JP2011011417A - Tension adding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tension adding device for adding uniform in-plane tension to a sheet body.SOLUTION: Each of heads 14, 20, 26 and 32 is arranged at the center of the corresponding side of a screen 500, and then, positioned and secured to the corresponding base plate in the extending direction thereof. Each of other heads 11 to 13, 15 to 19, 21 to 25, 27 to 31, 33 and 34 is freely movable to the corresponding base plate in the extending direction thereof. The heads 11, 17, 23 and 29 and the heads 11 to 13, 15 to 19, 21 to 25, 27 to 31, 33 and 34 are connected, respectively, through a screwing structure. The screwing depth of a male screw to a female screw is variable with the rotating force work of a stepping motor attached to each of the heads 14, 20, 26 and 32. The four stepping motors are made synchronous with one another, and all the heads 11 to 34 are radially moved around a point P.

Description

  The present invention relates to a tension applying device, and more particularly to a tension applying device that applies tension in the surface direction of a sheet member.

A tensioning device as an example of a tension applying device is used in screen printing. The tensioning device is a device for applying tension in the surface direction of the screen (Patent Document 1). The configuration of the tension device according to the prior art will be described with reference to FIG.
As shown in FIG. 6A, in the tensioning device according to the related art, a plurality of air cylinders 911 to 930 are arranged so as to surround the outside of the target screen 950. Each of the air cylinders 911 to 930 is attached with clampers 911a to 930a arranged inward.

When tension is applied to the screen 950 using such a tensioning device, the screen 950 is disposed in an area surrounded by the air cylinders 911 to 930, and the edge of the screen 950 is used by using the clampers 911 a to 930 a. Clamp the part. Then, each rod of the air cylinders 911 to 930 is driven in the X-axis direction or the Y-axis direction.
As shown in FIG. 6B, when the rods of the air cylinders 911 to 930 are driven, tension is applied to the screen 950 in the direction along the surface (XY direction). The user applies a frame to the middle region 950a of the screen 950 in a state where the tension is applied, and joins the frame 950a with an adhesive or the like.

Meanwhile, as shown in FIG. 6 (b), (region indicated by an arrow _D 1 to D ₄₎ in the case of adding the tension in the X-axis direction and the Y-axis direction on the screen 950, the screen 950, each corner inner portion In particular, the distortion becomes large, and the area 950a for joining the frames must be reduced. An attempt to solve such a problem is the tensioning device shown in FIG. 7 (Patent Document 2).

  As shown in FIG. 7, in the tensioning device according to the conventional improved technique, air cylinders 911 to 930 for applying tension to the screen in the X-axis direction and the Y-axis direction are provided in FIG. Although the same as the tensioning apparatus shown, the tensioning apparatus according to the improved technique is different in that four air cylinders 931 to 934 for pulling the corner portion of the screen are added to these.

  7, the air cylinders 931 to 934 are driven to apply tension in the diagonal direction of the screen, and the other air cylinders 911 to 930 are driven in that state to complete the tensioning. It is something to be made. By using such an apparatus, a more uniform tension can be applied to the screen as compared with the conventional tensioning apparatus shown in FIG.

JP 2005-288790 A JP 09-109362 A

  However, in the tensioning device shown in FIG. 7, since the air cylinder that pulls the corner portion of the screen and the other air cylinders 911 to 930 are driven in a time-reversed state, distortion remains on the screen. Further improvements are needed. That is, in the tensioning device shown in FIG. 7, since the corner portion of the screen is first pulled by the air cylinders 931 to 934, the screen is already distorted when this pulling is performed. However, it is difficult to completely remove this distortion.

In the above, the tension device for applying tension to the screen used for screen printing is taken as an example. However, it is applied to mesh fabrics and other fabrics represented by the screen, and sheet materials such as resin flume and paper. Similar problems exist for devices that apply tension.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a tension applying device that can apply a uniform tension in a plane to a sheet body.

In order to achieve the above object, the present invention adopts the following configuration.
The tension applying device according to the present invention is a device that applies a tension in a direction along the surface of a sheet body having an n-gonal shape (n is an integer of 3 or more). The tension applying device according to the present invention includes n base plates, a plurality of movable heads, and a plurality of clampers as main elements.

