JPH0535790B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an air switching valve that periodically switches an air flow path, particularly to an air switching valve used in an air mat for preventing bedsores.

[Background Art] As an air mat for preventing bedsores, two air sac groups 5A and 5B are arranged alternately in parallel as shown in Fig. 5, and both air sac groups 5A and 5B are inflated and contracted alternately. There is something like this. This means that when one air sac group (for example, 5A) is inflated, the other air sac group 5B located between these air sac groups 5A is contracted, and conversely, the other air sac group 5A is inflated. When air sac group 5B is inflated, one air sac group 5A
By periodically repeating this action, the causes of bedsores, such as poor blood circulation and poor air circulation, which cause bedsores, are eliminated.

When supplying air to such an air mat, it is conceivable to interpose a solenoid valve between the air pump and the air mat and supply air by controlling the solenoid valve, but it is possible to switch periodically. Considering this, it is simpler to drive a rotary valve with a motor than with an electromagnetic valve that requires control using a timer or the like. That is, as shown in Fig. 5, one port (pump port 2P) of a 4-port rotary valve is connected to pump P,
Two ports (connection ports 25a, 25b) are opened to each air sac group 5A, 5B, the remaining port (exhaust port 21) is opened to the atmosphere, and two adjacent ports can be connected to the valve body. A pair of communication parts are provided, and as the valve body rotates, each air sac group 5A, 5
The ports 25a and 25b connected to B are sequentially connected to the pump port 2P and the exhaust pump port 21 through the communication portion.

Generally used rotary valves include a fixed elastic body type shown in FIG. 8 and a rotating elastic body type shown in FIG. 9. In the elastic body fixed type, the rotating body 1 and the base 2 are pressed together by an elastic body 19 disposed between the reducer 6 and the base 2, and the rotating body 1 is rotated by the output shaft 61 of the reducer 6. Note that with this structure, the elastic body 19 does not rotate.
However, since the output shaft 61 needs to have a length that passes through the elastic body 19 and the base 2 and reaches the rotating body 1,
If the output shaft 61 becomes very long and a force is applied to the tip of the output shaft 61, a large moment will be applied to the reducer 6, resulting in a disadvantage that the life of the reducer 6 will be shortened.

What has been proposed is an elastic body rotation type. In this elastic body rotating type, as in the elastic body fixed type, the rotating body 1 and the base 2 are pressed together by the elastic body 19 disposed between the reducer 6 and the base 2, and the output shaft 61 of the reducer 6 The rotating body 1 is configured to rotate. Therefore, the output shaft 61 for rotating the rotating body 1 can be shortened, and the reduction gear 6 has the advantage of having a long life. By the way, in this elastic body rotating type, since the rotating body 1 is located between the base 2 and the elastic body 19, the elastic body 19 rotates together with the rotating body 1. Therefore, a sliding surface is created between the sliding body 18 and the plate-shaped body 27 in addition to the sliding surface between the rotating body 1 and the base plate 2. Here, the rotating plate 1 is directly driven by the output shaft 61 and therefore continuously rotates, but the sliding body 18 is driven via the elastic body 19 and therefore does not continuously rotate. In other words, the sliding body 18 is prevented from sliding due to static frictional force with the plate-shaped body 27, but when the upper part of the elastic body 19 continuously rotates together with the rotary body 1, the elastic body 19 is twisted, and this torsion is repelled. When a force is applied to rotate the sliding body 18 and this torsional force exceeds the static frictional force acting between it and the plate-shaped body 27, the sliding body 18 resists the static frictional force between it and the plate-shaped body 27. This is because it slides and rotates. and,
When the rotation of the sliding body 18 reduces the torsional repulsive force of the elastic body 19, the rotation of the sliding body 18 stops. By repeating this operation, the sliding body 18
rotates intermittently as if skipping. At this time,
Impact noise and vibration are generated on the sliding surface between the sliding body 18 and the plate-like body 27, and when used in an air mat for preventing bedsores, the vibration is transmitted to the exterior case, becoming a source of noise in a quiet bedroom in the middle of the night. Disturbs user's sleep. In addition, by twisting the elastic body 19,
The repulsive force in the compression direction becomes weaker, causing the rotating body 1 to move to the base 2.
In addition, the pressing force on the sliding body 18 is reduced.
Since it rotates intermittently, as if skipping, there was a problem with air leakage.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and its object is to provide an air switching valve with less impact noise and vibration, and with less air leakage.

