JP7709692B2 - Piezoelectric Valve - Google Patents

Description

The present invention relates to a piezoelectric valve that uses the displacement of a piezoelectric element to open and close the valve.

Conventionally, piezoelectric valves that use the displacement of a piezoelectric element to open and close the valve and eject compressed gas are well known (see Patent Documents 1 and 2).

The piezoelectric valves described in Patent Documents 1 and 2 are equipped with an actuator that utilizes the characteristics of a piezoelectric element, which has excellent high-speed response performance, and the actuator is equipped with a displacement magnification mechanism that magnifies the small displacement of the piezoelectric element based on the principle of leverage.

The piezoelectric valve has excellent responsiveness, so when it is used as an ejector valve in an optical sorting machine for granular materials such as rice grains to remove defective products, it is less likely that good products will be removed as well, and it has been found from tests and experience that the rate of defective products mixed in with the removed defective products is higher than with electromagnetic valves.

When the piezoelectric valve is used as an ejector valve for the optical sorting machine, for example, as described in Patent Document 2, it is directly and continuously attached to a manifold having an internal space to which compressed air is supplied from a compressed air source, and multiple nozzle holes are opened at the tip of the ejector.

However, in the piezoelectric valves described in Patent Documents 1 and 2, the valve seat plate to which the actuator is fixed is housed inside the case of the valve body, and the actuator is equipped with a complex displacement magnification mechanism having an arm, a leaf spring, etc., and since the thickness and width dimensions of the actuator cannot be reduced, when multiple air exhaust ports are provided, it is difficult to reduce the pitch of the air exhaust ports.

The inventors therefore proposed a piezoelectric valve in which the actuator is equipped with a displacement magnification mechanism with a simple structure (see Patent Document 3; hereinafter referred to as the "prior invention").

The piezoelectric valve of the prior invention allows the thickness and width dimensions of the actuator to be smaller than conventional ones, so when multiple actuators are used, the pitch of the air outlets can be made smaller than in conventional piezoelectric valves.

However, when a drive voltage was applied to the piezoelectric element in the actuator of the piezoelectric valve of the previous invention, and the displacement of the valve element was measured when the piezoelectric element was expanded to drive the valve element to open, ripples were confirmed to occur in the displacement waveform, raising concerns that compressed air may not be able to be discharged stably from the air outlet, and there is therefore room for further improvement.

JP 2017-51894 A JP 2015-137664 A Patent Application No. 2020-154308

The present invention is an improvement over the piezoelectric valve of the previous invention, and aims to provide a piezoelectric valve that reduces ripples that occur in the displacement waveform of the valve body in the actuator and can stably discharge compressed gas from the gas outlet.

In order to achieve the above object, the present invention provides
An actuator that drives the valve body;
a valve seat plate having a valve seat and a discharge passage that are movable toward and away from the valve body and that fixes the actuator;
A piezoelectric valve including a main body case that houses the valve seat plate,
The actuator comprises:
a base portion fixed to the valve seat plate;
a piezoelectric element having one end connected to the mounting surface of the base and extending in a first longitudinal direction;
a support portion that is integrally provided on the base portion and extends in a second longitudinal direction that intersects with the first longitudinal direction alongside the piezoelectric element;
an action portion connected to the other end of the piezoelectric element and the tip end of the support portion, and displaced in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction in response to expansion and contraction of the piezoelectric element;
The valve body is provided on a side of the action portion in the direction of the displacement, and is driven by the displacement of the action portion,
the support portion has a constricted portion at an intermediate portion extending in the second longitudinal direction, and is fixed to the valve seat plate by utilizing an attachment hole provided between the constricted portion and the base portion,
The main body case includes:
a gas supply port through which compressed gas is supplied;
a gas exhaust port that exhausts the compressed gas supplied from the gas supply port through the exhaust path of the valve seat plate by separating the valve body from the valve seat;
The present invention is characterized by comprising:

