Planar actuator, conveyance device using the same, moving device, bedsore prevention device, and manufacturing method

Abstract

To provide a planar actuator in which a travel speed is large and manufacturing cost is low, to provide a conveyance device using the same, and to provide a moving device, a bedsore prevention device and a manufacturing method.SOLUTION: In an atmospheric pressure condition shown in (A), a pressure chamber 3-A (3-B, 3-C, 3-D) becomes a Y-shaped cross-sectional shape (flat condition). A sum of one outer side of the Y-shape at this time, that is, a width w11 of an upper side urethane sheet 1-1, and an inner side, that is, a width w12 of an upper urethane sheet 1-2 is defined as L1, and a distance between deposition end points E1, E2 is defined as W1. In a positive pressure state shown in (B), the pressure chamber 3-A (3-B, 3-C, 3-D) becomes a circular cross-sectional shape. A length of a semi-circumference at this time becomes L1 of (A) in Fig.3, and when the distance between the deposition end points E1, E2 is defined as W2, a relation exists in which W2=L1 / π. When the pressure chamber 3-A (3-B, 3-C, 3-D) changes from the atmospheric pressure condition to the positive pressure condition, an expansion width Δx is given in the following formula. Δx=W2-W1=L1 / π-W1. Therefore, a propulsion power can be increased.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a planar actuator that generates a traveling wave (backward wave) using fluid pressure energy, a transport device, a moving device, and a bedsore prevention device that use the same, and a manufacturing method thereof. [Background technology]

[0002] Gastropods such as snails and slugs move by generating traveling waves on their sheet-like abdominal feet. This gastropod locomotion method has many advantages, such as its ability to adapt to various types of terrain and narrow environments and its lack of environmental damage. Therefore, many planar actuators incorporating this operating principle have been developed. In particular, planar actuators have a flexible and thin structure driven by fluid pressure, making them advantageous for infiltrating narrow spaces. For example, their ability to propel themselves through irregularly shaped gaps, including those under human body load, without damaging the object they come into contact with, is thought to be of great use in devices to prevent bedsores in elderly care.

[0003] 21 is a perspective view showing a first conventional planar actuator (see Non-Patent Document 1). The planar actuator 100 shown in FIG. 21 generates a so-called shear wave type traveling wave.

[0004] In FIG. 21, the planar actuator 100 has dimensions of, for example, 90 mm in length, 130 mm in width, and 11 mm in height. It consists of a urethane sheet 112 formed inside with upper pressure chambers (chambers) 111-A-U, 111-B-U, 111-C-U,... and lower pressure chambers (chambers) 111-A-L, 111-B-L, 111-C-L,... arranged in parallel in the X direction, and a urethane sponge 113 provided on the urethane sheet 112. In this case, the thickness d1 of the urethane sheet 112 outside the upper chambers 111-A-U, 111-B-U, 111-C-U,... and the thickness d1 of the urethane sheet 112 outside the lower pressure chambers 111-B-L, 111-C-L, 111-A-L are smaller than the thickness d2 between the upper pressure chambers 111-A-U, 111-B-U, 111-C-U and the lower pressure chambers 111-B-L, 111-C-L, 111-A-L. That is, d1 < d2. The three-layer structure of d1, d2, and d1 can be obtained by welding three thermoplastic urethane sheets and a heat-resistant release sheet, for example, a cooking sheet, using a heat press machine.

[0005] FIG. 22 is a diagram for explaining the bending principle of the planar actuator of FIG. 21 and is an enlarged view of the vicinity of the upper pressure chamber 111-A-U in FIG. 21.

[0006] In FIG. 22, the thickness d1 of the thin portion 112T of the urethane sheet 112 above the upper pressure chamber 111-A-U is, for example, 0.3 mm, while the thickness d1 + d2 of the thick portion 112D of the urethane sheet 112 below the upper pressure chamber 111-A-U is 0.3 + 0.6 = 0.9 mm. Let the welded ends of the upper pressure chamber 111-A-U be E1 and E2.

[0007] As shown in (A) of FIG. 22, when the upper pressure chamber 111-A-U is in an unpressurized (atmospheric pressure) state, the upper pressure chamber 111-A-U is in a flat state. Therefore, both the thin portion 112T and the thick portion 112D of the urethane sheet 12 are in a flat state. As a result, the entire thin portion 112T and thick portion 112D are horizontal.

[0008] 22(B), when the upper pressure chamber 111-AU is pressurized (a positive pressure state greater than atmospheric pressure), the upper pressure chamber 111-AU is in an expanded state, and therefore the thin portion 112T of the urethane sheet 112 convex upward relative to the welded ends E1 and E2 of the upper pressure chamber 111-AU, and at the same time, the thick portion 112D of the urethane sheet 112 convex downward relative to the welded ends E1 and E2 of the upper pressure chamber 111-AU. At this time, the urethane sheet 112 outside the welded ends E1 and E2 is stronger integrated with the thicker portion 112D than the thin portion 112T between the welded ends E1 and E2, so the urethane sheet 112 outside the welded ends E1 and E2 and the thick portion 112D between the welded ends E1 and E2 are bent as a whole toward the thin portion 112T and convex downward. In this way, the urethane sheet 112 in the vicinity of the upper pressure chambers 111-AU, 111-BU, 111-CU, ... is curved upward. It should be noted that the lower pressure chambers 111-CL, 111-AL, 111-BL, ... are curved downward.

[0009] Fig. 23 is a diagram for explaining the operation of the planar actuator 100 of Fig. 21. In Fig. 23, the planar actuator 100 is fixed to a floor or the like and acts as a transport device for transporting an object O.

[0010] 23A, pressure chambers 111-AU, 111-AL, 111-BU, 111-BL, 111-CU, and 111-CL are respectively placed in a pressurized state, a non-pressurized state, and a non-pressurized state. As a result, pressure chambers 111-AU and 111-AL expand, and pressure chambers 111-BU, 111-BL, 111-CU, and 111-CL flatten, forming a shear-type traveling wave, which increases the pushing force of planar actuator 100. As a result, object O in pressure chambers 111-AU and 111-AL moves slightly to the left in the figure due to contact pressure with urethane sponge 13.

[0011] Next, referring to the B-phase pressurization in Figure 23(B), the pressure chambers 111-AU, 111-AL, 111-BU, 111-BL, 111-CU, and 111-CL are respectively set to a non-pressurized state, a pressurized state, and a non-pressurized state. The pressure chambers 111-BU and 111-BL expand, while the pressure chambers 111-AU, 111-AL, 111-CU, and 111-CL flatten, forming a shear-type traveling wave, increasing the pushing force of the planar actuator 1. As a result, the object O on the pressure chambers 111-BU and 111-BL moves slightly to the left in the figure due to the contact pressure with the urethane sponge 13.

[0012] 23(C), pressure control units 4-A, 4-B, and 4-C place pressure chambers 111-AU, 111-AL, 111-BU, 111-BL, 111-CU, and 111-CL in a non-pressurized state, a non-pressurized state, and a pressurized state, respectively. As a result, pressure chambers 111-CU and 111-CL expand, while 111-AU, 111-AL, 111-BU, and 111-BL flatten, forming a shear traveling wave that increases the pushing force of planar actuator 100. As a result, object O in pressure chambers 111-CU and 111-CL moves slightly to the left in the figure due to contact pressure with urethane sponge 113.

[0013] By repeating the operations of (A), (B), and (C) in FIG. 23 described above, a shear traveling wave consisting of three pressure chambers in a pressurized state for one period L is formed, and the object O moves to the left.

[0014] Incidentally, if the planar actuator 100 is turned upside down and made movable, it can function as a moving device.

[0015] However, in the first conventional planar actuator 100 shown in FIG. 21, when the supply pressure P of the pressure chamber is 100 kPa and the pressurization period T is 1 s (1 Hz), the movement velocity v of the object O is 8.3 mm / s when the load pressure WP of the object O is 0 kPa, as shown in FIG. 27. However, when the load pressure WP of the object O is 4.4 PkA, the movement velocity v of the object O becomes very small, at 0.6 mm / s. Furthermore, as the load pressure WP of the object O increases, the movement velocity v of the object O approaches 0 mm / s. This is because the vertical deformation of the shear-type traveling wave is inhibited by the large load. In particular, at a load pressure of 24 kPa, which corresponds to the sacrum, which is considered to be the highest load pressure in humans, the movement velocity v becomes small, at 0.6 mm / s, making it unsuitable for a bedsore prevention device. Note that the load pressure WP in FIG. 27 is the value obtained by dividing the mass of the load W by the sheet area of the planar actuator 100.

[0016] Fig. 24 is a perspective view showing a second conventional planar actuator (see Patent Document 1 and Non-Patent Document 2). The planar actuator 200 in Fig. 24 generates a so-called longitudinal wave type traveling wave.

