JP7700657B2 - Method and device for pressing skin material - Google Patents

Description

The present invention relates to a method and an apparatus for pressing a skin material.

Conventionally, in the processing of skin materials used in vehicle interior parts, the skin material is held in a fixed position by a skin frame and pressed by being sandwiched between upper and lower dies. With this method, the skin material is stretched by the pressure of the dies as pressing progresses.

At this time, the skin material is not stretched uniformly, but is stretched more in areas where curved or uneven sections are formed. If there is variation in the thickness of the skin material, there is a risk of breakage in the areas that are stretched more.

The following Patent Document 1 discloses a vacuum molding method for interior parts in which a skin material is attached to a base material in an inclined state in order to suppress variation in the thickness of the skin material. In this method, the skin material is inclined at an angle that minimizes the amount of interference between the skin material and the mold when the mold is closed and is balanced in the front, back, left and right directions, thereby reducing the distance between the skin material and the curved part of the base material.

JP 2009-78419 A

However, in the method described in Patent Document 1, the skin material is pressed while being held by a skin frame installed at a fixed position, so the skin material is still stretched as the mold moves. The skin material stretched in this way and attached to the substrate has high residual stress, and there is a risk of problems such as heat-resistant peeling. Therefore, there is room for improvement in order to improve the durability of the skin material.

SUMMARY OF THE PRESENT DISCLOSURE In consideration of the above, an object of the present invention is to provide a method and an apparatus for pressing a skin material, which can improve the durability of the skin material.

The pressing method of the present invention as set forth in claim 1 includes a placement step of holding the skin material with a pair of skin frames and placing the skin material between an upper die and a lower die that are arranged vertically in an open state, a one-die contact step of moving one of the upper and lower dies in a pressing direction to bring the one die into contact with the skin material, a second-die contact step of further moving the one die in the pressing direction until the skin material comes into contact with the other die and moving the pair of skin frames in synchronization with the one die so as to cancel the tension of the skin material that increases due to the movement of the one die, and and a mold closing step of moving at least one of the first mold and the other mold in a press direction to press the skin material up to a press end, and moving the pair of skin frames in synchronization with the molds so as to cancel out a tension in the skin material that increases due to the movement of the molds that move while in contact with the skin material, wherein in the other mold contact step and the mold closing step, a gripping interval of the skin material in the pair of skin frames is narrowed, and a speed at which the gripping interval of the pair of skin frames is narrowed in the mold closing step is faster than a speed at which the gripping interval of the pair of skin frames is narrowed in the other mold contact step.

According to the present invention described in claim 1, in the arrangement step, the skin material is held by a pair of skin frames and arranged between an upper mold and a lower mold that are arranged in a pair above and below in the mold open state. Then, in the one-mold contact step, one of the upper and lower molds is moved in the pressing direction until it comes into contact with the skin material. In other words, the upper mold is moved downward to come into contact with the upper surface of the skin material, or the lower mold is moved upward to come into contact with the lower surface of the skin material.

Next, in the other mold contact step, one of the molds in contact with the skin material is moved further in the press direction or the other mold is moved in the press direction until the skin material comes into contact with the other mold. Here, if one mold is moved further in the press direction, and one mold is moved in the press direction while the positions of the pair of skin frames are kept fixed, the skin material in contact with one mold will be stretched in proportion to the amount of movement of the one mold the more the one mold moves.

In contrast, according to the present invention described in claim 1, the pair of skin frames are moved in synchronization with one of the dies so as to cancel out the tension in the skin material that increases due to the movement of one of the dies. This makes it possible to suppress excessive stretching of the skin material during the contact process with the other die.

Furthermore, in the mold closing process, at least one of the upper and lower molds in contact with the skin material is moved in the press direction to the press end, whereby the skin material is clamped and pressing is completed. At this time, if the molds are moved in the press direction while the positions of the pair of skin frames are fixed, the skin material in contact with the molds will be stretched the more the molds move, depending on the amount of interference between the two molds and the skin material and the amount of the skin material pulled in along the detailed shapes of the two molds when the molds are clamped.

In contrast, according to the present invention described in claim 1, the pair of skin frames are moved in synchronization with the mold so as to counteract the tension of the skin material that increases due to the movement of the mold that moves while in contact with the skin material. This makes it possible to suppress excessive stretching of the skin material during the mold closing process.

As described above, according to the present invention as defined in claim 1, excessive elongation of the skin material is suppressed after the mold and the skin material come into contact with each other, so that it is possible to suppress a decrease in thickness of the skin material due to excessive elongation.
According to the present invention, when one of the dies in contact with the skin material is moved in the other die contacting step and when at least one of the dies is moved in the die closing step, the gripping distance of the pair of skin frames is narrowed. At this time, the skin material is not stretched by the shortened length in the gripping direction and can be deformed in other directions, so that excessive stretching of the skin material due to the movement of the dies is suppressed. Thus, excessive stretching of the skin material can be suppressed by one-dimensional control of the pair of skin frames.
Furthermore, according to the present invention, the speed at which the gap between the pair of grips is narrowed from the time when the other die and the skin material are brought into contact with each other until the pressing is completed is faster than the speed at which the gap between the pair of grips is narrowed from the time when one die and the skin material are brought into contact with each other die and the skin material.
Here, in the other mold contact step, if one mold in contact with the skin material is moved in the press direction at a constant speed while the gripping distance of the pair of skin frames is kept constant, the skin material is stretched by an amount corresponding to the amount of mold movement. On the other hand, in the mold closing step, if the mold in contact with the skin material is moved in the press direction at a constant speed while the gripping distance of the pair of skin frames is kept constant, the skin material is stretched not only by an amount corresponding to the amount of mold movement, but also by an amount corresponding to an interference between both molds and the skin material and an amount corresponding to the skin being drawn in along the detailed shape of the mold when the mold is closed.
According to the present invention described in claim 1, by making the speed at which the pair of skin frames are narrowed in the mold closing step faster than the speed at which the pair of skin frames are narrowed in the other mold contact step, the tension of the skin material can be kept substantially constant even when pressing is performed by moving the upper mold or the lower mold in the pressing direction at a substantially constant speed, thereby eliminating the need for complex control of the upper and lower molds.