In order to achieve the above object, the present invention provides a method for producing a liquid crystal display comprising:
A plurality of actuators each individually driving a plurality of valve bodies in a parallel plane;
a valve seat plate having a plurality of valve seats and discharge paths that are respectively connected to and separated from the plurality of valve bodies and that fixes the plurality of actuators;
A piezoelectric valve including a main body case that houses the valve seat plate,
Each of the plurality of actuators is
a base portion fixed to the valve seat plate;
a piezoelectric element having one end connected to the mounting surface of the base and extending in a first longitudinal direction;
a support portion that is integrally provided on the base portion and extends in a second longitudinal direction that intersects with the first longitudinal direction alongside the piezoelectric element;
an action portion connected to the other end of the piezoelectric element and the tip end of the support portion, and displaced in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction in response to expansion and contraction of the piezoelectric element;
The valve body is provided on a side of the action portion in the direction of the displacement, and is driven by the displacement of the action portion,
the support portion has a constricted portion at an intermediate portion extending in the second longitudinal direction, and is fixed to the valve seat plate by utilizing an attachment hole provided between the constricted portion and the base portion,
The main body case includes:
a gas supply port through which compressed gas is supplied;
a plurality of gas exhaust ports that individually exhaust the compressed gas supplied from the gas supply port through each of the exhaust paths of the valve seat plate by separating the plurality of valve bodies from the plurality of valve seats;
The present invention is characterized by comprising:

The present invention relates to
It is preferable that the support portion be integrally provided on the base portion by being molded integrally with the base portion from a metal material such as stainless steel including Invar.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
The support portion can also be provided integrally with the base by attaching a separate member made of, for example, stainless steel containing Invar to the base.

The present invention relates to
It is preferable that the base is fixed to the valve seat plate at least on a side to which one end of the piezoelectric element is connected.
The present invention relates to
The base portion may be fixed to the valve seat plate on the side where the support portion is provided.

The present invention relates to
It is preferable that the amount of displacement of the valve body be adjusted by changing the length from the narrowed portion to the tip end of the support portion.

The present invention relates to
The support portion is provided with a plurality of mounting holes along the second longitudinal direction between the constricted portion and the base portion, the mounting holes being closer to the base portion than the constricted portion;
The support portion is preferably screwed to the valve seat plate using at least one of the mounting holes.

The present invention relates to
At least one of the one end and the other end of the piezoelectric element is preferably connected to the attachment surface of the base or the operating portion via a connecting portion made of a material having a larger linear expansion coefficient than the supporting portion.

The present invention relates to
The connecting portion is integrally provided with the action portion,
It is preferable that the other end of the piezoelectric element is connected to the action portion via the connection portion made of a material having a linear expansion coefficient larger than that of the support portion.

The present invention relates to
It is preferable that the connecting portion be integrally provided with the operating portion by being molded integrally with the operating portion using a metal material such as aluminum.

The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of:
The connecting portion can be provided integrally with the acting portion by attaching a separate member, such as an aluminum block, to the acting portion.

The present invention relates to
It is preferable that the actuator further includes a compression member connected to each of the base portion and the action portion, and compressing the piezoelectric element in the first longitudinal direction.

The present invention relates to
It is preferable that the actuator includes a compression member connected to each of the base portion and the action portion, the compression member compressing the piezoelectric element in the first longitudinal direction, the compression member being positioned approximately on a central axis of the piezoelectric element.

The present invention relates to
It is preferable that a gap formed between the base portion and the action portion, the piezoelectric element and the support portion is filled with silicone, so that the gap is filled with the silicone.

The present invention relates to
It is preferable that the gaps formed between the base portion and the action portion, between the piezoelectric element and the support portion are equally spaced, and that the gaps are filled with the silicone.

The present invention relates to
It is preferable to fill a gap formed between the base and the action portion, between the side where the piezoelectric element extends in the first longitudinal direction and the side where the support portion extends in the second longitudinal direction, with silicone, thereby filling the gap with the silicone.

The present invention relates to
It is preferable that the gap formed between the base portion and the action portion, between the side where the piezoelectric element extends in the first longitudinal direction and the side where the support portion extends in the second longitudinal direction, is equally spaced.

The piezoelectric valve of the present invention comprises an actuator including a base fixed to the valve seat plate, a piezoelectric element having one end connected to the mounting surface of the base and extending in a first longitudinal direction, a support portion integral with the base and extending in a second longitudinal direction intersecting the first longitudinal direction alongside the piezoelectric element, an action portion connected to the other end of the piezoelectric element and the tip of the support portion and displaced in a displacement direction different from the first longitudinal direction and the second longitudinal direction as the piezoelectric element expands and contracts, and a valve body provided on the side of the displacement direction of the action portion and driven by the displacement of the action portion, and the support portion has a constricted portion in the middle portion extending in the second longitudinal direction and is fixed to the valve seat plate on the side of the constricted portion of the base, so that the ripples generated in the displacement waveform of the valve body in the actuator are reduced compared to conventional piezoelectric valves, and compressed gas can be discharged in a stable state from the gas exhaust port.