[0017] 24, pressure chambers 202-A, 202-B, 202-C, ... are arranged in parallel in the X direction and are partitioned by thermoplastic material partition sheets, such as urethane partition sheets 201-0, 201-1, 201-2, ..., 201-9, which are located between a lower urethane sheet 201-D and an upper urethane sheet 201-D and have a V-shaped cross section along the Y direction. Every third pressure chamber 202-A, 202-A, ... constitutes an A phase, every third pressure chamber 202-B, 202-B, ... constitutes a B phase, and every third pressure chamber 202-C, 202- C, ... constitutes phase C. Both ends of the pressure chambers 203-A, 202-B, 202-C, ... are sealed to prevent air from leaking or entering.

[0018] Figure 25 is a diagram for explaining the states of pressure chambers 202-A, 202-B, 202-C, 202-A, 202-B, 202-C in Figure 24, where (A) shows a non-pressurized (atmospheric) state, and (B) shows a steady state where positive and negative pressures are mixed. Here, positive pressure is pressure greater than atmospheric pressure, and negative pressure is pressure less than atmospheric pressure.

[0019] As shown in Figure 25 (A), when each pressure chamber 202-A, 202-B, 202-C, 202-A, 202-B, 202-C is in a non-pressurized state (atmospheric pressure state), the "L" shape of the urethane partition sheets 201-0, 201-1, 201-2, ..., 201-6 is maintained, so the Z-direction height H0 is low, for example, about 0.8 mm.

[0020] If all pressure chambers 202-A, 202-B, 202-C, 202-A, 202-B, 202-C were in a negative pressure state, the "L" shape of all urethane partition sheets 201-0, 201-1, 201-2, ..., 201-6 would be further bent and flattened, so the Z-direction height H2 of the central portion would be very small, the thickness of urethane partition sheets 201-0, 201-1, 201-2, ..., 201-6 would be, for example, about 0.2 mm, and the X-direction length L2 would be small. Furthermore, if all pressure chambers 202-A, 202-B, 202-C, 202-A, 202-B, 202-C are in a positive pressure state, all urethane partition sheets 201-0, 201-1, 201-2, ..., 201-6 will no longer be in a "L" shape and will be in an extended state, so the Z-direction height H1 will be very large, and the Z-direction height H1 of the extended urethane partition sheets 201-0, 201-1, 201-2, ..., 201-6 will be, for example, approximately 8 to 10 mm, and the X-direction length L1 will be large.

[0021] As shown in Figure 25 (B), even when the A-phase pressure chambers 202-A, 202-A and the B-phase pressure chambers 202-B, 202-B are in a positive pressure state and the C-phase pressure chambers 202-C, 202-C are in a negative pressure state, the urethane partition sheets 201-0, 201-1, 201-2, ..., 201-6 are all in an extended state, and therefore the Z-direction height H1 of the chambers 202-A, 202-B, 202-A, 202-B is large at 8 to 10 mm, and the Z-direction height H2 of the central portions of the pressure chambers 202-C, 202-C is small at 0.2 mm. In other words, the Z-direction height H1 of the pressure chambers 202-A, 202-A; 202-B, 202-B in a positive pressure state is greater than the Z-direction height H2 of the central portion of the pressure chambers 202-C, 202-C in a negative pressure state, and the length L1 of the pressure chambers 202-A, 202-A; 202-B, 202-B in a positive pressure state is greater than the length L2 of the pressure chambers 202-C, 202-C in a negative pressure state. Therefore, the volume of the pressure chambers 202-A, 202-A; 202-B, 202-B in a positive pressure state is larger than the volume of the pressure chambers 202-B, 202-B in a negative pressure state, and by sequentially putting the pressure chambers 202-A, 202-A; 202-B, 202-B; 202-C, 202-C in each chamber group into a positive pressure state and then a negative pressure state, a longitudinal wave type progressive wave (regressive wave) can be formed in one cycle L (= 2 L1 + L2) consisting of two pressure chambers (L1, H1) with large volumes and one pressure chamber (L2, H2) with small volumes.

[0022] Fig. 26 is a diagram for explaining the operation of the planar actuator 200 of Fig. 24. In Fig. 26, the planar actuator is fixed to a floor or the like and acts as a transport device for transporting an object O.

[0023] 26A, pressure chambers 202-A, 202-A; 202-B, 202-B; 202-C, 202-C are respectively placed in a positive pressure state, a positive pressure state, and a negative pressure state. As a result, the volumes of pressure chambers 202-A, 202-A, 202-B, 202-B are large, and the volumes of pressure chambers 202-C, 202-C are small. In this case, all urethane partition sheets 201-0, 201-1, 201-2, ..., 201-6 are in a highly stretched state.

[0024] Next, referring to Figure 26(B), for C-phase pressurization, pressure chambers 202-A, 202-A; 202-B, 202-B; 202-C, 202-C are respectively placed in a positive pressure state, a negative pressure state, and a positive pressure state. As a result, the volume of pressure chambers 202-B, 202-B decreases, while the volume of pressure chambers 202-C, 202-C increases. In this case, urethane partition sheets 201-2, 201-5 temporarily bend into a low, dogleg shape, but eventually, as shown in Figure 26(C), urethane partition sheets 201-2, 201-5 return to a highly stretched state. In this way, the contraction of pressure chambers 202-B and the expansion of pressure chambers 202-C form a traveling wave, and the bending / extension of urethane partition sheets 201-2 and 201-5 increases the pushing force of the planar actuator. As a result, object O in chambers 202-1 and 202-4 moves slightly to the right in the figure due to the contact pressure with pressure chambers 201-A and 201-A.

[0025] Next, referring to Figure 26(D), for B-phase pressurization, pressure chambers 202-A, 202-A; 202-B, 202-B; 202-C, 202-C are respectively placed in a positive pressure state, a positive pressure state, and a negative pressure state. As a result, the volume of pressure chambers 202-A, 202-A decreases, while the volume of pressure chambers 202-B, 202-B increases. In this case, urethane partition sheets 201-1, 201-4 temporarily bend into a low, dogleg shape, but eventually, as shown in Figure 26(E), urethane partition sheets 201-1, 201-4 return to a highly stretched state. In this way, a traveling wave is formed by the contraction of pressure chambers 202-A and 202-A and the expansion of pressure chambers 202-B and 202-B, and the bending / extending motion of urethane partition sheets 201-1 and 201-4 is added, increasing the pushing force of planar actuator 200. As a result, object O on pressure chambers 202-C and 220-C moves slightly to the right in the figure due to the contact pressure with pressure chambers 202-C and 202-C.

[0026] Next, referring to Figure 26(F), for A-phase pressurization, pressure chambers 202-A, 202-A; 202-B, 202-B; 202-C, 202-C are respectively placed in a positive pressure state, a positive pressure state, and a negative pressure state. As a result, the volumes of pressure chambers 2-C, 2-C decrease, while the volumes of pressure chambers 202-A, 202-A increase. In this case, urethane partition sheets 201-0, 201-3, 201-6 temporarily bend into a low "L" shape, but eventually, as shown in Figure 26(G), urethane partition sheets 201-0, 201-3, 201-6 return to a highly stretched state. In this way, a traveling wave is formed by the contraction of pressure chambers 202-C and 202-C and the expansion of pressure chambers 202-B and 202-B, and the bending / extending motion of urethane partition sheets 201-0, 201-3, and 201-6 is added, increasing the pushing force of planar actuator 200. As a result, object O on pressure chambers 202-B and 202-B moves slightly to the right in the figure due to the contact pressure with pressure chambers 202-B and 202-B.

[0027] By repeating the operations of (A), (B), (C), (D), (E), and (F) in Figure 26 described above, a longitudinal traveling wave is formed over one period L (= 2 L1 + L2) consisting of two chambers (length L1) in a positive pressure state and one pressure chamber (length L2) in a negative pressure state, and the urethane partition sheets 201-0, 201-1, ... are bent / extended, causing the object O to move to the right. Note that in the steady state of (A), (C), (E), and (G) in Figure 26, there are two pressure chambers in a positive pressure state and one pressure chamber in a negative pressure state. In any case, by making the number of pressure chambers in a positive pressure state and the number of pressure chambers in a negative pressure state in the steady state different, a longitudinal traveling wave (backward wave) can be formed.

[0028] If the planar actuator 200 is not fixed to the floor or the like but is made movable, it can function as a moving device.

[0029] In this way, with the second conventional planar actuator 200 shown in FIG. 24, two of the A-phase, B-phase, and C-phase systems are pressurized, and the remaining system is under negative pressure, thereby supporting the load at a constant height, and the horizontal deformation of the longitudinal traveling wave is not hindered by a large load.

