can be molded. On the other hand, when the clamp portion occupancy rate K exceeds 25 (%), the temperature transferred to the work 50 by the radiant heat of the heater 41 is lower than the lower limit side temperature TL as shown in FIG. Therefore, heat molding performed by holding the work 50 with the clamp 31 formed in a state where the clamp portion occupancy rate exceeds K25 (%) causes the generation of defective molding 60X as shown in FIG.

Further, in the heating portion structure of the heat forming apparatus of the present embodiment, the clamp 31 connects two support portions 32 arranged in parallel to each other and a connecting portion 33 at a distance corresponding to the thickness t of the work 50. The outer edge 50F side of the work 50 is formed so as to be connected in the shape of a sword, and the direction orthogonal to the height direction CH along the thickness direction of the work 50 with respect to the clamp 31 under the state where the clamp 31 holds the work 50. When the width direction CW extending in the width direction and the depth direction CL extending from the outer edge 50F of the work 50 to the inside of the surface of the work 50, the support portion 32 sets the width m, which is the size of the width direction CW, to the size of the depth direction CL. It is characterized in that it is smaller than the depth n and is formed up to twice the thickness t (2t) of the work 50 to be held.

Due to this feature, the clamp 31 can be gripped or released from the work 50 with a simple structure, and can be versatilely adapted to the size and shape of the work 50 to be held. Moreover, even if the heat of the heater 41 is transferred to the work 50 under the heating of the work 50 held by the clamp 31, it is possible to prevent the clamp 31 from becoming an obstructive factor that blocks the heat transfer to the work 50. can. Therefore, as shown in FIGS. 6A and 6B, the entire work 50 including the work holding band 51Q can be heated at a uniform temperature in the molding temperature band 50H.

Further, in the heating unit structure of the heat molding apparatus of the present embodiment, the heating means is a heater 41 that heats the work 50 by radiant heat.

Due to this feature, the work 50 can be heated at a uniform temperature regardless of the presence or absence of a holding portion of the work 50 by the clamp 31.

Further, the heat molding apparatus 1 of the present embodiment is characterized in that, as described above, it is configured by the heating portion structure of the heat molding apparatus of the present embodiment.

Due to this feature, since the work 50 having a size smaller than the mold 10 is molded to manufacture the resin molded product 60, after the work having a size larger than the mold is heat-molded, the trimming of unnecessary parts of the molded product caused by heating is performed. Compared to the case where this is done, the thermoplastic resin material used as a material is hardly disposed of. Therefore, the heat molding apparatus 1 can be an environmentally friendly apparatus on the earth from the viewpoint of environmental protection, resource protection, etc., and can contribute to global efforts to reduce the disposal of plastic products.

Although the present invention has been described above in accordance with the embodiment, the present invention is not limited to the above embodiment, and can be appropriately modified and applied without departing from the gist thereof.

For example, in the embodiment, the clamp group 30 is configured by the clamp 31 illustrated in FIG. 4, but the specifications such as the shape and structure of the clamp are not limited to the embodiment, and the shape and material characteristics of the work and the like. Various changes can be made according to the molding conditions of the work and the like. Further, the portion that holds the end portion of the work by the clamp group is not limited to FIG. 1, and can be variously changed according to the forming conditions of the work.

1 Resin heat forming device 10 Mold 11 Upper mold 12 Lower mold 30 Clamp group 31 Clamp 31A 1st clamp (clamp)
31B 2nd clamp (clamp)
32 Support part 33 Connection part 40 Heating part 41 Heater (heating means)
50 Work 50F Work outer edge 51 End 51Q Clamp work holding band CH (clamp) height direction CW (clamp) width direction CL (clamp) depth direction t Work thickness m Support width (width direction size) difference)
n Depth of support (size in width direction)

Claims (4)

Compared to a resin heat-molding device that molds a flat plate-shaped work made of a thermoplastic resin material with a pair of upper and lower dies under a heated state, the work has a size smaller than that of the dies. In the heating part structure of the resin heat molding apparatus provided with the heating part for heating by the heating means.
A group of clamps having a clamp capable of gripping or releasing the work and having at least one of the clamps can be arranged in the heating portion together with the work .
Prior Symbol clamp group, of the end portion including an outer edge of the workpiece, with one side forming the outer edge, a workpiece holding band requiring retention by the clamp, the arrangement form partitioned by a clamp holding the reference pitch P as a reference , The clamps are arranged intermittently,
The clamp holding reference pitch P is a local portion of the work that is attached to the clamp unit and is held by the clamp of the single unit, and is a holding portion region P1 that is a distance along the one side and the holding portion region. Next to P1, it is one pitch of the work holding band consisting of the non-holding portion area P2 which is the distance along the one side at the local part of the work which is not held by the clamp.
Said clamp, said one clamp holding the reference pitch P, the condition 0 <aspects filled with K ≦ 25 (%) of the holding portion area clamping site occupancy occupy P1 K = P1 / (P1 + P2), provided al Re That
By satisfying the condition 0 <K≤25 (%), even if a portion where the work is held by the clamp exists, the heat generated by the heating means is applied to the work as in the case where the portion is not held by the clamp. The work can be heated at a temperature within the molding temperature range suitable for molding by the mold while suppressing the influence of the presence of the clamp.
The heating part structure of the resin heat molding apparatus. In the heating part structure of the resin heat molding apparatus according to claim 1,
The clamp is formed by connecting two support portions arranged in parallel with each other and a connection portion in a U shape at a distance corresponding to the thickness of the work.
Under the state where the clamp holds the work, the direction orthogonal to the height direction along the thickness direction of the work with respect to the clamp is the width direction extending toward the outer edge side of the work and from the outer edge of the work. When the depth direction extends to the inside of the surface of the work,
The support portion is formed so that the size in the width direction is smaller than that in the depth direction and the size is equivalent to twice the thickness of the work to be held.
The heating part structure of the resin heat molding apparatus. In the heating section structure of the resin heat molding apparatus according to claim 1 or 2.
The heating means is a heater that heats the work by radiant heat.
The heating part structure of the resin heat molding apparatus. When a flat plate-shaped work made of a thermoplastic resin material is molded with a pair of upper and lower molds under a heated state, the work having a size smaller than the mold is heated by a heating means. In a resin heat molding apparatus provided with a heating part for heating,
The heating unit is configured by the heating unit structure of the resin heat molding apparatus according to any one of claims 1 to 3.
A resin heat molding device characterized by.

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