The piezoelectric valve of the present invention can adjust the amount of compressed gas discharged from the gas discharge port by adjusting the amount of displacement of the valve body by the length from the constricted portion to the tip of the support portion.

In the piezoelectric valve of the present invention, if at least one of the one end or the other end of the piezoelectric element is connected to the mounting surface of the base or the operating part via a connecting part made of a material with a linear expansion coefficient larger than that of the support part, the effect of thermal expansion or thermal contraction of the piezoelectric element due to temperature change can be reduced or eliminated.

In the piezoelectric valve of the present invention, if the actuator further includes a compression member that is connected to each of the base and the action portion and compresses the piezoelectric element in the first longitudinal direction, damage to the piezoelectric element, which is easily damaged by a load in the tensile direction, can be prevented.

In the piezoelectric valve of the present invention, if the actuator is connected to each of the base and the action part, and the compression member that compresses the piezoelectric element in the first longitudinal direction is positioned approximately on the central axis of the piezoelectric element, no torsional force is applied to the piezoelectric element by the compression member, and damage to the piezoelectric element can be effectively prevented.

The piezoelectric valve of the present invention can further effectively reduce ripples in the displacement waveform of the valve body by filling the gap formed between the base and the operating part, and between the piezoelectric element and the support part, with silicone.

The piezoelectric valve of the present invention is between the base and the operating part, and if the gaps formed between the piezoelectric element and the support part are equally spaced and the gaps are filled with the silicone, it is easy to fill the gaps with silicone.

FIG. 1 is a perspective view of a piezoelectric valve. FIG. 2 is an explanatory diagram of a piezoelectric valve. FIG. 4 is a perspective view of a state in which an actuator is fixed to a valve seat plate. FIG. 4 is an explanatory diagram of a state in which an actuator is fixed to a valve seat plate. FIG. 4 is an explanatory diagram of a state in which an actuator is fixed to a valve seat plate. FIG. 13 is an explanatory diagram of an actuator in the previous invention. FIG. 13 is an explanatory diagram of a displacement waveform of a valve body in the actuator of the previous invention. FIG. 2 is an explanatory diagram of an actuator according to the first embodiment of the present invention. 5 is an explanatory diagram of a displacement waveform of a valve body in the actuator according to the first embodiment of the present invention. FIG. FIG. 11 is an explanatory diagram of an actuator according to a second embodiment of the present invention. 7 is an explanatory diagram of a displacement waveform of a valve body in an actuator according to a second embodiment of the present invention. FIG. 11 is an explanatory diagram of an actuator according to a third embodiment of the present invention. FIG. 13 is an explanatory diagram of a displacement waveform of a valve body in an actuator according to a third embodiment of the present invention. FIG.

An embodiment of the present invention will be described with reference to the drawings.
[Basic structure of piezoelectric valve]
First, the basic configuration of the piezoelectric valve of the present invention will be described.
Fig. 1 shows a perspective view of a piezoelectric valve, and Fig. 2 shows an explanatory diagram of the piezoelectric valve as seen from the side.
The piezoelectric valve 1 includes a valve body 2, an actuator 3 (described later), and a valve seat plate 4 (described later) that is disposed inside the valve body 2 with the actuator 3 fixed thereto.

The valve body 2 is a case having an opening at the rear (the bottom in Figs. 1 and 2), and includes a gas pressure chamber therein which receives a supply of compressed gas from an external compressed gas supply source (not shown).
In addition, a connector portion 5 is provided on the front surface (the upper surface in Figures 1 and 2) of the valve body 2 for attachment to a manifold (not shown) having an internal space to which compressed gas is supplied from a compressed gas source.

A gas intake port 51 for drawing compressed gas into the valve body 2 and a plurality of gas exhaust ports 52 for discharging the compressed gas are opened on the front surface of the connector portion 5 .
In addition, a gas supply port (not shown) that communicates with the gas intake port 51 of the connector portion 5, and a plurality of gas exhaust ports (not shown) that communicate with each of the gas exhaust ports 52 are opened on the front surface of the valve body 2.
The rear surface of the valve body 2 is closed by a cover body 6, and the cover body 6 is provided with a wiring connector 61 for supplying power to a piezoelectric element 32, which will be described later.

