JP2023118572A - Switch structure and medical device - Google Patents

Abstract

To provide a switch structure and a medical device that can improve durability.SOLUTION: A switch structure includes a circuit board having a tact key, and a flexible push button portion having a tact key pressing portion that presses the tact key and a board pressing portion arranged to press the circuit board when the tact key pressing portion presses the tact key. For example, the board pressing portions are arranged on both sides of the tact key pressing portion in a direction orthogonal to the pressing direction in which the tact key is pressed.SELECTED DRAWING: Figure 3

Description

(1) Affiliated company of Fukuda Denshi Co., Ltd. Sale date November 2, 2021 Fukuda Denshi UK limited November 24, 2021 Fukuda Denshi Kinki Sales Co., Ltd. November 26, 2021 Fukuda Denshi West Kanto Sales Co., Ltd. (4 other companies)

The present invention relates to switch structures and medical devices.

Conventionally, a housing having a front panel, a display unit and an operation switch arranged on the front panel are provided, and by pressing the operation switch to conduct electrical contacts provided inside the housing, the display unit is operated. is known as a medical display device that displays biological information.

In such a medical display device, for example, liquid that has entered the interior of the housing through the gap between the front panel and the operation switch can be discharged outside the housing without contacting electronic devices such as electrical contacts. , it is required to ensure drip-proofness. Further, in the switch structure, it is preferable to generate a click feeling in order to give the operator a sense of security that the operation switch has been reliably pressed.

As a switch structure that can ensure drip-proofness, for example, an electrical contact arranged on a circuit board, a contact rubber arranged along the circuit board, and a contact rubber formed to cover the electrical contact It has a dome-shaped and elastically deformable rubber dome portion, an operating element integrally formed with the rubber dome portion, and a contact piece attached to the lower surface of the operating element for pressing the electrical contact, and the rubber dome portion A switch structure capable of ensuring drip-proofness by covering electrical contacts has been disclosed (see Patent Document 1, for example).

Further, as a switch structure capable of obtaining a click feeling, for example, a tactile key (tactile switch) arranged on a circuit board, an elastic deformation portion forming a skirt shape so as to cover the tactile key, and an elastic deformation portion integrally formed. , and a tactile key pressing portion that presses a tact key, and a skirt-shaped elastically deforming portion bends and rebounds when the tact key is pressed, thereby enabling a click feeling to be obtained (for example, , see Patent Document 2).

Japanese Patent Application Laid-Open No. 2021-009782 JP 2005-216609 A

By the way, in the switch structure described in Patent Document 1, when the electrical contact is pressed, the pressing force is applied intensively to the contact piece and the electrical contact. , there is a problem that the durability of the contact piece and the electrical contact is lowered.

In addition, in the switch structure described in Patent Document 2, when the tactile key is pressed, the pressing force is applied intensively to the tactile key pressing portion and the tactile key. There is a problem that the durability of the tact key pressing portion and the tact key is lowered.

SUMMARY OF THE INVENTION An object of the present invention is to provide a switch structure and a medical device capable of improving durability.

In order to achieve the above objects, the switch structure in the present invention is
a circuit board having a tactile key;
a flexible push button portion having a tactile key pressing portion for pressing the tactile key, and a board pressing portion arranged to press the circuit board when the tactile key pressing portion presses the tactile key;
Prepare.

The medical device in the present invention is
A switch structure as described above.

According to the present invention, durability can be improved.

1 is an external perspective view of a medical display device according to an embodiment of the present invention; FIG. 1 is a front view of a front panel of a medical display device according to an embodiment of the present invention; FIG. It is sectional drawing which shows the XZ cross section of switch structure. It is a sectional view showing a YZ section of a switch structure. It is an arrow line view when a push button part is seen from the back side. It is sectional drawing which shows the XZ cross section of a push button part. It is sectional drawing which shows the YZ cross section of a push button part.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a medical display device according to an embodiment of the present invention. The X, Y and Z axes are depicted in FIG. In FIG. 1, the direction from the lower left to the upper right is called the X direction, the horizontal direction, or both directions, the upper right direction is called the "+X direction" or the right side, and the lower left direction is called the "-X direction" or the left side. In FIG. 1, the vertical direction is called the Y direction or the vertical direction, the upward direction is called the "+Y direction" or upward, and the downward direction is called the "−Y direction" or downward. In FIG. 1, the direction from the lower right to the upper left is called the Z direction or the depth direction, the lower right direction is called the "+Z direction" or front side, and the upper left direction is called the "-Z direction" or the back side.

