JPH0442531Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] Industrial application field The present invention relates to a pump for delivering liquids such as fuel oil and lubricating oil.

Conventional technology As a fuel pump for a conventional kerosene combustor,
Electromagnetic pumps are widely used, but since such pumps are large in size and are frequency controlled, they have the disadvantage that when a low flow rate is used, the flow rate pulsates and combustion becomes unstable. Furthermore, these electromagnetic pumps generate a lot of noise, consume a lot of power like electric pumps, and are expensive compared to their capacity.

Therefore, it has been proposed to use a pump that uses a piezoelectric vibrator instead of the conventional electromagnetic pump. An oil pump is disclosed (FIG. 2). The oil pump in this example has a piezo element c on a metal disc b.
Check valves e and f are provided at both ends of a liquid pressurizing chamber d, which is constructed by opposing the vibrator a obtained by joining the vibrator a, so that the vibrator a sucks liquid by alternately deforming into concave and convex shapes. It is designed to be discharged.

However, with this type of pump, the phase of the input to the vibrator a can be controlled using a commercial power supply, which has the advantage of reducing pulsation even at low flow rates, but since the amount of deformation of the vibrator a is relatively small, the required flow rate is In order to ensure this, it is necessary to take a large area, and the shape of the liquid pressurizing chamber d must become large. As a result, air and the like tend to remain in the liquid pressurizing chamber, which absorbs changes in volume and deteriorates the pump's function, and also causes problems such as a delay in stabilizing the liquid delivery rate.

In order to solve the above-mentioned problems with conventional piezoelectric pumps, the inventors of the present invention created a pump section that sucks in and discharges liquid in a fixed direction using a reciprocating piston below the liquid surface, and supports it in a cantilevered manner. A small piezoelectric pump characterized in that a piezoelectric vibrator is provided above the liquid surface, and the motion of the vibrating end of the piezoelectric vibrator is transmitted to the piston by a joint member provided through the liquid surface. We have proposed and applied for a patent.

Problems to be Solved When such a new piezoelectric pump is used as an oil pump for a kerosene-burning heater, for example, when the air temperature, that is, the temperature of the oil pump, is low, the output of the piezoelectric element is low and the amount of oil sent is small. Therefore, there was a problem that the heater did not work sufficiently, and the amount of oil delivered could only be secured when the temperature of the heater became high, and there was also a problem of poor ignitability.

Therefore, an object of the present invention is to provide a pump that can maintain a predetermined oil supply amount regardless of the environmental temperature.

[Structure of the idea]

Means for Solving the Problems The piezoelectric pump of the present invention, which can achieve the above object, has a pump section below the liquid surface that sucks in and discharges liquid in a fixed direction using a reciprocating piston, and has a cantilever shape. A piezoelectric pump configured such that a supported piezoelectric vibrator is provided above a liquid level, and the motion of a vibrating end of the piezoelectric vibrator is transmitted to the piston by a joint member provided through the liquid level,
The piezoelectric vibrator is characterized in that a constant temperature device having a means for sensing the environmental temperature of the piezoelectric vibrator and a heat supply means for changing the amount of heat supplied according to the sensed temperature is provided near the piezoelectric vibrator. be.

The piezoelectric pump of the present invention has a structure as shown in FIG. 1, for example. In the figure, 1
is the pump case, and the pump chamber 1 is located at the lower end of the pump case.
a is formed. A suction port 1c is provided on the lower side of the pump chamber 1a via an inlet check valve 1b, and a passage communicating with the supply port 1e via an outlet check valve 1d is provided on the upper side. Further, a cylinder part 1f is provided on the side of the pump chamber 1a, and a piston 2 is slidably mounted on the cylinder part 1f.

3 is a plate-shaped piezoelectric vibrator, the upper end 3a is fixed to form a cantilever shape, and the lower end 3b is fixed by applying an alternating voltage to electrodes provided on both sides of the piezoelectric vibrator.
is designed to vibrate (in the left-right direction in the figure). An electrically insulating joint 4 is fixed to the vibrating end 3b of the piezoelectric vibrator, and a rod-shaped joint member 5 is provided along the extending direction of the piezoelectric vibrator 3 via the joint 4.

The joint member 5 is inserted into a through hole 2a formed at the rear end of the piston 2 near its tip, and amplifies the horizontal vibration of the piezoelectric vibrator 3 and transmits it to the piston 2, so that the piston 2 It is configured to move back and forth within the

6 is a protective cover provided to surround the pump section including the pump chamber 1a portion, the suction port 1c, the cylinder section 1f, the piston 2, etc., and the window section 6a provided on the side surface is made of, for example, a fine woven mesh. It is blocked by a filter medium 7 made of a material such as the like, so that only liquid can pass through.

Here, HL is the upper limit liquid level and LL is the lower limit liquid level.

A space accommodating the piezoelectric vibrator 3 of the piezoelectric pump configured in this way is provided with a constant temperature device 8, which is a combination of a PTC thermistor and a heater, for example, and is connected to a control circuit 9 by an electric wire 8a. .

On the other hand, AC power of, for example, 100V is supplied to the control circuit 9 via a power supply line 9a, and a drive signal controlled by a flow rate adjustment signal inputted from a signal line 9b is transmitted to the piezoelectric vibrator 3 via an output line 9c. Output to.

Function: When the piezoelectric pump is energized when the environment is cold, the constant temperature device 8 generates heat immediately, heats the space in which the piezoelectric vibrator 3 is housed, and heats the piezoelectric vibrator 3 to a predetermined temperature suitable for operation. Warm up rapidly. After reaching a predetermined temperature, it works to maintain that temperature. Therefore, even if the environmental temperature changes significantly,
Since the piezoelectric vibrator 3 can operate at a high output within a short time from the start of operation, the piezoelectric pump is capable of faithfully feeding liquid in accordance with the liquid feeding amount adjustment signal at any time.

[Effect of idea]

The piezoelectric pump of the present invention can realize a liquid feeding amount that is faithful to the set value, regardless of the temperature of the air temperature, and even the temperature of the piezoelectric pump. Therefore, when used as an oil pump in a kerosene-burning heater, etc., a sufficient amount of oil can be delivered even when the room is cold, and kerosene can be ignited and burned without any problems from the start of operation. be.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of an example of the piezoelectric pump of the present invention, and FIG. 2 is a sectional view of a conventional piezoelectric oil pump. 1...Pump case, 1a...Pump chamber, 1f
... Cylinder part, 2 ... Piston, 3 ... Piezoelectric vibrator, 4 ... Joint, 5 ... Joint member, 6 ...
...Protective cover, 7...Filter material, 8...Thermostat, 9
...control circuit.

Claims (1)

[Claims for Utility Model Registration] (1) A pump section that draws in and discharges liquid in a fixed direction using a reciprocating piston is provided below the liquid level, and a piezoelectric vibrator supported in a cantilevered manner is provided above the liquid level. , a piezoelectric pump configured to transmit the motion of the vibrating end of the piezoelectric vibrator to the piston by a joint member provided through the liquid surface, a means for sensing an environmental temperature of the piezoelectric vibrator; A piezoelectric pump characterized in that a constant temperature device having a heat supply means that changes the amount of heat supplied accordingly is provided near the piezoelectric vibrator. (2) The piezoelectric pump according to claim 1, wherein the constant temperature device is equipped with a PTC thermistor.