Fig. 3 is a perspective view of a state in which an actuator is fixed to a valve seat plate. Here, the state in which an actuator of a prior invention is fixed is shown as an example of an actuator. Fig. 4 is an explanatory diagram of a state in which an actuator is fixed to a valve seat plate, and shows a view from the side of the valve seat plate in Fig. 3. Fig. 5 is an explanatory diagram of a state in which an actuator is fixed to a valve seat plate, and shows a view from the front side of the valve seat plate in Figs. 3 and 4.
The piezoelectric valve 1 includes a valve seat plate 4 to which an actuator 3 is fixed, which is housed inside the valve body 2 .
The valve seat plate 4 is an example of a valve seat plate capable of mounting two actuators, and has a valve seat portion 41 in the central portion, and valve seats 42 are provided on both opposing side surfaces of the valve seat portion 41 against which the valve body 35 of the actuator 3 abuts.

On one surface of the valve seat plate 4 , a mounting portion 43 for the actuator 3 is formed at a position facing one side surface of the valve seat portion 41 .
Further, on the other surface side of the valve seat plate 4 , a mounting portion 44 for the actuator 3 is formed at a position facing the other side surface of the valve seat portion 41 .
The two actuators 3 are disposed on the mounting portions 43, 44 of the valve seat plate 4 and fixed by screws so that the valve bodies 35 face the valve seats 42, respectively.

A plurality of discharge passages 45 opening into the valve seat surface of each of the valve seats 42 are formed in the valve seat portion 41, and each of the discharge passages 45 opens into the front surface (upper surface in FIG. 4) of the valve seat plate 4.
The valve seat plate 4 is disposed inside the valve body 2 with the two actuators 3 fixed thereto, and the front surface is fixed from the front side of the valve body 2 with screws, so that each of the exhaust passages 45 communicates with each of the gas exhaust ports opening on the front surface of the valve body 2.

The piezoelectric valve 1 has two valve seat plates 4 stored side by side in the width direction inside the case of the valve body 2, and four gas exhaust ports are opened on the front surface of the valve body 2.

The piezoelectric valve has four actuators disposed within the case of the valve body 2 and four gas exhaust ports opening on the front surface of the valve body, but this is not limited to this and one or more actuators can be disposed within the valve body.

[Actuator of the Prior Invention]
FIG. 6 is an explanatory diagram of an actuator provided in a piezoelectric valve of the prior invention.
The actuator 3 of the prior invention comprises a base 31 fixed to a valve seat plate, a piezoelectric element 32 having one end connected to a mounting surface of the base 31 and extending in a first longitudinal direction, and a support part 33 integrally molded with the base 31 and extending alongside the piezoelectric element 32 in a second longitudinal direction intersecting the first longitudinal direction.

The actuator 3 of the prior invention also includes an action portion 34 that is connected to the other end of the piezoelectric element 32 and the tip of the support portion 33 and displaces in a direction different from the first longitudinal direction and the second longitudinal direction as the piezoelectric element 32 expands and contracts, and a valve body 35 that is provided on one side of the tip of the action portion 34 in the direction of displacement and is driven by the displacement of the action portion 34.

As the piezoelectric element 32 expands and contracts, the actuator 3 has the action portion 34 displaced in a plane approximately parallel to a plane including the first longitudinal direction and the second longitudinal direction, in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction.
At this time, by providing a constricted portion 331 at the intermediate portion extending in the second longitudinal direction of the support portion 33, the displacement of the action portion 34 accompanying the expansion and contraction of the piezoelectric element 32 can be enlarged.

A connecting member 311, for example made of an aluminum block, can be attached to the mounting surface of the base 31.

The actuator 3 can also connect the base 31 and the action part 34 with a compression member 36.

FIG. 7 is an explanatory diagram of the displacement waveform of the valve disc in the actuator of the prior invention.
The displacement waveform of the valve disc 35 shown in FIG. 7 was obtained by measuring the amount of displacement of the valve disc 35 by a laser measuring device when a drive voltage is applied to the piezoelectric element 32 in the actuator 3 of the prior invention shown in FIG. 6 to expand the piezoelectric element 32 and drive the valve disc 35 to open.

The experiment was carried out by applying a drive voltage to the piezoelectric element 32 based on the method described in [Example] of JP 2017-160973 A. The experimental conditions were as follows. Each time condition of the input signal was set to an optimal value that minimized ripples in the valve body displacement waveform.
(1) Driving voltage: 72V
(2) Input signal: first prepulse time t1=0.097 ms
First pause time t2 = 0.077 ms
Second prepulse time t3 = 0.6 ms
Second pause time t4 = 0.01 ms
Main pulse time t5 = 0.216 ms
(Power supply time of piezoelectric element: 1 ms)

As shown in FIG. 7, in the actuator 3 of the prior invention, it can be seen that a plurality of large ripples, which are presumably due to resonance, occur in the displacement waveform of the valve disc.
Therefore, there is a concern that the piezoelectric valve of the prior invention may not discharge the compressed gas from the gas discharge port in a stable manner.