A medical display apparatus 1 shown in FIG. 1 is, for example, a biological information monitor (also referred to as a bedside monitor) that measures and displays biological information such as the heart rate and blood pressure of a patient in a hospital room or an operating room. The medical display device 1 has a main body 10 . The body portion 10 has a display portion 11, an external input terminal group 12, a housing 20, and a push button portion 30 (operation switches). The housing 20 accommodates a control module, a circuit board such as a measurement module, and a battery. The display unit 11 is, for example, a touch panel type liquid crystal display panel, and displays biological information. The external input terminal group 12 has various connectors for connecting a measuring section such as a cuff. The push button unit 30 is, for example, a power standby switch (sub power switch).

The housing 20 has a main body case 21 and a front panel 22 . The main body case 21 accommodates the circuit board and the battery. The front panel 22 is arranged on the front side (+Z direction) of the main body case 21 . A display unit 11 is attached to the front side of the front panel 22 . A thermoplastic resin such as a mixed material of PC resin (polycarbonate resin) and ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin) is used for each material of the main body case 21 and the front panel 22 .

FIG. 2 is a front view of the front panel of the medical display device. As shown in FIGS. 1 and 2, front panel 22 has a rectangular peripheral edge 23 . The peripheral edge portion 23 has a left edge portion 23A and a right edge portion located on the left side (−X direction), right side (+X direction), upper side (+Y direction) and lower side (−Y direction) of the rectangular central portion. 23B, an upper edge 23C and a lower edge 23D.

FIG. 3 is a sectional view showing the XZ section of the switch structure. FIG. 4 is a sectional view showing the YZ section of the switch structure. As shown in FIGS. 3 and 4, a circuit board 25 having a tactile key 26 is arranged on the far side (-Z direction) of the lower edge portion 23D of the front panel 22. As shown in FIG. The circuit board 25 is fixed with screws to the lower edge portion 23D. The lower edge portion 23D has a cylindrical hole 22A that is arranged opposite to the position of the tact key 26 and penetrates in the depth direction (Z direction). The cylindrical hole 22A has a peripheral wall portion 22B extending from the opening peripheral edge portion 22C to the far side (-Z direction). The front end (+Z direction) of the peripheral wall portion 22B is continuous with the opening peripheral edge portion 22C of the tubular hole 22A.

As shown in FIGS. 3 and 4, the switch structure 3 includes a front panel 22, a circuit board 25, a push button portion 30, and an elastic deformation portion 33. As shown in FIG. Silicon rubber, for example, is used as the material of each of the push button portion 30 and the elastic deformation portion 33 .

FIG. 5 is an arrow view when the push button portion is viewed from the back side. FIG. 6 is a sectional view showing an XZ section of the push button portion. FIG. 7 is a sectional view showing a YZ section of the push button portion. As shown in FIG. 5, the push button portion 30 is formed in the shape of an elliptical column whose major axis is in the horizontal direction (X direction). As shown in FIGS. 6 and 7, the elliptical columnar axis of the push button portion 30 has an elliptical columnar portion 31 extending in the depth direction (Z direction). As shown in FIGS. 3 and 4 , the elliptical cylindrical portion 31 is arranged on the front side (+Z direction) of the tactile key 26 . The elliptical cylindrical portion 31 is inserted through the tubular hole 22A. The front end (+Z direction) of the elliptical columnar portion 31 is surrounded by the opening peripheral edge 22C of the cylindrical hole 22A and coincides with the opening peripheral edge 22C in the depth direction (Z direction).

As shown in FIGS. 5, 6 and 7, the rear (−Z direction) end of the elliptical cylindrical portion 31 has a tactile key pressing portion 37 and a board pressing portion 38 . The end of the elliptical cylindrical portion 31 on the far side (−Z direction) has a circumferential groove 32 surrounding the tactile key pressing portion 37 . The groove depth direction of the circumferential groove 32 is the depth direction (Z direction), and the groove depth from the inner end surface is set to 5.0 [mm], for example.