[0030] Furthermore, when the C-phase (A-phase, B-phase) pressure chamber is pressurized under negative pressure, the preceding B-phase (C-phase, A-phase) pressure chamber is placed under negative pressure, the boundary urethane partition sheet is made V-shaped to increase the length of the preceding pressure chamber, and then the C-phase (A-phase, B-phase) pressure chamber is pressurized, thereby increasing the propulsive force of the planar actuator 200. As shown in Fig. 27, when the supply pressure P of the pressure chamber is 100 kPa and the pressurization period T is 1 s (1 Hz), when the load pressure WP of the object O is small, the movement speed of the object O is approximately 4 mm / s, which is slower than that of the first conventional planar actuator 100 shown in Fig. 21, but when the load pressure WP of the object O is large, it is faster than that of the first conventional planar actuator 100 shown in Fig. 21. In particular, at a load pressure of 24 kPa, which corresponds to the sacrum, where the load pressure WP is greatest in humans, the movement speed is 3.0 mm / s, making this device suitable for use as a bedsore prevention device. [Prior art documents] [Patent documents]

[0031] [Patent Document 1] JP 2021-121751 A (Patent No. 7378786 A) [Non-patent literature]

[0032] [Non-Patent Document 1] M. Watanabe and H. Tsukagoshi, “Soft sheet actuator generating traveling waves inspired by gastropod's locomotion”, in Int. Conf. on Robotics and Automation, Singapore, May 2017. [Non-patent document 2] Takahiro Kasahara and Hideyuki Tsukagoshi, "Proposal of Wavy-sheet-III, a sheet-like actuator for human transport," JSME Robotics and Mechatronics Conference, 1P2-H06, 2020. Summary of the Invention [Problem to be solved by the invention]

[0033] However, the second conventional planar actuator 200 shown in FIG. 24 is configured to move forward by the amount of contraction when the pressure chamber contracts due to negative pressure. Therefore, when a load acts perpendicular to the surface, the negatively pressurized pressure chamber cannot support the load and collapses, reducing the amount of contraction. As a result, there is a problem that the movement speed tends to decrease significantly as the load increases. Furthermore, since negative pressure is used, a vacuum pump or the like is required, which results in a complicated drive system and piping, and also raises the problem of high manufacturing costs. [Means for solving the problem]

[0034] To solve the above-mentioned problems, a planar actuator according to the present invention comprises three or more pressure chambers extending in a first direction and arranged in parallel in a second direction different from the first direction, each pressure chamber having a Y-shaped cross section as viewed from the first direction when under atmospheric pressure and a circular cross section as viewed from the first direction when under a positive pressure higher than atmospheric pressure, and further comprising control means for controlling each pressure chamber between an atmospheric pressure state and a positive pressure state. That is, when a pressure chamber expands under positive pressure, it moves forward by the amount of expansion. Therefore, even if a load acts in a direction perpendicular to the surface, it is possible to support the load and move forward while expanding. As a result, even if the load increases to a certain value, the movement speed can be maintained without decreasing.

[0035] Furthermore, in a method for manufacturing a planar actuator according to the present invention, each pressure chamber comprises a first upper sheet provided along a first direction, a second upper sheet narrower than the first upper sheet, and a first lower sheet provided along the first direction, and a second lower sheet narrower than the first lower sheet, one end of the first upper sheet and one end of the second upper sheet are connected at a first connection part, one end of the first lower sheet and one end of the second lower sheet are connected at a second connection part, and the other end of the first upper sheet and the other end of the first lower sheet are connected at a second connection part. a first step of forming the second upper sheet by cutting and bending the first thermoplastic sheet; a second step of forming the second lower sheet by cutting and bending the second thermoplastic sheet; and a step of attaching the first adhesion prevention sheet, the first upper sheet made of a thermoplastic material, and the second adhesion prevention sheet to form a first adhesion prevention sheet / first upper sheet. a third step of bonding the first adhesion prevention sheet, a first upper sheet made of a thermoplastic material, and a second adhesion prevention sheet to form a first adhesion prevention sheet / first upper sheet / second adhesion prevention sheet bonded body; a fourth step of bonding the third adhesion prevention sheet, a first lower sheet made of a thermoplastic material, and a fourth adhesion prevention sheet to form a third adhesion prevention sheet / first lower sheet / fourth adhesion prevention sheet bonded body; a fifth step of inserting the third anti-adhesion sheet / first lower sheet / fourth anti-adhesion sheet laminate into the slit in the first thermoplastic sheet; a sixth step of inserting the third anti-adhesion sheet / first lower sheet / fourth anti-adhesion sheet laminate into the slit in the second thermoplastic sheet; a seventh step of overlapping the first and second thermoplastic sheets after the fifth and sixth steps; an eighth step of adhering the first and second upper sheets and the first and second lower sheets together after the seventh step; and a ninth step of removing the second and fourth anti-adhesion sheets between the pressure chambers after the eighth step. [Effects of the Invention]

[0036] According to the present invention, each pressure chamber changes from a Y-shaped cross section (flattened state) to a circular cross section when it changes from atmospheric pressure to positive pressure, generating a large propulsive force, thereby increasing the movement speed. Furthermore, since a vacuum pump or the like is not required to switch between atmospheric pressure and positive pressure, manufacturing costs can be reduced. [Brief explanation of the drawings]

[0037] [Figure 1] 1A and 1B show an embodiment of a planar actuator according to the present invention, in which (A) is a top view and (B) is a cross-sectional view. [Figure 2] 2 is a top view photograph of the planar actuator of FIG. 1(A). [Figure 3] 2A and 2B are diagrams for explaining the extension length of the pressure chamber in FIG. 1, in which (A) shows an atmospheric pressure state (non-pressurized state), and (B) shows a positive pressure state (pressurized state) where the positive pressure is greater than atmospheric pressure. [Figure 4] 4 is a diagram for explaining the internal pressure distribution in the flattened state of the pressure chamber of FIG. 3(A). FIG. [Figure 5] 2 is a diagram for explaining the forward movement of the planar actuator of FIG. 1. FIG. [Figure 6] 2 is a diagram for explaining the retreating operation of the planar actuator of FIG. 1. FIG. [Figure 7] FIG. 2 is a diagram showing details of the drive unit of FIG. 1. [Figure 8] 2A to 2C are diagrams illustrating a method for manufacturing the planar actuator of FIG. 1. [Figure 9] 2A to 2C are diagrams illustrating a method for manufacturing the planar actuator of FIG. 1. [Figure 10] FIG. 10 is a perspective view showing a heat press machine used in the welding step of FIG. 9(B). [Figure 11] FIG. 3 is a cross-sectional view showing a second embodiment of a planar actuator according to the present invention. [Figure 12] 12 is a diagram for explaining the internal pressure distribution in the flattened state of the pressure chamber in FIG. 11. FIG. [Figure 13] 12 is a diagram for explaining the forward movement of the planar actuator of FIG. 11. FIG. [Figure 14]12 is a graph showing the moving speed of the planar actuator of FIGS. 1 and 11. [Figure 15] 1 and 11 show a first modified example of the planar actuator, where (A) is a top view, (B) is a perspective photograph for explaining the effect without a rubber band, and (C) is a perspective photograph for explaining the effect with a rubber band. [Figure 16] 1 and 11, where (A) is a top view and (B) is a photograph of (A). [Figure 17] 12A and 12B show a third modified example of the planar actuator of FIGS. 1 and 11, where (A) is a top view and (B) is a cross-sectional view taken along line BB of (A). [Figure 18] FIG. 17 shows the cases where the pressure chamber is in an atmospheric pressure state, a positive pressure state, a positive pressure state, and an atmospheric pressure state. [Figure 19] 1 is a diagram showing a bedsore prevention device to which the present invention is applied. [Figure 20] 20 is a photograph showing the results of an experiment under human body load similar to that of the bedsore prevention device of FIG. 19. [Figure 21] FIG. 1 is a perspective view showing a first conventional planar actuator. [Figure 22] 22 is an enlarged view of the vicinity of the upper pressure chamber in FIG. 21, illustrating the principle of bending of the planar actuator in FIG. 21. FIG. [Figure 23] 22 is a diagram for explaining the operation of the planar actuator of FIG. 21. FIG. [Figure 24] FIG. 10 is a perspective view showing a second conventional planar actuator. [Figure 25] 25A and 25B are diagrams for explaining the state of the pressure chamber in FIG. 24, in which (A) shows a no-pressure (atmospheric) state, and (B) shows a steady state where positive and negative pressures are mixed. [Figure 26] 25 is a diagram for explaining the operation of the planar actuator of FIG. 24. FIG. [Figure 27] 25 is a graph showing the moving speed of the planar actuator of FIGS. 21 and 24. DETAILED DESCRIPTION OF THE INVENTION

[0038] FIG. 1 shows a first embodiment of a planar actuator according to the present invention, (A) is a top view, (B) is a cross-sectional view, and FIG. 2 is a top photograph of (A) in FIG. 1. The planar actuator in FIG. 1 has excellent moving performance against a soft load, for example, a human body load.