[Actuator of the present invention]
The piezoelectric valve of the present invention improves upon the actuator of the piezoelectric valve of the previous invention.

Example 1
FIG. 8 is an explanatory diagram of the actuator according to the first embodiment of the present invention.
The actuator 3 of embodiment 1 comprises a base 31 fixed to the valve seat plate 4, a piezoelectric element 32 having one end connected to the mounting surface of the base 31 and extending in a first longitudinal direction, and a support portion 33 formed integrally with the base 31 and extending alongside the piezoelectric element 32 in a second longitudinal direction intersecting the first longitudinal direction.

The actuator 3 of the first embodiment also includes an action portion 34 that is connected to the other end of the piezoelectric element 32 and the tip of the support portion 33 and displaces in a direction different from the first longitudinal direction and the second longitudinal direction as the piezoelectric element 32 expands and contracts, and a valve body 35 that is provided on one side of the tip of the action portion 34 in the direction of displacement and is driven by the displacement of the action portion 34.

In the actuator 3 of the first embodiment, the base 31 includes a side to which one end of the piezoelectric element 32 is connected and a side to which the support portion 33 is integrally provided, and is fixed to the valve seat plate 4 by screws on the side to which the piezoelectric element 32 is connected and the side to which the support portion 33 is provided.

In the actuator 3 of embodiment 1, the support portion 33 has a constricted portion 331 in the middle portion extending in the second longitudinal direction, and is fixed to the valve seat plate 4 by a screw using a mounting hole 38 provided between the constricted portion 331 and the base 31 on the base 31 side of the constricted portion 331.

The base 31 only needs to be fixed to the valve seat plate 4 at least on the side to which one end of the piezoelectric element 32 is connected.

Here, the base portion 31 and the support portion 33 can be integrally formed by punching out a metal material such as stainless steel including Invar.
If the base portion 31 and the support portion 33 are integrally formed by stamping out the metal material, the number of parts is reduced, and the assembly of the actuator 3 becomes easier.

In addition, the base 31 and the support 33 can be formed from separate members, and the support 33, which is a separate member, can be attached to the base 31, so that the support 33 is provided integrally with the base 31.

In the actuator 3 of the first embodiment, the action portion 34 can be made of a lightweight material such as aluminum. If the action portion 34 is made of a lightweight material such as aluminum, it is preferable in terms of displacing the action portion 34.
The valve body 35 is made of rubber or the like, and is preferably made of a lubricating rubber.

The actuator 3 can be configured such that a compression member 36 connects the base portion 31 and the action portion 34 .
Piezoelectric elements are easily damaged by loads in the tensile direction, but by connecting the base 31 and the acting portion 34 with the compression member 36, the piezoelectric element 32 can be compressed in the first longitudinal direction, thereby preventing damage to the piezoelectric element 32.

FIG. 9 is an explanatory diagram of a displacement waveform of the valve disc in the actuator according to the first embodiment of the present invention.
The displacement waveform of the valve body 35 shown in FIG. 9 is obtained by measuring the amount of displacement of the valve body 35 by a laser measuring device when a drive voltage is applied to the piezoelectric element 32 in the actuator 3 of embodiment 1 shown in FIG. 8 to expand the piezoelectric element 32 and drive the valve body 35 to open.

The experiment was carried out by applying a drive voltage to the piezoelectric element 32 based on the method described in [Example] of JP 2017-160973 A. The experimental conditions were as follows. Each time condition of the input signal was set to an optimal value that minimized ripples in the valve body displacement waveform.
(1) Driving voltage: 72V
(2) Input signal: first prepulse time t1=0.06 ms
First pause time t2 = 0.012 ms
Second prepulse time t3 = 0.89 ms
Second pause time t4 = 0.035 ms
Main pulse time t5 = 0.003 ms
(Power supply time of piezoelectric element: 1 ms)

As shown in FIG. 9, it can be seen that in the actuator 3 of the first embodiment, almost no ripples are generated in the displacement waveform of the valve element 35.
Therefore, by being equipped with the actuator 3 of embodiment 1, the piezoelectric valve of the present invention can discharge compressed gas from the gas discharge port in a stable state, compared to the piezoelectric valve of the prior invention.