The pressing method for the skin material according to the present invention described in claim 2 is the invention described in claim 1, in which the pair of skin frames are moved so that the tension of the skin material is approximately constant from the time when the one die and the skin material come into contact until the pressing is completed.

According to the present invention described in claim 2, the tension of the skin material is kept substantially constant from the time the skin material comes into contact with one of the dies until pressing is completed by moving the pair of skin frames. In other words, the skin material is pressed throughout while maintaining the tension it had when it came into contact with one of the dies.

Generally, when curved or uneven parts are formed on the upper and lower molds, the amount of stretch is not uniform, which makes it easy for the thickness of the skin material to vary. And when the thickness of the skin material varies, there is a risk of breakage in areas that are stretched significantly.

In the present invention described in claim 2, the tension of the skin material is kept substantially constant, so that excessive stretching of the entire skin material caused by the movement of the mold in the pressing direction can be suppressed, while partial excessive stretching of the skin material when the mold is closed to conform to the detailed shape of the mold can be suppressed. This makes it possible to further improve the durability of the skin material. Furthermore, when a patterned skin material is used, it is possible to suppress pattern bending, which is a distortion of the pattern when processing.

The pressing method for the skin material according to the present invention described in claim 3 is the invention described in claim 1 or claim 2, in which when the one die and the skin material are brought into contact, the pair of skin frames hold the skin material in a flat, unfolded state.

According to the present invention described in claim 3, when one of the dies and the skin material come into contact, the skin material is held in a flat, unfolded state. In other words, the skin material comes into contact with one of the dies without any slack. This makes it possible to prevent wrinkles from forming in the skin material during pressing.

The pressing method for a skin material according to the present invention as set forth in claim 4 is the invention as set forth in claim 2 or 3 , wherein the pair of skin frames are moved in a pressing direction in the die closing step and in the other die contact step when the one die is moved.

According to the invention described in claim 4 , when the die moves in the pressing direction while in contact with the skin material, the pair of skin frames are not only moved in the direction narrowing the gripping distance, but also moved in the pressing direction. This makes it possible to avoid interference with the moving die. In particular, even when pressing the skin material while being inclined obliquely to match the shape of the die, it is possible to grip the skin material at an appropriate position while avoiding interference between the pair of skin frames and the moving die, thereby suppressing excessive stretching of the skin material. Therefore, the skin material can be processed using the minimum amount of raw material required.

The pressing method for a skin material according to the present invention described in claim 5 is the invention described in any one of claims 1 to 4 , wherein the positions of the pair of skin frames are controlled by a servo mechanism so as to be synchronized with the mold which moves in a state of contact with the skin material.

According to the present invention , the positions of the pair of skin frames are controlled by a servo mechanism. As a result, even if there is variation in the moving speed of the pair of skin frames, the pair of skin frames are positioned at accurate positions, and therefore excessive stretching of the skin material can be further suppressed.

The method for pressing a skin material according to the present invention described in claim 6 is the same as any one of claims 1 to 4 , in which a base material is fixed to the upper mold or the lower mold, and the skin material is attached to the base material.

According to the sixth aspect of the present invention , the residual stress after the skin material is attached to the substrate can be reduced, and therefore the skin material can be prevented from peeling off from the substrate after attachment.

The press working device for a skin material according to the present invention as set forth in claim 7 includes an upper die and a lower die provided as a pair above and below, and a pair of skin frames configured to be able to grip a skin material, and in a positioning step, the skin material is gripped by the pair of skin frames, and the skin material is positioned between the upper die and the lower die which are arranged in a die open state, in a one-die contact step, one of the upper die and the lower die is moved in a pressing direction to bring the one die into contact with the skin material, and in a other-die contact step, the one die is further moved in the pressing direction until the skin material comes into contact with the other die, and the pair of skin frames are moved in synchronization with the one die so as to cancel out the tension of the skin material which increases due to the movement of the one die, or the pair of skin frames are moved in synchronization with the one die while keeping the gripping distance of the pair constant. a control unit that performs processing for moving the other die in the press direction until the skin material comes into contact with the other die, and moving at least one of the one die and the other die in the press direction to press the skin material up to a press end in a die closing step, and moving the pair of skin frames in synchronization with the dies so as to cancel out tension in the skin material that increases due to the movement of the dies that move while in contact with the skin material, wherein the control unit narrows a gripping interval of the skin material in the pair of skin frames in the other die contact step and the die closing step, and controls so that a speed at which the gripping interval of the pair of skin frames is narrowed in the die closing step is faster than a speed at which the gripping interval of the pair of skin frames is narrowed in the other die contact step .
According to the present invention, when one of the dies in contact with the skin material is moved in the other die contacting step and when at least one of the dies is moved in the die closing step, the gripping distance of the pair of skin frames is narrowed. At this time, the skin material is not stretched by the shortened length in the gripping direction and can be deformed in other directions, so that excessive stretching of the skin material due to the movement of the dies is suppressed. Thus, excessive stretching of the skin material can be suppressed by one-dimensional control of the pair of skin frames.
Furthermore, according to the present invention, the speed at which the gap between the pair of grips is narrowed from the time when the other die and the skin material are brought into contact with each other until the pressing is completed is faster than the speed at which the gap between the pair of grips is narrowed from the time when one die and the skin material are brought into contact with each other die and the skin material.
Here, in the other mold contact step, if one mold in contact with the skin material is moved in the press direction at a constant speed while the gripping distance of the pair of skin frames is kept constant, the skin material is stretched by an amount corresponding to the amount of mold movement. On the other hand, in the mold closing step, if the mold in contact with the skin material is moved in the press direction at a constant speed while the gripping distance of the pair of skin frames is kept constant, the skin material is stretched not only by an amount corresponding to the amount of mold movement, but also by an amount corresponding to an interference between both molds and the skin material and an amount corresponding to the skin being drawn in along the detailed shape of the mold when the mold is closed.
According to the seventh aspect of the present invention, by making the speed at which the pair of skin frames are narrowed in the mold closing step faster than the speed at which the pair of skin frames are narrowed in the other mold contact step, the tension of the skin material can be kept substantially constant even when pressing is performed by moving the upper mold or the lower mold in the pressing direction at a substantially constant speed, thereby eliminating the need for complex control of the upper and lower molds.