As shown in FIGS. 3 to 7, the tactile key pressing portion 37 is separated from other portions (including the substrate pressing portion 38) of the cylindroid portion 31 by the circumferential groove 32. As shown in FIG. The tact key pressing portion 37 is arranged in the central portion of the cylindric shape in the major axis direction (X direction) so as to face the tact key 26 in the depth direction (Z direction). As a result, when the push button portion 30 is pushed to the far side (-Z direction), the tactile key pressing portion 37 presses the tact key 26 . Hereinafter, the far side (-Z direction) will be referred to as the "pressing direction". The XY cross section of the tactile key pressing portion 37 has an elliptical shape. The back side end surface of the tactile key pressing portion 37 is a plane orthogonal to the depth direction (Z direction). The gap between the rear end surface of the tact key pressing portion 37 and the tact key 26 is set to 0.2 [mm], for example. The amount of movement of the tact key 26 is set to 0.2 [mm], for example.

As shown in FIG. 5, the substrate pressing portion 38 is arranged on the right side (+X direction) and left side (−X direction) of the tactile key pressing portion 37 in the major axis direction (X direction) of the elliptical cylinder. The substrate pressing portion 38 is separated from the tactile key pressing portion 37 by the circumferential groove 32 , but is formed continuously without being separated from the other portions of the cylindric columnar portion 31 . The XY cross section of the substrate pressing portion 38 arranged on the right side of the tactile key pressing portion 37 has the shape of the right half of an ellipse. The XY cross section of the board pressing portion 38 arranged on the left side of the tactile key pressing portion 37 has the shape of the left half of an ellipse. As shown in FIGS. 3 and 6, each of the right and left substrate pressing portions 38 tapers toward the back side (+Z direction). The inner end surfaces of the right and left substrate pressing portions 38 are planes orthogonal to the depth direction (Z direction). A gap between the inner end surface of each of the right and left board pressing portions 38 and the circuit board 25 is set to, for example, 1.0 [mm] from the viewpoint of obtaining a click feeling through experiments and simulations. As a result, when the tactile key 26 moves 0.2 mm toward the back side (−Z direction), that is, when each of the tact key pressing portion 37 and the substrate pressing portion 38 moves 0.4 mm toward the back side (−Z direction), The gap between the back end face of the board pressing portion 38 and the circuit board 25 is 0.6 mm, which is the subtracted value obtained by subtracting this 0.4 mm from the gap of 1.0 mm. From this state, when the substrate pressing portion 38 moves (0.6+α) mm (where α>0) to the far side (−Z direction), the substrate pressing portion 38 presses the circuit board 25 . In other words, the deflection of the substrate pressing portion 38 is α mm. At this time, the tact key pressing portion 37 also moves (0.6+α) mm to press the tact key 26 . In other words, the deflection of the tact key pressing portion 37 is (0.6+α) mm. If the total length of the tactile key pressing portion 37 in the depth direction (Z direction) is equal to the total length of the substrate pressing portion 38 in the depth direction (Z direction) (total length = L), the distortion of the tactile key pressing portion 37 is (0. 6+α)/L, and the strain of the substrate pressing portion 38 is α/L. Therefore, the strain of the tactile key pressing portion 37 is larger than the strain of the board pressing portion 38 . The operation force applied to the push button portion 30 is distributed between the pressing force for pressing the tact key 26 via the tact key pressing portion 37 and the pressing force for pressing the circuit board 25 via the board pressing portion 38, thereby From the viewpoint of preventing the pressing force for pressing the tactile key 26 from becoming an excessive load that exceeds the withstand load of the tactile key 26, the tactile key pressing portion 37 and the substrate pressing portion 38 may begin to bend at the same time. Since the tactile key pressing portion 37 should be bent to some extent before the pressing portion 38 is bent, the strain of the tactile key pressing portion 37 should be equal to or greater than the strain of the substrate pressing portion 38 .