<Embodiment 2>
FIG. 10 is an explanatory diagram of an actuator according to a second embodiment of the present invention.
The actuator 3 of embodiment 2 is the actuator 3 of embodiment 1 described above, in which the other end of the piezoelectric element 32 is connected to the action portion 34 via a connecting portion 37 made of a material having a larger linear expansion coefficient than the support portion 33.

In the actuator 3 of the second embodiment, the other end of the piezoelectric element 32 is connected to the action part 34 via a connecting part 37 made of a material with a linear expansion coefficient larger than that of the support part 33, so that the effect of thermal expansion or thermal contraction of the piezoelectric element 32 due to temperature change can be reduced or eliminated.

In the actuator 3 of the second embodiment, the connecting portion 37 is provided integrally with the action portion 34, and can be formed integrally by, for example, punching a metal material such as aluminum.
If the action portion 34 and the connection portion 37 are integrally formed by stamping out a lightweight metal material such as aluminum, the number of parts can be reduced, and assembly of the actuator 3 can be facilitated.

The connecting portion 37 can also be formed from a separate member, such as an aluminum block, and the connecting portion 37 can be attached to the action portion 34 as a separate member, so that the connecting portion 37 is integral with the action portion 34.

In addition, by forming the connecting portion 37 from a separate member, such as an aluminum block, one end of the piezoelectric element 32 can be connected to the mounting surface of the base portion 31 via the connecting portion 37.

FIG. 11 is an explanatory diagram of a displacement waveform of a valve disc in an actuator according to the second embodiment of the present invention.
The displacement waveform of the valve body 35 shown in FIG. 11 is obtained by measuring the amount of displacement of the valve body 35 by a laser measuring device when a drive voltage is applied to the piezoelectric element 32 in the actuator 3 of embodiment 2 shown in FIG. 10 to expand the piezoelectric element 32 and drive the valve body 35 to open.

The experiment was carried out by applying a drive voltage to the piezoelectric element 32 based on the method described in [Example] of JP 2017-160973 A. The experimental conditions were as follows. Each time condition of the input signal was set to an optimal value that minimized ripples in the valve body displacement waveform.
(1) Driving voltage: 72V
(2) Input signal: first prepulse time t1=0.058 ms
First pause time t2 = 0.008 ms
Second prepulse time t3 = 0.877 ms
Second pause time t4=0.046ms
Main pulse time t5 = 0.011 ms
(Power supply time of piezoelectric element: 1 ms)

As shown in FIG. 11, in the actuator 3 of embodiment 2, almost no ripples are generated in the displacement waveform of the valve body 35, or even if ripples are generated, the ripples are reduced compared to the actuator 3 of the prior invention shown in FIG.
Therefore, by being equipped with the actuator 3 of embodiment 2, the piezoelectric valve of the present invention can discharge compressed gas from the gas discharge port in a stable state, compared to the piezoelectric valve of the prior invention.

<Embodiment 3>
FIG. 12 is an explanatory diagram of an actuator according to a third embodiment of the present invention.
The actuator 3 of embodiment 3 is the actuator 3 of embodiment 2 described above, further comprising the compression member 36 connected to the base 31 and the acting portion 34, which compresses the piezoelectric element 32 in the first longitudinal direction, and positioned approximately on the central axis of the piezoelectric element 32 along the first longitudinal direction.

The actuator 3 of the third embodiment is provided with the compression member 36, which is connected to the base 31 and the action portion 34 and compresses the piezoelectric element 32 in the first longitudinal direction, positioned approximately on the central axis of the piezoelectric element 32. Therefore, no torsional force is applied to the piezoelectric element 32 by the compression member 36, and damage to the piezoelectric element 32 can be effectively prevented.

FIG. 13 is an explanatory diagram of a displacement waveform of a valve disc in an actuator according to the third embodiment of the present invention.
The displacement waveform of the valve body 35 shown in Figure 13 is also obtained by measuring the amount of displacement of the valve body 35 by a laser measuring device when a drive voltage is applied to the piezoelectric element 32 in the actuator 3 of embodiment 3 shown in Figure 12, causing the piezoelectric element 32 to expand and drive the valve body 35 to open.