N base plates; they are arranged so as to surround the outer side of the n-gonal shape (the shape of the target sheet body) and along each side thereof.
A plurality of movable heads: attached to each corresponding base plate in a state of surrounding the outside of the n-gonal shape.
A plurality of clampers; each of which is attached to each of the plurality of movable heads, and each clamps the edge of the sheet body.

The base plate is fixed in position with respect to the extending direction of the corresponding side in the n-gonal shape and is movable in a direction orthogonal to the extending direction.
The plurality of movable heads include a center head provided corresponding to the center of each side of the n-gonal shape and a corner head provided corresponding to each corner.
Each of the central heads is fixed to the corresponding base plate in the extending direction of the base plate, and each of the corner heads corresponds to the corresponding sides on the n-gonal shape. The base plate is movable in the extending direction of the base plate.

Each of the corner heads and the two central heads arranged corresponding to the sides on both sides of the corner head are connected via a screwed structure of a male screw and a female screw. The male screw and the female screw are formed in the same screw direction and the same screw pitch.
Here, the screwing depth of the male screw with respect to the female screw is changed by the action of the rotational force input to the male screw or the female screw of each central head, and each corner head has a corresponding corner. The distance in the extending direction of the base plate changes according to the change in the screwing depth of the male screw with respect to the female screw with respect to both of the two central heads arranged corresponding to both sides of the head. It is characterized by.

  As described above, in the tension applying device according to the present invention, the plurality of movable heads including the central head and the corner head surround the outside of the n-gonal shape (the shape of the sheet body to which tension is applied). It is arranged. Each of the corner heads and the two central heads arranged corresponding to both sides of the corner head are connected via a screwed structure of a male screw and a female screw. The screwing depth of the male screw relative to the female screw can be changed by the rotational force input to the head. As a result, the distance between the center head and the corner head is accurately changed according to the pitch of the screws.

Further, the central head and the corner heads on both sides thereof are attached to the base plate, and the base plate is fixed in a direction along the side of the n-gonal shape in a direction perpendicular to the side. Is free to move. Then, the corner head moves as described above with respect to the central head corresponding to the sides on both sides, and thus moves by the combined displacement.
Therefore, in the tension applying device according to the present invention, the central head and the corner head in the plurality of heads can move radially with respect to their centers. Since the screw pitch and the thread cutting direction of the male screw and the female screw are the same in all, if the input of the rotational force to each central head is synchronized, all of them move in a synchronized state. Therefore, in the tension applying device according to the present invention, it is possible to apply a uniform in-plane tension to the sheet body.

In the tension applying device according to the present invention, for example, the following variations can be employed.
In the tension applying device according to the present invention, a rotatable rotating shaft is inserted between the central head and the corner head, and the rotational force input to the central head is transmitted via the rotating shaft. The structure of being transmitted to a male screw or a female screw is employable.

In the tension applying device according to the present invention, the plurality of movable heads include intermediate heads inserted between the central heads and the corner heads. It is also possible to adopt a configuration in which the head and the intermediate part head and the corner part head are in an equal pitch relationship.
In the tension applying device according to the present invention, a configuration in which the plurality of movable heads are arranged with a point-symmetrical relationship in a direction corresponding to the surface of the sheet member may be employed.

  In the tension applying device according to the present invention, a stepping motor is connected to each of the central heads, and all the stepping motors rotate with respect to each central head in a synchronized state. A configuration of inputting force can be employed.

It is a top view which shows the structure of the tension apparatus 1 which concerns on embodiment. 1 is a partial perspective view partially showing a main part of a tensioning device 1. It is a fragmentary sectional view which shows the internal structure of the principal part of the tension apparatus. It is a fragmentary sectional view of the principal part of tensioning device 1, and shows the state where movable heads 27-29 moved. It is a top view which shows the state which added the tension | tensile_strength to the screen 500 which is tension | tensile_strength addition object by the tension apparatus 1. FIG. (A) is a top view which shows the structure of the tension apparatus based on a prior art, (b) is a top view which shows the state which added the tension | tensile_strength to the screen 950 using the tension apparatus based on the said prior art. is there. It is a top view which shows the structure of the tension apparatus based on the improvement technique in the past.

