JPH0231167Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a liquid flow rate adjustment mechanism used, for example, to adjust the amount of paint delivered to a coating machine such as a spray gun.

``Prior art'' and ``Problems to be solved by the invention'' For example, in painting automobile bodies, uniformity of the paint film is an important requirement in order to obtain a beautiful finish using an automatic painting machine. becomes. However, from the viewpoint of paintability, it is necessary to intentionally thicken the paint film on certain parts of the car body, etc., and the amount of paint discharged from a coating machine such as a spray gun must be adjusted to correspond to changes in film thickness. Quick and accurate adjustment is required.
Therefore, there are the following known examples of paint metering devices that can accommodate the above-mentioned coating film fluctuations.

Specifically, as shown in FIG. 4A, one method is to apply air pressure from the arrow A shown in the figure and move the needle valve 4 forward and backward using the air pressure to adjust the paint flow path shown by the arrow P in the drawing, thereby controlling the discharge amount. The other one is a pneumatic regulator for automatic adjustment, as shown in Figure 4B, the adjustment screw 1
Move the needle valve 4 forward or backward by adjusting the rotation of step 5.
Similarly, there is a screw type regulator that manually adjusts the discharge amount. However, among the above conventional structures, although the former has the ability to meter quickly, it has poor metering accuracy due to relative fluctuations in air pressure due to the influence of paint pressure, and has the disadvantage of being inferior in fine adjustment. The latter method has advantages and disadvantages in that although the metering accuracy is improved, the adjustment speed is slow and the metering lacks quickness.

The object of the present invention is to provide a novel liquid flow rate adjustment mechanism that overcomes the drawbacks of the conventional structure described above.

``Means for Solving the Problems'' The present invention achieves the above objectives by ``consisting of a pulse drive part consisting of a pulse motor having an encoder, a flow rate adjustment part having a motion conversion mechanism and a needle valve, section and flow rate adjustment section.
The rotation of the pulse motor in response to a pulse signal is transmitted to the flow rate adjustment unit via the cable, and the liquid flow is controlled by advancing and retracting the needle valve in synchronization with the pulse signal. It consists of a structure that automatically adjusts the play in the passageway and the amount of liquid delivered.

"Examples" and "Operations" Hereinafter, the structure and operation of the present invention will be explained in detail using Examples. Referring to FIGS. 1 to 3 showing an embodiment applied to adjusting the amount of paint delivered, the liquid flow rate adjustment mechanism of the present invention (hereinafter simply referred to as the flow rate adjustment mechanism) is rotationally driven by a pulse signal. It has a pulse drive unit 1, is connected to the pulse drive unit 1 by a cable 3, and has a needle valve 4,
It also consists of a flow rate adjustment unit 2 that incorporates a motion conversion mechanism 5 that converts the rotational operation of the cable 3 into the forward and backward movement of the needle valve 4, and the liquid flow path is adjusted by moving the needle valve 4 back and forth in response to pulse signals of a predetermined program. It has a structure that controls the amount of output.

Specifically, the pulse drive unit 1 has a known stepping motor drive mechanism, and is composed of a pulse motor 6, an encoder 7, and a reduction unit 8. The pulse signal group 9 input to the encoder 7 is organized, and the pulse The rotation conditions of the pulse motor 6 are controlled by detecting the rotor position of the motor 6, and a speed reducer 8 is provided on the output side of the pulse motor 6. Then, the rotational operation of the pulse motor 6 is decelerated (1/30 deceleration in this embodiment) and the rotation is transmitted to the cable 3.

On the other hand, the flow rate adjusting section 2 is housed in a housing as shown in FIG.
A needle valve 4 that adjusts the amount of play, and a cable 3
The motion converting mechanism 5 has a built-in gear train to control the rotation of the cable 3 before deceleration in the pulse drive unit 1. A cam body 11 is provided at the output end, and the cam body 11 and the end portion 12 of the needle valve 4 are mechanically connected, so that the rotational movement of the cam body 11 is transmitted mechanically. The motion is converted into a linear motion, allowing the needle valve 4 to move forward and backward accurately.

The cam body 11 and the needle valve 4 of this embodiment are connected by engaging an eccentric pin provided on the cam body 11 with the end portion 12, and the rotational operation of the cam body 11 is converted into the forward and backward movement of the needle valve 4. This is the structure that will be used.