According to the seventh aspect of the present invention, in the placement step, the skin material is held by a pair of skin frames and placed between the upper and lower dies placed in an open state by the control unit. Next, in the one-die contact step, the control unit moves one of the upper and lower dies in the pressing direction until the one die comes into contact with the skin material.

Next, in the other mold contact step, the control unit moves one of the molds in contact with the skin material further in the press direction or moves the other mold in the press direction until the skin material comes into contact with the other mold. Here, when one mold is moved further in the press direction, the pair of skin frames are moved in synchronization with one mold so as to cancel out the tension in the skin material that increases due to the movement of the one mold. This makes it possible to suppress excessive stretching of the skin material in the other mold contact step.

Furthermore, in the mold closing process, the control unit moves at least one of the upper and lower molds in the press direction to the press end, clamping the skin material and completing the press. At this time, the pair of skin frames are moved in synchronization with the molds so as to counteract the tension in the skin material that increases due to the movement of the molds that move while in contact with the skin material. This makes it possible to suppress excessive stretching of the skin material in the mold closing process.

As described above, the method, the apparatus, and the program for press working a skin material according to the present invention as set forth in claims 1 and 7 have the excellent effect of improving the durability of the skin material.
Furthermore, the method of press working a skin material according to the present invention has the excellent effect of being able to suppress excessive elongation of the skin material by simple one-dimensional control.
Furthermore, the method of pressing a skin material according to the present invention has the excellent effect of eliminating the need for complex control of the upper and lower dies.

The press processing method for skin materials according to the present invention described in claim 2 has the excellent effect of further improving the durability of the skin material while suppressing the bending of the skin material pattern and improving the design of the product to which the skin material is applied.

The method for pressing a skin material according to the present invention described in claim 3 has the excellent effect of suppressing wrinkles in the skin material and improving the design of the product to which the skin material is applied.

The method for press working a skin material according to the present invention as set forth in claim 4 has an excellent effect of reducing costs.

The method for press working a skin material according to the present invention as set forth in claim 5 has the excellent effect of accurately controlling the positions of the pair of skin frames and further suppressing excessive stretching of the skin material.

The method for press working a skin material according to the present invention as set forth in claim 6 has an excellent effect of improving the durability of a product in which a skin material is attached to a substrate.

1 is a schematic diagram of a press processing device for a skin material according to an embodiment of the present invention. 2 is a configuration diagram of a servo mechanism included in the press processing device for a skin material shown in FIG. 1 . 2 is a process diagram showing all steps up to completion of pressing in a press working method for pressing a skin material using the press working apparatus for a skin material shown in FIG. 1 . 3 is a diagram showing a skin mold contact step of the press working method of the skin material shown in FIG. 2. [0023] FIG. 3 is a diagram showing a die closing step of the press working method for the skin material shown in FIG. 2. FIG. 1A and 1B are diagrams illustrating a conventional press working method in which a skin material is pressed while being gripped at a constant gripping distance. 1A and 1B are diagrams illustrating a conventional press working method in which a skin material is pressed while being loosened. 1A and 1B are diagrams illustrating a conventional pressing method in which a skin material is released from a skin frame during pressing.

Below, using Figures 1 to 8, a press processing device 10 for skin material according to one embodiment of the present invention (hereinafter simply referred to as "press processing device 10") and a press processing method for skin material using the press processing device 10 will be described. Note that the arrow UP shown appropriately in each figure indicates the vertical upward direction, and the arrows LH and RH indicate the left and right sides of the press processing device, respectively. Furthermore, in the following description, unless otherwise specified, when the up and down directions are used, they refer to the up and down in the vertical up and down direction, and when the left and right directions are used, they refer to the left and right of the press processing device. Furthermore, the depth direction of the press processing device is the direction along the depth direction of the paper in Figures 1 and 3 to 8.

First, the configuration of the press processing device 10 according to this embodiment will be described with reference to Figures 1 and 2, and then the press processing method using the press processing device 10 will be described with reference to Figures 3 to 5.

[Configuration of the press working device 10]
FIG. 1 shows a schematic diagram of a press processing apparatus 10. The press processing apparatus 10 according to this embodiment is an attachment apparatus that forms an instrument panel of a vehicle (not shown) by attaching fabric 82 as a skin material to a substrate 80 obtained in advance by injection molding a resin. The press processing apparatus is not limited to the instrument panel of a vehicle, and may be an apparatus that presses skin materials used in other products. Also, the press processing apparatus may be an apparatus that attaches other skin materials, not limited to fabric, to the substrate. Furthermore, the material of the substrate and the molding method are not limited to those described above.

The press working apparatus 10 is configured to include a holding means 12 for holding the fabric 82, a base material mold 14 as an upper mold and a skin mold 16 as a lower mold that apply pressure by vertically sandwiching the fabric 82. The press working apparatus 10 also includes a base material mold lifting means 18 for supporting the base material mold 14 so as to be vertically movable, and a support frame lifting means 54 (see FIG. 2) for supporting the holding means 12 of the fabric 82 so as to be vertically movable. Furthermore, as shown in FIG. 1, the press working apparatus 10 includes a skin mold fixing part 20 for fixing the skin mold 16. The skin mold fixing part 20 is placed on the floor surface.

(Base material type 14)
The substrate mold 14 is a convex mold, and has a convex curved portion 22 at the bottom that is convex in the downward direction. The convex curved portion 22 is configured so that the substrate 80 can be set from the lower side, and the lower surface of the convex curved portion 22 is shaped to fit the shape of the substrate 80. When the instrument panel is mounted on a vehicle (not shown), the substrate 80 has a curved surface 80A that is convex toward the rear side of the vehicle in a side view of the vehicle, and is formed in a substantially J-shape that is open to the front and lower sides in a side view of the vehicle.

The convex curved portion 22 is configured to be able to hold the substrate 80 with the longitudinal direction of the substrate 80 aligned with the depth direction of the press processing device 10 and with the substrate 80 oriented in a substantially J-shape when viewed from the front of the press processing device 10. In other words, the left side portion that forms the left side of the convex curved portion 22 is shorter than the right side portion that forms the right side of the convex curved portion 22.

The convex curved portion 22 of the base mold 14 has a recessed portion 22A that is open downward and has a concave shape when viewed from the front, at the center in the depth direction of the page (see FIG. 3(A)). This recessed portion 22A corresponds to the air outlet of the air conditioning device of the vehicle in which the instrument panel (not shown) is mounted.