The best mode for carrying out the present invention will be described below with reference to the drawings. Note that the embodiment described below is used as an example for easily explaining the structural features of the present invention and the effects obtained from the characteristic configurations. Except for essential features, there is no limitation on the following contents.
[Embodiment]
1. Configuration In the present embodiment, an explanation will be given below by taking as an example a tensioning device 1 that targets a screen that is a kind of sheet body.

As shown in FIG. 1, the tensioning device 1 according to the present embodiment includes 24 heads 11 to 34 and clampers 48 to 71 attached to each of the heads 11 to 34. The 24 heads 11 to 34 are arranged in a frame shape so as to surround the outside of the target screen 500 in the X-axis direction and the Y-axis direction.
Of the 24 heads 11 to 34, the heads 14, 20, 26, and 32 arranged corresponding to the centers of the sides in the X-axis direction and the Y-axis direction of the screen 500 include stepping motors 36 to 36. 39 is attached. Although not shown, a motor driver is connected to each of the stepping motors 36 to 39 so that they can be driven synchronously.

Further, the screen 500 that is the target of tension application is substantially square. An arrangement configuration of the heads 11 to 17, the heads 17 to 23, the heads 23 to 29, and the heads 29 to 11 corresponding to each side of the screen 500 will be described with reference to FIG.
As shown in FIG. 2, the heads 23 to 29 are mounted on a single base plate 72. The base plate 72 has a length in the X-axis direction that is longer than a width in the Y-axis direction and a thickness in the Z-axis direction. The head 26 arranged corresponding to the center of one side of the screen 500 is fixed to the base plate 72.

On the other hand, the other heads 23 to 25 and 27 to 29 are slidable in the X-axis direction. That is, as shown in a portion C surrounded by a two-dot chain line, a guide rail 75 is laid on the base plate 72, and guide blocks 76 of the heads 23 to 25 and 27 to 29 are attached thereto. .
Two guide blocks 73 and 74 are attached to the lower side of the base plate 72, and each is attached to the guide rails 44 and 45. The guide rails 44 and 45 are extended in the Y-axis direction orthogonal to the extending direction of the guide rail 75.

  Although not shown in FIG. 2, the heads 11 to 17, the heads 17 to 23, and the heads 29 to 11 are also arranged with the same configuration as described above. Returning to FIG. 1, the base plate (not shown) to which the heads 11 to 17 are attached is slidable in the Y-axis direction along the guide rails 40 and 41, and the base to which the heads 17 to 23 are attached. A plate (not shown) is slidable along the guide rails 42 and 43, and a base plate (not shown) to which the heads 29 to 11 are attached is slidable along the guide rails 46 and 47.

The heads 11, 17, 23, and 29 arranged corresponding to the corners of the screen 500 are slidable with respect to the base plates corresponding to the sides on both sides. For example, the head 23 can move in the X-axis direction along the guide rails 42 and 43, and can also move in the Y-axis direction along the guide rails 44 and 45.
In the tensioning device 1, the 24 heads 11 to 34 are arranged in a point-symmetric relationship with respect to the virtual center (point P) related to these arrangements.

As shown in a portion B surrounded by a two-dot chain line, the screen 500 as a target of tension application is a sheet body having a fine mesh shape in the X-axis direction and the Y-axis direction. The material used is, for example, polyester. In addition, as the screen 500, a screen with a bias tension may be employed.
As shown in a portion A surrounded by a two-dot chain line, each of the clampers 48 to 71 has clamp claws 63a and 63b, and the edge of the screen 500 can be clamped by the engagement. Among the clampers 48 to 71, the four clampers 48, 54, 60, 66 arranged corresponding to the corners of the screen 500 are arranged so that the clamp claws face the point P. The other clampers 49 to 53, 55 to 59, 61 to 65, and 67 to 71 are arranged so that the clamp claws face the X axis direction or the Y axis direction. In the 24 clampers 48 to 71, each clamp claw clamps the edge of the screen 500 at a substantially equal pitch.

2. Internal Structure of Heads 11 to 34 The internal structure of the heads 11 to 34 will be described using the heads 26 to 29 as an example with reference to FIG.
As shown in FIG. 3, the rotating shaft 104 is provided in a state where the heads 26 to 29 are inserted. A rotating shaft 125 is also provided toward the right side of the figure.

