JPH0323790B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention circulates working fluid between a storage chamber and a pressure chamber using an electromagnetic pump, thereby applying pressure generated in the pressure chamber to a load. The present invention relates to an actuator that obtains a driving force for driving.

[Conventional technology]

In this type of actuator, the pressure generated in the pressure chamber is pumped to the pressure chamber by an electromagnetic pump if the opening area of the orifice provided in the passage for returning the working fluid from the pressure chamber to the storage chamber is constant. If this flow rate is constant, it is proportional to the opening area of the orifice.
Therefore, if you want to hold a response body that is displaced in response to the pressure in the pressure chamber at a position midway through its movement range, you must change the discharge volume of the electromagnetic pump or the opening area of the orifice in addition to starting and stopping the electromagnetic pump. This is necessary. However, it is not easy to accurately change the discharge amount of the electromagnetic pump or the opening area of the orifice.

[Problem to be solved by the invention]

Since the conventional actuator is constructed as described above, for example, in a gas combustion equipment having two types of burners, a pilot burner and a main burner, the pilot valve and the main valve must be driven by separate actuators. As a result, there were problems such as the equipment becoming larger and the opening/closing sequence of the two valves not being accurate, resulting in abnormal ignition of gas.

This invention was made in order to solve the above-mentioned problem, and aims to obtain a safe and compact actuator that can operate two valves in different pressure ranges.

[Means to solve the problem]

The actuator according to the present invention includes an electromagnetic pump that pumps the working fluid in the storage chamber to the first pressure chamber, a first passage and a second passage for returning the working fluid in the first pressure chamber to the storage chamber. a passage, a first orifice provided in the first passage, a second orifice provided in the second passage and having a larger opening area than the first orifice, and a solenoid valve. , the first pressure chamber is displaced against the biasing spring according to the pressure in the first pressure chamber.
a first response body that drives the valve; a second pressure chamber communicating with the first pressure chamber via a passage; and a second pressure chamber having a pressure receiving area smaller than the first pressure receiving area.
and a second responsive body that is displaced against the biasing spring due to the pressure in the pressure chamber of the valve to drive the second valve.

[Effect]

The actuator of the present invention has two functions, even if the discharge amount of the electromagnetic pump is constant, depending on whether the working fluid is returned from the first pressure chamber to the storage chamber through the first passage or through the second passage. A pressure region is generated, and in these two pressure regions, the first reaction body and the second
By operating the response bodies separately, the two valves can be opened and closed safely and reliably.

〔Example〕

Hereinafter, a case where an actuator according to an embodiment of the present invention is applied to a flow rate control device will be described with reference to the drawings. The flow rate control device shown in FIG.
It is composed of a pressure generating section A that generates hydraulic pressure, a converting section B that converts this hydraulic pressure into displacement, and a control section C that is driven by this converting section B. This example shows a flow control device configured to control the flow rate of fuel gas supplied to a combustor, such as a water heater.

The pressure generating section A is an electromagnetic pump 13 consisting of a coil 11 and an actuating section 12 penetrating through the center hole thereof.
has. This electromagnetic pump 13 sucks the hydraulic oil contained in the storage chamber 14 from the passage 15 into the actuating part 12, and then passes it through the passage 16 to the pressure chamber 1.
7. Moreover, the pressure chamber 17 is
It communicates with the storage chamber 14 through a first passage 18 equipped with a first orifice 21 having an appropriate opening area, and communicates with the second pressure chamber 2 through a passage 19.
It also communicates with 0. Therefore, the electromagnetic pump 13
During operation, hydraulic oil flows from the storage chamber 14 to the passage 1.
5, circulates through the operating part 12, the passage 16, the pressure chamber 17 and the passage 18, and returns to the storage chamber 14;
Due to the action of the orifice 21 provided in the passage 18, a pressure corresponding to the discharge flow rate of the electromagnetic pump 13 is applied to the pressure chamber 17.
occurs within. This pressure is also transmitted to the pressure chamber 20 via the passage 19.

On the other hand, a bypass passage 22 is formed that connects the suction side passage 15 and the discharge side passage 16 of the electromagnetic pump 13, and the bypass passage 22 is in a closed position only while the electromagnetic pump 13 is operating normally. A retained bypass valve 23 is provided. Therefore, when the electromagnetic pump 13 stops operating after the pressure in the pressure chamber 17 has increased, the bypass valve 23 immediately moves to the open position, thereby instantly releasing the pressure in the pressure chamber 17.