[0039] In FIGS. 1 and 2, four pressure chambers 3-A, 3-B, 3-C, and 3-D are formed by welding a wide upper urethane sheet 1-1 with an X-direction width w11, a narrow upper urethane sheet 1-2 with an X-direction width w12 (<w11), a wide lower urethane sheet 2-1 with an X-direction width w21, and a narrow lower urethane sheet 2-2 with an X-direction width w22 (<w21). In this case, in order to be vertically symmetric, w11 = w21 w12 = w22 However, it is also possible to set w11 / w12 = w21 / w22, making the upper and lower urethane sheets asymmetric. Furthermore, the upper urethane sheets 1-1 and 1-2, the lower urethane sheets 2-1 and 2-2, the upper urethane sheets 1-1 and 2-1, and the upper urethane sheets 1-2 and 2-2 are welded (bonded) at welded sections (adhesive sections) M1, M2, M3, and M4. In this case, between each pressure chamber 3-A, 3-B, 3-C, and 3-D, two urethane sheets 2-1 and 2-2 and two urethane sheets 1-1 and 1-2 overlap and are welded at welded section M4 (M3). Note that 1 denotes the urethane sheet that is the base of the upper urethane sheet 1-2, and 2 denotes the urethane sheet that is the base of the lower urethane sheet 2-2 (see FIG. 8A). One side end of the pressure chambers 3-A, 3-B, 3-C, and 3-D is closed. Meanwhile, urethane tubes 4-A, 4-B, 4-C, and 4-D are provided at the other ends of the pressure chambers 3-A, 3-B, 3-C, and 3-D. In this case, the urethane tubes 4-A, 4-B, 4-C, and 4-D exist both inside and outside the urethane sheets 1 and 2. However, the urethane tubes 4-A, 4-B, 4-C, and 4-D can also be sandwiched between the urethane sheets 1 and 2 that make up the pressure chambers 3-A, 3-B, 3-C, and 3-D, significantly reducing friction between the urethane tubes 4-A, 4-B, 4-C, and 4-D and the object. Drive units 5-A, 5-B, 5-C, and 5-D switch the pressure of each pressure chamber 3-A, 3-B, 3-C, and 3-D via the urethane tubes 4-A, 4-B, 4-C, and 4-D, and a control unit 6 controls the drive units 5-A, 5-B, 5-C, and 5-D. The control unit 6 is a computer configured with a central control unit (CPU), a read-only memory (ROM), a random access memory (RAM), etc., and together with the drive units 5-A, 5-B, 5-C, and 5-D, constitutes a control means.

[0040] Figure 3 is a diagram for explaining the extension length of pressure chamber 3-A (3-B, 3-C, 3-D) in Figure 1, where (A) shows the atmospheric pressure state (unpressurized state) and (B) shows the positive pressure state (pressurized state) where the positive pressure is greater than atmospheric pressure. The anti-welding sheets MA1-1 and MA2-1 in Figure 3 are used to prevent the upper urethane sheets 1-1 and 1-2 from welding to the lower urethane sheets 2-1 and 2-2 during the welding process, and are made, for example, of cooking paper or a composite sheet (plastic sheet) of silicone-coated paper / adhesive sheet that is easy to fix.

[0041] In the atmospheric pressure state shown in Figure 3(A), the pressure chamber 3-A (3-B, 3-C, 3-D) has a Y-shaped cross section (flattened state). The sum of the width w11 of one outer edge of the Y shape, i.e., the width w12 of the inner edge, i.e., the width of the upper urethane sheet 1-1, and the width w12 of the upper urethane sheet 1-2, is taken as L1, and the distance between the welding end points E1 and E2 is taken as W1. On the other hand, in the positive pressure state shown in Figure 3(B), the pressure chamber 3-A (3-B, 3-C, 3-D) has a circular cross section. In this state, the length of the semicircle is L1 in Figure 3(A), and if the distance between the welding end points E1 and E2 is taken as W2, then W2=L1 / π Therefore, when the pressure chamber 3-A (3-B, 3-C, 3-D) changes from atmospheric pressure to positive pressure, the expansion width Δx is given by the following equation: Δx=W2-W1 =L1 / π-W1 This expansion width Δx is larger than the contraction width due to negative pressure of the second conventional planar actuator 200 shown in FIG. 24, and therefore the propulsive force can be increased, resulting in an increase in payload and movement speed.

[0042] 4 is a diagram for explaining the internal pressure distribution of the pressure chambers 3-A, 3-B, 3-C, and 3-D in the flattened state in FIG. 3A. Note that the anti-welding sheets MA1-1 and MA2-1 are omitted in FIG. 4. That is, as shown in FIG. 4, internal pressures F1 and F2 (=F1) act on the inner surfaces of the pressure chambers 3-A, 3-B, 3-C, and 3-D in the flattened state, and the resultant vertical force F of the internal pressure F1 is v is the load bearing capacity, and the horizontal force F HTherefore, when the atmospheric pressure state changes to a positive pressure state, the vertical force F v becomes larger and supports the load, and the horizontal force F H becomes larger and exerts a driving force.

[0043] FIG. 5 is a diagram for explaining the forward movement of the planar actuator of FIG. 1, in which the upper and lower sides of the planar actuator are in contact with, for example, a person and a bed.

[0044] First, in the initial state of Figure 5(A), the pressure chambers 3-A and 3-D are in a circular cross-sectional state under positive pressure and are in contact at fixed points PA, PA, PD, and PD, while the pressure chambers 3-B and 3-C are in a flat, slippery floating state (non-contact or light contact state) under atmospheric pressure.

[0045] Next, when pressure chamber 3-D is changed from positive pressure to atmospheric pressure, as shown in Figure 5(B), pressure chamber 3-D changes from a circular cross section to a flattened cross section, and therefore moves back a small distance (Δ). As a result, pressure chambers 3-B, 3-C, and 3-D enter a slippery floating state.

[0046] Next, when the pressure chamber 3-B is changed from atmospheric pressure to positive pressure, as shown in FIG. 5(C), the pressure chamber 3-B is subjected to a vertical force F v and horizontal force F H As a result, pressure chamber 3-B comes into contact with fixed points PB and PB, but pressure chambers 3-C and 3-D remain in a slippery floating state and move forward by a large distance (Δx).

[0047] Next, when the pressure chamber 3-C is changed from atmospheric pressure to positive pressure, as shown in FIG. 5(D), the pressure chamber 3-C is subjected to a vertical force F v and horizontal force F HAs a result, pressure chamber 3-B, which has a circular cross section, expands with fixed points PB, PB as the fulcrum. As a result, pressure chamber 3-C, which has a circular cross section, comes into contact at fixed points PC, PC, but pressure chamber 3-D remains in a slippery floating state and moves forward a large distance (Δx). At the same time, or around the same time, if pressure chamber 3-A is changed from a positive pressure state to an atmospheric pressure state, pressure chamber 3-A changes from a circular cross section state to a flattened state and moves forward a large distance (Δx).

[0048] Next, when the pressure chamber 3-D is changed from atmospheric pressure to positive pressure, as shown in FIG. 5(E), the pressure chamber 3-D is subjected to a vertical force F v and horizontal force F H As a result, pressure chamber 3-C, which has a circular cross section, expands with fixed points PC and PC as fulcrums. As a result, pressure chamber 3-D, which has a circular cross section, comes into contact at fixed points PD and PD. At the same time as, or before or after, pressure chamber 3-B is changed from a positive pressure state to an atmospheric pressure state, pressure chamber 3-B changes from a circular cross section state to a flattened state, and moves forward a large distance (Δx) together with pressure chamber 3-A.

[0049] Next, when the pressure in the pressure chamber 3-C is changed from a positive pressure state to an atmospheric pressure state, as shown in FIG. 5(F), the pressure chamber 3-C changes from a circular cross section to a flattened state, and moves forward by a large distance (Δx) together with the pressure chambers 3-A and 3-B.

[0050] Finally, when the pressure chamber 3-A is changed from atmospheric pressure to positive pressure, as shown in FIG. 5(G), the pressure chamber 3-A is subjected to a vertical force F v and horizontal force F H As a result, the pressure chambers 3-A, 3-B, 3-C, and 3-D change from a flattened state to a circular cross-section state, and only the pressure chamber 3-A moves back by a large distance (Δx). As a result, the pressure chambers 3-A, 3-B, 3-C, and 3-D become in the same state as the initial state shown in Figure 5(A), that is, in a positive pressure state, an atmospheric pressure state, an atmospheric pressure state, and a positive pressure state.