Gears 102 and 103 are attached to the ends of the rotary shafts 104 and 125 on the head 26 side. Each of the gears 102 and 103 has a “helical leaf shape”, and similarly has a “helical leaf shape” and meshes with a gear 101 attached to the tip of the motor shaft 100 of the stepping motor 38.
Three gears 105 to 107 are attached to the rotating shaft 104 on its axis, and are attached to the heads 26 to 29 via bushes 108 to 111. Therefore, the rotating shafts 104 and 125 are rotatable by receiving the rotational force of the stepping motor 38.

  Each of the heads 26 to 28 is provided with gears 112, 116, and 120 that mesh with the gears 105 to 107 attached to the rotary shaft 104. Bolts 113, 117, and 121 that rotate integrally with the gears 112, 116, and 120 are joined to the gears 112, 116, and 120, respectively. The bolts 113, 117, and 121 are attached to the heads 26 to 28 via bushes 114, 118, and 122.

  The bolts 113, 117, and 121 are in a state where their tip portions have entered the adjacent heads 27 to 29, and are provided with male screws. Nuts 115, 119 and 123 corresponding to the bolts 113, 117 and 121 are joined to the heads 27 to 29. The bolts 113, 117, and 121 and the corresponding nuts 115, 119, and 123 have the same screw pitch and thread cutting direction.

In FIG. 3, the internal structures of some of the heads 26 to 29 are shown, but the other heads 11 to 25 and 30 to 34 have the same structure.
3. Slide of the Heads 11 to 34 The slide drive of the heads 11 to 34 will be described using the heads 26 to 29 as an example with reference to FIG.

  As shown in FIG. 4, when the rotational force is transmitted from the stepping motor 38 through the motor shaft 100 to the rotary shaft 104, the bolts 113, 117, 121 are transmitted through the gears 105 to 107, 112, 116, 120. Rotate by the same angle. When the bolts 113, 117, and 121 rotate, the bolts 113, 117, and 121 relatively move in a direction in which they are removed from the nuts 115, 119, and 123 fixed to the heads 27 to 29.

  Since the screw pitches of the bolts 113, 117, 121 and nuts 115, 119, 123 are all the same, a gap x 1 formed between the head 26 and the head 27 and a gap x 2 formed between the head 27 and the head 28. The gaps x3 formed between the head 28 and the head 29 are all equal. Further, the gaps x1, x2, and x3 are amounts corresponding to changes in the screwing depths of the bolts 113, 117, and 121 with respect to the nuts 115, 119, and 123.

As described above, since the stepping motors 36 to 39 are driven in a synchronized state, all the heads 11 to 34 have the same gap therebetween.
FIG. 5 shows the state after the above driving.
As shown in FIG. 5, gaps having the same dimensions are generated between the heads 11 to 34, and the outer dimensions of the heads 11 to 34 are (w3 × w4). Here, the following relationship is satisfied for the external dimensions (w1 × w2) shown in FIG.

[Formula 1] w3-w1 = w4-w2
The heads 11, 17, 23, and 29 arranged corresponding to the corner portions are slid radially around the point P by the synthesis of the slides from both sides.
4). Superiority In the tensioning device 1 according to the present embodiment, the heads 11 to 34 are connected to each other via a threaded structure of a male screw and a female screw, and the heads 14, 20, 26, The screwing depths of the bolts 113, 117, and 121 with respect to the nuts 115, 119, and 123 can be changed by the rotational force input from the stepping motors 36 to 39 attached to 32. Thereby, the heads 11 to 34 spread the points P radially as shown in FIG.

Therefore, in the tensioning device 1 according to the present embodiment, since the plurality of heads 11 to 34 can move radially around the point P, and the rotational driving of the stepping motors 36 to 39 is synchronized, the screen A uniform tension can be applied to 500 in the plane.
5. Other Matters In the tensioning device 1 according to the above embodiment, the configuration including the 24 heads 11 to 34 is employed as an example, but the number of heads is not limited to this. In particular, it is desirable from the viewpoint of uniformly pulling a sheet body such as a screen to include a large number of heads as a configuration within a mechanically possible limit and within a cost allowable limit. As for the arrangement of the clampers, it is desirable to make the pitches as equal as possible from the viewpoint of applying a uniform tension to the sheet body.