As shown in FIGS. 3 to 7, the elastic deformation portion 33 is formed integrally with the push button portion 30. As shown in FIG. The elastically deforming portion 33 has a skirt portion 34 that spreads in a skirt shape toward the back side (−Z direction) so as to cover the tactile key 26 together with the elliptical columnar portion 31 from the front side (+Z direction). When the push button portion 30 is pushed inward (-Z direction), the skirt portion 34 bends against the restoring force and rebounds due to the restoring force. As a result, the elastically deforming portion 33 urges the push button portion 30 pushed to the far side (−Z direction) toward the near side (+Z direction). The thickness of the skirt portion 34 is set to, for example, 0.5 [mm] from the viewpoint of obtaining a click feeling through experiments and simulations.

A waist portion 34 a of the skirt portion 34 is connected to the rear end of the peripheral wall portion of the elliptical columnar portion 31 . A hem portion 35 of the skirt portion 34 has a seal portion 36 disposed so as to close a gap S1 (see FIGS. 3 and 4) between the peripheral wall portion 22B of the cylindrical hole 22A and the circuit board 25. As shown in FIG. As shown in FIGS. 3, 4, and 5, the seal portion 36 has an elliptical outer shape with its major axis extending in the horizontal direction (X direction) and a thickness in the depth direction (Z direction).

As shown in FIGS. 3 and 4, the thickness of the seal portion 36 in the depth direction (Z direction) is set larger than the width of the gap S1. As a result, since the seal portion 36 is sandwiched and compressed from both sides in the depth direction (Z direction) by the peripheral wall portion 22B and the circuit board 25, the seal portion 36 is in close contact with the inner end of the peripheral wall portion 22B and the circuit board 25, respectively. do. A closed space 40</b>A is formed between the peripheral wall portion 22</b>B and the cylindric columnar portion 31 by the sealing portion 36 coming into close contact with the rear end of the peripheral wall portion 22</b>B. A lower (−Y direction) wall portion of the peripheral wall portion 22B has a drain hole 22D (see FIG. 4). Liquid may enter the closed space 40A through the gap between the elliptical columnar portion 31 and the opening peripheral portion 22C of the cylindrical hole 22A. In this case, the liquid that has entered falls downward inside the closed space 40A. That is, the liquid collects on the lower wall of the peripheral wall 22B. The collected liquid is discharged outside the closed space 40A through the drain hole 22D.

In addition, a closed space 40B closed by the elliptical columnar portion 31, the skirt portion 34, and the circuit board 25 is formed by closing the gap S1 with the seal portion 36. As shown in FIG. As shown in FIGS. 4 and 5, a communication hole 36a is arranged between the seal portion 36 and the circuit board 25 to communicate the inside and the outside of the closed space 40B. The communication holes 36a are arranged at the center of the elliptical shape in the horizontal direction (X direction) and at both ends in the vertical direction (Y direction). The communication hole 36a is formed by recessing the surface of the sealing portion 36 on the back side (−Z direction) that contacts the circuit board 25 toward the front side (+Z direction). Due to the arrangement of the communication hole 36a, no pressure difference occurs between the inside and outside of the closed space 40B. In addition, since the closed space 40B is separated from the closed space 40A by the skirt portion 34, the liquid inside the closed space 40A does not enter the closed space 40B. No infiltration.

The switch structure 3 according to the above embodiment includes a circuit board 25 having a tact key 26, a tact key pressing portion 37 that presses the tact key 26, and when the tact key pressing portion 37 presses the tact key 26, the circuit board 25 is pressed. and a push button portion 30 having a substrate pressing portion 38 arranged as follows.

According to the above configuration, the operating force applied to the push button portion 30 is dispersed into the pressing force that presses the tact key 26 via the tact key pressing portion 37 and the pressing force that presses the circuit board 25 via the substrate pressing portion 38. . As a result, for example, the pressing force for pressing the tactile key 26 does not become an excessive load exceeding the withstand load of the tactile key 26, so that the durability of the switch structure 3 can be improved.

Further, in the switch structure 3 according to the above-described embodiment, the board pressing portion 38 is arranged on both sides of the tactile key pressing portion 37 in the direction orthogonal to the pressing direction (−Z direction). When the push button section 30 is operated, the push button section 30 may move in a direction oblique to the pressing direction (-Z direction). However, in this case, the tactile key pressing portion 37 presses the tact key 26 , and the board pressing portion 38 arranged on at least one of both sides of the tactile key pressing portion 37 presses the circuit board 25 . As a result, the operating force applied to the push button portion 30 is distributed between the pressing force for pressing the tact key 26 and the pressing force for pressing the circuit board 25, so that the durability of the switch structure 3 can be improved.