[Disclosure of the Invention] (Structure) The present invention includes a base including a pump port, an exhaust port, and a pair of connection ports, and a base that is rotatably driven with respect to the base and is disposed approximately in the center. A rotating body with a pair of communication parts that connect adjacent ports of the base plate as it rotates, and a stepped cylindrical shape with a small diameter on the rotating body side and a large diameter on the opposite side. It consists of a sliding body disposed at a position facing the body, and an elastic body disposed between the rotating body and the sliding body and around the small diameter part of the sliding body to press the rotating body against the base, and the above-mentioned separate body A rotating body, an elastic body, and a sliding body are rotated together, and by continuously rotating the sliding body together with the rotating body and the elastic body without using the elastic body, intermittent rotation is achieved so that the sliding body skips. This eliminates the impact noise and vibrations caused by this, and also eliminates the intermittent rotation of the sliding body and the twisting of the elastic body, thereby reducing air leakage.

(Embodiment) An embodiment of the present invention is shown in FIGS. 1 to 7.
The air switching valve of this example has pump port 2P.
, an exhaust port 21, and a pair of connection ports 25
The rotating body 1 is rotatably driven by a synchronous motor M via a speed reducer 6. The base 2 is formed in a cylindrical shape with a peripheral wall 26 at the bottom, and a plate-shaped body 2 is provided at the lower end opening of the peripheral wall 26.
7 is disposed, and a reducer 6 and a motor M are disposed under this plate-like body 27 in an overlapping manner. Rotating body 1
is supported by the gear carriage 11 and is disposed in a space surrounded by the peripheral wall 26 of the base 2. This rotary body 1 is rotatable relative to the base 2 by meshing with the gear block 11 into which the shaft 28, whose both ends are supported by the base 2 and the plate-shaped body 27, is fitted, with some play. , and is pressed against the base 2 by an elastic body 19 formed of a compression coil spring or the like, which is disposed between the plate-shaped body 27 and the plate-like body 27 . A gear 16 attached to the lower part of the gear block 11 meshes with a gear 60 attached to the output shaft 61 of the reducer 6, and the rotating body 1 is brought into close contact with the base 2 by the rotation of the motor M. The gear block 11 is rotated around the shaft 28 thereof. On the lower surface of this rotating body 1, a fourth
As shown in the figure, the protrusion 12 is integrally formed. The sliding body 18 has a stepped cylindrical shape with a small diameter on the rotary body 1 side and a large diameter on the opposite side, and is disposed at a position facing the rotary body 1, and the protrusion 80 that engages with the protrusion 12 of the rotary body 1 is located on the small diameter portion. It is formed in Elastic body 1
9 is between the rotating body 1 and the sliding body 18 and is located between the rotating body 1 and the sliding body 18
The rotating body 1 is placed around the small diameter portion of the base plate 2 and is pressed against the base plate 2. By meshing the protrusions 12 and 80, the separate rotating body 1, sliding body 18, and elastic body 19 rotate together.

As shown in FIG. 3, a pump port 2 connected to a pump P is provided on the contact surface of the base 2 with the rotating body 1.
P, a pair of ports 25a and 25b connected to the two air sac groups 5A and 5B, and an exhaust port 21 open to the atmosphere, a total of four ports are open on the same circumference. The pump port 2P and one port 25b are connected to the rotating body 1 indicated by the chain line arrow in the figure.
In the rotational direction of the rotary body 1, the central angle is widened in a direction opposite to the rotational direction of the rotating body 1, and the central angle is made larger than that of the exhaust port 21 and the other port 25a.

On the other hand, as shown in FIG.
0 and 10 are both formed as arcuate grooves. Both communication parts 10, 10 are point symmetrical with respect to the rotation center, and by being rotationally driven with respect to the base 2, each communication part 10, 10 communicates between adjacent ports on the base 2. To go.

Assuming that the state shown in FIG. 6a is a state where each rotation is 0°, at this time, the pump port 2P and the port 25b connected to the air sac group 5B are communicated with each other through one of the communication portions 10, and the air is exhausted. Port 21 and port 25a connected to air sac group 5A are in communication. Therefore, the air sac group 5B is in an expanded state due to the air sent from the pump P, and the air sac group 5A is in an expanded state.
is in a contracted state due to exhaust through the exhaust port 21. When the rotating body 1 rotates 30 degrees from this state, the communication parts 10, 10
Since only the ports 25b and 25a are overlapped, respectively, the air sac groups 5B and 5A maintain the above state.

