JPS6233573A - High-viscosity fluid sprayer - Google Patents

Abstract

PURPOSE:To obtain excellent responsiveness when a discharge pressure changes and to maintain always the specified pressure of a coating film by proportionally controlling the discharge pressure of a sealant according to the characteristics of an electropneumatic proportional valve with regard to the change of the moving speed of a nozzle. CONSTITUTION:Plural setting means 20 by which the fluid discharge pressures required for every change point of the coating speed of the nozzle 8 are alternately selected according to the preliminarily variably set speed change command given at every change point of the coating speed are provided to a device for coating high-viscosity fluid to a material to be painted to a bead shape by the nozzle 8 which moves along the prescribed locus when a position command is given thereto. The discharge pressure from the nozzle 8 for the fluid is controlled by a pilot regulator 15 provided to a fluid supply system 14 connecting the nozzle 8 and a fluid supply source and the pilot pressure of the regulator 15 is proportionally controlled according to the command signal of the selected means 20 in the electropneumatic proportional valve 18.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for applying a high viscosity fluid such as a sealant or adhesive in the form of a bead.

BACKGROUND OF THE INVENTION In conventional technology, for example, in the manufacturing of automobiles, it is necessary to apply a sealant to prevent water from seeping into the joints of body panels, and this work is mainly performed by dedicated sealing robots and the like.

FIG. 5 shows a typical system, in which the sealant in the main tank 1 is passed through a primary supply pump 2 and a primary supply pipe line 3 to supply a fixed amount each time.

The pump (secondary supply pump) 41-1 is replenished for one shot, and the sealing agent from the quantitative supply pump 4 is further discharged to the sealing gun 6 by the action of the hydraulic cylinder 5.

The sealing gun 6 is moved along a predetermined trajectory by the action of the sealing robot 7, thereby applying the sealant to the object to be coated from a nozzle 8 at the tip of the gun. In this case, it is important that the bead of sealant after application is uninterrupted and that the applied film thickness is constant.By the way, the above-mentioned application film thickness t of the sealant is important when the sealing gun 6 is moved. There is a relationship between speed and completion, and if the viscosity and discharge pressure of the sealant are constant, the rJ coating film thickness will decrease when the sealing gun 6 moves at a high speed, and conversely, when the sealing gun 6 moves at a high speed. It gets louder when it's low.

For example, for a curved part as shown in FIG.
When trying to apply the curve, the trajectory control needle is normally controlled by the CP system (pseudo CP control), and in the curvature section from point A to point B, it is necessary to perform one circular interpolation. Therefore, the moving speed of the sealing gun 6 in the curved portion Q has to be slower than in the other straight portions R.

However, as described above, if the viscosity and discharge pressure of the sealant are constant, the thickness of the coating film of the sealant in the curvature section Q becomes thicker in the curved portion due to the speed change.

In order to eliminate variations in coating film thickness due to such speed changes, conventionally, the hydraulic control device 9 guarantees the pressure to prevent pulsation, and also controls the speed change part due to interpolation as described above. The pressure of the hydraulic cylinder 5 is adjusted by the hydraulic control device 9 to change the discharge pressure of the sealing gun 6.

In addition, 10 in Figure 5 is a replenishment pump, 11μ starvation plate, 12
is a hydraulic unit.

Problems to be Solved by the Invention In the conventional system as described above, since the pressure of the hydraulic cylinder 5, which is the actuator of the metering pump 4, is adjusted (the responsiveness when the discharge pressure changes is Bad.Especially when changing the discharge pressure of the sealant from high pressure to low pressure, the pressure adjustment of the hydraulic cylinder 5 has to be done by the bleed-off circuit of the hydraulic control device, resulting in a long response delay and energy waste. It turns out.

Means for Solving the Problem The present invention is intended to provide a device that is particularly responsive when calculating discharge pressure.Specifically, as shown in the embodiment, In a device that applies a bead-like coating to a highly viscous fluid to be coated by a nozzle that moves along a predetermined trajectory, the fluid discharge pressure required at each point of change in the nozzle coating speed increases. provided in a fluid supply system connecting a nozzle and a fluid supply source to a setting means for ff1fi which is variably set in advance and selectively selected according to a speed change command given at each change point of the coating speed; Secondary discharge pressure of fluid '5!0: Consists of a pilot type regulator to be adjusted and an electropneumatic proportional valve that proportionally controls the pilot pressure of the pilot type regulator in accordance with the command signal of the selected setting means. .

According to the present invention, the discharge pressure of the sealant is proportionally controlled in accordance with the characteristics of the electropneumatic proportional valve with respect to a change in the nozzle moving speed θ).

Embodiment FIG. 1 is a diagram showing a more specific embodiment of the present invention, in which a sealing gun 6 is attached to the wrist part of a sealing robot 7, and a nozzle 8 of the sealing gun 6 is The discharge pump 137J is a fluid supply source.
A sealant is supplied.

A high pressure pilot type regulator 15 is installed in the supply pipe line 14 connecting the nozzle 8 and the discharge pump 13, and this pilot type regulator 15 controls the pilot pressure P3.
The secondary discharge pressure f of the sealant and the discharge pressure from the nozzle 8 are adjusted according to the size difference.