The experiment was carried out by applying a drive voltage to the piezoelectric element 32 based on the method described in [Example] of JP 2017-160973 A. The experimental conditions were as follows. Each time condition of the input signal was set to an optimal value that minimized ripples in the valve body displacement waveform.
(1) Driving voltage: 72V
(2) Input signal: first prepulse time t1=0.054 ms
First pause time t2 = 0.015 ms
Second prepulse time t3 = 0.875 ms
Second pause time t4=0.046ms
Main pulse time t5 = 0.01 ms
(Power supply time of piezoelectric element: 1 ms)

As shown in FIG. 13, it can be seen that, also in the actuator 3 of embodiment 3, almost no ripples are generated in the displacement waveform of the valve body 35, or, even if ripples are generated, the ripples are reduced compared to the actuator 3 of the prior invention shown in FIG. 7.
Therefore, even when the piezoelectric valve of the present invention is equipped with the actuator 3 of embodiment 3, it can discharge compressed gas from the gas discharge port in a stable manner, compared to the piezoelectric valve of the prior invention.

<Other embodiments>
The actuator 3 in the above embodiment of the present invention can adjust the amount of displacement of the valve body 35 by adjusting the length from the constriction portion 331 of the support portion 33 to the tip of the support portion 33 connected to the action portion 34, thereby adjusting the amount of compressed gas discharged from the gas discharge port.
In other words, by using an actuator 3 having a support portion 33 that has a long length from the constriction portion 331 to the tip portion, the piezoelectric valve of the present invention can increase the amount of displacement of the valve body 35 and increase the amount of compressed gas discharged from the gas exhaust port.
Furthermore, by using an actuator 3 having a support portion 33 with a short length from the constriction portion 331 to the tip portion, the piezoelectric valve of the present invention can reduce the amount of displacement of the valve body 35 and decrease the amount of compressed gas discharged from the gas exhaust port.

In the actuator 3 in the embodiment of the present invention described above, the support portion 33 is provided with a plurality of mounting holes 38 along the second longitudinal direction on the side of the base 31 closer to the constriction portion 331, and the support portion 33 can be screwed to the valve seat plate 4 using at least one of the mounting holes 38.
In the actuator 3 according to the embodiment of the present invention described above, a plurality of mounting holes 38 are provided in the support portion 33 along the second longitudinal direction on the side of the base portion 31 closer to the constricted portion 331, and the support portion 33 is screwed to the valve seat plate 4 using at least one of the mounting holes 38. By adjusting the position of the mounting hole 38 that fixes the support portion 33 to the valve seat plate 4, the amount of displacement of the valve body 35 can be adjusted, and the amount of compressed gas discharged from the gas discharge port can be adjusted.

In the actuator 3 in the above embodiment of the present invention, the gap formed between the base 31 and the action portion 34, the piezoelectric element 32 and the support portion 33 can be filled with silicone, and the gap can be filled with the silicone.

In the actuator 3 in the above embodiment of the present invention, when at least one of the one end or the other end of the piezoelectric element 32 is connected to the mounting surface of the base 31 or the action part 34 via a connecting part 37 made of a material with a linear expansion coefficient larger than that of the support part 33, the gap formed between the piezoelectric element 32 and the connecting part 37 and the support part 33 can be filled with silicone to fill the gap with the silicone.

In the actuator 3 in the above embodiment of the present invention, if the gap formed between the base 31 and the action portion 34, and between the side where the piezoelectric element 32 extends in the first longitudinal direction and the side where the support portion 33 extends in the second longitudinal direction, is filled with silicone, the ripples occurring in the displacement waveform of the valve body 35 can be further effectively reduced.

In addition, in the actuator 3 in the above embodiment of the present invention, the gap formed between the base 31 and the action portion 34, and between the piezoelectric element 32 and the support portion 33 can be made to be equally spaced.

In the actuator 3 in the above embodiment of the present invention, the gaps formed between the base 31 and the action portion 34, and between the side where the piezoelectric element 32 extends in the first longitudinal direction and the side where the support portion 33 extends in the second longitudinal direction, are equally spaced, and the gaps are filled with silicone, so that the silicone can be easily filled into the gaps.

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment, and the configuration can be modified as appropriate without departing from the scope of the invention.

The piezoelectric valve of the present invention is extremely useful because it reduces ripples that occur in the displacement waveform of the valve body and allows compressed gas to be discharged in a stable manner from the gas outlet.