[0051] In one cycle in Figure 5, the front end of the sheet moves back a small distance (Δ) once, moves forward a large distance (2·Δx) twice, and moves forward a small distance (Δ) once, resulting in a large distance (2·Δx) in the end. On the other hand, the rear end of the sheet moves forward a large distance (3·Δx) three times, and moves back a large distance (Δx) once, resulting in a large distance (2·Δx) in the end.

[0052] FIG. 6 is a diagram for explaining the retreating movement of the planar actuator of FIG. 1, and in this case too, it is assumed that the upper and lower sides of the planar actuator are in contact with, for example, a person and a bed.

[0053] First, in the initial state of Figure 6 (A), the pressure chambers 3-A and 3-D are in a circular cross-sectional state under positive pressure and are in contact at fixed points PA, PA, PD, and PD, while the pressure chambers 3-B and 3-C are in an atmospheric pressure state and are in a flat, slippery floating state (non-contact or light contact state).

[0054] Next, when the pressure in the pressure chamber 3-A is changed from positive pressure to atmospheric pressure, the pressure chamber 3-A changes from a circular cross section to a flattened cross section and moves forward by a large distance (Δx), as shown in Figure 6(B). As a result, the pressure chambers 3-A, 3-B, and 3-C enter a slippery floating state (non-contact or light contact state).

[0055] Next, when the pressure chamber 3-C is changed from atmospheric pressure to positive pressure, as shown in FIG. 6(C), a vertical force F v and horizontal force F H As a result, pressure chamber 3-C comes into contact with fixed points PC and PC, but pressure chambers 3-C and 3-D remain in a slippery floating state and move backward by a large distance (Δx).

[0056] Next, when the pressure chamber 3-B is changed from atmospheric pressure to positive pressure, as shown in FIG. 6(D), the pressure chamber 3-B is subjected to a vertical force F v and horizontal force F HAs a result, pressure chamber 3-C, which has a circular cross section, expands with fixed points PC, PC as a fulcrum. As a result, pressure chamber 3-B, which has a circular cross section, comes into contact at fixed points PB, PB, but pressure chamber 3-A remains in a slippery floating state and retreats a large distance (Δx). At the same time, or around the same time, if pressure chamber 3-D is changed from a positive pressure state to an atmospheric pressure state, pressure chamber 3-D will change from a circular cross section to a flattened state and retreat a large distance (Δx).

[0057] Next, when the pressure chamber 3-A is changed from atmospheric pressure to positive pressure, as shown in FIG. 6(E), the pressure chamber 3-A is subjected to a vertical force F v and horizontal force F H As a result, pressure chamber 3-B, which has a circular cross section, expands with fixed points PB, PB as the fulcrum. As a result, pressure chamber 3-A, which has a circular cross section, comes into contact at fixed points PA, PA. Simultaneously with, or before or after, this, if pressure chamber 3-C is changed from a positive pressure state to an atmospheric pressure state, pressure chamber 3-C changes from a circular cross section state to a flattened state, and moves back a large distance (Δx) together with pressure chamber 3-D.

[0058] Next, when pressure chamber 3-B is changed from a positive pressure state to an atmospheric pressure state, as shown in Figure 6(F), pressure chamber 3-B changes from a circular cross-section state to a flattened state, and moves back a large distance (Δx) along with pressure chambers 3-D and 3-C.

[0059] Finally, when pressure chamber 3-D is changed from atmospheric pressure to positive pressure, as shown in Figure 6(G), pressure chamber 3-D changes from a flattened state to a circular cross-section, and only pressure chamber 3-D moves forward by a large distance (Δx). As a result, pressure chambers 3-A, 3-B, 3-C, and 3-D are in the same state as the initial state shown in Figure 6(A), i.e., positive pressure, atmospheric pressure, atmospheric pressure, positive pressure.

[0060] In one cycle in Figure 6, the rear end of the sheet moves forward by a large amount (Δx) once and moves backward by a large amount (Δx) three times, so it ultimately moves backward by a large amount (2 Δx). On the other hand, the front end of the sheet moves backward by a large amount (3 Δx) three times and moves forward by a large amount (Δx) once, so it ultimately moves backward by a large amount (2 Δx). Note that the forward movement speed tends to be slower than the backward movement speed due to the Y-shape.

[0061] In Figure 1, when the number of pressure chambers is four, a large forward or backward thrust of 2·Δx can be obtained. In general, when the number of pressure chambers is N (N is an integer greater than or equal to 3), a large forward or backward thrust of (N-2)·Δx can be obtained, enabling a large payload and high movement speed.

[0062] Fig. 7 is a diagram showing details of the drive unit 5-A (5-B, 5-C, 5-D) in Fig. 1. The drive units 5-A, 5-B, 5-C, 5-D have the same configuration.

[0063] In Fig. 7, drive unit 5-A is made up of solenoid valves 51 and 52 and a normal pump 53 provided between solenoid valves 51 and 52, and solenoid valves 51 and 52 are controlled by control signals C61 and C62 from control unit 6, and pump 53 is controlled by a drive signal from control unit 6. Reference numeral 54 denotes an intake valve and 55 denotes an exhaust valve. That is, in Fig. 7, a negative pressure pump (vacuum pump) is not provided.

[0064] 7A will be explained. When control signals C61 and C62 are set to the on level ("1") and drive signal C63 is set to a drive level corresponding to the positive pressure, pump 53 operates, solenoid valve 51 is turned on to connect intake valve 54 to intake port 53a of pump 53, and solenoid valve 52 is turned on to connect exhaust port 53b of pump 53 to urethane tube 4-A. As a result, air is sent from intake valve 54 to urethane tube 4-A via solenoid valve 51, pump 53, and solenoid valve 52. Therefore, pressure chamber 3-A connected to urethane tube 4-A is put into a positive pressure state.

[0065] 7B will be explained. When control signals C61 and C62 are set to the off level ("0") and drive signal C63 is set to the off level, pump 53 is turned off, solenoid valve 51 is turned off, that is, spring return is performed to connect pressure chamber 3-A to intake port 43a of pump 53, and solenoid valve 52 is turned off, that is, spring return is performed to allow air to flow out of urethane tube 4-A. Therefore, pressure chamber 3-A connected to urethane tube 4-A is at atmospheric pressure.

[0066] 8 and 9 are diagrams for explaining a method for manufacturing the planar actuator of FIG. 1, with the upper side of each diagram being a top view and the lower side being a central cross-sectional view.

[0067] First, referring to the short width urethane sheet cutting process in Figure 8 (A), a lower urethane sheet 2 and an upper urethane sheet 1 are prepared, and cuts 81 are made in the lower urethane sheet 2 and the upper urethane sheet 1 and bent, thereby forming four lower urethane sheets 2-2 for short widths on the lower urethane sheet 2, and four upper urethane sheets 1-2 for short widths on the upper urethane sheet 1.

[0068] On the other hand, referring to the anti-welding sheet / long width sheet / anti-welding sheet bonding process in Fig. 8(B), four anti-welding sheets MA2-1 (four anti-welding sheets MA1-1), four long width urethane sheets 2-1 (four urethane sheets 1-1), and four anti-welding sheets MA2-2 (four anti-welding sheets MA1-2) are prepared, and each anti-welding sheet MA2-1 (MA1-1), each urethane sheet 2-1 (1-1), and each anti-welding sheet MA2-2 (MA2-1) are bonded together as shown in Fig. 8(B) to form six anti-welding sheet / long width sheet / anti-welding sheet bonded bodies. In addition, two urethane sheet 2-1, 1-1 / anti-welding sheet MA1-1 (MA2-1) bonded bodies and two anti-welding sheets MA1-1, MA2-1 are also prepared.

[0069] Next, referring to the assembly process in Fig. 8(C), two combinations are formed by inserting the anti-welding sheet MA2-1 (MA1-1) / urethane sheet 2-1 (1-1) / anti-welding sheet MA2-2 (MA1-2) laminate shown in Fig. 8(B) into the cut 81 in the urethane sheet 2(1) shown in Fig. 8(A). Note that there is no anti-welding sheet MA2-2 (MA1-2) on the outside of the urethane sheet 2-1 (1-1) on the left, and only anti-welding sheet MA2-2 (MA1-2) on the outside of the urethane sheet 2-2 (1-2) on the right.

[0070] Next, referring to the upper / lower urethane sheet assembling step in FIG. 9(A), the upper urethane sheet 1 is turned over and placed on the lower urethane sheet 2 to form an upper / lower urethane sheet combination U / L.