When the rotating body 1 further rotates by 30° and the rotation angle becomes 60°, as shown in FIG. 6c, one of the communicating portions 10 still overlaps only the port 25b; In the other communicating portion 10, since the central angle of the pump port 2P is made large,
Since the port 25a and the pump port 2P are communicated with each other, the air sac group 5A is expanded. When the rotation angle of the rotating body 1 reaches 90°, the air sac group 5
B contracts. In other words, the air sac group 5A expands before the air sac group 5B contracts.

When the rotation angle of rotating body 1 reaches 120°, the sixth
As shown in FIG. When the angle reaches 150°, as shown in FIG. 6f, one communicating portion 10 still overlaps only the exhaust port 21, while the other communicating portion 10 overlaps only the exhaust port 25b. Since the central angle is made large, the air sac group 5B expands because the port 25b and the pump port 2P are communicated with each other. When the rotation angle of the rotating body 1 reaches 180°, as shown in FIG. 6a, the air sac group 5A
contracts. In other words, the air sac group 5B expands before the air sac group 5A contracts.
In FIG. 6, the chain arrow indicates the direction of rotation of the rotating body 1, the white arrow indicates the flow of air from the pump P, and the solid arrow indicates the flow of discharged air.

FIG. 7 shows a time chart of air pressure changes in both air sac groups 5B and 5A. The broken line in the figure indicates the inflow of air. As is clear from the figure, the timing of suction and expulsion in both air sac groups 5B, 5A is different, and before one air sac group 5A, 5B starts to contract, the other air sac group 5B, 5A starts to contract. In addition, the inflation time in both air sac groups 5A and 5B is the same (T = T ₁ + T ₂ ), and the air inflow time to each air sac group 5A and 5B (T ₀ = Ta +
The same is true for Tb). Moreover, each port 25a,
When the port 25b overlaps the communicating portion 10, it always overlaps only one of the communicating portions 10, so that no pressure interference occurs between the ports 25a and 25b. Further, in this air switching valve, one cycle of suction and discharge for each air pouch group 5A, 5B is made by half a revolution of the rotating body 1.

[Effects of the Invention] As described above, the present invention includes a base including a pump port, an exhaust port, and a pair of connection ports, and is driven to rotate with respect to the base, and as the base rotates, the adjacent bases are rotated. It consists of a rotating body with a pair of communicating parts that communicate the ports, an elastic body that presses the rotating body against the base, and a sliding body that is disposed at a position facing the rotating body with the elastic body in between. Since the separate rotating body, elastic body, and sliding body are rotated together, the sliding body does not rotate through the elastic body, but continuously rotates together with the rotating body and the elastic body. Intermittent rotation such as skipping can be prevented, thereby eliminating impact noise and vibration.
Moreover, since intermittent rotation of the sliding body and twisting of the elastic body do not occur, air leakage can be reduced.In addition, since the sliding body and the driving body are constructed as separate bodies, the driving body tends to be tilted at an angle during operation. no force is generated,
There is no uneven contact between the sliding body and the sliding surface, and the bearing part does not wear unevenly, so wear of the bearing part can be minimized.
It has the effect of prolonging life.

[Brief explanation of the drawing]

FIGS. 1 a to c are a plan view, a front view, and a cutaway front view of an embodiment of the present invention, FIGS. A plan view, FIG. 4 is an exploded perspective view of the same as above, FIG. 5 is a plan view showing the state of use of the same, FIGS. 6 and 7 are explanatory diagrams of the same as above, respectively, and FIG. 8 is a conventional elastic body fixing. Figures 9a to 9c are plan views of a conventional elastic body rotating type air switching valve;
They are a front view and a cutaway front view. 1 is a rotating body, 2 is a base, 10 is a communication part, 12,
80 is a protrusion, 18 is a sliding body, 19 is an elastic body, 2P
is the pump port, 21 is the exhaust port, 25a, 2
5b is a connection port.

Claims (1)

[Claims] 1. A base including a pump port, an exhaust port, and a pair of connection ports, and a drive body that is rotatably driven with respect to the base and is disposed approximately in the center. and a rotating body having a pair of communication parts that communicate the adjacent ports of the base board with this rotation, and a stepped cylindrical shape having a small diameter on the side of the rotating body and a large diameter on the opposite side and facing the rotating body. It consists of a sliding body arranged at a position, and an elastic body disposed between the rotating body and the sliding body and around the small diameter part of the sliding body to press the rotating body against the base, and the above-mentioned separate rotating body and An air switching valve characterized by consisting of an elastic body and a sliding body that rotate together. 2. The air switching valve according to claim 1, wherein projections are formed on the rotating body and the sliding body, and the projections are engaged with each other to rotate the rotating body and the sliding body.