REFERENCE SIGNS LIST 1 Piezoelectric valve 2 Valve body 3 Actuator 31 Base 311 Connecting member 32 Piezoelectric element 33 Support portion 331 Narrowed portion 34 Action portion 35 Valve body 36 Compression member 37 Connecting portion 38 Mounting hole 4 First valve seat plate 41 Valve seat portion 42 Valve seat 43 Mounting portion 44 Mounting portion 45 Exhaust path 5 Connector portion 51 Gas intake port 52 Gas exhaust port 6 Cover body 61 Wiring connector

Claims (10)

An actuator that drives the valve body;
a valve seat plate having a valve seat and a discharge passage that are movable toward and away from the valve body and that fixes the actuator;
A piezoelectric valve including a main body case that houses the valve seat plate,
The actuator comprises:
a base portion fixed to the valve seat plate;
a piezoelectric element having one end connected to the mounting surface of the base and extending in a first longitudinal direction;
a support portion that is integrally provided on the base portion and extends in a second longitudinal direction that intersects with the first longitudinal direction alongside the piezoelectric element;
an action portion connected to the other end of the piezoelectric element and the tip end of the support portion, and displaced in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction in response to expansion and contraction of the piezoelectric element;
The valve body is provided on a side of the action portion in the direction of the displacement, and is driven by the displacement of the action portion,
the support portion has a constricted portion at an intermediate portion extending in the second longitudinal direction, and is fixed to the valve seat plate by utilizing an attachment hole provided between the constricted portion and the base portion,
The main body case includes:
a gas supply port through which compressed gas is supplied;
a gas exhaust port that exhausts the compressed gas supplied from the gas supply port through the exhaust path of the valve seat plate by separating the valve body from the valve seat;
A piezoelectric valve comprising: A plurality of actuators each individually driving a plurality of valve bodies in a parallel plane;
a valve seat plate having a plurality of valve seats and discharge paths that are respectively connected to and separated from the plurality of valve bodies and that fixes the plurality of actuators;
A piezoelectric valve including a main body case that houses the valve seat plate,
Each of the plurality of actuators is
a base portion fixed to the valve seat plate;
a piezoelectric element having one end connected to the mounting surface of the base and extending in a first longitudinal direction;
a support portion that is integrally provided on the base portion and extends in a second longitudinal direction that intersects with the first longitudinal direction alongside the piezoelectric element;
an action portion connected to the other end of the piezoelectric element and the tip end of the support portion, and displaced in a displacement direction different from each of the first longitudinal direction and the second longitudinal direction in response to expansion and contraction of the piezoelectric element;
The valve body is provided on a side of the action portion in the direction of the displacement, and is driven by the displacement of the action portion,
the support portion has a constricted portion at an intermediate portion extending in the second longitudinal direction, and is fixed to the valve seat plate by utilizing an attachment hole provided between the constricted portion and the base portion,
The main body case includes:
a gas supply port through which compressed gas is supplied;
a plurality of gas exhaust ports that individually exhaust the compressed gas supplied from the gas supply port through each of the exhaust paths of the valve seat plate by separating the plurality of valve bodies from the plurality of valve seats;
A piezoelectric valve comprising: The piezoelectric valve according to claim 1 or 2, wherein the base is fixed to the valve seat plate at least on the side to which one end of the piezoelectric element is connected. A piezoelectric valve according to any one of claims 1 to 3, in which the amount of displacement of the valve body is adjusted by the length from the constricted portion to the tip of the support portion. A piezoelectric valve according to any one of claims 1 to 4, wherein at least one of the one end or the other end of the piezoelectric element is connected to the mounting surface of the base or the working part via a connecting part made of a material having a linear expansion coefficient larger than that of the support part. The connecting portion is integrally provided with the action portion,
The piezoelectric valve according to claim 5 , wherein the other end of the piezoelectric element is connected to the action portion via the connecting portion made of a material having a linear expansion coefficient larger than that of the support portion. The piezoelectric valve according to any one of claims 1 to 6, wherein the actuator further comprises a compression member connected to each of the base and the action portion, and compressing the piezoelectric element in the first longitudinal direction. The piezoelectric valve according to claim 7, wherein the actuator is connected to the base and the action part, and includes a compression member that compresses the piezoelectric element in the first longitudinal direction, approximately on the central axis of the piezoelectric element. A piezoelectric valve according to any one of claims 1 to 8, in which a gap formed between the base and the action part, the piezoelectric element and the support part, is filled with silicone. A piezoelectric valve according to any one of claims 1 to 9, in which the gaps formed between the base and the action part, the piezoelectric element and the support part are equally spaced, and the gaps are filled with silicone.