[0071] Next, referring to the welding process shown in Figure 9(B), the overlapping upper and lower urethane sheets 1 and 2 are welded from above and below using a heat press machine (Tex-4050FH) HP (shown in Figure 10) with a maximum press pressure of 700 kg. First, in the preheating process, the heat press machine HP is preheated to 175°C for 30 seconds. Next, the upper and lower urethane sheet combination U / L shown in Figure 9(A) is placed in the heat press machine HP, and welding is performed for approximately 100 to 200 seconds at 175°C, slightly higher than the urethane welding temperature of 170°C. Note that welding at a temperature much higher than the welding temperature of 170°C can generate internal bubbles, causing peeling when the interface is pulled. Next, the sheets are cooled for, for example, 300 seconds, until the temperature drops below 164°C, at which point the vapor pressure of the volatile components contained within the sheets becomes atmospheric pressure. As a result, the upper and lower urethane sheets are welded together, but the anti-welding sheets MA1-1, MA1-2, MA2-1, and MA2-2 prevent the upper and lower urethane sheets 1-1 and 1-2 from welding to each other and to each other, respectively. This allows for the creation of multiple pressure chambers 3-A, 3-B, 3-C, and 3-D, each containing the anti-welding sheets MA1-1, MA1-2 and MA2-1 and MA2-2. In other words, the upper and lower urethane sheets 1-1 and 1-2 and the lower urethane sheets 2-1 and 2-2 are connected by welds M1, M2, M3, and M4.

[0072] Although the welding step in FIG. 9(B) is performed by welding using a heat press, other bonding methods, such as adhesive, may also be used.

[0073] Finally, referring to the finishing process in Figure 9(C), unnecessary parts are removed. For example, the anti-welding sheets MA1-2 and MA2-2 between the pressure chambers 3-A, 3-B, 3-C, and 3-D are removed. Note that the anti-welding sheets MA1-1 and MA2-1 cannot be removed because they are present inside the pressure chambers 3-A, 3-B, 3-C, and 3-D. Furthermore, the urethane tubes 4-A, 4-B, 4-C, and 4-D are connected to the pressure chambers 3-A, 3-B, 3-C, and 3-D, completing the finishing process.

[0074] Fig. 11 is a cross-sectional view showing a second embodiment of a planar actuator according to the present invention. Note that this differs from the planar actuator of Fig. 1 only in the pressure chamber, and exhibits excellent movement characteristics under a highly rigid load.

[0075] In the pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D of Fig. 11, elastic bodies 8-A, 8-B, 8-C, and 8-D are inserted into the pressure chambers 3-A, 3-B, 3-C, and 3-D of the planar actuator of Fig. 1. The cross-sectional shape of the elastic bodies 8-A, 8-B, 8-C, and 8-D is, for example, pentagonal, but is not limited to this. Furthermore, the elastic bodies 8-A, 8-B, 8-C, and 8-D suppress deformation of the urethane sheets 1-1, 1-2, 2-1, and 2-2, and are preferably made of a material that is resistant to crushing and does not impair the flexibility of the planar actuator, such as a soft gel, rubber block, or hard sponge rubber.

[0076] Figure 12 is a diagram for explaining the internal pressure distribution in the flattened state of the pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D of Figure 11. Note that the anti-welding sheets MA1-1 and MA2-1 are omitted in Figure 12. That is, as shown in Figure 12, internal pressures F1 and F2 (=F1) of the same magnitude as in Figure 4 act on the inner surfaces of the flattened pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D. However, the vertical force F' of the resultant force of the internal pressure F1, which acts as a load support force, is vThe horizontal force F' of the resultant internal pressure F2, which acts as a driving force, becomes larger. H In other words, the internal pressure F1 is inclined more vertically than the internal pressure F1 in FIG. 4 due to the presence of the elastic body 8-A (8-B, 8-C, 8-D), and the internal pressure F2 is inclined more horizontally than the internal pressure F2 in FIG. 4 due to the presence of the elastic body 8-A (8-B, 8-C, 8-D). Therefore, when the pressure state changes from atmospheric pressure to positive pressure, a larger vertical force F' v becomes larger and supports the load, and a larger horizontal force F' H becomes even larger and exerts a driving force.

[0077] FIG. 13 is a diagram for explaining the forward movement of the planar actuator of FIG. 11, and assumes that the planar actuator is in contact with the lower and upper sides, for example, between a bed and a person.

[0078] First, in the initial state of Figure 13 (A), the pressure chambers 3'-A and 3'-D are in a circular cross-sectional state under positive pressure and are in contact at fixed points PA, PA, PD, and PD, while the pressure chambers 3'-B and 3'-C are in an atmospheric pressure state and are in a flat, slippery floating state (non-contact or light contact state).

[0079] Next, when the pressure in the pressure chamber 3'-D is changed from positive pressure to atmospheric pressure, the pressure chamber 3'-D changes from a circular cross section to a flattened cross section, as shown in Figure 13(B), and therefore moves back a small distance (Δ'). As a result, the pressure chambers 3'-B, 3'-C, and 3'-D enter a slippery floating state.

[0080] Next, when the pressure chamber 3'-B is changed from atmospheric pressure to positive pressure, as shown in FIG. 13(C), a large vertical force F' v and a large horizontal force F' H As a result, pressure chamber 3'-A, which has a circular cross section, expands with fixed points PA and PA acting as fulcrums (stoppers). As a result, pressure chamber 3'-B comes into contact at fixed points PB and PB, but pressure chambers 3'-C and 3'-D remain in a slippery floating state and move forward by a large distance (Δx'). In this case, Δx' > Δx (Figures 5 and 6).

[0081] Next, when the pressure chamber 3'-C is changed from atmospheric pressure to positive pressure, as shown in FIG. 13(D), a large vertical force F' v and a large horizontal force F' H As a result, pressure chamber 3'-B, which has a circular cross section, expands with fixed points PB, PB as a fulcrum. As a result, pressure chamber 3'-C, which has a circular cross section, comes into contact at fixed points PC, PC, but pressure chamber 3'-D remains in a slippery floating state and moves forward a large distance (Δx'). At the same time, or before or after this, if pressure chamber 3'-A is changed from a positive pressure state to an atmospheric pressure state, pressure chamber 3'-A changes from a circular cross section state to a flattened state and moves forward a large distance (Δx').

[0082] Next, when the pressure chamber 3'-D is changed from atmospheric pressure to positive pressure, as shown in FIG. 13(E), a large vertical force F' v and a large horizontal force F' H As a result, pressure chamber 3'-C, which has a circular cross section, expands with fixed points PC, PC as fulcrums. As a result, pressure chamber 3'-D, which has a circular cross section, comes into contact at fixed points PD, PD. Simultaneously with, or before or after, this, if pressure chamber 3'-B is changed from a positive pressure state to an atmospheric pressure state, pressure chamber 3-B changes from a circular cross section state to a flattened state and moves forward a large distance (Δx') together with pressure chamber 3'-A.

[0083] Next, when the pressure chamber 3'-C is changed from a positive pressure state to an atmospheric pressure state, as shown in Figure 13 (F), the pressure chamber 3'-C changes from a circular cross-section to a flattened state, and moves forward a large distance (Δx') together with the pressure chambers 3'-A and 3'-B.

[0084] Finally, when the pressure chamber 3'-A is changed from atmospheric pressure to positive pressure, as shown in FIG. 13(G), a large vertical force F' v and a large horizontal force F' H As a result, the pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D return to the initial state shown in Figure 13(A), that is, the positive pressure state, the atmospheric pressure state, the atmospheric pressure state, and the positive pressure state.

[0085] In one cycle in Figure 13, the front end of the sheet moves back once by a small amount (Δ'), moves forward twice by a large amount (2·Δx'), and moves forward once by a small amount (Δ'), so it ultimately moves forward by a large amount (2·Δx'). On the other hand, the rear end of the sheet moves forward three times by a large amount (3·Δx') and moves back once by a large amount (Δx'), so it ultimately moves forward by a large amount (2·Δx'). In this case, Δx' > Δx and Δ' ≒ Δ, so the planar actuator in Figure 11 moves forward more than the planar actuator in Figure 1.

[0086] Regarding the backward movement of the planar actuator in Figure 11, although not shown, in one cycle, the rear end of the seat moves backward by a large amount (Δx') three times and forward by a large amount (Δx'), so ultimately it moves backward by a large amount (2 Δx'). On the other hand, the front end of the seat moves backward by a large amount (3 Δx') three times and forward by a large amount (Δx'), so ultimately it moves backward by a large amount (2 Δx'). Note that the forward movement speed tends to be slower than the backward movement speed due to the Y-shape.

[0087] The planar actuator of Figure 11 is also manufactured by the manufacturing method shown in Figures 8 and 9. However, in the finishing process of Figure 9(C), after unnecessary portions are cut away, the side opposite to the connection points of urethane tubes 4-A, 4-B, 4-C, and 4-D is cut open and elastic bodies 8-A, 8-B, 8-C, and 8-D are inserted into pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D, and then the cut-open areas are re-welded to close them.