An electropneumatic proportional valve 18 is interposed in a pilot pipe line 17 connecting the pilot type regulator 15 and the air pressure source 16, and has a function of variably controlling the pilot pressure P3. This electro-pneumatic proportional valve 18 is a type of servo pulp controlled by a servo controller 19, and uses a proportional solenoid in which the input current and attraction force are proportional, and the pilot pressure P3 can be adjusted steplessly. be. Furthermore, a potentiometer controller 2o is provided before the servo controller 19.

As shown in FIG. 2, the servo controller 19 includes a preamplifier 21, a gain adjustment circuit 22. Integrating circuit 23. It includes a voltage comparison circuit 24, a drive circuit 25, and the like.

As shown in FIG. 2, the potentiometer controller 201d has a large number of rotary potentiometers 26a, 26 arranged in parallel with each other as secondary discharge pressure setting means.
b, 260...26 n. These potentiometers 26a to 26H are used to indicate the secondary discharge pressure of the nozzle 8, ``high high pressure'', ``high medium pressure'', and ``high medium pressure'' in column 'C'.
Multi-stage discharge pressure covers such as "high/low pressure", "medium/high pressure", etc. are set within the range of DCO ~ 10V,
As will be described later, when any one discharge pressure cover turn is selected, the corresponding discharge pressure command is 711! '
As a jU change, the electropneumatic proportional valve 181 is designed to be operated manually.

-r In other words, assuming that N types of coating speeds are required for the interpolation described in a for the sealing locus that the sealing robot 7 executes in one cycle, then in order to keep the coating film thickness l of the sealant constant, N types of secondary discharge pressure cover turns corresponding to N types of coating speeds are set in the potentiometers 26 jL - J26n.

Since a speed change command is issued from the robot controller 27 at each point of change in the coating speed, this speed change command is also used as a discharge pressure change command and input to the potentiometer controller 20 to obtain the required coating speed C.
: One of the corresponding potentiometers 26a to 26nυ is selected to select the corresponding secondary discharge pressure cover turn 1.

The coating device constructed as described above operates in the following manner.

・As shown in Figure 41, "C1 Discharge Pump 13" Seal AIL H Sealing Gun 6 will discharge from nozzle 8, but the discharge pressure from nozzle 8 at that time (secondary discharge pressure) The e-go pilot formula is determined by the regulator L5.

For example, when trying to change the coating speed of the nozzle 8 to vl, which is slower than v'4 at point A in FIG. The discharge pressure of the nozzles 8 and 1 must also be lowered in accordance with the decrease in speed.

In this case, if the discharge pressure of the nozzle 8 corresponding to the speed V1 is, for example, a high or low pressure set by the potentiometer 26C, a speed change command from the coating speed V to vl is sent from the robot controller 27 to the potentiometer 26C.
is given as a discharge pressure change command, and the corresponding potentiometer 26C is selected.

As a result, all relays CR1 to CR except 1j relay CR3 corresponding to the selected potentiometer 26e
Contacts crl to crn (excluding cr3) of n are turned on, and the "high/low pressure" discharge pressure command is given from the servo controller 19 to the electropneumatic proportional valve 18 as a current change.

Therefore, the opening degree of the electropneumatic proportional valve 18 is proportionally controlled according to the input current, and the pilot type regulator 18 is controlled to the selected "high or low pressure" according to the change in the pilot pressure P3. Adjust the secondary discharge pressure from the nozzle 8.

Furthermore, when the coating speed is changed to the high speed side at point B in FIG. 4, the operation is basically the same as described above.

In this way, by changing the discharge pressure in accordance with changes in the coating speed, the continuity of the coating bead is not impaired and the coating film thickness can be kept constant.

Here, in the above embodiment, the discharge pressure Pt (primary discharge pressure) of the discharge pump 13 is C: 235 Kgf/crI
When K, the relationship between the pilot pressure P3 and the discharge pressure (secondary discharge pressure) P2 of the nozzle 8 is as shown in FIG.

Effects of the Invention According to the present invention, in addition to a pilot type regulator that adjusts the secondary discharge pressure from the nozzle and an electro-pneumatic proportional valve that adjusts the pilot pressure of this pilot type regulator, there is also a pilot type regulator that adjusts the secondary discharge pressure from the nozzle. This is a combination of multiple setting means that are selected according to the speed change command given for each speed change point, and the discharge pressure required for the speed change is set in advance. It has good responsiveness when switching from high pressure to low pressure, can maintain a constant coating film thickness, and can also be expected to save energy.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
Figure 3 is a characteristic diagram showing the relationship between pilot pressure and secondary discharge pressure, Figure 4 is an explanatory diagram of sealant application and one step, and Figure 85 is a conventional It is an explanatory view of a coating device. 6...Sealing gun, 7...Sealing robot 8...Nosle, 13...Discharge pump, 15...Pilot type curator, 18...Electro-pneumatic proportional valve, 19
... Servo controller, 20... Potentiometer controller, 26a-261k... Potentiometer. Figure 3 Figure 5

Claims (1)

[Claims] (1) In a device that applies a high viscosity fluid to a workpiece in a bead shape using a nozzle that moves along a predetermined trajectory when a position command is given, the a plurality of setting means in which the fluid discharge pressure to be applied is variably set in advance and selectively selected according to a speed change command given at each change point of the coating speed; and a fluid supply connecting the nozzle and the fluid supply source. A pilot type regulator installed in the system to adjust the discharge pressure from a fluid nozzle, and an electropneumatic proportional valve that proportionally controls the pilot pressure of the pilot type regulator in accordance with a command signal from a selected setting means. A high viscosity fluid application device characterized by: