JPH0442533Y2 - - 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.

PRIOR ART Conventional fuel pumps for kerosene burners include:
Electromagnetic pumps are widely used, but because they are large in size and frequency controlled, they have the disadvantage that when the flow rate is low, the flow rate pulsates and the combustion becomes unstable.Furthermore, these electromagnetic pumps have the problems of being noisy, consuming a lot of power like electric pumps, and being 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. 3). 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 source, 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 has to 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 In this new piezoelectric pump, since the piezoelectric vibrator vibrates at a position away from the liquid, electrical insulation is easy and energy loss is small. However, when transmitting the vibrations of the piezoelectric vibrator to the piston below the liquid surface,
When the piston and the joint member vibrate, agitation of the liquid also occurs, and energy loss due to this cannot be ignored.

Therefore, the present invention aims to provide such a new piezoelectric pump with a structure that has low energy loss and high vibration efficiency.

[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 joint member is a rigid rod-shaped body with a substantially circular cross section, one end of which is fixed to the vibrating end of the piezoelectric vibrator via an electrically insulating joint, and the other end is immersed in liquid in the extending direction of the vibrating end. The device is characterized in that it is configured to engage with the provided piston.

An example of the piezoelectric pump of the present invention is shown in FIG. In the figure, 1 is a pump case, and a pump chamber 1a is formed at its lower end. Pump room 1a
A suction port 1c is provided on the lower side via an inlet check valve 1b, and a passage communicating with the supply port 1e is provided on the upper side via an outlet check valve 1d. 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 a small-diameter rod-shaped body having a substantially circular cross section, and is required to be made of a strong and rigid material such as piano wire. As shown in FIG. 2, for example, the joint member 5 has a base end 5a embedded and fixed in a joint 4 made of, for example, hard synthetic resin, and the joint 4 absorbs vibrations of the piezoelectric vibrator 3. The ends 3b are fixedly connected so as to be sandwiched from both sides. The tip portion 5b of the joint member 5 is inserted into a through hole 2a formed at the rear end portion of the piston 2, and the horizontal vibration of the piezoelectric vibrator 3 is amplified and transmitted 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.

On the other hand, 8 is a control circuit, for example, 100V AC power is supplied from a power supply line 8a, and a signal line 8b
A drive signal controlled by a flow rate adjustment signal input from the piezoelectric vibrator 3 is outputted to the piezoelectric vibrator 3 via an output line 8c.

Function The piezoelectric pump of the present invention as described above uses a joint 4 fixed to the vibrating end 3b of the piezoelectric vibrator 3 to absorb the transverse vibration of the piezoelectric vibrator 3.
The vibration is transmitted to the joint member 5 via the joint member 5. Since the joint member 5 is provided extending in the direction from the fixed end 3a of the piezoelectric vibrator 3 to the vibrating end 3b, the amplitude increases toward the tip. Therefore, a large reciprocating distance is given to the piston whose tip 5b is inserted and engaged.

[Effect of idea]

In the piezoelectric pump of the present invention, the length of the joint member that transmits the motion of the piezoelectric vibrator to the pump piston is such that the piezoelectric vibrator is above the high limit liquid level and the pump piston is below the low limit liquid level. Since it has a sufficient length for coupling, there is no problem in ensuring the insulation of the piezoelectric vibrator, and it also has the effect of increasing the amplitude.Also, since it is a thin rod-shaped body with an approximately circular cross section, This has the advantage of not only having less parts immersed in the liquid, but also having less fluid resistance and realizing highly energy-efficient pump drive.

[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, Fig. 2 is a front view of a joint member fixed to the piezoelectric vibrator, and Fig. 3 is a diagram of a conventional piezoelectric oil pump. FIG. 1...Pump case, 1a...Pump chamber, 1f
... Cylinder part, 2 ... Piston, 3 ... Piezoelectric vibrator, 4 ... Joint, 5 ... Joint member, 6 ...
...protective cover, 7...filter medium, 8...control circuit.

Claims (1)

[Scope of utility model registration request] A pump section that draws in and discharges liquid in a fixed direction using a reciprocating piston is provided below the liquid surface, and a piezoelectric vibrator supported in a cantilevered manner is provided above the liquid surface.
In 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, the joint member is made of a rigid rod-shaped body with a substantially circular cross section, one end of which is The piezoelectric vibrator is fixed to the vibrating end of the piezoelectric vibrator via an electrically insulating joint, and the other end is configured to engage with the piston provided in the liquid in the extending direction of the vibrating end. piezoelectric pump.