Further, in the switch structure 3 according to the above-described embodiment, the push button portion 30 is formed in an elliptical columnar shape, and has the elliptical columnar portion 31 in which the columnar axis of the elliptical columnar shape extends in the pressing direction (−Z direction). Each of the tactile key pressing portion 37 and the substrate pressing portion 38 is arranged at an end portion of the elliptical cylindrical portion 31 in the pressing direction. The board pressing portions 38 are arranged on both sides of the tactile key pressing portion 37 in the major axis direction of the elliptical cylinder. When the push button portion 30 is operated, it is preferable to press the center of the elliptical columnar portion in the major axis direction, but there are cases where the end of the elliptic columnar portion in the major axis direction is pressed. In this case, the elliptical columnar portion moves obliquely with respect to the pressing direction. However, even in this case, the tactile key pressing portion 37 presses the tactile key 26 , and the board pressing portion 38 arranged on at least one of both sides of the tactile key pressing portion 37 in the longitudinal direction presses the circuit board 25 . As a result, the operating force applied to the push button portion 30 is dispersed into the pressing force that presses the tact key 26 and the pressing force that presses the circuit board 25 . As a result, the durability of the switch structure 3 can be improved.

Further, in the switch structure 3 according to the above embodiment, the elliptical columnar portion 31 has the circumferential groove 32 surrounding the tactile key pressing portion 37 . The circumferential groove 32 separates the tactile key pressing portion 37 from the substrate pressing portion 38 arranged around the tactile key pressing portion 37 . As a result, even if the substrate pressing portion 38 is bent due to the reaction force from the circuit board 25 , the tactile key pressing portion 37 is not affected by the bending of the substrate pressing portion 38 . Further, even if the tactile key pressing portion 37 is bent by the reaction force from the tact key 26, the substrate pressing portion 38 is not affected by the bending of the tactile key pressing portion 37. FIG. This makes it easy to set the gap between the board pressing portion 38 and the circuit board 25 to obtain a click feeling or to improve durability, for example.

Further, in the switch structure 3 according to the above-described embodiment, the elastically deformable portion 33 has the skirt portion 34 that spreads like a skirt so as to cover the tactile key 26 together with the elliptical cylindrical portion 31 . Further, the hem portion 35 of the skirt portion 34 has a seal portion 36 arranged so as to close the gap S1 between the peripheral wall portion 22B of the cylindrical hole 22A and the circuit board 25. As shown in FIG. As a result, for example, even if liquid enters through a gap between the opening peripheral edge portion 22C of the cylindrical hole 22A and the elliptical columnar portion 31, the tactile key 26 is covered with the skirt portion 34 and the elliptical columnar portion 31, and a seal is maintained. Since the gap S1 between the peripheral wall portion 22B of the tubular hole 22A and the circuit board 25 is closed by the portion 36, it is possible to secure the drip-proof property of the tact key 26. FIG.

Further, in the switch structure 3 according to the above-described embodiment, between the seal portion 36 and the circuit board 25, the closed space 40B closed by the cylindroid portion 31, the skirt portion 34, and the circuit board 25 is provided. A communication hole 36a is arranged to communicate with the outside. By arranging the communication hole 36a, no pressure difference occurs between the inside and outside of the closed space 40B. As a result, the skirt portion 34 bends and repels without being affected by the pressure difference, so that a sufficient click feeling can be obtained.

Further, in the switch structure 3 according to the above-described embodiment, the board pressing portions 38 arranged on the right and left sides of the tactile key pressing portion 37 are tapered toward the back side (+Z direction). As a result, when the board pressing part 38 presses the circuit board 25, the board pressing part 38 gradually becomes difficult to bend. As described above, at the initial stage when the operating force applied to the push button portion 30 is dispersed into the pressing force for pressing the tact key 26 via the tact key pressing portion 37 and the pressing force for pressing the circuit board 25 via the board pressing portion 38, , the ratio of sharing the operating force can be made smaller on the substrate pressing portion 38 side than on the tactile key pressing portion 37 side. Therefore, since the operating force does not suddenly increase, the operability is not deteriorated. On the other hand, at the final stage when the operating force is dispersed, the proportion of the operating force shared by the substrate pressing portion 38 side can be made larger than that on the tact key pressing portion 37 side. Therefore, since the pressing force for pressing the tactile key 26 is prevented from becoming an excessive load exceeding the withstand load of the tactile key 26, the durability of the switch structure 3 can be further improved.