  In the above embodiment, the square screen 500 is the target of tension application, but the shape of the screen 500 is not limited to this. For example, a triangular shape, pentagonal shape, or higher polygon shape can be employed. In the above embodiment, the configuration of the present invention is applied to the tensioning device as an example of the tension applying device. However, in addition to this, the application of applying tension to the resin film, the application of applying tension to the paper, etc. Also, the present invention can be applied.

Moreover, in the said embodiment, although the structure provided with the four stepping motors 36-39 was employ | adopted, it is good also as distributing and transmitting rotational force from one motor. In addition to the motor, a power source such as a rotary actuator may be employed.
In the above embodiment, the rotational force is input to the bolts 113, 117, and 121. However, the same effect as described above can be obtained by inputting the rotational force to the nut.

  Although not described in detail in the above embodiment, it is desirable that the size of each clamp pawl in the clampers 48 to 71 is such that the edge of the screen can be clamped in as small an area as possible. That is, when each clamp area is increased, when a tension is applied (state of FIG. 5), the distortion of the screen near the clamp portion becomes large. By making each clamp area as small as possible, the distortion at the edge of the screen can be kept small.

  As shown in FIGS. 1 and 5, in the tensioning device 1 according to the above embodiment, the direction of each clamp claw in the clampers 49 to 53, 55 to 59, 61 to 65, and 67 to 71 is set in the X-axis direction. Alternatively, although the Y-axis direction is used, if it is allowed in terms of the manufacturing cost of the apparatus, the clamp claws can be arranged so as to face the point P.

  INDUSTRIAL APPLICABILITY The present invention is effective for realizing a tension applying device that can apply a uniform tension in a plane when applying tension to a screen in screen printing, and can perform highly efficient work.

1. Tightening device 11-34. Head 36-39. Stepping motor 40-47,75. Guide rail 48-71. Clamper 72. Base plate 73, 74, 76. Guide block 100. Motor shafts 101 to 103, 105 to 107, 112, 116, 120, 124. Gears 104, 125. Rotating shafts 108-111, 114, 118, 122. Bush 113,117,121. Bolt 115,119,123. Nut 500. screen

Claims (5)

A tension applying device that applies tension to a sheet body having an n-gonal shape (n is an integer of 3 or more) in a direction along the surface of the sheet body,
N base plates that surround the outside of the n-gonal shape and are arranged in a state along each side of the shape;
A plurality of movable heads attached to the n base plates;
A clamper attached to each of the plurality of movable heads and clamping an edge of the sheet body;
With
The base plate is fixed in position with respect to the extending direction of the corresponding side in the n-gonal shape, and is movable in a direction perpendicular to the extending direction,
The plurality of movable heads include a center head provided corresponding to the center of each side in the n-gonal shape, and a corner head provided corresponding to each corner,
Each of the central heads is fixed to the corresponding base plate in the extending direction of the base plate,
Each of the corner heads is movable in the extending direction of the base plate with respect to the base plate provided corresponding to the corresponding sides.
Each of the corner heads and the two central heads arranged corresponding to the sides on both sides of the corner head are connected via a screwed structure of male and female screws. And
All the male screws and the female screws are formed in the same screw direction and the same screw pitch,
The screwing depth of the male screw with respect to the female screw is changed by the action of the rotational force input to the male screw or female screw of the central head,
Each of the corner portion heads, according to the change in the screwing depth of the male screw with respect to the female screw, with respect to both of the two central portion heads arranged corresponding to both sides of the corner portion head, The tension applying device is characterized in that an interval in the extending direction of the base plate changes. Between each of the central head and the corner head, a rotatable rotating shaft is inserted,
The tension applying device according to claim 1, wherein the rotational force input to the central head is transmitted to the male screw or the female screw via the rotating shaft. The plurality of movable heads include an intermediate head inserted between each central head and each corner head,
3. The tension applying device according to claim 1, wherein the central portion head and the intermediate portion head, and the intermediate portion head and the corner portion head are in an equal pitch relationship. The tension applying device according to any one of claims 1 to 3, wherein the plurality of movable heads are arranged with a point-symmetrical relationship. A stepping motor is connected to each of the central heads,
5. The tension applying device according to claim 1, wherein all stepping motors input a rotational force to each central head in a synchronized state.

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