The pulse drive unit 1 and the flow rate adjustment unit 2, which are isolated and connected by a cable 3, are synchronized in the number of pulses and the amount of movement of the needle valve 4. The operating conditions are set such that the valve 4 moves forward and backward in steps of 0.01 mm. Therefore, the maximum stroke of 10 mm for forward and backward movement of the needle valve 4 is 1000
It is structured so that it can be controlled extremely precisely by dividing it into points.

In the flow rate adjustment mechanism of the present invention having the above configuration, as shown in FIG. The pulse drive unit 1 is
It is connected via a cable 3, and a paint pipe 16 for pumping paint is connected to the flow rate adjustment unit 2 and arranged therein. Then, a pulse signal based on a predetermined program corresponding to the coating conditions of the object to be coated is inputted, and the needle valve 4 in the flow rate adjusting section 2 is precisely controlled to advance or retreat in synchronization with the pulse signal. The amount of paint delivered to the coating machine 14 is automatically controlled sequentially and continuously.

The flow rate adjustment mechanism of the present invention may be provided separately from the coating machine 14 such as a spray gun, as in the above embodiment, but the flow rate adjustment mechanism 2 having the above structure may be built into the coating machine 14 such as a spray gun. However, the flow rate adjustment section 2 itself may be a main part of a coating machine such as a spray gun.

According to the flow rate adjustment mechanism of the present invention having the above configuration,
Since the needle valve 4 can be moved forward and backward precisely in synchronization with a pulse signal, and the amount of movement of the needle valve 4 can be controlled steplessly and extremely precisely, the amount of liquid such as paint delivered by the needle valve 4 can be controlled. Adjustment becomes extremely accurate, and flow rate adjustment performance is greatly improved. Further, the forward and backward movement of the needle valve 4 can be controlled numerically by the number of pulses, and the amount of forward and backward movement can be quickly adjusted, so that the adjustability of paint and the like and the speed of adjustment are improved. Furthermore, the forward and backward movement of the needle valve 4 is not affected by fluctuations or pulsations in the pumping pressure of the paint or the like due to its structure, so that the amount of paint or the like that is fed out after adjusting the flow rate is stabilized.

In addition, in the pulse drive unit 1 of the above embodiment, the rotation of the pulse motor 6 is decelerated by the reduction unit 8 and transmitted to the cable 3, so that the rotation transmission by the cable 3 is stable and the rotation of the pulse motor 6 is controlled with precision. It can be well transmitted to the needle valve 4.

Furthermore, the flow rate adjustment mechanism of the present invention has a cable 3
Since the flow rate adjusting section 2 and the pulse driving section 1 are arranged in isolation through the above structure, it is possible to sufficiently ensure explosion-proofness of the coating machine, etc. Furthermore, it has the advantage of being lightweight and compact in structure, and can also be used to adjust the flow rate of high-pressure liquids such as high-pressure paint.

The flow rate adjustment mechanism of the present invention is applicable not only to the paint used in the above-mentioned embodiments but also to a wide variety of liquid flow rate adjustments, such as flow rate adjustment of liquid fuels that require explosion-proof properties.

"Effects of the invention" As explained above, the flow rate adjustment mechanism of the invention is
Adjustment of the amount of liquid such as paint sent to a coating machine, etc. is accurate, stable, and quick, and the adjustment performance is significantly improved, and the amount of liquid sent out can be automatically controlled by the number of pulses. Furthermore, it has great effects such as ensuring the explosion-proof properties of the coating machine, etc., and contributing to improving the coating quality.

[Brief explanation of the drawing]

Figure 1: Overall front view showing the flow rate adjustment mechanism of one embodiment of the present invention, Figure 2: Partial front view showing main parts of the embodiment of Figure 1, Figure 3: Spray gun of the example product of Figure 1 Perspective view showing the installation state in Figure 4 A and B:
FIG. 2 is a front view showing the basic structure of a conventional paint metering device. Main symbols: 1...Pulse drive unit, 2...Flow rate adjustment unit, 3...Cable, 4...Needle valve, 5...
...Motion conversion mechanism, 6...Pulse motor, 7...Encoder, 8...Reduction unit, 9...Pulse signal, 1
1...Cam body, 12...Terminal part of needle valve, 1
8...Paint flow path, 16...Paint pipe.

Claims (1)

[Scope of utility model registration request] It consists of a pulse drive section consisting of a pulse motor having an encoder, and a flow rate adjustment section having a motion conversion mechanism and a needle valve. A liquid flow rate adjustment mechanism, characterized in that the rotation of the pulse motor is transmitted to the flow rate adjustment section via the cable, and the delivery amount is adjusted by advancing and retracting the needle valve in synchronization with the pulse signal.