In the switch structure 3 according to the above-described embodiment, the communication hole 36a is formed by recessing the surface of the sealing portion 36 on the back side (−Z direction) that contacts the circuit board 25 toward the front side (+Z direction). However, the present invention is not limited to this. For example, the circuit board 25 in contact with the seal portion 36 may be formed by recessing the surface on the front side (+Z direction) toward the back side (−Z direction). may For example, it may be recessed by forming a through hole in the circuit board 25 .

Further, in the switch structure 3 according to the above-described embodiment, the present invention is applied to a biological information monitor, but the present invention is not limited to this, and can be effectively applied to a wide range of medical devices, for example. Especially in medical equipment, drip-proofness and durability are required, so the switch structure of the present invention is very effective.

In addition, each of the above-described embodiments is merely an example of specific implementation of the present invention, and the technical scope of the present invention should not be construed as being limited by these. . Thus, the invention may be embodied in various forms without departing from its spirit or essential characteristics.

INDUSTRIAL APPLICABILITY The present invention is suitably used for medical equipment having a switch structure that requires improved durability.

Reference Signs List 1 medical display device 3 switch structure 10 main body 11 display 12 external input terminal group 20 housing 21 main body case 22 front panel 22A cylindrical hole 22B peripheral wall 22C opening peripheral edge 22D drain hole 23 peripheral edge 23A left edge 23B Right edge 23C Upper edge 23D Lower edge 25 Circuit board 26 Tact key 30 Push button (operation switch)
31 Cylindrical portion 32 Circumferential groove 33 Elastic deformation portion 34 Skirt portion 34a Waist portion 35 Bottom portion 36 Seal portion 36a Communication hole 37 Tact key pressing portion 38 Board pressing portion 40A, 40B Closed space

Claims (8)

a circuit board having a tactile key;
a flexible push button portion having a tactile key pressing portion for pressing the tactile key, and a board pressing portion arranged to press the circuit board when the tactile key pressing portion presses the tactile key;
comprising
switch structure. When the tactile key pressing part presses the tactile key and the board pressing part presses the circuit board, the strain of the tactile key pressing part is configured to be greater than or equal to the strain of the board pressing part.
The switch structure according to claim 1. The substrate pressing portion is arranged on both sides of the tactile key pressing portion in a direction orthogonal to the pressing direction in which the tactile key is pressed.
3. A switch structure according to claim 1 or 2. The push button portion has an elliptical columnar portion formed in an elliptical columnar shape, the columnar axis of the elliptical columnar shape extending in the pressing direction,
each of the tactile key pressing portion and the substrate pressing portion is arranged at an end portion of the elliptical cylindrical portion in the pressing direction,
The board pressing portion is arranged on both sides of the tactile key pressing portion in the major axis direction of the elliptical cylindrical shape.
The switch structure according to claim 3. further comprising an elastically deforming portion integrally formed with the push button portion and biasing the push button portion pressed in the pressing direction in a direction opposite to the pressing direction;
The elastic deformation portion has a skirt portion that spreads like a skirt so as to cover the tactile key together with the elliptical cylindrical portion,
The switch structure according to claim 4. Further comprising a panel having a cylindrical hole through which the elliptical columnar part is inserted and arranged opposite to the position of the tact key,
the hem of the skirt portion has a seal portion arranged to block a gap between the peripheral wall portion of the cylindrical hole and the circuit board;
The switch structure according to claim 5. Between the seal portion and the circuit board, a communication hole that communicates the inside and the outside of a closed space closed by the elliptical columnar portion, the skirt portion, and the circuit board is arranged.
The switch structure according to claim 6. A medical device comprising a switch structure according to any one of claims 1-7.