As shown in FIG. 1, the upper part of the base mold 14 is fixed to the base mold lifting means 18. The base mold lifting means 18 is equipped with a base mold lifting motor 50 (see FIG. 2). This allows the base mold 14 to move up and down. FIG. 1 shows the mold open state in which the base mold 14 is located at the upper end T (see FIG. 3(A)) away from the skin mold 16. As shown in FIGS. 3(A) to 3(F), the lifting range of the base mold 14 is from the upper end T in the mold open state to the press end B where mold clamping is completed.

(epidermal type 16)
1, the skin mold 16 provided on the lower side is a concave metal mold with respect to the convex base mold 14 provided on the upper side. The skin mold 16 has a concave curved portion 24 that is open upward and has a substantially J-shape when viewed from the front. The upper surface of the concave curved portion 24 is shaped to correspond to the curved surface 80A of the base material 80 set in the convex curved portion 22 of the base mold 14.

Also, as shown in Figures 3(A) and 3(E), the concave curved portion 24 is formed with a protrusion 24A that is convex in front view and protrudes upward in a shape and position corresponding to the recessed portion 22A of the base mold 14. Note that, although this embodiment has been described as the base mold 14 provided on the upper side being formed in a convex shape and the skin mold 16 provided on the lower side being formed in a concave shape, this is not limited to this. Also, the recessed portion 22A and the protrusion 24A are examples of detailed shapes and are not limited to this.

(Holding means 12)
The holding means 12 includes a support frame 26 formed in a substantially rectangular frame shape in a plan view, and a pair of skin frames 28 configured to be able to grip a fabric 82 that is substantially rectangular in a plan view. The pair of skin frames 28 each include a gripping portion 34 that can grip a short end portion 82A of the fabric 82 in a substantially vertical direction along the longitudinal direction of the fabric 82. The support frame 26 and the pair of skin frames 28 each extend with the depth direction of the press working device 10 as the longitudinal direction. The support frame 26 is connected to a support frame lifting means 54 (see FIG. 2), which allows the entire holding means 12 to move in the vertical direction. As shown in FIG. 2, the support frame lifting means 54 includes a support frame lifting motor 52.

As shown in FIG. 1, the holding means 12 is arranged at an angle so that the right side is higher than the left side, in accordance with the shape of the base material 80, which is formed in a roughly J-shape when viewed from the front. In other words, of the pair of skin frames 28, the upper right skin frame 30 on the right side is arranged at a higher position than the lower left skin frame 32 on the left side. This allows the pair of skin frames 28 to be arranged so that the fabric 82 is deployed in an oblique direction slightly rotated counterclockwise when viewed from the front, with the longitudinal direction as the axial direction from the horizontal direction.

Here, guide rails 36 extending in the short direction are provided at both longitudinal ends of the support frame 26. In addition, block-shaped movable tables 38 slidably connected to the guide rails 36 are provided below both longitudinal ends of the pair of skin frames 28.

Furthermore, on the upper side of one longitudinal side of the support frame 26, a motor 40 for moving the upper right skin frame is provided at the right end, and a motor 42 for moving the lower left skin frame is provided at the left end. The motor 40 for moving the upper right skin frame and the upper right skin frame 30 are connected via a ball screw mechanism having a screw shaft (not shown). Similarly, the motor 42 for moving the lower left skin frame and the lower left skin frame 32 are connected via a ball screw mechanism having another screw shaft (not shown). In other words, when each screw shaft rotates around its axis, each movable table 38 moves along the guide rail 36. In this way, the upper right skin frame 30 and the lower left skin frame 32 are controlled separately, and the pair of skin frames 28 move parallel to each other on the same plane, making it possible to change the gripping distance of the pair of skin frames 28. Note that the mechanism described above is one example of a mechanism for changing the gripping distance of the pair of skin frames 28, and is not limited thereto.

(Servo mechanism 44)
2, the press working device 10 includes a servo mechanism 44. The servo mechanism 44 includes a controller 46 including a PLC (Programmable Logic Controller), and a driver 48 as a control unit that receives command signals from the controller 46 and drives the base material mold lifting motor 50, the support frame lifting motor 52, the upper right skin frame moving motor 40, and the lower left skin frame moving motor 42. The base material mold lifting motor 50, the support frame lifting motor 52, the upper right skin frame moving motor 40, and the lower left skin frame moving motor 42 are, for example, AC servo motors each including an encoder (not shown) and configured to be able to feed back position information and speed information to the driver 48.

[Press processing method]
Next, a method of pressing fabric 82 using press working device 10 will be described with reference to Figures 3 to 5. A series of press working steps described below are executed by processing by controller 46 and driver 48 of press working device 10 shown in Figure 2 based on a program inputted to controller 46. In addition to speed control, position control is performed on base material mold 14, upper right skin frame 30, and lower left skin frame 32 by mutually monitoring each other's positions using the synchronization function of servo mechanism 44.

Figures 3(A) to 3(F) show how the substrate mold 14 gradually moves downward in the pressing direction from the upper end T to the press end B to attach the fabric 82 to the substrate 80. Figures 3, 4, and 5 are schematic cross-sectional views of the center of the depth direction of the press processing device shown in Figure 1 to explain each process. In these figures, hatching is omitted for areas other than the substrate 80 and fabric 82.

(Placement process)
First, as shown in Fig. 3(A), the base material mold 14 is placed at the upper end T to open the mold. Then, the fabric 82 is gripped by the pair of skin frames 28 and placed between the base material mold 14 and the skin mold 16, which are placed apart in the vertical direction. At this time, the pair of skin frames 28 grip and place the fabric 82 in a state in which it is developed in a plane. An adhesive is applied to the back surface of the fabric 82 for pasting it on the base material 80. The process of arranging the fabric 82 between the base material mold 14 and the skin mold 16 in this manner is called the placement process.

(Base material type contact process)
Next, the substrate mold 14 is lowered from the mold open state shown in Fig. 3(A) by the substrate mold lifting means 18. As shown in Fig. 3(B), the timing when the substrate 80 set in the substrate mold 14 comes into contact with the fabric 82 is referred to as substrate contact time. The process from the mold open state shown in Fig. 3(A) to the substrate contact time shown in Fig. 3(B) is referred to as a substrate mold contact step as one-side mold contact step.