[0088] FIG. 14 is a graph showing the movement speed of the planar actuator of FIGS.

[0089] In the planar actuator of FIG. 1, if the overall size is 70 mm wide x 100 mm long x 12 mm high, the number of pressure chambers is four, the size of the pressure chambers under atmospheric pressure is 20 mm wide x 85 mm long x 12 mm high, the supply pressure is 100 kPa, and the pressurization period T is 1 s (1 Hz), when the load on the object O is small, the movement speed is high at approximately 9 mm / s, which is therefore faster than the first and second conventional planar actuators 100 and 200 of FIGS. 21 and 24. As the load on the object O increases, the movement speed v gradually decreases, but is still higher than the second conventional planar actuator 200 of FIG. 24. In particular, since the movement speed is high at approximately 3 mm / s even under a load pressure of 24 kPa, which is equivalent to the sacrum, this is suitable for use as a bedsore prevention device.

[0090] On the other hand, in the planar actuator of Figure 11, in addition to the conditions of the planar actuator of Figure 1, if the elastic bodies 8-A, 8-B, 8-C, and 8-D are made of sponge rubber and are 10 mm wide, 50 mm long, and 10 mm high, when the load of the object O is small, the movement speed v is 7 mm / s, which is smaller than that of the planar actuator of Figure 1. This is because, when the load is extremely small, the pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D are not completely flat but are slightly open. Furthermore, when the load pressure WP increases to 12 kPa, the movement speed v gradually increases to about 12 mm / s. This is because the pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D deform vertically under the load, expanding their horizontal deformation. Furthermore, when the load pressure WP exceeds 12 kPa, the movement speed v gradually decreases. This is because the height of the pressurized support section and the height of the unpressurized non-support section become closer, causing the non-support section to experience friction between the load and the load, canceling out the propulsive force. Even in this case, the movement speed is high at about 8.2 mm / s even under a load pressure of 24 kPa, equivalent to the sacrum, making it suitable for use as a bedsore prevention device. Therefore, the width of elastic bodies 8-A, 8-B, 8-C, and 8-D is determined so that appropriate load support and propulsive force are obtained. For example, the width is set to about half the width of the pressure chamber in the flattened state.

[0091] Figure 15 shows a first modified example of the planar actuator of Figures 1 and 11, where (A) is a top view, (B) is a perspective photograph to explain the effect without rubber bands, and (C) is a perspective photograph to explain the effect with rubber bands. In FIG. 15, the pressure in each pressure chamber 3-A, 3-B, 3-C, 3-D, 3-E, 3-F, 3-G, 3-H (or 3'-A, 3'-B, 3'-C, 3'-D, 3'-E, 3'-F, 3'-G, 3'-H, the same applies below) is assumed to be independently driven by eight drive units, and in order to balance the operation, the urethane tubes 4-A, 4-C, 4-E, 4-G of the pressure chambers 3-A, 3-C, 3-E, 3-G and the urethane tubes 4-B, 4-D, 4-F, 4-H of the pressure chambers 3-B, 3-D, 3-F, 3-H are assumed to be located on opposite sides of the surface actuator in the Y direction. However, urethane tubes 4-A, 4-B, 4-C, 4-D, 4-E, 4-F, 4-G, and 4-H are present both inside and outside the urethane sheets 1 and 2.

[0092] As shown in Figure 15(A), the ends of the urethane tubes 4-A, 4-C, 4-E, and 4-G that protrude from the pressure chambers 3-A, 3-C, 3-E, and 3-G to the outside of the urethane sheet 1(2) are bundled with rubber bands 7. Similarly, to maintain balance in operation, the ends of the urethane tubes 4-B, 4-D, 4-F, and 4-H that protrude from the pressure chambers 3-B, 3-D, 3-F, and 3-H to the outside of the urethane sheet 1(2) are bundled with rubber bands 7'. This increases the restoring force of the pressure chambers 3-A, 3-B, 3-C, 3-D, 3-E, 3-F, 3-G, and 3-H from their circular cross-sectional shape to a flattened shape when they are naturally exhausted from a positive pressure state to atmospheric pressure. Therefore, a high payload was achieved, and the effect of the rubber bands shown in Figure 15(C) was a movement speed of 3 mm / s, which is about three times faster than the movement speed of 1 mm / s without the rubber bands shown in Figure 15(B). Note that other elastic string members may be used instead of the rubber bands 7 and 7'.

[0093] FIG. 16 shows a second modification of the planar actuator of FIGS. 1 and 11, where (A) is a top view and (B) is a photograph of (A) taken from above.

[0094] 16, pressure chambers 3-A, 3-B, 3-C, 3-D; 3-E, 3-F, 3-G, 3-H; 3-I, 3-J, 3-K, 3-L; 3-M, 3-N, 3-O, 3-P (or 3'-A, 3'-B, 3'-C, 3'-D; 3'-E, 3'-F, 3'-G, 3'-H; 3'-I, 3'-J, 3'-K, 3'-L; 3'-M, 3'-N, 3'-O, 3'-P, the same applies below) are provided. In this case, pressure chambers 3-A, 3-E, 3-I, 3-M form chamber group A, which is driven by drive unit 5-A. Pressure chambers 3-B, 3-F, 3-J, 3-N form chamber group B, which is driven by drive unit 5-B. Pressure chambers 3-C, 3-G, 3-K, and 3-O form chamber group C, which is driven by drive unit 5-C. Pressure chambers 3-D, 3-H, 3-L, and 3-P form chamber group D, which is driven by drive unit 5-D. Therefore, each of chamber groups A, B, C, and D is controlled to atmospheric pressure or positive pressure, enabling a payload four times larger than that of the planar actuators of Figures 1 and 11. Note that although the number of chamber groups is four, it can also be 2, 3, 5, .... In other words, N chamber groups are configured with pressure chambers for each N (N is a natural number greater than or equal to 3).

[0095] In addition, in FIG. 16, one flexible silicone tube 4-a is welded to four urethane tubes 4-A, 4-E, 4-I, and 4-M to connect them to drive unit 5-A; one flexible silicone tube 4-b is welded to four urethane tubes 4-B, 4-F, 4-J, and 4-N to connect them to drive unit 5-B; one flexible silicone tube 4-c is welded to four urethane tubes 4-C, 4-G, 4-K, and 4-O to connect them to drive unit 5-C; and one flexible silicone tube 4-d is welded to four urethane tubes 4-D, 4-H, 4-L, and 4-P to connect them to drive unit 5-D. This reduces the number of tubes. Adjacent silicone tubes 4-a and 4-b, and adjacent silicone tubes 4-c and 4-d are welded together in a wavy pattern. This ensures equal crossings across the flow paths across all systems, ensuring symmetry in the flow rates.

[0096] Furthermore, the urethane tubes 4-A, 4-B, 4-C, 4-D, 4-E, 4-F, 4-G, and 4-H and the silicone tubes 4-a, 4-b, 4-c, and 4-d are sandwiched between the urethane sheets 1 and 2 that form the pressure chamber. This significantly reduces friction between these tubes and the object. This is particularly useful for reducing friction in narrow environments under human body load, such as in bedsore prevention devices.

[0097] 1 and 11, (A) is a top view, and (B) is a cross-sectional view taken along line BB in (A). Note that the modification in FIG. 17 is applied to the planar actuator in FIG. 11, but it can also be applied to the planar actuator in FIG. 1.

[0098] In Figure 17, anti-slip members 9-B, 9-C, and 9-D are attached to the outside of upper urethane sheet 1-1 and lower urethane sheet 2-1, which are wider than pressure chambers 3'-B, 3'-C, and 3'-D. Anti-slip members 9-B, 9-C, and 9-D exert a large supporting force (frictional force) at the fixed points shown in Figures 5, 6, and 13 when pressure chambers 3'-B, 3'-C, and 3'-D assume a circular cross-sectional shape under positive pressure. They are made of, for example, foamed thermosetting resin. In this case, it is preferable that the thermosetting resin be thin and have an adhesive sheet on one side for attachment.

[0099] 17, sliding fins 10-A, 10-B, and 10-C are provided at welded portions M1 and M2 of pressure chambers 3'-A, 3'-B, and 3'-C so as to completely cover anti-slip members 9-B, 9-C, and 9-D of pressure chambers 3'-B, 3'-C, and 3'-D. The leftmost pressure chamber 3'-A does not have an anti-slip member, but is provided with sliding fin 10-0 to reduce sliding friction under load. In this case, sliding fins 10-0, 10-A, 10-B, and 10-C are provided to reduce friction and facilitate sliding when not pressurized (atmospheric pressure), and are formed, for example, by adhering sliding tape made of fluororesin or silicone resin to a thin urethane sheet.