Further, the pressure chamber 1 is arranged in parallel with the first passage 18.
7 and the storage chamber 14 is formed, and this passage 24 includes a solenoid valve 25 that opens and closes in response to an external signal, and a second orifice having a larger opening area than the first orifice 21. 26 are provided.

Conversion section B provided adjacent to pressure generation section A
has two reaction bodies 31 and 32. 1st
The response body 31 is in contact with the inside of the pressure chamber 17 via a bellows frame, and is fixed to the tip of a rod 33 that is movable in the axial direction, and is supported by a spring 34.
is urged toward the inside of the pressure chamber 17 by.
The second response body 32 is in contact with the pressure chamber 20 via a bellows frame, and is supported by the tip of a rod 35 that is movable in the axial direction, and directed toward the inside of the pressure chamber 20 by a spring 36. is being pressed down. Therefore, when the pressure in pressure chambers 17 and 20 increases, reaction bodies 31 and 32 move against springs 34 and 36, respectively,
When the pressure decreases, it returns to its original position, and pressure-displacement conversion is performed here. The pressure receiving area of the second reaction body 32 is smaller than that of the first reaction body 31, and therefore the pressure at which the second reaction body 32 starts to be displaced is higher than that of the first reaction body 31.

The control section C has an inlet passage 41, a communication passage 42, and an outlet passage 43, in which a regulator (not shown) is preferably provided. The opening/closing valve 45 is pressed against the valve seat 44 by the action of a spring 46. and a valve rod 47 that supports the on-off valve 45.
is in contact with the tip of the rod 33 mentioned above. Further, the communication passage 42 and the outlet passage 43 are connected to the valve seat 48.
A proportional valve 50 is pressed against the valve seat 48 by a spring 49. A valve rod 51 provided at the center of the proportional valve 50 is in contact with the tip of the rod 36 at one end thereof. The proportional valve 50 moves between a fully closed position in close contact with the valve seat 48 and a fully open position furthest away from the valve seat 48, thereby allowing the proportional valve 50 to
The flow rate of the controlled fluid, such as fuel gas, flowing from the outlet passage 43 to the outlet passage 43 can be proportionally controlled.

Next, the operation will be explained. Electromagnetic pump 13
When a drive signal of an arbitrary waveform such as an AC half-wave rectified waveform or a square wave is supplied to the coil 11 from an external drive circuit (not shown), the bypass valve 23 moves to the right in the drawing. At the same time, the working fluid in the storage chamber 14 flows to the passage 15 through the filter, and the working part 1
It flows into the center of 2. Working fluid is sucked from the center of the working part 12, pressurized by a plunger inside, and discharged from the periphery of the working part 12, and is forced into the pressure chamber 17 through the passage 16. At this time, the solenoid valve 25 is opened by an external signal. Therefore, the working fluid in the pressure chamber 17 flows through the second orifice 26 with a large opening area.
Therefore, if the discharge amount of the electromagnetic pump 13 is constant, the pressure in the pressure chamber 17 is determined by the opening area of the second orifice 26. The pressure increases to 1. This pressure is also transmitted to the second pressure chamber 20 via the passage 19, but only the first response body 31 is displaced by this pressure, thereby causing the on-off valve 4
Only 5 will be opened. In this state, the entrance passage 41
The fuel gas inside flows into the communication passage 42 and is supplied to a pilot burner (not shown).

After confirming that the pilot burner has ignited,
The solenoid valve 25 is closed by an external signal. As a result, the passage 24 is blocked, so that the fluid in the pressure chamber 17 passes only through the passage 18 to the storage chamber 1.
Return to 4. Since the opening area of the orifice 21 provided in this passage 18 is smaller than the opening area of the second orifice 26, even if the discharge amount of the electromagnetic pump 13 is constant, the pressure in the pressure chambers 17 and 18 is Rise. This pressure causes the second response body 32 to displace by a predetermined distance, thereby causing the proportional valve 50 to
is opened, fuel gas flows to a main burner (not shown) connected to the outlet passage 43, and main combustion is started. Also, in this state, the coil 1 of the electromagnetic pump 13
1, the position of the proportional valve 50 can be proportionally controlled by changing the discharge amount by changing the current value of the drive signal supplied to the proportional valve 50.

In addition, in order to ensure that when the solenoid valve 25 is open, only the on-off valve 45 is opened and the proportional valve 50 is closed, the first pressure chamber 17 and the second pressure chamber are opened, as shown in FIG. In the passage 19 connecting with the room 20,
A solenoid valve 27 can be provided which operates alternately with the solenoid valve 25.