(Skin type contact process)
3(B) to 3(D), the base mold 14 is further lowered by the base mold lifting means 18. As shown in Fig. 3(D), the timing when the lowered fabric 82 comes into contact with the upper end 16A of the skin mold 16 is referred to as the skin mold contact time, and the process from the base contact time shown in Fig. 3(B) to the skin mold contact time shown in Fig. 3(D) is referred to as the skin mold contact step as the other mold contact step.

This skin mold contact process will be explained in more detail using Figure 4. Figures 4(A) to 4(C) correspond to Figures 3(B) to 3(D), respectively, with Figure 4(A) showing the state when the substrate is in contact and Figure 4(C) showing the state when the skin mold is in contact. In Figure 4 and Figure 5 described later, the two-dot chain lines indicate the position of the pair of skin frames 28 in the state of the previous drawing, and the arrows indicate the amount by which the pair of skin frames 28 have moved on the support frame 26 from the state of the previous drawing.

In the skin mold contact process shown in Figures 4(A) to 4(C), a pair of skin frames 28 are moved in synchronization with the base mold 14 to counteract the increased tension in the fabric 82 caused by the lowering of the base mold 14, i.e., to prevent the fabric 82 from being stretched.

As shown in FIG. 4(B), in the early stage of the skin mold contact process, the gripping distance between the pair of skin frames 28 is narrowed. More specifically, the upper right skin frame 30 and the lower left skin frame 32 are moved in a direction approaching each other so that the tension of the fabric 82 is approximately constant from the time of contact with the substrate shown in FIG. 4(A) to the state shown in FIG. 4(B). At this time, the substrate mold 14, the upper right skin frame 30, and the lower left skin frame 32 are controlled so that the time required for each to reach the state shown in FIG. 4(B) from the state shown in FIG. 4(A) is the same.

Next, as shown in FIG. 4(C), in the latter stage of the skin mold contact process, the gripping distance between the pair of skin frames 28 is narrowed and the holding means 12 (see FIG. 1) is lowered at the same time. As a result, the pair of skin frames 28 narrow their gripping distance as they are lowered. More specifically, the pair of skin frames 28 are lowered while the upper right skin frame 30 and the lower left skin frame 32 are moved in directions approaching each other so that the tension of the fabric 82 is approximately constant from the state shown in FIG. 4(B) to the skin mold contact shown in FIG. 4(C). At this time, the base material mold 14, the upper right skin frame 30, and the lower left skin frame 32 are controlled so that the time required for each to reach the state shown in FIG. 4(C) from the state shown in FIG. 4(B) is the same.

(Mold closing process)
Next, returning to Fig. 3, the mold closing step will be described. As shown in Fig. 3(D) to Fig. 3(E), the base mold 14 is lowered by the base mold lifting means 18 until the fabric 82 comes into contact with the protrusions 24A of the skin mold 16. As shown in Fig. 3(E), the fabric 82
The timing at which the protrusion 24A of the skin mold 16 comes into contact with the protrusion 24 is referred to as the protrusion contact time.

The process from when the skin mold contacts as shown in FIG. 3(D) to when the protrusion contacts as shown in FIG. 3(E) is referred to as the first mold closing process. In the first mold closing process, as in the skin mold contact process, the holding means 12 is lowered while narrowing the gripping distance between the pair of skin frames 28 in synchronization with the base mold 14.

Then, as shown in FIG. 3(F), the substrate mold 14 is further lowered to the press end B to press the adhesive-coated fabric 82 and the substrate 80 together, completing the pressing. The timing at which the pressing is completed as shown in FIG. 3(F) is referred to as the time of pressing completion. The process from the time of contact of the convex portions shown in FIG. 3(E) to the time of pressing completion shown in FIG. 3(F) is referred to as the second mold closing process. In the second mold closing process, as in the skin mold contact process and the first mold closing process, the holding means 12 is lowered in synchronization with the substrate mold 14 while narrowing the gripping distance between the pair of skin frames 28.

The first and second mold closing steps will be described in more detail with reference to Fig. 5. Fig. 5(A) to Fig. 5(C) correspond to Fig. 3(D) to Fig. 3(F), respectively, with Fig. 5 (A) showing the state when the base material is in contact, Fig. 5(B) showing the state when the protrusion is in contact, and Fig. 5(C) showing the state when pressing is completed.

During the mold closing process, the pair of skin frames 28 are moved in synchronization with the base mold 14 so as to counteract the increased tension in the fabric 82 caused by the lowering of the base mold 14, i.e., so that the fabric 82 is not stretched.

As shown in Figures 5(A) and 5(B), in the first mold closing step, the upper right skin frame 30 and the lower left skin frame 32 are moved in directions approaching each other while the holding means 12 (see Figure 1) is lowered so that the tension of the fabric 82 remains substantially constant from when it contacts the skin mold to when it contacts the protrusions. At this time, the base mold 14, the upper right skin frame 30, and the lower left skin frame 32 are controlled so that the time it takes for each of them to reach the state shown in Figure 5(B) from the state shown in Figure 5(A) is the same.

As shown in Fig. 5(B) to Fig. 5(C), in the second mold closing step, the upper right skin frame 30 and the lower left skin frame 32 are moved toward each other while the holding means 12 (see Fig. 1) is lowered so that the tension of the fabric 82 remains substantially constant from when the protrusions contact the fabric 82 until pressing is completed. At this time, the base mold 14, the upper right skin frame 30, and the lower left skin frame 32 are controlled so that the time it takes for each of them to reach the state shown in Fig. 5(C) from the state shown in Fig. 5(B) is the same.

Here, the descent speed of the base material mold 14 is substantially constant from the mold open state shown in FIG. 3(A) until the convex portion contacts as shown in FIG. 3(E). In contrast, in the second mold closing process after the convex portion contacts, the descent speed of the base material mold 14 is slower than in the previous processes. The descent speed of the base material mold 14 is not limited to the above. For example, the descent speed of the base material mold 14 in the second mold closing process may be the same as that in the previous processes. In this case, the tension of the fabric 82 can be maintained substantially constant by making the speed at which the gripping interval of the pair of skin frames 28 in the second mold closing process faster than the speed at which the gripping interval of the pair of skin frames 28 in the first mold closing process is narrowed, taking into account the amount of fabric 82 that is pulled in along the detailed shapes of the base material mold 14 and the skin mold 16 when the molds are closed.