[0100] Figure 18 shows the cases where the pressure chambers 3'-A, 3'-B, 3'-C, and 3'-D in Figure 17 are in atmospheric pressure, positive pressure, positive pressure, and atmospheric pressure states (see Figure 13(D)). In this case, in the pressure chambers 3'-B and 3'-C, part of the anti-slip members 9-B and 9-C, i.e., the upper and lower ends, are not covered by the sliding fins 10-A and 10-B, i.e., are exposed, and therefore the frictional force increases, increasing the load-bearing capacity. On the other hand, the pressure chambers 3'-A and 3'-D are covered by the sliding fins 10-A and 10-C, making them more slippery.

[0101] The planar actuator of the above-described embodiment can be used as a transport device and a moving device. That is, if the planar actuator is fixed to a floor or the like, it functions as a transport device, and if the planar actuator is not fixed to a floor or the like, it functions as a moving device.

[0102] Furthermore, because the planar actuator according to the present invention can move under human body load and distribute body pressure, it can be applied to a bedsore prevention device for a narrow environment, as shown in FIG. 19. In FIG. 19, the planar actuator shown in FIG. 1 or 11 is inserted between a person 191 and a flexible bed 192, and the planar actuator is moved up and down by a winding motor 193 controlled by the control unit 6 (FIG. 1). This makes it possible to propel the planar actuator with a load pressure of 24 kPa or more, which is considered to be the area that is prone to developing bedsores, such as the buttocks and scapulae. FIG. 20 shows the results of an experiment under human body load similar to that of the bedsore prevention device. In FIG. 20, the subject sat on a soft chair and moved the planar actuator according to the present invention under the left thigh. As a result, a movement speed of 10 mm / s was measured at a load pressure of 20 kPa, and a movement speed of 8.4 mm / s was measured at a load pressure of 24 kPa.

[0103] The urethane sheet in the above embodiment may be made of a thermoplastic material other than urethane.

[0104] The present invention can be applied to any modifications within the scope of the above-described embodiment. [Industrial Applicability]

[0105] As described above, the present invention can be used as a transport device, a moving device, and a bedsore prevention device in hospitals and the like. [Explanation of symbols]

[0106] 1, 2: Urethane sheet 1-1, 1-2: Upper urethane sheet 2-1, 2-2: Lower urethane sheet 3-A, 3-B, 3-C, 3-D; 3'-A, 3'-B, 3'-C, 3'-D: pressure chamber 4-A, 4-B, 4-C, 4-D: Urethane tube 5-A, 5-B, 5-C, 5-D: Drive unit 6: Control unit 7, 7': Rubber band 8-A, 8-B, 8-C, 8-D: Elastic body 9-B, 9-C, 9-D: Anti-slip material 10-0, 10-A, 10-B, 10-C, 10-D: Sliding fins M1, M2, M3, M4: Welded part E1, E2: Welding end point MA1-1, MA1-2, MA2-1, MA2-2: Anti-weld sheet HP: Heat press machine 100: Planar actuator 1a: Case 111-AU, 111-BU, 111-CU: Upper pressure chamber 111-AL, 111-BL, 111-CL: Lower pressure chamber 112, 112-1, 112-2, 112-3: Urethane sheet 113: Urethane sponge O: Object 200: Planar actuator 201-U: Upper urethane sheet 201-D: Lower urethane sheet 201-0, 201-1, 201-2, ...: Urethane partition sheet 202-A, 202-B, 202-C: Pressure chambers L: One wavelength of the traveling wave (backward wave)

Claims

1. three or more pressure chambers extending in a first direction and arranged in parallel in a second direction different from the first direction; each pressure chamber has a Y-shaped cross section when viewed from the first direction in an atmospheric pressure state, and has a circular cross section when viewed from the first direction in a positive pressure state higher than atmospheric pressure; The planar actuator further comprises a control means for controlling each of the pressure chambers to be in the atmospheric pressure state or the positive pressure state.

2. Each pressure chamber is a first upper sheet provided along the first direction and a second upper sheet narrower than the first upper sheet; a first lower sheet provided along the first direction and a second lower sheet narrower than the first lower sheet; Equipped with one end of the first upper sheet and one end of the second upper sheet are connected at a first connection portion; one end of the first lower sheet and one end of the second lower sheet are connected at a second connection portion; the other end of the first upper sheet and the other end of the first lower sheet are connected at a third connection portion, 2. The planar actuator according to claim 1, wherein the other end of the second upper sheet and the other end of the second lower sheet are connected at a fourth connecting portion.

3. If the width of the first upper sheet is w11, the width of the second upper sheet is w12, the width of the first lower sheet is w21, and the width of the second lower sheet is w22, then: w11 = w21 w12 = w22 3. The planar actuator according to claim 2, wherein:

4. If the width of the first upper sheet is w11, the width of the second upper sheet is w12, the width of the first lower sheet is w21, and the width of the second lower sheet is w22, then: w11 / w12=w21 / w22 3. The planar actuator according to claim 2, wherein:

5. 2. The planar actuator according to claim 1, further comprising an elastic body provided in each of the pressure chambers.

6. a plurality of first tubes connected to one end sides of the pressure chambers of the first group; a plurality of second tubes connected to one end sides of the pressure chambers of a second group different from the first group; a first elastic string member that binds the plurality of first tubes together; a second elastic string member that binds the plurality of second tubes together; Equipped with 2. The planar actuator according to claim 1, wherein the plurality of first tubes and the plurality of second tubes are positioned on opposite sides of the planar actuator in the first direction.

7. (N+1) chamber groups are formed by N (N is a natural number equal to or greater than 3) pressure chambers, 2. The planar actuator according to claim 1, wherein said control means controls said pressure chambers belonging to each of said chamber groups to be in an atmospheric pressure state or in a positive pressure state higher than atmospheric pressure.

8. 8. The planar actuator according to claim 7, wherein one ends of the pressure chambers belonging to each chamber group are connected by a single tube.

9. 9. The planar actuator according to claim 8, wherein the tubes of each adjacent chamber group are crossed in a wavy pattern.

10. 9. The planar actuator according to claim 8, wherein the tube is sandwiched between sheets that form the pressure chamber.

11. moreover, an anti-slip member attached to an outer surface of the first upper sheet and an outer surface of the first lower sheet of each pressure chamber; sliding fins provided at the first connecting portion and the second connecting portion of each pressure chamber; Equipped with When each pressure chamber is in an atmospheric pressure state, the anti-slip member of each pressure chamber is covered by the sliding fin of the pressure chamber preceding or succeeding the pressure chamber, 3. The planar actuator according to claim 2, wherein when each of the pressure chambers is in a positive pressure state, a portion of the anti-slip member of each of the pressure chambers is exposed.

12. A transport device comprising the planar actuator according to claim 1.

13. A moving device comprising the planar actuator according to claim 1.

14. A bedsore prevention device comprising the planar actuator according to claim 1.

15. 3. A method for manufacturing the planar actuator according to claim 2, comprising the steps of: a first step of slitting and bending a first thermoplastic sheet to form the second upper sheet; a second step of scoring and bending a second thermoplastic sheet to form the second bottom sheet; a third step of bonding a first adhesion-preventing sheet, the first upper sheet made of a thermoplastic material, and a second adhesion-preventing sheet to form a first adhesion-preventing sheet / first upper sheet / second adhesion-preventing sheet laminate; a third step of bonding a first adhesion-preventing sheet, the first upper sheet made of a thermoplastic material, and a second adhesion-preventing sheet to form a first adhesion-preventing sheet / first upper sheet / second adhesion-preventing sheet laminate; a fourth step of bonding a third adhesion-preventive sheet, the first lower sheet made of a thermoplastic material, and a fourth adhesion-preventive sheet to form a third adhesion-preventive sheet / first lower sheet / fourth adhesion-preventive sheet laminate; a fifth step of inserting the first adhesive prevention sheet / first upper sheet / second adhesive prevention sheet laminate into the incision in the first thermoplastic sheet; a sixth step of inserting the third adhesive prevention sheet / first bottom sheet / fourth adhesive prevention sheet laminate into the incision in the second thermoplastic sheet; a seventh step of overlapping the first and second thermoplastic sheets after the fifth and sixth steps; an eighth step of adhering the first and second upper sheets and the first and second lower sheets together after the seventh step; a ninth step of removing the second and fourth anti-adhesion sheets between the pressure chambers after the eighth step; A method for manufacturing a planar actuator comprising:

16. 16. The method for manufacturing a planar actuator according to claim 15, wherein the eighth step is a welding step in which welding is performed from above and below using a heat press machine.

17. moreover, 16. A method for manufacturing a planar actuator according to claim 15, further comprising a tenth step, after the eighth step, of cutting open one side of each pressure chamber and inserting an elastic body, and closing the cut-out area after inserting the elastic body.

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