Furthermore, instead of the electromagnetic valve 27, a valve 28 having a structure as shown in FIG. 3 may be provided. In FIG. 3, a diaphragm 63 supporting a valve body 62 is provided in the center of the housing 61, and the valve body 62 is supported by the action of a spring 64 provided between the housing 61 and the diaphragm 63. It is pressed against a valve seat 65 provided in the housing 61. Therefore, in this state, the inlet port 66 connected to the pressure chamber 17 and the diaphragm chamber 67 are cut off. Here, the pressure on the inlet port 66 side acts on the pressure receiving surface of the valve body 62 in a direction that presses the spring 61, so when the pressure reaches the set value, the valve body 62 resists the spring 61 and pushes against the valve seat 61.
, thereby entering the working fluid diaphragm chamber 67 in the inlet port 66 and then flowing to the pressure chamber 20 via the outlet port 68 . diaphragm 6
3 is significantly larger than the pressure receiving area of the valve body 62 when it is in contact with the valve seat 65, so when the valve body 62 slightly leaves the valve seat 65, the diaphragm 63 is suddenly displaced. The valve body 62 is moved in a direction away from the valve seat 65, and this state is maintained until the pressure becomes significantly lower than the pressure at which the valve body 62 begins to open.

That is, the electromagnetic pump 13 operates and the pressure chamber 17
In the process of increasing internal pressure, this pressure becomes the first
When the set value is reached, first the first response body 31 is displaced and the on-off valve 45 is moved to the open position. This allows the fuel gas to flow from the inlet passage 41 to the communication passage 42.
It then flows to the pilot burner and is ignited. However, in this state, the proportional valve 50 is closed, so the pressure in the second pressure chamber 20 is low.

Next, when the pressure within the pressure chamber 17 further increases and reaches the opening pressure of the valve 28, the valve body 62 rapidly moves to the open position and is held at this position as described above, so that the working fluid can flow through the passage. By flowing into the pressure chamber 20 through 16 and 19 and then returning to the storage chamber 14 through the orifice 21 and the passage 18, a pressure approximately equal to that in the pressure chamber 17 is generated in the pressure chamber 20. Therefore, the responsive body 32 is displaced according to the pressure within the pressure chamber 20, causing the proportional valve 50 to operate proportionally,
The flow rate of fuel gas supplied from the communication passage 42 to the main burner via the outlet passage 43 is proportionally controlled. Conversely, in the process of decreasing the pressure inside the pressure chamber 17, the valve 28
remains open.

[Effects of the Invention] As described above, according to the present invention, two independent passages are formed in order to return the working fluid from the pressure chamber to the storage chamber, each of which is provided with an orifice having a different opening area, and further A solenoid valve is installed in the passageway on the side that has an orifice with a large opening area, and by opening and closing this solenoid valve, the pressure in the pressure chamber can be easily changed to two levels even if the discharge amount of the solenoid pump is constant. Since the configuration allows the two valves to be operated safely and reliably using the first and second response bodies that respond to each pressure, the device can be downsized and the two valves can be operated safely and reliably. This has the effect of making the opening/closing sequence more accurate and improving controllability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a flow control device equipped with an actuator according to one embodiment of the present invention, FIG. 2 is a hydraulic system diagram of an actuator according to another embodiment, and FIG.
The figure is a longitudinal sectional view of a valve applicable to the actuator of FIG. 2. A...Pressure generation section, B...Conversion section, C...Control section, 1
1... Coil, 13... Electromagnetic pump, 14... Storage chamber,
17...pressure chamber, 18, 19...passage, 20...pressure chamber, 21 orifice, 23...bypass valve, 24...
Passage, 25... Solenoid valve, 26... Orifice, 27...
Solenoid valve, 28... Valve, 31, 32... Response body, 41...
Entrance passage, 42...Connection passage, 42...Exit passage, 4
5... Opening/closing valve, 50... Proportional valve, 61... Housing,
62...Valve body, 63...Diaphragm.

Claims (1)

[Claims] 1 an electromagnetic pump that pumps the working fluid in the storage chamber to the first pressure chamber; a first passage and a second passage for returning the working fluid in the first pressure chamber to the storage chamber;
a passage, a first orifice provided in the first passage, a second orifice provided in the second passage and having a larger opening area than the first orifice, and a solenoid valve. , a first response body that is displaced against a biasing spring in response to the pressure in the first pressure chamber to drive the first valve; and a second response body that communicates with the first pressure chamber via a passage. a pressure chamber, and a second responsive body whose pressure receiving area is smaller than the first pressure receiving area and which is displaced against the biasing spring in response to the pressure in the second pressure chamber to drive the second valve. equipped actuator.