In addition, in the first mold closing step shown in Fig. 5(A) to Fig. 5(B), the fabric 82 interferes with the upper end 16A of the skin mold 16. As described above, in the press working device 10, the lowering speed of the base mold 14 is substantially constant from the mold open state shown in Fig. 3(A) to the time of contact with the protruding portion shown in Fig. 3(E). Therefore, in the first mold closing step shown in Fig. 5(A) to Fig. 5(B), the fabric 82 is drawn in faster than in the skin mold contact step shown in Fig. 4(A) to Fig. 4(C) by the amount of interference between the fabric 82 and the upper end 16A of the skin mold 16. Therefore, in the first mold closing step shown in Fig. 5(A) to Fig. 5(B), the tension of the fabric 82 can be kept substantially constant by controlling the speed at which the gripping interval of the pair of skin frames 28 is narrowed to be faster than in the skin mold contact step shown in Fig. 4(A) to Fig. 4(C).

5(B) to 5(C), the fabric 82 is pulled in to conform to the detailed shape of the substrate 80, for example by being sandwiched between the protrusions 24A and the recesses 22A and deforming. For this reason, in the second mold closing process, it is necessary to take into consideration the amount by which the fabric 82 is pulled in with the amount by which the substrate mold 14 is lowered, the amount by which the fabric 82 is pulled in as the fabric 82 interferes with the skin mold 16, and the amount by which the fabric 82 is pulled in to conform to the detailed shape of the substrate 80. In other words, if the substrate mold 14 is controlled to be lowered at the same speed as before in the second mold closing process, it is necessary to control the speed at which the gripping distance of the pair of skin frames 28 is narrowed to be faster than in the first mold closing process shown in FIGS. 3(D) to 3(E). However, in the press processing method according to this embodiment, in the second die closing process shown in Figures 3(E) to (F), the base die 14 descends slower than in the process up to the protruding portion contact shown in Figures 3(A) to (E), so the speed at which the gripping distance of the pair of skin frames 28 is narrowed is also set to a speed corresponding to this.

In the press processing method described above, the pair of skin frames 28 are moved so that the tension of the fabric 82 remains approximately constant from the time of contact with the substrate until pressing is completed.

(Mold opening process)
After the pressing is completed, the work is cooled by holding it for a certain period of time, and then the substrate mold 14 is raised to the upper end T (see Figure 3 (A)) to open the mold, and the instrument panel formed by pasting the fabric 82 to the substrate 80 is removed from the press processing device 10.

(Actions and Effects of the Present Embodiment)
Next, the operation and effects of this embodiment will be described.

According to the press processing method using the press processing device 10 of this embodiment, in the placement step, the fabric 82 is held by a pair of skin frames 28 and placed between the base material mold 14 and the skin mold 16, which are arranged in a pair above and below in the mold open state. Then, in the base material mold contact step, the base material mold 14 is lowered until the set base material 80 comes into contact with the fabric 82.

Next, in the skin mold contact process, the base mold 14, in which the fabric 82 and the base material 80 are in contact, is further lowered until the fabric 82 and the skin mold 16 come into contact. At this time, the pair of skin frames 28 are moved in synchronization with the base material mold 14.

Furthermore, in the mold closing process, the base mold 14 is lowered to the press end, clamping the mold and completing the pressing. At this time, the pair of skin frames 28 are moved in synchronization with the base mold 14.

Figures 6(A) to 6(E) show, as a comparative example, a conventional pressing method for skin material, in which a pair of skin frames 100 are fixed in position while pressing and attaching skin material 102 to substrate 104 from the mold open state shown in Figure 6(A) to the mold closed state shown in Figure 6(E).

6(B) to 6(C), in this conventional method, in the skin mold contact step, the skin material 102 in contact with the base mold 106 is stretched in proportion to the distance the base mold 106 moves. As an example, if the stretch amount of the skin material 102 until the base mold 106 comes into contact with the skin material 102 is 100%, the skin material 102 is stretched by 10% from the time of contact with the base mold shown in FIG. 6(B) to the time of contact with the skin mold shown in FIG. 6(C), resulting in a stretch amount of 110%.

Also, as shown in Figures 6(C) and 6(D) in this conventional method, the more the base mold 106 moves during the mold closing process, the more the skin material 102 in contact with the base mold 106 is stretched in accordance with the amount of movement, the amount of interference between the skin mold 108 and the skin material 102, and the amount of the skin material 102 pulled in along the detailed shapes of the base mold 106 and the skin mold 108 when the mold is closed. As an example, the amount of skin stretch is 135% when the convex parts come into contact as shown in Figure 6(D), and the amount of skin stretch is 150% when pressing is completed as shown in Figure 6(E).

In contrast, according to the press processing method using the press processing device 10, the pair of skin frames 28 are moved in synchronization with the base material mold 14 so as to counteract the tension in the fabric 82 that increases as the base material mold 14 moves. This makes it possible to suppress excessive stretching of the fabric 82.

As described above, the press processing method using the press processing device 10 suppresses excessive stretching of the fabric 82, thereby preventing the thickness of the fabric 82 from becoming thin due to excessive stretching. This improves the durability of the fabric 82.

In addition, according to the press processing method using the press processing device 10, the pair of skin frames 28 move, so that the tension of the fabric 82 is kept substantially constant from the time when the fabric 82 comes into contact with the substrate 80 set in the substrate mold 14 until the time when pressing is completed and the mold is closed. In other words, the fabric 82 is pressed while maintaining the tension it had when it came into contact with the substrate 80 set in the substrate mold 14, and the amount of elongation is 100% throughout.

In general, when curved or uneven parts are formed on the upper and lower dies, the skin material is not stretched uniformly, which makes it easy for the thickness of the skin material to vary. If the thickness of the skin material varies, there is a risk of breakage in areas that are stretched significantly.

In contrast, according to the press processing method using the press processing device 10, the tension of the fabric 82 is kept substantially constant, so that excessive stretching of the entire fabric 82 caused by the descent of the base material mold 14 can be suppressed, while also suppressing partial excessive stretching of the fabric 82 when the mold is closed to conform to the detailed shapes of the base material mold 14 and the skin mold 16. This makes it possible to further improve the durability of the fabric 82. Furthermore, when using a patterned fabric 82, it is possible to suppress pattern bending, in which the pattern is distorted during processing. This makes it possible to further improve the durability of the fabric 82, while suppressing pattern bending of the fabric 82, thereby improving the design of the instrument panel.

Figure 7 shows a conventional pressing method in which the skin material 102 is pressed in a slackened state to prevent excessive stretching of the skin material 102. In this conventional method, first, as shown in Figures 7(A) to 7(B), the gripping distance between a pair of skin frames 200 is narrowed by a certain amount to slacken the skin material 102 before the base material 104 comes into contact with the skin material 102. Then, as shown in Figures 7(B) to 7(D), while maintaining the narrowed gripping distance and keeping the skin material 102 slack, the skin material 102 is pressed by the base material mold 202 and the skin mold 204 and attached to the base material 104.

Also, FIG. 8 shows a conventional pressing method in which the skin material 102 is released from the pair of skin frames 300 during pressing to prevent excessive stretching of the skin material 102. In this conventional method, first, as shown in FIG. 8(A)-FIG. 8(B), the substrate mold 302 is lowered while maintaining a constant gripping distance between the pair of skin frames 300, and a certain amount of the skin material 102 is covered at the tip of the substrate 104. As shown in FIG. 8(C), when a certain amount of the skin material 102 has been covered, the gripping parts 306 provided on the pair of skin frames 300 are opened to release the skin material 102. Then, as shown in FIG. 8(D), the released skin material 102 is pressed by the substrate mold 14 and the skin mold 308 which are further lowered.

In the conventional methods shown in Figures 7 and 8, the skin material 102 is pressed in a released state, which makes it prone to wrinkles and poor adhesion due to air entrapment in the skin material 102.

In contrast, according to the press processing method using the press processing device 10, when the base material mold 14 and the fabric 82 come into contact, the fabric 82 is held in a flat, unfolded state. In other words, the fabric 82 comes into contact with the base material mold 14 without any slack. Then, from this state, the fabric 82 is pressed while maintaining a substantially constant tension. This makes it possible to prevent wrinkles from occurring in the fabric 82 during pressing. Therefore, by preventing wrinkles in the fabric 82, the design of the instrument panel can be further improved.

Furthermore, according to the press processing method using the press processing device 10, when the base material mold 14 that has contacted the fabric 82 is lowered in the skin mold contact step and the mold closing step, the gripping distance between the pair of skin frames 28 is narrowed. At this time, the fabric 82 is not stretched by the amount that has been shortened in the gripping direction, and can be deformed in other directions. This prevents excessive stretching of the fabric 82. Therefore, excessive stretching of the fabric 82 can be prevented by one-dimensional control.

Furthermore, according to the press processing method using the press processing device 10, the speed at which the gripping distance between the pair of skin frames 28 is narrowed in the first die closing step is faster than the speed at which the gripping distance between the pair of skin frames 28 is narrowed in the other die contact step.

In the skin mold contact process, if the base mold 14 is lowered at a constant speed while the gripping distance between the pair of skin frames 28 is kept constant, the fabric 82 is stretched by an amount corresponding to the descent of the base mold 14. On the other hand, in the first mold closing process, if the base mold 14 is lowered at a constant speed while the gripping distance between the pair of skin frames 28 is kept constant, the fabric 82 is stretched not only by an amount corresponding to the descent of the base mold 14, but also by an amount corresponding to the interference between the skin mold 16 and the fabric 82.

As in the press processing method using the press processing device 10, by making the speed at which the pair of skin frames 28 are narrowed in the first mold closing process faster than the speed at which the pair of skin frames 28 are narrowed in the skin mold contact process, the tension of the fabric 82 can be kept substantially constant even if the base mold 14 is lowered at a substantially constant speed. This eliminates the need for complex control of the base mold 14.

In addition, according to the press processing method using the press processing device 10, the holding means 12 is raised and lowered by the support frame raising and lowering means 54. As shown in FIG. 4(C) and FIG. 5(A) to FIG. 5(C), the holding means 12 is lowered through the latter part of the skin mold contact step, the first mold closing step, and the second mold closing step. As a result, the pair of skin frames 28 are moved not only in the direction narrowing the gripping distance during pressing, but also downward.

Therefore, even if the fabric 82 is pressed in an obliquely inclined state as in this embodiment, the pair of skin frames 28 can be appropriately disposed at appropriate positions where the tension of the fabric 82 can be kept substantially constant while avoiding interference between the descending base material mold 14 and the pair of skin frames 28. Therefore, the fabric 82 can be processed using the minimum necessary amount of raw material while suppressing excessive stretching, thereby reducing costs.

Furthermore, according to the press processing method using the press processing device 10, the pair of skin frames 28 are positionally controlled by the servo mechanism 44. As a result, even if there is variation in the moving speed of the pair of skin frames 28, the pair of skin frames 28 are positioned at accurate positions. Therefore, excessive stretching of the fabric 82 can be further suppressed.

Furthermore, according to the press processing method using the press processing device 10, it is possible to reduce residual stress after the fabric 82 is attached to the base material 80. Therefore, it is possible to prevent the fabric 82 of the instrument panel from peeling off from the base material 80 after attachment. This makes it possible to improve the durability of the instrument panel.

In addition, according to the press processing method using the press processing device 10, the lowering speed of the base material mold 14 is kept substantially constant until the protrusion contacts, and after the protrusion contacts, the lowering speed of the base material mold 14 in the second mold closing process is slower than in the previous processes. Here, even in the second mold closing process, the pair of skin frames 28 are moved in synchronization with the base material mold 14 according to the amount of fabric 82 pulled in. This makes it possible to reliably make the fabric 82 conform to the detailed shape while preventing damage to the mold.

Furthermore, the press processing device 10 is a press device that raises and lowers only the base material mold 14 provided on the upper side, and the skin mold 16 provided on the lower side is fixed to a skin mold fixing part 20 placed on the floor surface. Therefore, equipment costs can be reduced compared to a device that forms a pit on the floor surface and raises and lowers only the lower mold or both the upper and lower molds.

[Supplementary explanation of the above embodiment]
In the above embodiment, the substrate mold 14 provided on the upper side is raised and lowered by the substrate mold raising and lowering means 18, and the skin mold 16 provided on the lower side is fixed to the skin mold fixing part 20 placed on the floor surface, but this is not limited thereto. For example, the press processing device may be a device that raises and lowers only the lower mold provided on the lower side, or may be a device that raises and lowers both the upper and lower molds.

For example, when using a vertically driven press machine capable of raising and lowering both the upper and lower dies, one die may be moved in the press direction to contact the skin material, and then the other die may be moved in the press direction to contact the skin material. In this case, the gripping distance between the pair of skin materials is kept constant until the other die and the skin material come into contact, and after the other die and the skin material come into contact, when at least one of the dies are moved in the press direction, the pair of skin frames are moved in synchronization with the moving dies, thereby preventing excessive stretching of the skin material.

In the above embodiment, the pair of skin frames 28 are moved so that the tension of the fabric 82 is approximately constant after contact with the base material, but this is not limited to the above. For example, the pair of skin frames 28 may be controlled in stages to cancel out the tension of the skin material increased by the movement of the mold in stages.

In addition, in the above embodiment, the pair of skin frames 28 are described as gripping the fabric 82 in a flat, flat state when in contact with the base material, but this is not limited thereto, and the fabric may be gripped in a slightly loosened state.

Furthermore, in the above embodiment, the pair of skin frames 28 are described as narrowing their gripping distance continuously from when the substrate comes into contact until pressing is completed, but this is not limited to the above. For example, in the latter stage of skin mold contact, the holding means 12 may be controlled to lower while keeping the gripping distance of the pair of skin frames 28 constant.

In the above embodiment, the speed of descent of the base mold 14 is substantially constant until the protruding portions come into contact, and the speed at which the gripping interval of the pair of skin frames 28 is narrowed in the first mold closing step is set to be faster than the speed at which the gripping interval of the pair of skin frames 28 is narrowed in the skin mold contact step. However, this is not limiting, and it is sufficient that the skin material is pressed without being stretched by synchronously controlling the descent of the base mold 14, the descent of the holding means 12, and the narrowing of the gripping interval of the pair of skin frames 28.

In the above embodiment, the press processing device 10 has been described as being equipped with a support frame lifting means 54 (not shown) that can raise and lower the holding means 12, but this is not limited to this. For example, if the holding means 12 including a pair of skin frames 28 is positioned so that it does not interfere with the base material mold 14 at all times, it is possible to synchronize only the reduction in the gripping distance between the pair of skin frames 28 with the descent of the base material mold 14, without raising and lowering the holding means 12.

Furthermore, in the above embodiment, synchronous control is described as being performed using a servo, but this is not limiting, and for example, a linear scale and a hydraulic device may also be used.

In the above embodiment, the press processing device 10 has been described as a pasting device that pastes the fabric 82 onto the base material 80, but the present invention is not limited to this and may be a press processing device that forms a single layer of skin material that is pasted onto the base material in a later process.

10 Press processing equipment (skin material press processing equipment)
14 Base mold (upper mold)
16 Epidermal mold (lower mold)
28 Pair of skin frames 44 Servo mechanism 80 Base material 82 Fabric (skin material)
B Press end

Claims (7)

a placement step of holding the skin material by a pair of skin frames and placing the skin material between an upper mold and a lower mold that are arranged in a pair above and below in an open mold state;
a one-die contacting step of moving one of the upper die and the lower die in a pressing direction to bring the one die into contact with the skin material;
a second die contacting step of moving the first die further in the pressing direction until the first die comes into contact with the skin material and moving the pair of skin frames in synchronization with the first die so as to cancel out the tension of the skin material that increases due to the movement of the first die;
a die closing process in which at least one of the one die and the other die is moved in a pressing direction to press the skin material up to a pressing end, and the pair of skin frames is moved in synchronization with the die so as to cancel out the tension of the skin material that increases due to the movement of the die that moves in contact with the skin material;
having
In the other mold contact step and the mold closing step, a gripping interval of the skin material between the pair of skin frames is narrowed,
a speed at which the gripping interval between the pair of skin frames is narrowed in the mold closing step is faster than a speed at which the gripping interval between the pair of skin frames is narrowed in the other mold contact step;
A method for pressing skin materials. the pair of skin frames are moved so that the tension of the skin material is kept substantially constant from the time when the one die comes into contact with the skin material until the pressing is completed;
A method for press working the skin material according to claim 1. When the one die and the skin material are brought into contact with each other, the pair of skin frames hold the skin material in a state in which the skin material is developed into a flat shape.
A method for press working the skin material according to claim 1 or 2. In the die closing step and the other die contact step when the one die is moved, the pair of skin frames are moved in a pressing direction.
A method for press working the skin material according to claim 2 or 3 . a servo mechanism is used to control the positions of the pair of skin frames so as to synchronize with the mold that moves while in contact with the skin material;
A method for press working the skin material according to any one of claims 1 to 4 . The method for press working a skin material according to any one of claims 1 to 5, further comprising the steps of: fixing a substrate to the upper mold or the lower mold; and attaching the skin material to the substrate. An upper mold and a lower mold are provided as a pair at the top and bottom,
A pair of skin frames configured to be able to grip a skin material;
a control unit which performs a process of: in a positioning step, causing the pair of skin frames to hold the skin material, and placing the skin material between the upper mold and the lower mold which are placed in a mold open state; in a one-mold contact step, moving one of the upper mold and the lower mold in a press direction to bring the one mold into contact with the skin material; in a other-mold contact step, moving the one mold further in the press direction until the skin material comes into contact with the other mold, and moving the pair of skin frames in synchronization with the one mold so as to cancel the tension of the skin material which increases due to the movement of the one mold ; and in a mold closing step, moving at least one of the one mold and the other mold in the press direction to press the skin material to a press end, and moving the pair of skin frames in synchronization with the mold so as to cancel the tension of the skin material which increases due to the movement of the mold which moves in a state of contact with the skin material.
having
The control unit is
In the other mold contact step and the mold closing step, a gripping interval of the skin material between the pair of skin frames is narrowed,
a speed at which the gripping interval between the pair of skin frames is narrowed in the mold closing step is controlled to be faster than a speed at which the gripping interval between the pair of skin frames is narrowed in the other mold contact step;
Press processing equipment for covering materials.